real world of
edited by
K. E. KOLB Bradley University Peoria. IL 61625
Chem
HAROLD WITTCOFF Systems. International. Ltd. 28 St. James Square
London S W l Y 4JH. Endand
The Second 50 Industrial Chemicals, Part 1 Phlllp J. Chenierl and Danelte S. Artibee University of Wisconsin-Eau Claire, Eau Claire, WI 54702 For many years C'hemicolond hgineering N P K Shas published a yearly list of the top 50 rhemicals ~ r o d u c e din the United States arranged in order of decreasing production (I). This has become a handy and valuable reference for industrial chemists, together with an annual analysis of top polymers (2) and a top 100 chemical company list (3). The top 50 chemicals are also a valuable starting point for teaching industrial chemistry to students (41, and a recent text (5) on industrial chemistry starts with a detailed treatment of these important chemicals. To our knowledge, no previous attempt has been made to develop a list of the second 50 chemicals arranged by annual U S . production. This would also prove to he a valuable reference for all those with an interest in industrial chemistry. Consequently, we have studied the readily available literature and have designed such a list that we believe will be quite useful. An introduction to this list and short summaries of the manufacturing methods and uses of chemicals 51-75 are given in this first article. A later article will complete the treatment with chemicals 76-100. Production figures are sometimes very difficult to obtain for chemicals. A number of sources have been examined in detail (6-10) and recent production amounts were found for most chemicals in a preliminary "guess list" of approximately 170 candidates. The year of production that is used in Table 1 varies, hut all are from data of the last 10 years and most are from 1985 or later. We make no claim that the order is exact. Nor do we suggest that no chemicals have been overlooked.2 Specialized trade literature has not been examined. Generally, the guidelines for selection are similar to those for the top 50 list. A single chemical, or a commercially useful, closely related familv of chemicals often used as a single entity.~isincluded. Oie might argue against the families being listed, as is dune for linear ~lr)ha-oiefins.fluorocarbons, n-paraffins, linear alkylbenzedes, ethanolamines, hexanes, and alkylamines. However, these families are important in the industry, and it is instructive to include them, even though they are not chemically homogeneous and may not have made the list if their components were considered separately. No polymers are included. Sometimes chemicals donot appear on the list or are lower than what they might he due to a large captive use and unofficially reported production; for example, adiponitrile is not listed even though it is the precursor of hexamethyleneAuthor lo whom correspondence shoulo be addressed Tne authors welcome corrections and addit om. Pease wr te to PJC w~thyour suggest~ons and so,rces and perhaps a f~t-rerevlsion can be published. I
244
Journal of Chemical Education
diamine. Production figures are not readily available for these chemicals, and we hesitated to estimate their amount. Nevertheless, we feel the list as developed is quite functional. Characteristics of the Second 50 Chemicals The most immediate characteristic of the second 50 that is very striking is the dominance of organic chemicals, a totalof 47, leaving as the only inorganics phosphorus (68), sodium chlorate (82), and potassium hydroxide (87), though some might claim phosgene and hydrogen cyanide as being borderline inorganics. In contrast, the top 50 have 28 organics and 22 inorganics, a more balanced distribution, and eight of the top 10 are inorganic. Organics in the second 50 own 32 of a total of 34 billion pounds of chemical production for all 50; in the ton 50 the inoreanics win in total nroduction a t 351 hillion vs. ~,rganicsat188 billion pounds,due mainly to those n . second 50 big eight inoreanics. Inrrsnd t ( m I ~ r ~ d u c t i othe at34billion pounds isonly a fraction of thk top 50's 539 billion pounds, barely 6% of the higher list. While the top 50 varies in production from sulfuric acid a t 73.64 billion pounds to sodium tripolyphosphate a t 1.27 billion pounds, the second 50 extends from acetic anhydride a t 1.64 billion pounds to 1-butene a t the 0.34 billion pound level. As is obvious from this mention, we believe four chemicals might be candidates for the