Materials Handbook 15th ed - G. Brady_ H. Clauser_ J. Vaccari (McGraw-Hill_ 2002) WW Part 14 pdf

Green fruits, especially bananas, often contain much starch, but the
ripening process changes the starch to sugars.
In general, starch is a white, amorphous powder having a specific
gravity from 0.499 to 0.513. It is insoluble in cold water but can be
converted to soluble starch by treating with a dilute acid. When
cooked in water, starch produces an adhesive paste. Starch is easily
distinguished from dextrins as it gives a blue color with iodine while
dextrins give violet and red. The starch molecule is often described as a
chain of glucose units, with the adhesive waxy starches as those with
coiled chains. But starch is a complex member of the great group of
natural plant compounds consisting of starches, sugars, and cellulose,
and originally named carbohydrates because the molecular formula
could be written as C
n
(H
2
O)
x
; but not all now-known carbohydrates can
be classified in this form, and many now-known acids and aldehydes
can be indicated by this formula.
Starch can be fractionated into two polymers of high molecular
weight. Amylose is a straight-chain fraction having high adhesive
properties for coatings and sizings, and amylopectin is a
branched-chain fraction best known as a suspending agent for food-
stuffs. Amylose is chemically identical with cellulose, but the chain
units of the molecule have an alpha linkage and are coiled, while the
cellulose molecule is rigid. It has a molecular weight of 150,000, while
amylopectin has a molecular weight above 1 million. The 1–4 alpha
linkage of amylopectin with random branches at the 6-carbon position
makes the material easily dispersible in cold water but resistant to

gelling. Amylopectin is thus best suited for thickening, but because it
can be combined and cross-linked with synthetic resins and is highly
resistant to deterioration, it is used with resins for water-resistant
coatings for paper and textiles.
Tapioca is the starch from the root of the large tuber Manihot
utilissima, now grown in most tropical countries. It is called cassava
in southern Asia, manioc in Brazil, mandioca in Paraguay, and
yuca in Cuba. This perennial vegetatively propagated shrub was cul-
tivated as far back as 2,500 years ago, and there is some indirect evi-
dence that it has been grown for 4,000 years in the Americas. Its
fresh roots contain 30 to 40% dry matter and have a starch content of
approximately 85% of the dry matter. It is used in enormous quanti-
ties for food in some countries, and in some areas much is used for the
production of alcohol. In the United States it is valued for adhesives
and coatings, and only a small proportion in globules and flakes,
known as pearl tapioca, is used in foodstuffs. Gaplek, used for cat-
tle feed in Asia, is not the starch, but is dried and sliced cassava root.
Tapioca starch may be sold under trade names. Kreamgel, used as a
thickener for canned soups, sauces, and pastries, is refined tapioca
that gives clear solutions without imparting odor or flavor.
910 STARCH
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Potato starch, produced from the common white potato,
Solanum tuberosum, has been the most important starch in Europe,
but in the United States it is usually more expensive than cornstarch.
It forms heavier hot pastes than tapioca. It is also free of flavor and is
used as a thickener in foods. It does not crystallize easily. Arogum, of

Morningstar-Paisley, Inc., is potato starch used to give tough, resilient
coatings on paper and textiles, and Arojel P is pregelatinized potato
starch used as a beater additive to improve the strength and scuff
resistance of kraft paper. Sweet-potato starch is from the tuber
Opomoea batata. An average of 10 lb (4.5 kg) of starch is produced per
bushel. The root has poor shipping qualities, and the starch is expen-
sive, but it has excellent colloidal qualities and gelatinizes completely
at 165°F (74°C). It is used in some foodstuffs. It has a pleasant, sweet-
ish flavor, and in Latin countries great quantities are marketed in the
form of a stiff gel as a dessert sweet known as dulce de batata.
Arrowroot starch is from the tubers of the Maranta arundinacea
of the West Indies. It is easily digested and is used in cookies and
other food products, especially baby foods. Florida arrowroot is
from Zamia floridana. East Indian arrowroot is from the plant
Curcuma angustifolia, which belongs to the ginger family. Arrowroot
from St. Vincent, used in instant-pudding mixes and icings, is mar-
keted as a precooked powder of about 200 mesh. It swells in cold
water and does not add flavor.
The starches do not crystallize as sugar does, and they may be
added to some confections to minimize crystallization. They are also
used as binders in candies and in tablet sugar, but any considerable
quantity in such products is considered as an adulterant. Metabolism
of starch in the human system requires conversion to sugars, and the
taking in of excessive quantities of uncooked starch is undesirable.
Modified starches are starches with the molecule altered by chemi-
cal treatment to give characteristics suitable for particular industrial
requirements. The modified starches and especially prepared starches
are usually sold under trade names. Superlose is amylose from corn-
starch, and Auperlose is amylose from potato starch. Ramalin is
amylopectin. Amylon, of National Starch & Chemicals Corp., is corn-

starch containing 57% amylose, and Kosul is cornstarch high in amy-
lopectin. Textaid, of the same company, is a modified starch which
reacts with water to form a grainy structure. It is used in commin-
uted meat products to give a firm texture. The ColFlo thickening
agents, stable and soluble in frozen foods, are modified, waxy corn-
starches, high in amylopectin. Pregelatinized starches are
pre-heat-treated starches that require no cooking for use in dry food
mixes or adhesives. Snow Flake starch is a cornstarch of this type.
Wheat starch is a fine, white starch made by separating out the
gluten of wheat flour by wash flotation. It is used in prepared mixes
STARCH 911
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Materials, Their Properties and Uses
for foam-type cakes and pie crusts to improve texture, add volume,
and reduce the amount of shortening needed. It replaces up to 30% of
the wheat-flour content of the mix. Starbake starch, of Hercules, is
wheat starch. Paygel, of General Mills, is also wheat starch, but
alant starch, or inulin, (C
6
H
10
O
5
)
6
и H
2
O, is not a starch in the ordi-

nary sense, but is an insoluble sugar which occurs as the reserve
polysaccharide in many plants. It is obtained from the roots of the
artichoke, Helianthus tuberosis, native to America but now grown
widely in Europe. Unlike starch, the molecule has fructose units held
in glucoside linkage, and hydrolysis converts it to fructose.
Starch acetate, or acetylated starch, is used for textile sizing, in
adhesives, and for greaseproofing paper. The insertion of acetate radi-
cals reduces the tendency of the molecular chains to cling together.
The acetylated starches are gums which gelatinize at lower tempera-
tures than starch, and produce stable, nonlumping pastes which give
strong, flexible films. Miralloid and Mira-Film, of A. E. Staley Mfg.
Co., are acetylated cornstarches. Morgum is a hydroxyethyl ether-
ized starch which gives high film strength in coatings. The Kofilms
of General Mills are acetylated cornstarches which give greaseproof,
craze-resistant coatings on paper and textiles.
Laundry starches are usually ordinary starches, but silicone resin
emulsions may be added to starches to permit higher ironing tempera-
tures, improve slipperiness, and improve the hand of the starched fabric.
The so-called permanent starches, for household use, that are not
removed by washing, are not starch, but are emulsions of polyvinyl
acetate. Oxidized starch, a resistant starch for coatings, is made by the
chloro-oxidation of a starch solution. Sumstar 190 is a diallyl starch
made by acid oxidation of cornstarch. Small amounts of the powder added
to kraft, tissue, or toweling pulp increase the wet and dry strengths and
the folding endurance of the papers. An ammoniated starch called Q-
Tac starch is cornstarch reacted with quaternary ammonium groups. A
less than 1% solution improves paper strength. Sulfonated starches
are used as dirt-suspending agents with detergents for cleaning textiles.
Nu-Film is a starch of this type. Clear Flo starch is a modified starch
containing a carboxyl group and a sulfonic acid group in the molecule. It

has high hydrating capacity and gelatinizes sharply at low temperatures.
It is used in adhesives and water paints. Cato starch is a carboxymethyl
starch used in paper sizing to add strength. Dry Flo starch is modified
to contain a hydrophobic radical, such as CH
2
, which makes the mate-
rial insoluble in water but soluble in oils. It is used in paints.
Many enzymes hydrolyze starch to maltose, but some enzymes con-
vert the starch to the hard, tough glucosides known as mannans,
such as the mannose of the ivory nut. Phospho mannan, produced
by the fermentation of starch, is such a material used in adhesives.
912 STARCH
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Granular starch, used in enzyme conversion processing, is in dense,
granular particles produced by flash drying. Easy-Enz starch is
such a starch. Cationic starch is a starch with the molecules of sta-
ble negative polarity to give higher adhesion on the cellulose fibers of
paper or textiles. Molding starch, for adding to sugar candies to give
sharp molding characteristics, is starch containing an edible oil.
The phosphate starch of American Maize Products Co. is an
orthophosphate ester of cornstarch, marketed in sodium salt form as
a light-tan, dry powder. It has high thickening power and makes a
clearer paste than cornstarch. It has superior water-binding proper-
ties at low temperatures. Frozen foods made with it do not curdle or
separate when thawed, and canned foods thickened with the starch
can be stored for long periods without clouding. It is also used as a
briquetting binder for charcoal.

