Document Z4MQrp55Jdg1NkLVjYV9eMyDZ

Vo!. 5 CIIIXmOCAKBONS AND CHLOUOHYDKOCAKIJONS 171 vinvXj cin.oniDK Vinyl chloride (chloroethylcnc, inonochloroolliyleno), CIIr=CIlCl, at ordinary temperature and normal pressure, is a colorless gas .with an irritant action on the eyes fine! an odor reminiscent of that of ethyl chloride. Industrially, vinyl chloride is handled as the liquid (bp, -- l.'UKC). To prevent its polymerization during storage or transport, stabilizers may be added. It is readily Hummable, has a very low flash point, and forms explosive mixtures with air. Vinyl chloride is very slightly soluble in water, and soluble in most of the common industrial solvents. Its toxicity is less than lliat of carbon tetrachloride or chloroform, ami it has a narcotic effect, similar to that of ethyl chloride, By far, the most important use of vin}d chloride is in the manufacture of polyvinyl chloride (BVC) and related plastics. It is used to a small extent as a special solvent, a refrigerant, and in chemical synthesis. Vinyl chloride was first prepared and described by Uegnault, in 183.r>. lie ob tained it by reacting dichlorocthauo with alcoholic potash- Rcgnaull allowed that on prolonged exposure to sunlight in a scaled lube the liquid deposited white flakes of solid. In the state of organic chemical theory and knowledge at that date, he could only record, without explanation, tins liquid-to-solid change, llegnault's white . solid was studied in 3S72 by Baumann without its nature being fully elucidated; lie described the material as "Kauprcnchlorid" and gave it the empirical formula (C2H*Ci). In 1911; Klattc and Rollctt investigated the reaction between hydrogen chloride and acetylene, and two years later, Grioshoim-Eleklron obtained a patent for the use of mercuric chloride as a catalyst in tins reaction, thus establishing an effective industrial route to vinyl chloride. The low price and ready availability of natural rubber and absence of technical interest in the type of plastic product produced from vinyl chloride limited develop ment of vinyl chloride manufacture prior to the outbreak of World War II. When that war cut off the Western powers from their natural rubber sources, product ion of vinyl chloride for PVC, as a rubber substitute, was established on a huge scale in the United States and the United Kingdom. Vinyl chloride is now one of the most important starting materials of the plastics industry. Physical and Chemical Properties The physical properties of vinyl chloride are given in Table 1. At 25C, 0.11 g v'rnyl chloride dissolves in 100 % water, and at --15C, 0.03 g water dissolves in 100 g vinyl chloride. Vinyl chloride is soluble in mineral oil, alcohol, the industrial chlorinated solvents, and a number of common organic liquids. No azeotropes have been reported. Reactions. In its chemical behavior, vinyl chloride obeys the general rule that the simple unsaturated chlorohydrocarbons are more stable than saturated ones. At about 4f>0C, vinyl chloride begins to decompose, forming small amounts of acetylene (2). In the presence of a copper, lead, tin. or cadmium catalyst, at *100*0, vinyl chloride forms 2-chloro-l,,'U>utadumo (3). When vinyl chloride is dry, no decom position lakes place in contact with metals at temperatures Mow those just indicated. Wet vinyl chloride, at elevated temperature, ronodes iron and steel. The. thermal and photochemical decompositions of vinyl chloride, in contact wit h air, do not appear to havo been systematically studied. The decomposition products (peroxygon com- NGC35548 m ciacmocAUKONS and crrr.ononYmtocAMiONS Tftble I. Vhysbsil VrnjMTtMw of Vinyl CIilurMo inciting point, *C boiling pomi. 7C0 nun Ilg, *C Specific gravity 13.9/4*C f*cM20/4*0 !. surface tension, air, lyn/cm -30*0 -20*C - -10*C Specific heat, ca!