top 50 list since they exceed 1.27 billion pounds: acetic anhydride, ethanol, liner alpha-olefins, and butyraldehyde.. Alsoincluded in Table 1 are long-term growth patterns for each of the second 50chemicald The percent averngr annual growth is given fur approxin~ntelyn 10.year duriltion, the exact years depending on the availahl' source used. Posiriw growth is widen1 for 33 chemicals uirh onlv five s h w i n e a net annual decrease in production over thisperiod. ~ o u G e digit positive percent annual growth rates are recorded for four chemicals, ethanol (521, linear alpha-olefins (53), acrylt in ic acid (65), and naphthalene (94). The l a r ~ e sdecreases production are exhibited by acetaldehyde (?3) and phosgene (84). The average annual growth rate for all the second 50 chemicals is +4%. The average price of commercial quantities in cents per pound are given in Table 1. Two chemicals are over b1.00 111, toluene diisocynnate ( : 5 , and potosiium hydroxide f87,. The cheapest of the second 50chemicals ii 11xslene (71). with hexanes (88, close to it. The awraee u . nrice f i r all the second 50 chemicals is $0.50/lb. Of interest are some other chemicals that were investieated in this study but whose recent production figures didnot qualify them for the second 50. However. due to their close proxit&y future figures may show that' they have indeed passed up others. Those closest, with total production in
Table 1.
Rank
-
51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 6kJ 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
The Second 50 Chemical8
Chemlcal
Production (bllllon lb)
Annual Orowlh (average %lo).
Average Price (Ollb).
acetic anhydride elhano1 linear alphaolefins (LAO) bmyraldehyde caprolactam fluorocarbons hydrogen cyanue acetone cyanohydrln nitrobenzene hexamethylenadiamlne(HMDA) melhyl methacrylate phmllc anhydride aniline bisphenol A acrylic acid cy~lohe~~nol isobqlene phosphorus rrbutyl alcohol rrparalfins *xylene tbmyl slcohof acetaldehyde carbon tetrachloride toluene diisocyanate (TDI) perchloroethylene 1.1.1-trlchloroethane llnear alkylbmrenes (LAB) melhyl ethyl ketone (MEK) 2-sthylhexanol elhanolamines sodium chlorate diethylene glycol phosgene propylene glycol methylene chloride potassium hydroxide hexanes methyl chloride methylene dlphenyl diisocyanate (MDI) b w l acrylate alkylamines glycerin naphthalene 1.4-butanedlol nonene dodecene maieic anhybide s~ichlorohvdrln
= mt foum
billions of ~ o u n d sare . acetvlene. 0.33: carbon disulfide. 0.32: hydrogen beroxide, 0.32;7hydrbfluo;ic acid, 0.31; sodium chromate and dichromate. 0.31;. ethyl . acrvlate. . . 0.30: sodium metal, 0.30; and sorbitol, 0.30. Derivatives of the Seven Basic Organic Chemicals The preponderance of organic chemicals in the list has i s to separate them according to the seven basic organic chemicals (ethylene, propylene, the C4 stream, benzene, toluene, xylene,and methane) on which they are based. Another source (11) lists the recent breakdown of the 28 organics in the top 50 as being eight from ethylene, six from propylene, three from the C4 stream, seven from benzene, one from toluene. and five from methane. Double countingis, of course, necessary since some derivatives are made from more than one basic organic. Table 2 shows the organic chemicals in the second 50 separated by basic source. The list includes nine from ethylene, 14 from propylene, eight
from the C4 stream, eight from benzene, two from toluene, two from xylene, and 15 from methane. Larger numbers of chemicals in the second 50 are derived from propylene and methane and, to a lesser extent, Cq chemistry. Examining this list more closely, we see that derivatives are not always obvious from a simple count of carbons. The manufacturing method (see a later section) must be considered. For instance, butyraldehyde is not made from the Cq stream, but by the 0x0 process with propylene and synthesis gas (carbon monoxidehydrogen). Thus, it is derived from propylene and methane. Similarly, 1,4-butanediol is derived from methane. Its major starting materials are two moles of formaldehyde and one acetylene. Acetylene, in turn, is made from methane, not ethylene. Oiher relationships are unique via some fascinating &anufacturing methods. Unlike the top 50 organics, the second 50 organics have some alternative sources other than the seven basic organics. Hexanes and n-paraffins are from various fractions of petroVolume 65 Number 3 March 1988
245
Table 2.