Starch sponge is an edible starch in the form of a coarse-textured,
porous, crispy, spongelike material, used for confections by impregnat-
ing with chocolate or sweets. In crushed form it is added to candy or
cookies. It is produced by freezing, thawing, and pressing starch paste.
The freezing insolubilizes the starch so that no soluble starch goes off
when the water is pressed out. Lycasin and Polysorb are hydro-
genated starch hydrolysates produced by Roquette Corp. for food and
feed applications. Nitrostarch, or starch nitrate, C
12
H
12
O
10
(NO
2
)
3
, is
a fine, white powder made by treating starch with mixed acid. It is
highly explosive and is used for blasting, as a military explosive, and
in signal lights. Grenite is nitrostarch mixed with an oil binder for
use in grenades. Trojan explosive is a mixture of 40% nitrostarch
with ammonium and sodium nitrates and some inert material to
reduce the sensitiveness. Sepol starch coagulants, of Grace Dearborn,
are used to break emulsions in waste treatment of lubricating oils, sol-
uble oils, and synthetic coolants, including oils containing dissolved
solids and water.
STATUARY BRONZE. Copper alloys used for casting statues, plaques,
and ornamental objects that require fine detail and a smooth, red-
dish surface. Most of the famous large bronze statues of Europe con-

tain from 87 to 90% copper, with varying amounts of tin, zinc, and
lead. Early Greek statues contained from 9 to 11% tin with as much
as 5% lead added apparently to give greater fluidity for crisp details.
A general average bronze will contain 90% copper, 6 tin, 3 zinc, and 1
lead. Statuary bronze for cast plaques used in building construction
contains 86% copper, 2 tin, 2 lead, 8 zinc, and 2 nickel. The nickel
improves fluidity and hardens and strengthens the alloy, and the
lead promotes an oxidized finish on exposure. The statuary bronze
used for hardware has 83.5% copper, 4 lead, 2 tin, and 10 zinc.Ω
STATUARY BRONZE 913
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Materials, Their Properties and Uses
STEARIC ACID. A hard, white, waxlike solid of composition
CH
3
(CH
2
)
16
COOH, obtained from animal and vegetable fats and oils
by splitting and distilling. The hard cattle fats are high in stearic
acid, but other fats and oils contain varying amounts. It is also called
octodecanoic acid, and it can be made by hydrogenation of oleic
acid. Stearic acid has a specific gravity of 0.922 to 0.935 and a melt-
ing point of about 130°F (54°C), and it is soluble in alcohol but insolu-
ble in water. It is marketed in cakes, powder, and flakes. Emory
3101-D is isostearic acid which has the solubility and physical
properties of oleic acid while retaining the heat and oxidation stabil-

ity of stearic acid. Pearl stearic acid is the material in free-flowing
bead powder. The acid is used for making soaps, candles, paint driers,
lubricating greases, and buffing compositions, and for compounding
in rubbers, cosmetics, and coatings.
Successive pressings remove liquid oils, thus raising the melting
point and giving a whiter, harder product of lower iodine value. Oleo
oil is a yellow oil obtained by cold-pressing the first-run cattle tallow.
Tallow oil is the oil following the first two grades of oleo oil.
Industrene 4518 is the single-pressed grade, available as a molten
liquid or in flakes, from Humko Chemical Div. of Witco Corp.
Industrene 5016 is the double-pressed variety. Oleostearin, used for
treating leather, is the stearin remaining after extraction of the oils.
Stearin is the glyceride of stearic acid. Acetostearins are the
monoglycerides acetylated with acetic anhydride. They are closely
related to fats, but are nongreasy and are plastic even at low temper-
atures. The highly acetylated stearins melt below body temperature
and are edible. Acetostearins are used as plasticizers for waxes and
synthetic resins to improve low-temperature characteristics. Stearite
is a trade name for synthetic stearic acid made by the hydrogena-
tion of unsaturated animal and fish oils. It is used in rubber com-
pounding, as it is more uniform than ordinary stearic acid. Hystrene,
of Humko Chemical, is purified and hardened stearic acid in grades of
70, 80, and 97% stearic acid, with the remainder palmitic acid, used
for candles, cosmetics, and stearates. However, Hystrene 5016 is a
triple-pressed oil. Intarvin is a synthetic edible fat made from stearic
acid by converting it to margaric acid, or daturic acid,
C
16
H
33

COOH, and then esterifying with glycerin. It is used as a fat
for diabetics as it does not undergo the beta oxidation to lose two car-
bon atoms at a time and produce acetoacetic acid in the system as do
the even-carbon food acids.
Wilmar 272 is refined stearic acid in flake form for use in candles
and coatings. Hydrofol is a double- and triple-pressed rubber grade
that is also used in coatings and candles. It is produced by Sherex
Chemical Co. Flexchem B is sodium stearate, NaC
18
H
35
O
2
, in the
914 STEARIC ACID
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Materials, Their Properties and Uses
form of a water-soluble, white powder which is insoluble in oils. It is
used as a bodying agent in cosmetic creams. Myvacet is an ace-
tostearin used as an edible plastic coating for poultry, cheese, and
frozen fish and meats to prevent loss of the natural color and flavor. It
is a white, waxy solid with melting points from 99 to 109°F (37 to
43°C), but it also comes as an oil with congealing point of 45°F (7°C) for
use as a release agent on bakery equipment. Alfol is a high-purity, syn-
thetic, linear primary alcohol from Vista Chemical Co. A similar stearyl
alcohol, Adol, is from Sherex Chemical and is used as a chemical inter-
mediate. Cachalot is a food-grade product of M. Michel and Co.
Stearin pitch is a brown-to-black by-product residue obtained in

the splitting and distillation of fats and oils in the manufacture of
soaps, candles, and fatty acids. While the word stearin implies that it
contains only stearic acid, it usually comes from a variety of oils and
has mixed acids, and it may take the name of the oil, such as linseed
pitch or palm pitch. It is used in varnishes and cold-molding
compositions.
STEEL. Iron alloyed with small amounts of carbon, 2.5% maximum,
but usually much less. The two broad categories are carbon steels
and alloy steels, but they are further classified in terms of composi-
tion, deoxidation method, mill-finishing practice, product form, and/or
principal characteristics. Carbon is the principal influencing element
in carbon steels, although manganese, phosphorus, and sulfur are
also present in small amounts, and these steels are further classified
as low-carbon steels (up to 0.30% carbon), medium-carbon steels
(0.30 to 0.60), and high-carbon steels (more than 0.60). The greater
the amount of carbon, the greater the strength and hardness, and the
less the ductility. Alloy steels are further classified as low-alloy
steels, alloy steels, and high-alloy steels, those having as much as
5% alloy content being the most widely used. The most common desig-
nation systems for carbon and alloy steels are those of the American
Iron and Steel Institute and the SAE, which follow a four- or five-digit
numbering system based on the key element or elements, with the
last two digits indicating carbon content in hundredths of a percent.
Plain carbon steels (with 1% maximum manganese) are desig-
nated 10XX; resulfurized carbon steels, 11XX; resulfurized and
rephosphorized carbon steels, 12XX; and plain carbon steels with 1 to
1.65% manganese, 15XX. Alloy steels include manganese steels
(13XX), nickel steels (23XX and 25XX), nickel-chromium steels (31XX
to 34XX), molybdenum steels (40XX and 44XX), chromium-molybde-
num steels (41XX), nickel-chromium-molybdenum steels (43XX,

47XX, and 81XX to 98XX), nickel-molybdenum steels (46XX and
48XX), chromium steels (50XX to 52XX), chromium-vanadium steels
STEEL 915
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Materials, Their Properties and Uses
(61XX), tungsten-chromium steels (72XX), and silicon-manganese
steels (92XX). The letter B following the first two digits designates
boron steels, and the letter L leaded steels. The suffix H is used to
indicate steels produced to specific hardenability requirements.
High-strength, low-alloy steels are commonly identified by a 9XX
designation of the SAE, where the last two digits indicate minimum
tensile yield strength in 1,000 lb/in
2
(6.9 MPa).
In contrast to rimmed steels, which are not deoxidized, killed
steels are deoxidized by the addition of deoxidizing elements, such as
aluminum or silicon, in the ladle prior to ingot casting. Thus we have
such terms as aluminum-killed steel. Deoxidation markedly
improves the uniformity of the chemical composition and resulting
mechanical properties of mill products. Semikilled steels are only
partially deoxidized, thus intermediate in uniformity to rimmed and
killed steels. Capped steels have a low-carbon steel rim characteris-
tic of rimmed-steel ingot and central uniformity more characteristic of
killed-steel ingot, and are well suited for cold-forming operations.
Steels are also classified as air-melted, vacuum-melted, or vacuum-
degassed. Air-melted steels are produced by conventional melting
methods, such as open hearth, basic oxygen, and electric furnace.
Vacuum-melted steels are produced by induction vacuum melting