/(gX*0) liquid, 20*C vapor, 25"C critical temperature, 6C critical pressure, atm dielectric constant, 17.2*C heat of combustion, 1S*C, constant pressure, kcal/g-mole latent beat of evaporation, nai/g bp 25*C latent beat of fusion, enl/g - Basil point pen cup, *F dosed cup, *C self-ignition temperature, *C explosive limits in air,* % by vol viscosity, liquid, cP --40*C --30*C --20*C -10*C vapor pressure *C -30 -20 -10 0 10 . ptm 0.50 0.77 1.17 1.70 2.43 1 The most readily ignilable mixture is that containing 7% vinyl chloride (I). -153.7 --13.0 .O.W 0.0121 1.40US 23.87 22.27 20.83 0.33 0.205 153.4 52.7 6.20 2S0.10 79.53 71.20 18.14 -- 103 -73 472 4-20 0.3330 0.3026 0.2780 0.2563 *C atm 20 3.33 30 4.51 40 5.94 50 7.SO CO 0.93 pouiuls) bring about polymerization, tints obscuring their .intermediate presence, and hindering their quantitative study. , With chlorine, vinyl chloride forms 1,1,2-trichloroothano (see p. 158), and with bromine, l-chloro-l,2-dibromoctham* (1). In the presence of zinc chloride on silica gel, hydrogen chloride combines with vinyl chloride, at about lOO^Q, to give 1,1- dichloruothane (sue p. 110); at room temperature and in absence of eatab'sfs, hydrogen iodide, in similar fashion, forms l-chloro-l-iodoethano. Sulfuryl chlcwklc (.SOiOb), in the presence of pyridine, reacts wilh vinyl chloride, at orditiary temperature;, to give Ipl^-triclilomolhiine and 2,`2-diehtorot`thano sulfonvl chloride. ITypocIdorotw acid and vinyl chloride react to yield tdilomaeetaldebyde, ClClhClI--O (5,0). In the presence of anhydrous aluminum chloride, vinyl chloride condenses with ethyl chloride, at 500C, yielding tin; products, 1 .l-dichlomothano and 1,1,3-triehloro- hulnnc (7). At 0-5C, vinyl chloride reacts`with benzene, in the presence of aluminum ryyiTnrw.TtTl-'r 1 1 % 4 i i i \ f l i l f r i r NGC35549 no CIILOKOCARHONS AND CIlLOROllYDROCAUHONS Other Processes. Production of vinyl chloride by pyrolysis of cthylidem* chlo ride, ClhCIICh, followed by reaction of the coproduet hydrogen chloride with acet ylene, lias been patented (110). Vinyl chluride is produced by treatment of 1,1,2trichlomethuiu;, at hi^h temperatures, with finely divided zinc, iron, or aluminum in the presence of steam (117). Economic Aspects In Table 2 are listed mimed outputs and sales of vinyl chloride in the U.S. for the period 1955-1902. These reflect the great and growing importance of polyvinyl chloride plastic. Other producing countries, including the United Kingdom, do not publish statistics of their vinyl chloride outputs. An indication of the scale of produc tion in l'Vancc is given by the Erench government's published plan to make 101,000 metric tons in 11)00. Reports indicate a considerable international trade in vinyl chloride between the countries of the European Economic Community. Table 2. U. S. Vinyl Chloride Production and Price Statistics" Sales Year Production, lb6 ' Quantity, lb6 Total value, $* Unit value, $/lb 1055 1950 1057 1058 1050 10G0 1061 1062 .. . 528,005 506,520 627,076 691,412 977,891 1,030,9S0 1,043,9S3 1,311,-ISO 76,002 103,878 179,756 200,4S8 329,300 352,314 424,303 515,522 7,935 11,133 10,561 22.161 35,817 35.S04 34,229 3S,5-18 0.10 0.11 0.11 0.11 o.n 0.10 0.03 0.07 According to U .8 . TarilT Commu&iou Reports. In thousands of pounds. * In thousands of dollars. Standards Technical-grade vinyl chloride should not contain more than .the following amounts of the indicated impurities: acetylene, 1 ppm; aldehyde (as acetaldehyde), 100 ppm; acid (as IIC!),0-1 ppm; water, 100 ppm; residue oil evaporation to dryness, 10 ppm. Acetaldehyde is nonexistent in vinyl chloride produced by cracking dichlorocthane. Handling and Toxicity When vinyl chloride is to lie stored or transported, phenolic or other type stabilizers arc sometimes added to prevent its polymerization. In small quantities, vinyl chloride is transported as the liquid, under pressure, in steel cylinders or drums. Hulk deliveries are made in road tank trucks. Vinyl chloride is