The Second 50 Chemicals as Derlvatlves of the Seven Baskc Organlcs
Ethylene acetaldehyde acetic anhydride alkyiamines diethylene giycol ethanol ethanaiamines perchlorcethyiene 1.1.1-trichioroethane iinear alpha-olefins
(73) (51) (92) (83) (52) (El) (76) (77) (53)
Benzene aniline bisphenoi A caproiactam cyclohexanol linear aikyibenzenes maleic anhydride methyiene diphenyl diisocyanate nitrobenzene
Toluene (58) toluene dllsocyanate (65) ~xyiene (92) (64) Xyiene (91) pMhaiic anhydride (69) o-xyiene (54) (99) Methane (80) acetic anhydride (931 alkyiamines . . (60) 1.4-butenedioi (57) butyl acryiata (61) ~ b u t yalcohol l (85) butyrsidehyde carbon tetrachloride C, Stream 2-ethyihexanol acetic anhydride (51) fiuoracarbons sikyiamines (92) hydrogen cyanide 1-butene (100) methyl chloride t-butyi alcohol (72) methyiene chloride hexamethyienediamlne (60) methyiene diphenyl diisocyanate bobuiylerm (67) methyl methscrylale msieic anhydride (98) phosgene methyi ethyl ketone (79)
Pmpvene acetone cyanahydrln acrylic acid slkyiamines bisphenoi A butyi acryiate ~ b u t yalcohol l butyraidehyde epichlorohydrin 2-ethyihexanoi oiycerin . . hexamethyienediamine hydrogen cyanide methyl methacrylate propylene glycol
(63) (64) (55) (66) (78) (98) (90) (59)
(75) (71)
(82) (71)
(95) (91) (69) (54) (74) (80) (56) (57) (89) (86) (90) (61) (84)
other sovrces 1,4-butanedioi dodecene ethanol hexanes linear alkylbenzenes
(95) (97) (51) (88) (78)
naphthalene nonene *paraffins
51, Acetic Anhydride
(94) (96) (70)
leum. na~hthaleneis from coal tar. noneneand dodecene are made primarily by dehydrogenation of n-paraffins, linear alkylbenzenes are made from n-paraffins in part, coke is an alternate source of l,Chutanediol, and fermentation of grains is used for a large amount of ethanol production.
Acetic anhydride may be produced by three different methods. The first procedure (eq 1) involves the in situ production from acetaldehyde of peracetic acid, which in turn reacts with more acetaldehyde to yield the anhydride. In the preferred process (eq 2), acetic acid (or acetone) is pyrolyzed to ketene, which reacts with acetic acid to form acetic anhydride. A new process (eq 3 ) to make acetic anhydride involves CO insertion into methyl acetate. This may he the process of the future. Approximately 80% of acetic anhydride is used as a raw material in the manufacture of cellulose acetate.
52, Ethanol
Synthetic ethanol is made by the hydration of ethylene over a pbosphoric-acid-on-celitecatalyst and accounts for one-third of all ethanol. The predominant method of ethanol manufacture. a t one time. was hv fermentation of sugars; this method went out of use in the" 1930's. corn fermentation is now asource of two-thirds of all ethanol and is used for gasohol, a 10% alcohol:90% gasoline blend used for automobile fuel. Uses of synthetic ethanol: solvents, 55% (includes coatings, inks, cosmetics and toiletries, pharmaceuticals, and detergents); chemical intermediates, 45% (includes vinegar,
ow ever,
Second 50 Chemical Palrs
The second 50 chemicals commonly are made with anuther representative of this same list as one of its precursors, while onlv orieinallv heine derived from a more basic chemical. h able 3 gkes 2 i suchpaired chemicals. These second 50 nairs are one reason whv an exact list of rankine-mav.not be possible, since so many production amounts are very close. The next section outlines these chemical relationshim in more detail for chemicals 51-75. Manufacture and Uses
The significance of industrial chemicals can he summari7ed by exnmining the manufacturing methods and the important usesor each chemical as given in a\,ailnhle references (5.12 161. The fnllowinc " srctions hrieflv mention the one or two processes used to make the chemical on a large scale. Then the chemical's uses are eiven with a~oroximate Der" .. centages where found. The total percentage of uses does not add UD to 100 because minor and miscellaneous ao~lications .. are not given, as well as a percentage exported (unless it is a large Dart of the total). A close studv of this chemistrv uncovers many interesting r e ~ a t i o n s h ~among ~s all 100 top chemicals in the United States. 246
Journal of Chemical Education
Table 3.