and consumable electrode vacuum melting. Vacuum-degassed
steels are air-melted steels that are vacuum processed before solidifi-
cation. Vacuum processing reduces gas content, nonmetallic inclu-
sions, and center porosity and segregation. Such steels are more
costly, but have better ductility and impact and fatigue strengths.
Steel-mill products are reduced from ingot into such forms as blooms,
billets, and slabs, which are then reduced to finished or semifinished
shape by hot-working operations. If the final product is produced by hot
working, the steel is known as hot-rolled steel. If the final product is
shaped cold, the steel is known as cold-finished steel or, more specifi-
cally, cold-rolled steel, or cold-drawn steel. Hot-rolled mill products
are usually limited to low- and medium-nonheat-treated carbon steels.
They are the most economical steels, have good formability and weld-
ability, and are widely used. Cold-finished steels, compared with
hot-rolled products, have greater strength and hardness, better surface
finish, and less ductility. Wrought steels are also classified in terms of
mill-product form, such as bar steels, sheet steels, and plate steels.
Bar steel used to reinforce concrete is called rebar, a low-grade steel
made from melted steel scrap and often coated with epoxy for corro-
sion protection. Fermar is a higher-quality more corrosion- and
fatigue-resistant steel developed at the University of California,
Berkeley. Containing less carbon, thus less carbides, it is less suscepti-
ble to electrolytic corrosion on water contact.
Cast steels refer to those used for castings, and PM (powder
metal) steels refer to powder compositions used for PM parts. Steels
916 STEEL
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Materials, Their Properties and Uses

are also known by their key characteristic from the standpoint of
application, such as electrical steels, corrosion-resistant stain-
less steels, low-temperature steels, high-temperature steels,
boiler steels, pressure-vessel steels, etc.
STEEL POWDER. Powder used mainly for the production of steel PM
parts made by consolidating the powder under pressure and then sin-
tering, and, to a limited extent, for steel-mill products, principally
tool-steel bar products. For PM parts, the powder may be admixed for
the desired composition or prealloyed; that is, each powder particle is
of the desired composition. For mill products, prealloyed powder is
used primarily. Steel powder is widely used to make small to moder-
ate-size PM parts, having compositions closely matching those of
wrought steels. Among the more common are carbon steels, copper
steels, nickel steels, nickel-molybdenum steels, and stainless steels.
Ancorsteel 41 AB, of Hoeganaes Corp., is a premixed, highly com-
pressible, low-alloy steel powder containing 0.5% carbon, 0.9 man-
ganese, 0.85 molybdenum, and 0.75 chromium. Formed parts are
intended for surface hardening by carburizing, nitriding, carbonitrid-
ing, or nitrocarburizing. Stainless Steel Plus, of the Specialty Metals
Division of Ametek, are powders of 303L, 304L, or 316L stainless
steels blended with 10% powder of 15 nickel, 8 tin and copper. They
are said to provide greater corrosion resistance than conventional
stainless steel powders. Powders for injection-molding PM parts are
often of iron-nickel or stainless steel but of very fine particle size.
STEEL WOOL. Long, fine fibers of steel used for abrading, chiefly for
cleaning utensils and for polishing. It is made from low-carbon wire
that has high tensile strength, usually having 0.10 to 0.20% carbon
and 0.50 to 1 manganese. The wire is drawn over a track and shaved
by a stationary knife bearing down on it, and it may be made in a con-
tinuous piece as long as 100,000 ft (30,480 m). Steel wool usually has

three edges but may have four or five, and strands of various types are
mixed. There are nine standard grades of steel wool, the finest of
which has no fibers greater than 0.005 in (0.0027 cm) thick, the most
commonly used grade having fibers that vary between 0.002 and 0.004
in (0.006 and 0.010 cm). Steel wool comes in batts, or in flat ribbon
form on spools usually 4 in (10 cm) wide. Stainless steel wool is also
made, and copper wool is marketed for some cleaning operations.
STILLINGIA OIL. A drying oil obtained from the kernels of the seeds of
the tree Stillingia sebifera, cultivated in China and the southern
United States. The seeds contain about 23% of a light-yellow oil
resembling linseed oil but of somewhat inferior drying power. The oil
has a specific gravity of 0.943 to 0.946 and iodine value of 160. It has
the peculiar property of expanding with great force at the congealing
STILLINGIA OIL 917
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Materials, Their Properties and Uses
point. Stillingia oil is edible, but deteriorates rapidly, becoming bitter
in taste and disagreeable in odor. Stillingia tallow, also known as
Chinese vegetable tallow, is obtained by pressing from the coating,
or mesocarp, of the seeds, yielding about 25 to 35% fat. Sometimes
the whole seed is crushed, producing a softer fat than the true tallow.
The tallow contains palmitic and oleic acids and is used in soaps and
for mixing with other waxes. Some stillingia trees are grown in Texas.
STRIPPABLE COATINGS. Coatings that are applied for temporary pro-
tection and can be readily removed. They are composed of such resins
as cellulosics, vinyl, acrylic, and polyethylene; they can be water-base,
solvent-base, or hot-melt. The choice of base depends on the surface to
be protected. Water-base grades are neutral to plastic and painted

surfaces, whereas solvent-base types affect those surfaces. Clear vinyl
strippable coatings, perhaps the most widely used, are usually
applied by spraying in thicknesses of 0.03 to 0.04 in (0.08 to 0.10 cm).
Acrylic strippable coatings impart a clear, high-gloss,
high-strength, temporary film to metal parts. Polyethylene strip-
pable coatings are relatively low-cost and can be used on almost all
surfaces except glass. Cellulosic strippable coatings are designed
for hot-dip application. Film thicknesses range widely and can go as
high as 0.2 in (0.51 cm). The mineral oil often present in these coat-
ings exudes and coats the metal surface to protect it from corrosion
over long periods.
STRONTIUM. A metallic element of the alkaline group. It occurs in
the minerals strontianite, SrCO
3
, and celestite, SrSO
4
, and resem-
bles barium in its properties and combinations, but is slightly harder
and less reactive and is not as white in color. It has a specific gravity
of 2.54 and a melting point of about 1418°F (770°C), and it decom-
poses in water. The metal is obtained by electrolysis of the fused chlo-
ride, and small amounts are used for doping semiconductors. Its
compounds have been used for deoxidizing nonferrous alloys, and
were used in Germany for desulfurizing steel. But the chief uses have
been in signal flares to give a red light, and in hard, heat-resistant
greases. Strontium 90, produced atomically, is used in ship-deck
signs as it emits no dangerous gamma rays. It gives a bright sign, and
the color can be varied with the content of zinc, but it is short-lived.
Strontium is very reactive and used only in compounds.
Strontium nitrate is a yellowish-white, crystalline powder,

Sr(NO
3
)
2
, produced by roasting and leaching celestite and treating
with nitric acid. The specific gravity is 2.96, the melting point is
1193°F (645°C), and it is soluble in water. It gives a bright, crimson
flame and is used in railway signal lights and in military flares. It is
918 STRIPPABLE COATINGS
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Materials, Their Properties and Uses
also used as a source of oxygen. The strontium sulfate used as a
brightening agent in paints is powdered celestite. The ore of Nova
Scotia contains 75% strontium sulfate. Strontium sulfide, SrS, used
in luminous paint, gives a blue-green glow, but it deteriorates rapidly
unless sealed in. Strontium carbonate, SrCO
3
, is used in pyrotech-
nics, ceramics, and ceramic permanent magnets for small motors.
Strontium hydrate, Sr(OH)
2
и 8H
2
O, loses its water of crystalliza-
tion at 212°F (100°C) and melts at 707°F (375°C). It is used in mak-
ing lubricating greases and as a stabilizer in plastics. Strontium
fluoride is produced in single crystals for use as a laser material.
When doped with samarium, it gives an output wavelength around

