166
I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
electrolytes, t’he weight nulmalities were calculated using the formula weight as the niolecular weight. Use of the real molecular weight (which, although unknown, is in the colloidal range) would accentuate the differences between these and the other salts. Again the Folubility of electrolytes in aqueous soap systems varies widely even on a molecular basis. In general, Figure 3 shows that those salts which salt in middle soap best are also most effective in salting out an isotropic solut.ion into neat soap, or nigre and lye. Homwer, this is not true of Calgon or the siliceous silicates. PHASE DATA
The data given show t’hatthe salting o u t of soaps by these electrolytes, some of which are alkaline as well as colloidal, is a complex process. All electrolytes do not behave in the same way, even on a molecular basis. The salt,ingout of nonassociated electrolytes of low molecular weight involves a reduction in the amount of water which acts as a solvent, because of hydration of the added ions. The salting out, of soap solutions is complicated by the existence in them of complex equilibria between free ions and various types and sizes of ion aggregates and micelles. The addition of salts is believed to increase the proportion and size of micelles until they link together and precipitate. Because of the presence of neutral molecules in the average micelle, the added salt may be incorporated in it and affect the equilibria involved. The effect of added salts on micelle formation, which can be very specific because of steric and other factors, is probably more important in determining its effect on soap solutions than is hydration of added ions. The unusually small solubility of soap in Calgon solutions suggests some sort of complex formation. Complexes with soap could also be formed by the colloidal siliceous silicates. This may explain the decreased effect, on a molecular basis, of the silicates of higher SiOg/Na20 ratio in salt,ing out soap solutions containing less than 20% soap. Another factor which may be involved is fractionation of the siliceous silicates. The salting out of soap solutions is also complicated by the multiplicity of crystalline and liquid-crystalline phases which aqueous soap systems form a t various concentrations and temperatures. In spite of the complexity of the subject, sufficient regularities exist so that t’he data of this paper can be used to predict phase diagrams for other soaps and concentrations. The regions of existence of isotropic solutions for other soaps in the presence of all these electrolytes should be predictable to a fairly accurate
Petrole
Vol. 39, No. 2
degree if this part of their diagram i s krioivri with any one salt. Phase diagrams at higher soap concentrations for this and other soaps can also be predicted from these data, although with less certainty. One of the practical industrial applications of such work is to predict the amounts of various builders which will dissolve in soaps a t crutching temperatures. LITERATURE CIIEI)
Baker, C. L., IND.EXG.CHEM.,23, 1025 (1931). Bats, dissertation, Karlsruhe, 1918. Bolton, H. L., IND. ENG.CHEY.,34, 737 (1942). Buerger, M . J., Smith, L. B., Ryer, I?. T ~ and , Spike, J. E., Pi.0~.Natl. B c n d . Sei. U . S.,31, 226 (1945). Cobbs, W. W., Harris, J. C., and Eek, J. R., Oil & S o a p , 17, 4 (1940); 19, 3 (1912). Dedrick, C. H., and Wills, J. H., Div. of I n d . Eng. Chern., A.C.S.. Atlantic Citv. 1946. Ferguson, R. H.. and Richardson, A. S.,IKD. EXG.CHEM..24, 1329 (1932). Ferguson. It. I-I., Hosevear, F. A,,and Stillman, R . C., Ihid., 35, 1005 (1943). Fischer, >I., “Soaps and Proteins”, New York. John Wiley & Sons, Inc., 1921.
Hofmeister. F., Arch. ezptl. Path. Pharmakol., 25, 6 (1888). Larnin, O., Arkiv. Kemi,MineTal. Geol., 17A, No. 26 (1944). Leimdoifer, J., Kolloidchem. Beihejte, 2, 1 (1911). McBain. J. IT.. in Alexander’s “Colloid Chemistrv”. Vol. I. D . 132, New York. Chemical Catalog Co., Inc., 1956. McBain, J. R., ,T. Chem. Sac., 127, 852 (1925). McBain, J. TT~,Block, G. C., T‘old, R. D., and Told, M. J., J. Am. Chem. Soc., 60, 1870 (1938). hIcBain, J. IT., Elford, W.J., and Vold, K. D., J. SOC.Chem. Ind , 59, 243 (1940). McBain, J. W., and Pitter, A V., J. Chem. Soc., 1926, 893. McBain, J. IT., Told, R. D., and Gardiner, K., Oil & S o a p , 20, 221 (1943). McBairi, J. IT.,T’old, M. J., and Porter, J. I,., IND.ESG. CHEM., 33, 1049 (1941). McBain, J. W., and Walls, E., 4th 12ept. Colloid Chem., Brit. Sssoc. Advancement Sei., p. 244, H.M. Stationery Office, London, 1922. Werklen. P.,“fitudes SUI la constitution des savons du oommerce”, Marseilles, 1906: German ed. tr. by F. Goldschmidt, 1907. Kichert, T., dissertation, Karlsruhe, 1918. Shreve, R. N., “Chemical Process Industries”, p. 601, Kew Y a k , McGraw-Hill Book Co., Inc.. 1945; U. 6 . Bur. of Census, private communication. Thorl, M.,dissertation, Karlsruhe, 1918. Vail, J . G., IND.ENG.CHEX.,28, 294 (1936). Vaughn, T. H., arid Vittone, A, Ibid., 35, 1094 (1943). Vold, R. D., and Lyon, L. I,.,I b i d . , 37, 497 (1945).
d
M. GLENN MAYBERRY, PAUL V. McICINNEY1, 4ND HARRY E. WESTLAKE, JR.* iWeElon Institute of Industrial Research, Pittsburgh, Pa.