Second 50 Chemical Palrs
Precursor acetaldehyde acetone cyanohydrin acrylic acid aniline I-butene sbutyl alcohol butyraldehyde carbon tetrachloride dodecene epichlorohydrin hydrogen cyanide Isobutyiene methyi chloride naphthalene nitrobenzene nitrobenzene nonene *paraffins +oarattins r+pemttins ~xylene
Derivative
,
.
(70) (70) (71)
acetic anhydride methyi methacrylate butyl aeryiate methyiene diphenyl dlisacyanate methyl ethyl ketone b W i acryiate 2-ethyihexanoi fluorocarbons iinear aikyibenzenes glycerin acetone cyanahydrln t-butyi alcohol methylene chloride phthaiic anhydride aniline methyiene diphenyl diisocyanate iinear alkvibenzenes linear alkylbenrenes dadecene twmn~ phthaiic anhydride
. . (78) (97) (98) (62)
glycol ethers. ethyl acrylate, ethylamines, and ethyl aretate). Fermentation ethanol uses: fuel romponent, 86oi; beverages, 10% chemicals and solvents, 3%,
Common uses for the fluorocarbons are as refrigerants (39%),foam blowing agents, (17%), solvents (14%),fluoropolymers (14%),and in aerosol propellants (2%).
53, Linear Alpha-Olefins (LA4
57, Hydrogen Cyanide
ZCH,
where n = 3 to 15. Linear hvdrocarbons with a double bond a t the end of the chain are k a d e by oligomerization of ethylene. Compounds with 6-18 carbons are the most . ~ o o u l a rZieeler . - catalvsts are used in this process. Note that certain olefins such as nonene and dodecene can also be made bv crackina and dehvdroaenation of n-paraffins (see Part 2, chemicals96 and 9?). LAO's are copolymerized with polyethylene to form the new linear low density polyethylene (LLDPE). 1-Hexene and 1-octene are especially useful for this purpose. LLDPE accounts for 23% of LAO's use, while detergent alcohols (20%), 0x0 alcohols for plasticizers (11%), lubricants and lubeoil additives (lo%), and surfactants (6%) are other important uses.
-
CH,=CH-CH,
+ 2NH3+ 30,
+ 2NH3+ 30,
-
-
2HCN + 6H,O
(4)
ZCH,=CH-IkN + 6H,O(+ HCN) ( 5 )
Approximately 80% of all hydrogen cyanide is manufactured by the reaction of air, ammonia, and natural gas over a platinum or platinum-rhodium catalyst at elevated temperature (eq 4). The reaction is referred to as the Andrussow process. Hydrogen cyanide is also available as a byproduct (eq 5) from acrylonitrile manufacture by ammoxidation (20%). Methvl methacrvlate oroduction accounts for 30% of hvdrogen fyanide use, adiionitrile for 40%. Other uses include cvanuric chloride (100i1.chelatine aeents (7%). and sodium cyanide (7%).
58, Acetone Cyanohydrin
OH
0
I/
CHa-C-CH3
Butyraldehyde is made by the reaction of propylene, carbon monoxide, and hydrogen a t 130-175 OC and 250 atm over acobalt carbonyl catalyst. The reaction is referred to as the 0x0 process, and a second product of the reaction is isobutyraldehyde. The ratio of nliso is 4:l. A new rhodium catalyst can be used a t lower temperatures and pressures and aives a ratio of 16:l. ~ i t y r a l d e h y d eis used most in the production of n-butyl alcohol, which is in turn used. unchanaed - or as its acetate, for lacquer solvents.