25,600 nin (650 nm).
STYRAX. A grayish-brown, viscous, sticky, aromatic balsam obtained
from the small tree Liquidambar orientalis of Asia Minor. It is also
called Levant styrax. It is used in cough medicines and for skin dis-
eases, as a fixative for heavy perfumes, and for flavoring tobacco and
soaps. American styrax is obtained by tapping the sweet gum, L.
styraciflua, of Alabama, a tree producing 8 oz (0.2 kg) of gum per year.
It is a brownish semisolid and has the same uses as Levant styrax. It
is shipped from Central America under the name liquidambar, and
in the southern United States is called sweet gum and storax. The
gum is not present in large amounts in the wood, but its formation is
induced by cuts. Benzoin is another balsam obtained from several
species of Styrax trees. It is a highly aromatic solid with an odor like
vanilla, and is used in medicine and in perfumes and incense.
Sumatra benzoin is from the tree S. benzoin and comes in
reddish-brown lumps or tears. In medicine it was originally called
gum Benjamin. Siam benzoin, from southern Asia, is from the
trees S. tonkinense and S. benzoides. It is in yellowish or brownish
tears. The Sumatra benzoin contains cinnamic acid, while the Asiatic
gum contains benzoic acid. Benzoic acid, or phenylformic acid,
C
6
H
5
COOH, formerly produced from benzoin, is now made syntheti-
cally from benzol and called carboxybenzene. It is a white, crys-
talline solid melting at 252°F (122°C), soluble in water and in alcohol.
It is used as a food preservative, as an antiseptic, for flavoring
tobacco, as a weak acid mordant in printing textiles, and in the man-
ufacture of dyestuffs, pharmaceuticals, and cosmetics. Because it is

poisonous, not more than 0.1% is used in food preserving in the form
of its salt, benzoate of soda, or sodium benzoate, C
6
H
5
COONa,
which is a white, crystalline powder. A potassium salt is also available
from Mallinckrodt, Inc. Sorbic acid, CH
3
CH:(CH)
2
:CHCOOH, a solid
melting at 273°F (134°C), occurs in unripe apples, but is made syn-
thetically. As a preservative and antimold agent it is more effective
STYRAX 919
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Materials, Their Properties and Uses
than benzoic acid, is nontoxic, and is readily absorbed in the human
system. It is used in cheese and other foods. Sorbistat is a food grade
with antimicrobial activity against yeast, mold, and bacteria from
Ashland Chemical Co. For food preservation it is used in the form of
the water-soluble salt potassium sorbate. In a concentration of
0.2% it does not affect taste or aroma. Preservastat, a sorbic acid
from Tri-K Industries, Inc., can be used at approximately 25% lower
levels than potassium sorbate to achieve the same results. It is avail-
able as a powder, as granules, or in crystal form. Anisic acid,
CH
3

OC
6
H
4
COOH, used for pharmaceuticals, is the methyl ether of
hydroxybenzoic acid. It is produced synthetically from carbon tetra-
chloride and phenol, and is a solid melting at 363°F (184°C). It is also
called methoxybenzoic acid, umbellic acid, and dragonic acid.
SUEDE. Also called napped leather. A soft-finished, chrome-tanned
leather made from calf, kid, or cowhide splits, or from sheepskin. It is
worked on a staking machine until it is soft and supple, and then
buffed or polished on an abrasive wheel. It has a soft nap on the pol-
ished side and may be dyed any color. Suede is used for shoe uppers,
coats, hats, and pocketbooks, but is now largely imitated with syn-
thetic fabrics. Artificial suede, or Izarine, of Atlas Powder Co., has
a base of rubber fabric. Fine cotton fibers dyed in colors are cemented
to one side, and the underside of the sheet is beaten to make the
fibers stand out until the cement hardens. The fabric looks and feels
like fine suede. Some suede is also made by chemical treatment of
sheepskins without staking. It has a delicate softness, but is not as
wear-resistant as calfskin.
SUGAR. A colorless to white or brownish, crystalline, sweet material
produced by evaporating and crystallizing the extracted juice of the
sugarcane or the sugar beet. Refined sugar is practically pure
sucrose, C
12
H
22
O
11

, and in addition to being a sweetening agent for
many foods it is a valuable carbohydrate food and a food preservative.
When used with cooked fruits to make jams and jellies, it is both a
preservative and an added food. Lack of sugar in the diet develops
ketosis, the disease of diabetics, and results in the wasting away of
muscles, using up of reserve fats, and the production of poisonous
ketones. When the blood-sugar level is low, a feeling of hunger is
induced which may not be satisfied even by overeating. A small
amount of sugar curbs the appetite and obviates surplus eating of
proteins and fats that create obesity. Natural brown sugar contains
about 2% of the minerals found in the plant, calcium, iron, phospho-
rus, magnesium, and potassium, and although these are valuable as
foods, they are lost in the refining process.
920 SUEDE
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Materials, Their Properties and Uses
Sugar is at present most valued as a food and for the production of
by-product alcohol from the residue molasses, but the sucrose mole-
cule is a convenient starting point for the production of many chemi-
cals. However, the production and distribution of sugar have been
hemmed in by restrictive laws based on its use for food. The sucrose
molecule has two complex rings, a glucosido and a fructose. It can be
regarded as a type of fructosido-glucose, but the fructose in sucrose
has a different structure, a furanose, or five-ring form, instead of the
pyranose, or six-ring structure, of ordinary fructose. Hydrolysis of
sucrose with acid gives dextrorotatory glucose and fructose, and the
mixture is called invert sugar. Numoline is a noncrystallizing
invert sugar made by hydrolyzing sucrose to split the molecule into

levulose and dextrose. It is used in confectionery and bakery prod-
ucts. Oxidation of sucrose produces oxalic acid and saccharic acid,
(HCOH)
4
(COOH)
2
, which can be reduced to adipic acid. Glycerin can
be made from sugar by hydrogenation to sorbitol and then splitting.
Thus, because of the great versatility of the sucrose molecule, and the
ease with which the sugar can be grown, sugar is one of the most
valuable chemical raw materials. Sucrose benzoate is a benzoic
acid derivative of sucrose used as a plasticizer and modifier for syn-
thetic resins for lacquers and inks.
Sugarcane, Saccharum officinarum, is a tropical plant, originating
in Asia and first brought to the Canary Islands in 1503 and thence to
the West Indies. The plant will not withstand frost, but can be grown
in a few favored regions outside of the tropics such as Louisiana. It is
now grown on plantations in Cuba, Hawaii, Brazil, the Philippines,
Indonesia, Puerto Rico, Peru, and many other countries. The cane or
stalks of the plant are crushed to extract the juice, which is then con-
centrated by boiling, crystallized, and clarified with activated carbon
or other material. The yield of sugar in Hawaii is about 14 tons
(12,698 kg) of raw sugar per acre (4,047 m
2
). Analysis of sugarcane
gives an average of 13.4% sucrose by weight of cane. The average yield
by milling is 91% of the contained sucrose, but yields as high as 98.8%
are obtained by diffusion extraction of the cut-cane chips.
The sugar beet is a white-rooted variety of the common beet, Beta
vulgaris, and grows in temperate climates. It is cut up and boiled to

extract the juice, and the production and refining of the sugar are
essentially the same as for cane sugar. There is no difference in the
final product, although raffinose, or melitriose, C
18
H
32
O
16
, a taste-
less trisaccharide, occurs in the sugar beet, and may not be com-
pletely changed to sucrose by hydrolysis, so that a greater quantity
may sometimes be needed to obtain equal sweetening effect.
The pectins and starches of the sugar beet are not extracted by the
use of the slicing and diffusion method.
SUGAR 921
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Materials, Their Properties and Uses
Refined commercial sugar contains 99.98% sucrose and is graded
by screening to crystal size. The best qualities are the larger crystals
from the first and second runs. The soft sugars are from further crys-
tallizing, until the noncrystallizing brown sugars are reached. Raw
sugar testing 96° by the polariscope is the grade used as a basis for
raw-sugar quotations. Commercial sugar may have starch added. The
ultrafine 6X confectioner’s sugar usually contains 4% cornstarch
as a noncaking agent, and block sugars may contain starch as a bind-
ing agent, but starch reduces the sweetening powder.
Cane sugar is the high-grade syrup or liquid sugar, while
molasses is the heavy residual syrup left after the crystallization.

Edible molasses is the yellow to brownish, light, purified residue
syrup. Blackstrap molasses is the final, inedible, unpurified residue
heavy syrup, used for the production of ethyl alcohol. It contains 50 to
60% sugar by weight, mostly sucrose but some glucose. A purified
grade which retains the minerals is marketed as an edible blackstrap
molasses.
Molasses powder, used for bakery products, is made by spray dry-
ing. It is a free-flowing, noncaking powder. Liquid sugar, much used
in food manufacturing because it saves handling costs, comes in vari-
ous liquid densities and in various degrees of invert. The liquid sug-
ars are usually not pure sucrose, and are called multisugars. For
food manufacturing the calcium and other minerals may be left in,
and they then have a yellow color. Multisugars with 90% sucrose and
10% levulose and dextrose crystallize in hard, aggregate clusters,
desirable in some confections. Flo-Sweet is liquid sugar. Sucrodex
is liquid sugar containing one-third dextrose and two-thirds sucrose,
with a solubility of 72% compared with only 45 for dextrose and 67 for
sucrose. Inverdex, for canning and for fountain syrups, is about 85%
invert sugar and 15 dextrose. Amberdex, used for cakes and cookies,
is an amber-colored 50–50 mixture of sucrose and dextrose with the
edible materials left in. Caramel, used for flavoring and coloring
foodstuffs and liquors, has a deep-brown color and a characteristic
taste. It is burnt sugar marketed as a liquid or powder.
The papelon of South America is solidified edible molasses. Gur is
unrefined brown sugar of India, and the pilancillo of Mexico is unre-
fined brown sugar. Treacle is an English name for edible molasses.
The refuse from sugar cane, called bagasse, is used as fuel and for
making paper and insulating board. Beet pulp, after extraction of
the juice, is marketed as cattle feed. Despite restrictive controls over
the world supply of sugar, much sucrose is being used in the produc-