transferred from tank trucks to Storage vessels by [jumping or blowing, sometimes under a nitrogen atmosphere. A thin layer of polymer may gradually form on the walls of steel storage vessels and pipes in the plant when using vinyl chloride; however, with the dry, pure, product this does not occur, ('upper or copper-alloy fittings should not be used, because of the ^ possibility of explosive acetylide formation with residual acetylene in the vinyl cltlo- Try NGC35550 Vol. 5 CIILOKOCAKUONS AN!) cnLOUOHYDUOCAKBONS- 177 ride. T<o;>ka^i:.s from storage vessels or ctsrnvlirru In Hie plant .arc located by means of soap .solution: because of the high flammability of vinyl chloride juul its formation of explosive mixtures with air, a halide lamp must never he used for its detection. Vinyl chloride is considerably less toxic than either eurUm tetrachloride or chloroform and is similar in toxicity to ethyl chloride. At concentrations, in air, of 20-40% (by vol-), it is rapidly fatal to small test mammals. It exerts a narcotic action similar to that of ethyl chloride. At concentrations of f>% (by vol), vinyl chloride gives warning of its presence by causing dizziness and disorientation. Concentra tion in the atmosphere of working spaces should never exceed GOO ppm (by vol). ^tet'e^s^u>-cv4donoe-()C-.dueetL_mjury--having-resulted from-proionged `exposure - to fConccntrationsoftliatKnder, ./ Uses .' Vinyl chloride would have attained little importance as an industrial chemical had it not been capable of polymerizing and copolymcming to materials which form ono of the most important groups of modern plastics. Tins use is dealt with under Vinyl compounds, resins, and plastics. The remaining applications of the compound are quantitatively insignificant. In the pharamaccutieal industry, vinyl chloride is used in the production of chloroacotal deliydo, an intermediate in the manufacture of the sulfa drugs. Conversion of vinyl chloride to 2-chloro-l,3-butadionc, the intermediate ju the production of chloroprenc rubber, has been patented (3S). Vinyl chloride has been used as a refrigerant and as an extraction solvent for heat-sensitive substances. Its use in those and similar applications, eg, as an aerosol propellant, is generally undesirable because of its flammability, toxicity, and readiness to polymerize. I Bibliography "Vinyl Chloride" under "Chlorine Compounds, Organic.*' in BUT Jsl oil., Vol. 3, p. 78G by Jesse Werner, General Aniline 6c Film Corp., General Aniline Works Division; "Vinyl Chloride" under "Vinyl Compounds" in KCT 1st cd., Vol. U, pp. 723-72G, by Claude II. Alexander and Gerald lr. Cohan, B. K Goodrich Chemical Company. 1. S. K. Rhaw, Bril. Bird. l!cs. Assoc. Itc/Hirt G/T3H77. 2. 12. II. It. Barton and lv. fi.JIuwleU, J.JJht m. Soc. 1910, IG(k 3. U.S. Bat. 1,SSI,DIE lOet. 25, 1952), C. J. Lcyes. 4. II. lWt*, Her. !>ml. Chtm. Gcx. 3."*, 3525 (UH)2). 5. Git. Pat. 49<>,OG2 (Oh. 23, 1927), 0. ICrnst and IT. Lange (In I. tl. FarbeninduMrie A.G.). 0. ILR. Pill. 2,<JW1,:HKJ (Si'V. 1<), lJ3U), ll. 1*. A. Grolt ami G. Hcarnv. 7. I*. Sehmevlmg, J. Am. Cht tu. Hue. GS, ) 955 (11) HI), 8. J. M. Oavidson and A. Dney, J. . I /. ('Jinn. .X'nc. SI, 2979 (I 9211). 0. Brit. Pat. 4li"vU~ ( Nnv. 3, lfKJ.7),/. G. laudteniiidu.sirie A.G. W. Brit. Pat. 332,095 (Aug. 21, 1930), 1. G. KarlM.-niinlustrin A.G. 11. Cun. Put. 447,930 (April 2(1, PUS), W. A. Kariw ami G. M. Whitman (t* Canadian Industries. Ltd.). 32. Brit. Pat. 011,015 (OH. 5, 1045), Rolvay * Co. 33. IKS. Put.2,0.15,051 ((VI. 21, 19.V2), H. X. Miller (to Air lhv}iirUi>n Cm). 34. U.R. But.2,1 Hi, 123 (July 7, 11)1X7/1*. Il..yi (to *h.nxai(m Cbrnmnl (V). 15.` U-S. Pat. 2,4 IS, 110 (An.'. 31, 111 IX), 11. S. Miller (to Air I {eduction Co.). 36. Jlril. Put. 01)5,11)5 (Mat eh 1, P.I5U), M. Ailenhccli and A. Sieidtiz. 17. Can. Pul. 488,723 (lk-r. 9, 1952), \V. It. Morgan (to B. I'. Goodrich 6c Co.). jj*;ya; ju. rnrTrrrr