I
+ HCN --r CHa-C-CHB I
C=N
Acetone cyanohydrin is manufactured by the direct reaction of hydrogen cyanide with acetone catalyzed by base, generally in a continuous process. Acetone cyanohydrin is an intermediate in the manufacture of methyl methacrylate.
59, Nitrobenzene
55, Caprolactam
Nitrobenzene is made by the direct nitration of benzene using a nitric acid-sulfuric acid mixture. The nitrator of the reaction is a specifically built cast-iron steel kettle. About 98% of nitrobenzene is used in the production of aniline. The other 2% goes toward the production of acetaminophen. Cyclohexanone (from cyclohexane or phenol) is converted into cyclohexanone oxime with hydroxylamine. The oxime undergoes Beckmann rearrangement to give caprolactam. The coproduct ammonium sulfate (or ammonium phosphate if phosphoric acid is used) can be made into fertilizer. Caprolactam is used almost exclusively in the production of nylon 6 fibers (87%)and films (10%).
60, Hexamethylenediamine
56, Fluorocarbons 3 HF
+ ZCCI, 3
CCI,F,
+ CC1,F + 3HC1
dichlorotrichlorodifluoromethane fluoromethane Freon 12 Freon 11 The fluorocarbons are manufactured by reacting hydrogen fluoride and carbon tetrachloride in the presence of a partially fluorinated antimony pentachloride catalyst in a continuous, liquid-phase process.
Hexamethylenediamine (HMDA) is produced from adiponitrile by hydrogenation. Adiponitrile comes from electrodimerization of acrylonitrile (32%)or from anti-Markovnikov addition of 2 mol of hydrogen cyanide to butadiene (68%). HMDA is used exclusively in the production of nylon 6,6. Volume 65 Number 3 March 1988
247
Bisphenol A (BPA) is made by reacting phenol with acetone in the presence of an acid catalyst. The temperature of the reaction is maintained a t 50 "C for about 8-12 hours. A slurry of BPA is formed, which is neutralized and distilled to remove excess phenol. The only major uses of BPA are in the production of epoxy (32%)and polycarhonate resins (50%).
6 1, Methyl Methacrylate
CHB
65, Acrylic Acid
Theonly method used in the United States for the production of methvl methacrvlate (MMA) is the acetone wanohydrin ~cetone'cyanoh~drin (from the reaction of acetone with hydrogen cyanide) is reacted with sulfuric acid to yield methacrylamide sulfate, which is further hydrolyzed and esterified in a continuous process. Other processes using different raw materials have been tried in the United States and abroad, but the acetone cyanohydrin process has prevailed over the years. MMA is being made in Japan by oxidation of isobutene or t-hutyl alcohol. Methyl methacrylate is polymerized to poly(methy1 methacrylate), which is used in surface coatings (33%), cast and extruded sheet (30%), and molding and extrusion compounds (25%).