tion of chemical products. Nonionic detergents, which are odorless,
biodegradable powders with low toxicity, are made by reacting
sucrose with fatty acid esters of volatile alcohols. Allyl sucrose is used
as a shellac substitute. Sucrose acetate isobutyrate is available in
922 SUGAR
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Materials, Their Properties and Uses
three grades: semisolid, in ethyl alcohol, in toluene. The pure chemi-
cal is a clear, viscous liquid boiling at 550°F (288°C), used as a plasti-
cizer in synthetic resins to improve extrusion and to give flexibility
and adhesiveness in coatings. As much as 70% is used in nitrocellu-
lose to give tough, flexible melt coatings. Nitto ester is sucrose
ester made with sugar and stearic acid. It is used as a food additive.
A type of edible sugar syrup is also obtained from the juice of a
variety of sorghum grass, Sorghum vulgare, native to South Africa,
but now grown in the southern United States. The juice or syrup,
called sorghum syrup, or sorgo syrup, is light in color, has a char-
acteristic delicate flavor, and contains gums and starch, which pre-
vent crystallization. It also contains other sugars besides sucrose, and
considerable mineral salts of value as foods. The total sugar in the
juice is from 9 to 17%, varying with the age of the plant. It is used in
some sections to replace sugar and is employed in some confectionery
to give a distinctive flavor.
Apple syrup, or apple honey, used as a sweetening agent in the
food industry, for curing hams, and as a substitute moistening agent
for tobacco, is made from cull apples. The reduced syrup is treated to
remove the bitter calcium malate. It contains 75% solids of which 65%
consists of the sugars levulose, dextrose, and sucrose. Palm sugar, or

jaggary, is the evaporated sap of several varieties of palm, including
the coconut and the palms from which kittool, gomuti, and palmyra
fibers are obtained. The sap contains about 14% sugar. It is much
used in India and the Pacific Islands. The palm wine known as
arrack is made by fermenting the juice, called taewak, of the flower
stems of the aren palm of Java. A liter (1.06 qt) of taewak yields
about 0.2 lb (0.09 kg) of brown palm sugar. Wood molasses is made
by concentrating and neutralizing the dilute sugar solution produced
by pressure hydrolysis of wood chips using dilute sulfuric acid at high
temperature. The molasses has a slightly bitter taste, but is used for
stock feed and for industrial purposes. Wood sugars contain xylose,
CHO(HCOH)
3
CH
2
OH, which belongs to the great group of pentosans
occurring in plant life. They have the same general formula with dif-
ferent numbers of the HCOH group. Oxidation converts them to the
respective acid, as xylonic acid from xylose, or arabinic acid from
the arabinose of gum arabic. They can also be converted to the lac-
tones, and are related to the furanes, so that the wood sugars have a
wide utility for the production of chemicals.
Other plants yield sweetening agents, but few are of commercial
importance. The leaves of the caá heé, a small plant of Paraguay, are
used locally for sweetening Paraguayan tea. The name, pronounced kah-
áh aye-áye, means sweet herb, and it has a more intense sweetening
effect than sugar. Miracle Fruit powder, of International Minerals and
Chemical Corp., is a complex protein-based chemical derived from the
SUGAR 923
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Materials, Their Properties and Uses
fruit pulp of the Agbayun shrub, Synsepalum dulcificum, of west Africa.
It has a strong sweetening effect and a pleasant natural flavor. Stevia, a
potent low-calorie sweetener from the leaf of the South American shrub
Stevi rebaudiana and also grown in China, is restricted to use as a
dietary supplement.
The 6-carbon sugar derivative known as glucoronic lactone, used
as an antiarthritic drug, is derived from dextrose. Amino sugar, or
glucosamine, has an NH
2
group in the molecule in place of the alpha
hydroxyl group of glucose. This sugar occurs in marine animals.
Synthetic sweetening agents of no food value are used in diabetic
foods and in dietetic foods for the treatment of obesity. Many of these
synthetic sweeteners are toxic in excess and are cumulative in the
human system. Thus, dietary foods that depend on the substitution
of chemicals in place of sugar should be taken only with caution and
under medical direction. Saccharin, produced from coal tar, is ben-
zoic sulfinide, C
6
H
4
SO
2
NHCO. It is 450 times sweeter than sugar
and has no food value, but it has a disagreeable aftertaste. It is a
water-insoluble white powder, but its salts, sodium saccharin, and
calcium saccharin, are soluble in water and are 300 times sweeter

than sugar. Saccharin is also used as a pH indicator, and as a bright-
ener in nickel-plating baths.
The cyclamates were widely used in beverages and diet foods,
but are now recognized as toxic drugs and are restricted. Sodium
cyclohexylsulfamate, or sodium cyclamate, Na(C
6
H
12
NO
3
S)
2
и
2H
2
O, is used in dietetic foods and in some soft drinks as it has no
food value. It is 30 times sweeter than sugar, but at the 25% sweet-
ening level of sugar it has an undesirable aftertaste, and at the
sugar-sweetness level the off-taste predominates. For both
sugar-free and salt-free diets, the calcium salt calcium cyclamate
is used. Sucaryl, of Abbott Laboratories, is sodium cyclamate, and
Cyclan, of Du Pont, is calcium cyclamate. Hexamic acid, a white,
crystalline powder which is cycle hexylsulfamic acid, is used as a
supplement sweetener and intensifier with the cyclamates and sac-
charin. Aspartame, also known as Nutrasweet, is a low-calorie
sweetener used alone or in combination with sugar or saccharin in
some breakfast cereals, diet soft drinks, and other ready-mixed bev-
erages. Peryllartine is the sweetest known substance, being 2,000
times sweeter than sucrose. It is a complex aldehyde derived from
terpenylic acid, which occurs in combined forms in turpentine and

many essential oils.
A number of other artificial sweeteners are also being developed.
Acesulfame-potassium, known as Sunette in the United States,
is available in a table-top formula, Sweet-One, and as an ingredi-
ent in chewing gum and dry beverage mixes. Produced by Hoechst
924 SUGAR
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Materials, Their Properties and Uses
Celanese Corp., it is 200 times sweeter than sugar and slightly
more so than aspartame. But since acesulfame-potassium suffers
from a slight aftertaste, it is usually mixed with other sweeteners;
the combination works synergistically, with the mixture being
sweeter than either component. Xylitol is a naturally derived
sugar alcohol made from birch bark. It offers few benefits over
sugar, since it is about as sweet and has the same number of calo-
ries. Produced in Finland, it is marketed in the United States by
American Xyrofin primarily for specialty diet foods, such as for dia-
betics and infants, in oral hygiene, and pharmaceutical products.
Alitame, formed from the amino acids L-aspartic acid and D-ala-
nine by Pfizer, Inc., is 2,000 times sweeter than sucrose, just as
heat-stable, and has a shelf life up to 4 times that of aspartame.
Sucralose, being developed by McNeil Specialty Products Co., is
600 times sweeter than sugar, from which it is derived. Natural
thaumatin, a protein that is 5,000 times sweeter than sugar, is
used mainly as a flavor enhancer. Isomalt, a modified sugar, is used
in chocolates and confectioneries in Europe and Asia, and is
produced by West Germany’s Subungsmittel GmbH. It is also used
as a bulking agent with the highly sweet products. Lev-O-Cal is a

left-handed L-sugar that is less sweet and has fewer calories than
the right-handed, or normal, sugar. Polydextrose is another
low-calorie bulking agent.
SUGAR PINE. The common name of the wood of the Pinus lamber-
tiana, a coniferous tree growing in California and Oregon. The tree
grows ordinarily to a height of 150 to 175 ft (46 to 53 m) with a diam-
eter of 4 to 5 ft (1.2 to 1.5 m). Occasional trees are more than 200 ft
(61 m) in height and 12 ft (3.7 m) in diameter, and are often free of
limbs up to 75 ft (23 m) from the ground. It is the largest of the
pines. Sugar pine is durable, has moderate strength and fairly even
grain, and is not subject to excessive shrinkage or warping. Because
of the latter quality it has come into use to replace the scarcer east-
ern pines for patterns. It does not darken on exposure as western
pine does. It is widely employed for construction work and for fac-
tory lumber for doors, frames, boxes, and wooden articles. Sugar
pine is classified into three standard classes of grades according to
freedom from knots and faults as select, commons, and factory, or
shop. The selects are designated as Nos. 1 and 2 clear, C select, and
D select. The commons are graded as Nos. 1, 2, 3, and 4; the factory
as No. 3 clear, No. 1 shop, No. 2 shop, and No. 3 shop. The shops are
judged with the idea that they will be cut up into small pieces, and
are consequently classified by the area of clear cuttings that can be
obtained.
SUGAR PINE 925
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Materials, Their Properties and Uses
SULFAMIC ACID. A white, crystalline, odorless solid of composition
HSO