Acrylic acid is made by the oxidation of propylene to acrolein and further oxidation to acrylic acid. Another common method of production is acrylonitrile hydrolysis. Acrylic acid and its salts are raw materials for an important range of esters, including methyl, ethyl, hutyl, and 2ethylhexyl acrylates. The acrylates are used in the form of emulsion polymers or copolymers as coatings, for paper treatment, leather finishing, adhesives in nonwoven fabrics, and processing aids for methacrylates. 66, Cyclohexanol
62, Phthalic Anhydride
3:l mixed oil
About 72% of the phtbalic anhydride made in the United States comes from the reaction of o-xylene with air. The rest is made from naphthalene, which is isolated from coal tar and petroleum. The trend toward o-xylene continues. Plasticizers, such as dioctyl phthalate (51%), polyester resins (25%),and alkyd resins (19%),account for the majority of phthalic anhydride use. 63, Aniline
Aniline is made by the reduction of nitrobenzene (81%)by either catalytic hydrogenation or acidic metal reduction. The reaction of ammonia and phenol is a newer process that shows promise and is being used (19%). Major uses of aniline include p-p'-methylene diphenyl diisocyanate (MDI) (65%) and rubber chemicals (13%) production. Ir is alsoused to asmaller extent in themanufacture of pesticides, fibers, dyes and pigments, hydroquinone, and pharmaceuticals. 64, Bisphenol A
Cyclohexanol is made by the air oxidation of cyclohexane with a cohalt(I1) naphthenate or acetate or benzoyl peroxide catalyst at 125-160 OC and 50-250 psi. Also used in its manufacture is the hydrogenation of phenol at elevated temperatures and pressures, in either the liquid or vapor phase and with a nickel mtalyst. The former production method accounts fur 80°i of cyclohexanol made in the L'nited States. Cyclohexanol is used primarily in the production of adipic acid (go%), which is further used as a raw material in nylon 6,6 production, and in methylcyclohexanol production (7%).
Isohutylene is made largely by the catalytic and thermal cracking of hydrocarbons. Other Cg productS formed in the reaction include other butylenes, butane, isobutane, and traces of butadiene. The most widely used process is the fluid catalytic cracking of gas oil; other methods are delayed coking and flexicoking. Isohutylene is used as a raw material in the production of t-butyl alcohol and methyl t-butyl ether (gasoline additives) and butylated hydroxytoluene (an important antioxidant). I t is also used in the alkylation of gasoline. 68, Phosphorus
2Ca3(P0,), + 10C + 6Si0, CH,
248
Journal of Chemical Education
-
PI + GCaSiO, + lOCO
Yellow phosphorus (known also as white phosphorus) is produced by reducing phosphate rock (calcium phosphate or calcium fluoropho~~hate) with carbon in the presence of silica as flux; heat of reaction is furnished by an electric-arc furnace.
Detergents and cleaners account for the majority of this chemical's use (45%), with metal treating (15%), food and beverages (lo%), and chemicals (10%)making up the rest.
72, t-Butyl Alcohol
69, n-Butyl Alcohol
Butanol can he obtained from carbohydrates (such as molasses and grain) by fermentation (eq 6). Acetone and ethanol are also produced. Synthetic processes account for the majority of current-day production. Propylene and synthesis gas gives n-butyl alcohol (eq 7). Isobutyl alcohol is a byproduct. n-Butyl alcohol is used as a solvent (25%). Other uses include glycol ethers and esters (15%), amine resine (15%), butyl acrylate (15%),plasticizers (lo%), and n-hutyl acetate (10%).
The production of the n-paraffins, especially CirCia, involves the use of zeolites to separate straight-chain compounds from the kerosene fraction of petroleum. The main use of n-paraffins is in the production of linear alkylhenzenes (68%) for the detergent industry. The other 32% goes toward solvents, chlorinated paraffins, and linear alcohols.
Isobutylene is absorbed in sulfuric acid to form t-butyl sulfate, which is subsequently hydrolyzed with water to tbutyl alcohol and dilute sulfuric acid. The main uses of t-butyl alcohol are in solvents, plasticizers, amine resins, glycol esters and ethers, and as a gasoline additive.
73,Acetaldehyde
Acetaldehyde may he made (1) from ethylene by direct oxidation, with the Wacker catalyst containing copper(I1) and palladium(I1) salts, (2) from ethanol by vapor-phase oxidation or dehydrogenation, or (3) from butane by vaporphase oxidation. The direct oxidation of ethylene is the most commonly used process, accounting for 80%of acetaldehyde production. The main use of acetaldehyde (70%) is in acetic acid and acetic anhydride production; other uses include pyridine bases (S%), pentaerythritol (7%), peracetic acid (6%), and 1,3-hutylene glycol (2%). 74, Carbon Tetrachloride
CS, + 3C1, CS,
-
+ 2S2C1,
S,C1, 6s
+ CC1,
+ CC1,
Carbon tetrachloride may he made from the reaction of carbon disulfide and chlorine (accounting for 85% of carbon tetrachloride), with sulfur monochloride as an important intermediate. Elemental sulfur can be reconverted to carbon disulfide by reaction with coke. Chlorination of methane and higher aliphatic hydrocarbons accounts for 15% of the carbon tetrachloride produced.