3
и NH
2
, very soluble in water, but only slightly soluble in alcohol.
The melting point is 352°F (178°C). The acid is stronger than other
solid acids, approaching the strength of hydrochloric. It is used in bat-
ing and tanning leather, giving a silky, tight grain in the leather. An
important use is for cleaning boiler and heat-exchanger tubes. It con-
verts the calcium carbonate scale to the water-soluble calcium sulfa-
mate, which can then be flushed off and combined with sodium
chloride; it also converts the rust to ferric chloride and then to the
water-soluble iron sulfamate. Pettibone Chemicals offers high-purity
grades for bleaching paper pulp and textiles, organic synthesis,
gas-liberating compositions, and as a catalyst for urea-formalde-
hyde resins. Ammonium sulfamate is the ammonia salt of the acid,
used as a cleanser and anodizer of metals, as a weed killer, and for
flameproofing paper and textiles. Lead ammonium sulfamate,
Pb(SO
3
NH
2
)
2
, used in lead plating, is very soluble in water and has high
throwing power. Aminoethylsulfamic acid, NH
2
CH
2
CH
2

OSO
3
H, is
used for treating paper and textile fibers to increase wet strength and
water repellency. Tobias acid, used in making azo dyes, is naphthy-
lamine sulfonic acid, NH
2
C
10
H
6
SO
3
H, in white needles decomposing
at 446°F (230°C).
SULFONATED OIL. A fatty oil that has been treated with sulfuric acid,
the excess acid being washed out and only the chemically combined
acid remaining. The oil is then neutralized with an alkali. Sulfonated
oils are water-soluble and are used in cutting oils and in fat liquors for
leather finishing. Sulfonated castor oil is called Turkey red oil.
Leatherlubric is the trade name of E. F. Houghton & Co. for sul-
fonated sperm oil used for leather. Solcod is the sulfonated cod oil of
the same company. Sulfonated stearin and sulfonated tallow are
also used in leather dressing. They are cream-colored pastes readily
soluble in hot water. Mahogany soap is a name for oil-soluble petro-
leum sulfonates used as dispersing and wetting agents, corrosion
inhibitors, emulsifiers, and to increase the oil absorption of mineral
pigments in paints. Petronate is a petroleum sulfonate containing
62% sulfonates, 35 mineral oil, and 3 water. Phosphorated oils, or
their sulfonates, may be used instead of the sulfonates as emulsifying

agents or in treating textiles and leathers. They are more stable to
alkalies. Phosoils are phosphorated vegetable oils. Aquasol, of
American Cyanamid Co., is a sulfonated castor oil used as an emulsify-
ing agent. Cream softener is a name used in the textile industry for
sulfonated tallow.
SULFUR. One of the most useful of the elements, symbol S. Its occur-
rence in nature is little more than 1% that of aluminum, but it is easy
926 SULFAMIC ACID
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Materials, Their Properties and Uses
to extract and is relatively plentiful. In economics, it belongs to the
group of “S” materials—salt, sulfur, steel, sugars, starches—whose
consumption is a measure of the industrialization and the rate of
industrial growth of a nation. Sulfur is obtained from volcanic
deposits in Sicily, Mexico, Chile, and Argentina, and along the Gulf
Coast in Louisiana, Texas, and Mexico it is obtained from great
underground deposits in the cap rock above salt domes. Offshore
deposits worked in the Gulf of Mexico are 2,000 ft (610 m) under the
bottom. Strict environmental laws are driving the production of sul-
fur recovered as a by-product of various industrial operations. It is
also obtained by the distillation of iron pyrites, as a by-product of cop-
per and other metal smelting, and from natural gas. The sterri
exported from Sicily for making sulfuric acid is broken rock rich in
sulfur. Brimstone is a very ancient name still in popular use for solid
sulfur, but the District Court of Texas has ruled that sulfur obtained
from gas is not subject to tax as brimstone.
Sulfur forms a crystalline mass of a pale-yellow color, with a Mohs
hardness of 1.5 to 2.5, a specific gravity of 2.05 to 2.09, and melting

point of 232°F (111°C). It forms a ruby vapor at about 780°F (416°C).
When melted and cast, it forms amorphous sulfur with a specific
gravity of 1.955. The tensile strength is 160 lb/in
2
(1 MPa), and com-
pressive strength is 3,300 lb/in
2
(23 MPa). Since ancient times it has
been used as a lute for setting metals into stone. Sulfur also con-
denses into light flakes known as flowers of sulfur, and the hydro-
gen sulfide gas, H
2
S, separated from sour natural gas, yields a
sulfur powder. Flotation sulfur is a fine, free-flowing sulfur dust
with particle sizes less than 157 ␮in (4 ␮m), recovered in gas produc-
tion from coal. Commercial crude Sicilian sulfur contains from 2 to
11% of impurities and is sold in three grades. Refined sulfur is mar-
keted in crystals, roll, or various grades of powder, and the Sicilian
superior grade is 99.5% pure. This is the grade used in rubber manu-
facture. Crystex is a sulfur, 85% insoluble in carbon bisulfide, used
in rubber compounding. The sulfur powder of Electronic Space
Products, Inc., used for semiconductors, is 99.9999% pure.
Sulfur has twice the atomic weight of oxygen but has many similar
properties and has great affinity for most metals. It has six valence
electrons, but also has valences of 2 and 4. The crystalline sulfur is
orthorhombic, which converts to monoclinic crystals if cooled slowly
from 248°F (120°C). This form remains stable below 248°F. When
molten sulfur is cooled suddenly, it forms the amorphous sulfur which
has a ring molecular structure and is plastic, but converts gradually
to the rhombic form. Sulfur has a wide variety of uses in all indus-

tries. The biggest outlet is for sulfuric acid, mainly for producing
phosphate fertilizers. Agri Sul, from Eagle-Picher Industries, Inc., is
available in prilled form or as a water-degradable grade, as a source
SULFUR 927
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Materials, Their Properties and Uses
of elemental sulfur for correcting sulfur deficiencies in crops and
grasses. Newsulfur, from Tri-K Industries, Inc., is a nonirritating
variety that can be mixed by hand with any kind of ingredient. It is
used for making gunpowder and for vulcanizing rubber, but for most
uses it is employed in compounds, especially as sulfuric acid or sulfur
dioxide. A vast number of so-called thio compounds have been pro-
duced. The thio alcohols, or mercaptans, have an SH group
instead of the OH of true alcohols, and they do not react as alcohols,
but the thio esters are made directly from the mercaptans. Thionyl
chloride, SOCl
2
, a yellow liquid, is a typical compound used as a
source of sulfur in synthesis. Most of the thio compounds have an
offensive odor. Vegetable sulfur does not contain sulfur, but is lyco-
podium, a fine, yellow powder from the spores of the club moss, a
fernlike plant, Lycopodium clavatum, which grows in North America
and Europe. It belongs to the group of lipochromes, or coloring mat-
ter of plants related to lycopene and carotene.
Sulfur dioxide, or sulfurous acid anhydride, is a colorless gas of
composition SO
2
, used as a refrigerant, as a preservative, in bleaching,

and for making other chemicals. It liquefies at about 14°F (Ϫ10°C). As
a refrigerant it has a condensing pressure of 51.7 lb (23.5 kg) at 86°F
(30°C). The gas is toxic and has a pungent, suffocating odor, so that
leaks are detected easily. It is corrosive to organic materials but does
not attack copper or brass. The gas is soluble in water, forming sul-
furous acid, H
2
SO
3
, a colorless liquid with suffocating fumes. The
acid form is the usual method of use of the gas for bleaching.
SULFURIC ACID. An oily, highly corrosive liquid of composition H
2
SO
4
,
having a specific gravity of 1.841 and a boiling point of 626°F
(330°C). It is miscible in water in all proportions, and the color is yel-
lowish to brown according to the purity. It may be made by burning
sulfur to the dioxide, oxidizing to the trioxide, and reacting with
steam to form the acid. It is a strong acid, oxidizing organic materi-
als and most metals. Sulfuric acid is used for pickling and cleaning
metals, in electric batteries and plating baths, for making explosives
and fertilizers, and for many other purposes. In the metal industries
it is called dipping acid, and in the automotive trade it is called
battery acid. Fuming sulfuric acid, or oleum, of 100% purity,
was called Nordhausen acid. The grade of sulfuric acid known as
oil of vitriol, or vitriol, is 66°Bé, or 93.2% acid. A 96% grade, called
Particulo, is available from General Chemical Co. Sulfur trioxide,
or sulfuric anhydride, SO

3
, is the acid minus water. It is a colorless
liquid boiling at 115°F (46°C) and forms sulfuric acid when mixed
with water. It is used for sulfonation. Sulfan, of Allied-Signal Corp.,
is sulfuric anhydride. Sulfodox is a liquid sulfur dioxide of high
928 SULFURIC ACID
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Materials, Their Properties and Uses
purity from Specialty Products Corp. It is used for acidifying and
bleaching. Chlorosulfonic acid, HClSO
3
, has equal amounts of sul-
fur trioxide and hydrochloric acid, and is a vigorous dehydrating
agent, used also in chlorosulfonating organic compounds. It has a spe-
cific gravity of 1.752 and boils at 311°F (155°C). Mixed with sulfur tri-
oxide, it has been called FS smoke for military smoke screens.
Niter cake, which is sodium acid sulfate, NaHSO
4
, or sodium
bisulfate, contains 30 to 35% available sulfuric acid and is used in
hot solutions for pickling and cleaning metals. It comes in colorless
crystals or white lumps, with a specific gravity of 2.435 and melting
point 572°F (300°C). Sodium sulfate, or Glauber’s salt, is a white,
crystalline material of composition Na
2
SO
4
и 10H

2
O, used in making
kraft paper, rayon, and glass. It was first produced from Hungarian
spring water by Johann Glauber, and when obtained from mineral
springs, it is called crazy water crystals. The burkeite, sodium
sulfate–sodium bicarbonate double salt, which separates out of
Searles Lake brine, is used to produce sodium sulfate and other
chemicals as by-products. Salt cake, Na
2
SO
4
, is impure sodium sul-
fate used in the cooking liquor in making paper pulp from wood. It is
also used in freezing mixtures. Synthetic salt cake, used for making
kraft pulp, is produced by sintering soda ash and sulfur. Chrome
cake is a greenish by-product salt cake which contains some
chromium as an impurity. It is used in papermaking. Kaiseroda is a
German name for salt cake of high purity obtained as a by-product
from the production of magnesium chloride from potash minerals.
Sodium sulfite, Na
2
SO
3
or Na
2
SO
3
и 7H
2
O, is a white to tan, crys-

talline powder very soluble in water but nonhygroscopic. Santosite,
of Monsanto, is a grade of sodium sulfite containing 93% sodium sul-
fite with the balance chiefly sodium sulfate.
Sodium sulfide, Na
2
S, is a pink, flaky solid, used in tanneries for
dehairing and in the manufacture of dyes and pigments. The commer-
cial product contains 60 to 62% Na
2
S, 3.5 NaCl, and other salts, and
the balance water of crystallization. Sodium sulfhydrate, NaSH, is
in lemon-yellow flakes. It has much less alkalinity than sodium sul-
fide, and is used in tanneries in unhairing solutions and for making
thiourea and other chemicals. It contains 62.6% by weight of sulfur
and is an economical material for sulfonating. Sodium dithionate,
Na
2
S
2
O
6
и 2H
2
O, is used in leather tanning, as an assist in textile dye-
ing and printing, and for making other chemicals. It comes in trans-
parent, prismatic crystals of bitter taste. Sodium thiosulfate,
Na
2
S
2

O
3
и 5H
2
O, known as hypo, is a white, crystalline compound
having a specific gravity of 1.73 and a melting point of 113°F (45°C).
It is used in photography to fix films, plates, and papers. White vit-
riol is zinc sulfate in colorless crystals soluble in water and melting
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Materials, Their Properties and Uses
at 102°F (39°C). It is used for making zinc salts, as a mordant, for
zinc plating, and as a preservative in adhesives.
SUMAC. The dried, ground leaves of the bush Rhus coriaria of Sicily,
or R. typhina of the eastern United States, used for tanning leather.
The Sicilian leaves contain up to 30% tannin, and the U.S. leaves up
to 38%. It contains gallotannin and ellagitannin and gives a rapid
tan. Sumac provides a light, strong leather of fine, soft grain and has
a bleaching action which can produce a white leather. It is used for
book and hatband leathers. Sumac grows profusely in the eastern
states, but the gathering of the leaves is not organized commercially.
SUNFLOWER OIL. A pale-yellow drying oil with a pleasant odor and
taste obtained from the large seeds of the common sunflower plant,
Helianthus annuus, of which there are many varieties. The plant is
native to Peru but is now grown in many parts of the world, particu-
larly in California, Canada, Argentina, Chile, Uruguay, and Russia. It
requires boron in the soil. The specific gravity of the oil is 0.925.
Sunflower oil is used in varnish and soap manufacture or as a food

oil. Refined and unrefined grades, with trade name Trisun, are avail-
able for these applications from SVO Enterprises. The by-product
cake is used chiefly for cattle feed, but sunflower meal is also
blended with wheat flour or cornmeal in foods. It is higher in vitamin
B than soybean flour. Sunflower seeds are also used as poultry feed.
Madia-seed oil is quite similar to sunflower oil and has the same
uses. It is obtained from the seeds of the plant Madia sativa, native to
California. The seeds contain 35% oil, and the cold-pressed oil has a
pleasant taste. Watermelon-seed oil, produced in Senegal as bereff
oil, is an edible oil similar to sunflower. It contains about 43%
linoleic, 27 oleic, 19.5 stearic, and 5 palmitic acids.
The leaves of selected varieties of some species of sunflower contain
from 1 to 6% sunflower rubber and up to 8 resin. The H. occiden-
talis, H. giganteus, H. maximiliani, and H. strumosus are cultivated in
Russia both for the oil seed and for the rubber in the leaves. These
perennials yield leaves up to 10 years. Another similar rubber-bearing
plant of southern Russia is Asclepias cornuti, known as vatochnik. It
is a perennial, producing leaves for 10 to 15 years. The leaves yield 1
to 6.5% rubber and large percentages of resin.
SUN HEMP. The bast fiber of the plant Crotalaria juncea. It is used
for cordage and rope in place of jute, but is lighter in color and is
more flexible, stronger, and more durable than jute. It resembles true
hemp, but is not as strong. It is more properly called sann hemp
930 SUMAC
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Materials, Their Properties and Uses
from the Hindu word sann. It is also known as sunn fiber, Indian
hemp, and Bombay hemp. The plant, which is a shrub, is cultivated

extensively in India. It grows to a height of about 8 ft (2.4 m), with
slender branches yielding the fiber. The method of extraction is the
same as for true hemp. The best fibers are retained locally for making
into cloth. It is also used in the United States for making cigarette
paper and for oakum. Madras hemp is from another species of the
same plant.
SUPERALLOYS. Iron-based, nickel-based, or cobalt-based alloys noted
primarily for high strength and oxidation and corrosion resistance at
high temperatures. Because of their excellent high-temperature per-
formance, they are also known as high-temperature, high-strength
alloys. Their strength at high temperatures is usually measured in
terms of stress-rupture strength or creep resistance. For high-stress
applications, the iron-base alloys are generally limited to a maximum
service temperature of about 1200°F (649°C), whereas the nickel-and
cobalt-based alloys are used at temperatures to about 2000°F (1093°C)
and higher. In general, the nickel alloys are stronger than the cobalt
alloys at temperatures below 2000°F, and the reverse is true at tem-
peratures above 2000°F. Superalloys are probably best known for air-
craft turbine applications, although they are also used in steam and
industrial turbines, nuclear power systems, and chemical and petro-
leum processing equipment. A great variety of cast and wrought alloys
are available, and in recent years, considerable attention has been
focused on the use of powder-metallurgy techniques as a means of
attaining greater compositional uniformity and finer grain size.
The iron-based superalloys include solid-solution alloys and
precipitation-hardening (PH), or precipitation-strengthened, alloys.
Solid-solution types are alloyed primarily with nickel (20 to 36%) and
chromium (16 to 21), although other elements are also present in lesser
amounts. Superalloy 16-25-6, for example, the alloy designation indi-
cating its chromium, nickel, and molybdenum contents, respectively,

also contains small amounts of manganese (1.35%), silicon (0.7), nitro-
gen (0.15), and carbon (0.06). Incoloy 800, 801, and 802, of Inco Alloys
International, Inc., contain slightly less nickel and slightly more
chromium with small amounts of titanium, aluminum, and carbon.
Incoloy 803, of Inco, was developed for pyrolysis tubing in severe ethyl-
ene furnaces and other petrochemical applications. It comprises 32 to
37% nickel, 25 to 29 chromium, 0.15 to 0.6 aluminum, 0.15 to 0.6 tita-
nium, 0.06 to 0.1 carbon, with maximum amounts of 1.5 manganese, 1
silicon, 0.75 copper, and 0.015 sulfur, balance iron. The alloy has high
resistance to oxidation and carburization. Protective scales, developed
SUPERALLOYS 931
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Materials, Their Properties and Uses
by high-temperature exposure, provide the self-healing quality. The
alloy has an ultimate tensile strength of 88,000 lb/in
2
(607 MPa) and
50% elongation. At 1800°F (980°C), the tensile strength is 15,000 lb/in
2
(103 MPa). N-155, or Multimet, an early sheet alloy, contains about
equal amounts of chromium, nickel, and cobalt (20% each), plus 3
molybdenum, 2.5 tungsten, 1 columbium, and small amounts of carbon,
nitrogen, lanthanum, and zirconium. At 1350°F (732°C), this alloy has
a 1,000-h stress-rupture strength of about 24,000 lb/in
2
(165 MPa).
PH iron-based superalloys provide greater strengthening by pre-
cipitation of a nickel-aluminum-titanium phase. One such alloy,

which may be the most well known of all iron-based superalloys, is
A-286. It contains 26% nickel, 15 chromium, 2 titanium, 1.25 molyb-
denum, 0.3 vanadium, 0.2 aluminum, 0.04 carbon, and 0.005 boron.
At room temperature, it has a tensile yield strength of about 100,000
lb/in
2
(690 MPa) and a tensile modulus of 21.1 ϫ 10
6
lb/in
2
(145,000
MPa). At 1200°F (649°C), tensile yield strength declines only slightly,
to 88,000 lb/in
2
(607 MPa), and its modulus is about the same or
slightly greater. It has a 1,000-h stress-rupture strength of about
21,000 lb/in
2
(145 MPa) at 1350°F (732°C). Other PH iron-based
superalloys are Discoloy, Haynes 556 (whose chromium, nickel,
cobalt, molybdenum, and tungsten contents are similar to those of
N-155); Incoloy 903 and Pyromet CTX-1, which are virtually
chromium-free but high in nickel (37 to 38%) and cobalt (15 to 16);
and V-57 and W-545, which contain about 14 chromium, 26 to 27
nickel, about 3 titanium, 1 to 1.5 molybdenum, plus aluminum, car-
bon, and boron. V-57 has a 1,000-h stress-rupture strength of about
25,000 lb/in
2
(172 MPa) at 1350°F and greater tensile strength, but
similar ductility, than A-286 at room and elevated temperatures.