a
CH, + 4CI, 250-
CC1,
+ 4HC1
The majority of carbon tetrachloride goes toward the making of fluorocarbons 11 and 12 (dichlorodifluoromethane and trichlorofluoromethane, respecti\.ely,: approxirnatclv 84% of all carbon tetrachloride 1.; used this way. 'l'hc remakder is used in metal degreasing, as a grain fumigant, and as a chemical intermediate. There are twomethods of manufacture of the xylenes. The major one is from petroleum by catalytic reforming with a platinum-alumina catalyst (eq 8). The second method (which has been developed recently) is by processes involving the disproportionation of toluene (eq 9) or the transalkylation of toluene with trimethylbenzenes (eq 10). The ortho isomer is separated from the meta and para isomer by fractional distillation. o-Xylene is used almost exclusively as feedstock for phthalic anhydride manufacture.
75, Toluene Diisocyanate (TO!)
Volume 65 Number 3 March 1988
249
Toluene diisocyanate (TDI) is made from the reaction of 2,4-toluenediamine and phosgene. The diamine is made by reduction of dinitrotoluene, which in turn is manufactured by nitration of toluene. Polvurethanes account for 100% of the use of TDI. APproximately of this goes toward foams (43% furniture, 21% transportation, 14% carpet underlay, 12% bedding), 5%toward polyurethane coatings, and 3%toward elastomers.
~.~ ~
Acknowledgment We thank Harold Wittcoff for comments and suggestions on the content of this paper. Literature Cited I. Published each year in April or May. The 1987 referenee is Reisch, M. Nelus 1937. (April 131, 20-23.
250
Journal of Chemical Education
S. Chrm. Eng.
2. 3. 4. 5.
Chorn.Ew. Nnm 1987. (April 131.23-24. Cham.Eng.Newr 1987, (Aprill3),9-14. Chenier,P.J.J.Chem.~duc.1984.61.997-999. chmier, P. J. suruey 01 ~ ~ n d ~chamistry; t n d w i ~ ~ ~ - ~ ~ t e ~NW ~ ~ i~eonr kc 1986; ,e : pp 28-209. 6. "Key ChemicsW, s leriesin Cham. Eng. Neu& 7. m~hemics~~rafi~es",aserieiin~hemico~~orketing~apn~t~ff Thiswepklyneu4paper also has up-to-date prices on moat chemicals. 8. ..Facts and Figures for theChemical Industry", published yearly in Cham Eng. N e u . 9, synthetic opganic c h r m i d a : published year]y by the US. tntmnai ~ r a d commise sion, U.S. ~ o v e m m e n~t r i n t i n goffice: wanhinpton, DC. 10. ChprnicolEconomicsHandbook Stanford Research Inetitute: Menlo Park, CA, 1937. 11. ~ef5,pp112-113. 12. ~ k kR., E.;and Othmer, n.F.Encyelopedio ofchemical Techhology, 3rded.; Wileytntemience: N ~ Wyork. 1930'3; 26 "oh. 13. Kirk,R.E.;snd Othmer,D.F.,ConelsoEncycl~pedia ofchomical Technology:Wileyinterscience: N ~ W~ o r k1985. , 14. Witfeoff. H. A.; Reuben, B. G. lnduatriol Organic Chornicols in Persperfiue; WiloyInterscience: New York, 1980: Parts 1 and 2. 15. Kent, J. A. Riegel's Hondbook far Industrid Chamisfry, 8th ed.: Van NasVand Reinhold: N~~ YO& 1983. 16. Lowenheim, F. A.; Moran. M. K. Faith, Keys, ond Clork'8 Indutriol ChoMcals, 4th ed.: Wiley-lntencien~e: New York. 1975.