Nickel-based superalloys are solid-solution, precipitation-hard-
ened, or oxide-dispersion-strengthened. All contain substantial
amounts of chromium, 9 to 25%, which, combined with the nickel,
accounts for their excellent high-temperature oxidation resistance.
Other common alloying elements include molybdenum, tungsten,
cobalt, iron, columbium, aluminum, and titanium. Typical solid-solu-
tion alloys include Hastelloy X (22 to 23% chromium, 17 to 20 iron,
8 to 10 molybdenum, 0.5 to 2.5 cobalt, 2 aluminum, 0.2 to 1 tungsten,
and 0.15 carbon); Inconel 600 (15.5 chromium, 8 iron, 0.25 copper
maximum, 0.08 carbon); and Inconel 601, 604, 617, and 615, of Inco
Alloys International, Inc., the latter containing 21.5 chromium,
9 molybdenum, 3.6 columbium, 2.5 iron, 0.2 titanium, 0.2 aluminum,
and 0.05 carbon. At 1350°F (732°C), wrought Hastelloy X (it is also
available for castings) has a 1,000-h stress-rupture strength of about
18,000 lb/in
2
(124 MPa) and has high oxidation resistance at tempera-
932 SUPERALLOYS
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Materials, Their Properties and Uses
tures to 2200°F (1204°C). Inconel 625 has a low-cycle (10
5
) fatigue
strength of 110,000 to 120,000 lb/in
2
(760 to 830 MPa). Inconel 625
LCF has low carbon, silicon, and nitrogen contents to improve resis-
tance to low-cycle fatigue. Inconel 725 is an age-hardenable version

of Inconel 625, providing comparable corrosion resistance but greater
strength. Inconel 783 is an oxidation-resistant, low-expansion,
nickel-cobalt-iron superalloy for aircraft turbine parts. RA333, from
Rolled Alloys, contains 45 nickel; 25 chromium; 18 iron; 3 each of
cobalt, molybdenum, and tungsten; 1 silicon; and 0.05 carbon. The
alloy features good resistance to oxidation and carburization to
2200°F (1200°C), has a tensile yield strength of 39,000 lb/in
2
(269
MPa), 47% elongation, and a creep-rupture strength of 4,300 lb/in
2
(30 MPa) for 10,000 h at 1400°F (760°C).
The precipitation-strengthened alloys, which are the most numer-
ous, contain aluminum and titanium for the precipitation of a second
strengthening phase, the intermetallic Ni
3
(Al,Ti) known as gamma
prime (␥′) or the intermetallic Ni
3
Cb known as gamma double
prime (␥″), during heat treatment. One such alloy, Inconel X-750
(15.5% chromium, 7 iron, 2.5 titanium, 1 columbium, 0.7 aluminum,
0.25 copper maximum, and 0.04 carbon), has more than twice the ten-
sile yield strength of Inconel 600 at room temperature and nearly 3
times as much at 1400°F (760°C). Its 1,000-h stress-rupture strength
at 1400°F is in the range of 20,000 to 30,000 lb/in
2
(138 to 207 MPa).
Still great tensile yield strength at room and elevated temperatures
and a 25,000 lb/in

2
(172 MPa) stress-rupture strength at 1400°F are
provided by Inconel 718 (19% chromium, 18.5 iron, 5.1 columbium, 3
molybdenum, 0.9 titanium, 0.5 aluminum, 0.15 copper maximum,
0.08 carbon maximum), a wrought alloy originally that also has been
used for castings. Inconel 718SPF is for superplastic forming, as the
designation implies. A vacuum-induction-melted and electroslag-
remelted alloy, it is produced to a fine grain size (ASTM 12), and
reduced carbon and columbium contents to minimize carbide precipi-
tation during forming. Gas pressure of only 300 lb/in
2
(2 MPa) at
1750°F (954°C) and low strain rates are sufficient to form complex
shapes. Because of the low strain rates, forming cycles are long: 1 to 3
h with mill-annealed sheet, which has an ultimate tensile strength of
162,000 lb/in
2
(1,117 MPa), a yield strength of 118,000 lb/in
2
(814
MPa), and 33% elongation. Aging increases the yield strength to
192,000 lb/in
2
(1,324 MPa). At 1200°F (649°C), the yield strength is
160,000 lb/in
2
(1,103 MPa). Among the strongest alloys in terms of
stress-rupture strength is the wrought or cast IN-100 (10%
chromium, 15 cobalt, 5.5 aluminum, 4.7 titanium, 3 molybdenum,
1 vanadium, less than 0.6 iron, 0.15 carbon, 0.06 zirconium, 0.015

SUPERALLOYS 933
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Materials, Their Properties and Uses
boron). Investment-cast, it provides a 1,000-h stress-rupture strength
of 75,000 lb/in
2
(517 MPa) at 1400°F (760°C), 37,000 lb/in
2
(255 MPa)
at 1600°F (871°C), and 15,000 lb/in
2
(103 MPa) at 1800°F (982°C).
Other precipitation-strengthened wrought alloys include Astroloy;
D-979; IN 102; Inconel 706 and 751; M252; Nimonic 80A, 90, 95,
100, 105, 115, and 263; René 41, 95, and 100; Udimet 500, 520, 630,
700, and 710; Unitemp AF2-1DA; and Waspaloy. Other cast alloys,
mainly investment-cast, include B-1900; IN-738; IN-792; Inconel
713C; M252; MAR-M 200, 246, 247, and 421; NX-188; René 77, 80,
and 100; Udimet 500, 700, and 710; Waspaloy; and WAZ-20.
A few of the cast alloys, such as MAR-M 200, are used to produce
directionally solidified castings, that is, investment castings in
which the grain runs only unidirectionally, as along the length of tur-
bine blades. Eliminating transverse grains improves stress-rupture
properties and fatigue resistance. Grain-free alloys, or single-crystal
alloys, also have been cast, further improving high-temperature
creep resistance. Developed mainly for aircraft-engine turbine blades,
the first such alloys were pioneered by Pratt & Whitney Aircraft with
PWA 1480 and also include AM1 and 3; CMSX-2, -3, and -6; Rene

N4; RR2000; SRR 99; and SX 792. These alloys contain 8 to 12%
chromium, 5 to 15 cobalt, 0 to 12 tantalum, 0 to 10 tungsten, 3.4 to
6.0 aluminum, 1 to 4.7 titanium, 0 to 3 molybdenum, and, in some
cases, small amounts of columbium, hafnium, and/or vanadium. They
have similar creep-rupture properties but differ in various other per-
formance criteria and single-crystal castability. These alloys were fol-
lowed with 3 to 6% rhenium alloys having less chromium (2 to 7) and
other compositional changes. They include CMSX-4 and -10, PWA
1484, SC 180, and Rene N5 and N6. Compared with rhenium-free
SRR 99, the 6 rhenium CMSX-10 (RR3000) increases 500-h creep
strength by 46% and 20,000-cycle fatigue strength by 59%.
At 1400°F (760°C), Cannon Muskegon’s CMSX-4 has a tensile yield
strength of 140,000 lb/in
2
(965 MPa), and it retains useful strength up
to 2125°F (1163°C). Regarding powder-metallurgy techniques, empha-
sis has been on the use of prealloyed powder made by rapid solidifi-
cation techniques (RST) and mechanical alloying (MA), a
high-energy milling process using attrition mills or special ball mills.
Dispersion-strengthened nickel alloys are alloys strengthened by
a dispersed oxide phase, such as thoria, which markedly increases
strength at very high temperatures but only moderately so at inter-
mediate elevated temperatures, thus limiting applications.
TD-nickel, or thoria-dispersed nickel, was the first of such super-
alloys, and it was subsequently modified with about 20% chromium,
TD-NiCr, for greater oxidation resistance. MA 754, 758, and 6000E
934 SUPERALLOYS
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Materials, Their Properties and Uses