MlJLTITUDlSOUB assortment of commercial products is produced by the general process of vulcanizing unsaturated compounds (4). They range from hard rubber and othcr resinous materials through elastometcrs and fuctices t o spcxial lubricating fluids. These products havc a common frature; their manufacture involves the reactioli of sulfur or dfur-bearing compounds with unsaturates, anti thc ease of this reaction has led to a widespread search for useful materia1.s. h h h y research projects have been reported 011 thp sulfuriaaticiri of unsaturated 1 Present
address, Sun Chemical Corporation, 100 dixth d v e . , New York
N. Y. 9 Present addresu, Calco Chetitictal Division, .imerican Cyanamid Company, Bound Brook. N. J .
hydrocarbons of high molecular rveight. For example, Srielling (6) produced rubberlike bodies from lubricating oil and sulfur chloride; Egloff (3) obtained a hard pitch from a cracked petroleum distillate and sulfur a t 260” C.; and Thomas ( 7 ) vulcanized a hydrocarbon polymer, formed by copolymerizing olefins and diolefins, in place in a mold. REACTION OF P&TROLEUM POLYMERS WITH SULFIJR
Some gasolirio,s madr: by the cracking of petroleum arc subjected to a refining treatment in clay towers. I n thcsc towers certain gum-forming compounds, such as diolefins, are removed from cracked gasoline hy polymerization. These polyrners are
February 1941
TABLE1.
INDUSTRIAL AND ENGINEERING CHEMISTRY
C h R A C T E R I S T I C S O F PETROLEUM POLYMERS USED
Gravity, 'A.P.I. Min. flash point, O C. Fire point, C . Saybolt Universal viscosity a t 210" F., sec. Max. pour point, C. hlin. iodine No. LIolecular weight, approx.
10-11 110 137.8 225-300 7 200 425
167
the sulfur added to the individual components in different proportions; and since sulfur is a good dehydrogenation element, it is also likely that some depolymerization occurred. This seems t,o be the best explanation of thP small increase in molecular weight of the resin. VALUEOFPRODUCTS
The sulfurized products are resistant to salts T A B L E 11. BINARY REACTION O F PETROLEUM POLYMERS WITH SULFCR and to low concentrations of sulfuric acid. p ~ i t ~ i ~ Properties of Product acid attacks them to form hard, brit>tle, easily Reaction Compn., % A.S.T.M. PetroReaction Reaction peneSoftening crumbled materials. Seither sodium hydroxide leum Time', Temp., trationa, point nor hydrochloric acid has any apparent effect, but polymer Sulfur Hr. c. mm. c.b , Remarks ... ,,, soft, almost liquid ammonia and calcium hydroxide have slight bleach95 5 9.2 80-108 90 10 10.8 80-120 ... ... Hard and brittle ing action. 85 15 9.3 80-120 35.9 51.0 Soft and plastic 85 15 9.0 105-130 2.3 72.5 Hard These products are far too brittle t o be of use 70 30 4 15.7 60.9 'Oft and plastic by themselves. It was shown ( 6 ) , however, that 70 30 5 .. 78 70-140 5.6 6 4.2 Brittle 30 6.7 95-135 2.8 63.0 Brittle both the binary and ternary reaction products can 70 60 40 8.2 95-130 1.2 73.2 Brittle 52 48 11.5 ' 95-128 1,6 69.8 Contains dissolved be compounded to give a mastic composition which free sulfur will flow to fill completely a simple mold cavity if a At 2 j o C., 100 grams, 5 seconds. heated under pressure. The binary product reb A.S.T.*M. bali a n d ring. quires the addition of factice to the filler. The properties of the mastic are dependent on those of the resin and also on the type and quantity of the separated from the gasoline by distillation and have become availfiller used. Fillers such as whiting, asbestos, wood flour, cottonable from several petroleum companies with about the same speciseed hull fibers, carbon black, lignin, slag, or a cornbination of fications; a typical range of specifications is given in Table I. these materials were found t o be satisfactory for the preparation Such polymers provided a previously untried unsaturate for of mastics suitable for floor tile, for example. Certain pigments sulfurization. Although they dissolved little sulfur below 100' could be used to obtain dark shades of red, brown, green, and C. ( I ) , above that temperature a reaction took place which reblack. The dark color of the resin prohibited lighter colors. sulted in the combination of sulfur, with evolution of hydrogen sulfide increasing as the temperature was raised. Above 140" C. excessive foaming ocTABLE 111. REACTION OF PETROLEUX POLYMERS, SULFUR,AND curred because of the rapid formation of hydrogen NATURAL OILS sulfide, and higher t,emperatures caused decomposiReaction Compn,, % Reaction Conditions tion of the product. The details of a representative Petroleum -__ Oil Time, Tfmp., series of experiments using t'he same petroleum polypolymer Sulfur % Name hr. C. Product 41
mer are given in Table 11. The properties of the 39.2 41.4 products depended on time, temperature, and con51 centration of sulfur, and varied from viscous liquids 50 to hard, brittle, shiny, black solids which broke with a conchoidal fracture. The most satisfactory resins were obtained by preparing a mixture of sulfur and a polymer (usually at 80" to 90" C.), which was then heated slowly to the reaction temperature during a period of about 1 hour and maintained a t the higher temperature for the rest of the reaction time shown in Table 11. Low concentrations of sulfur, short reaction time, and low temperature afforded soft products. Increasing any or all of these factors gave harder products. Phosphorus pentachloride and sulfur monochloride were tried unsuccessfully as catalysts for the reaction. The properties of the products coald be modified by the inclusion of unsaturates from other sources in the reaction mixture. Thus the inclusion of certain natural oils (8) gave tough, rubbery solids, which lost some elasticity when the reaction time was long or when the product had been allowed t o age. Table I11 gives experimental details of such preparation. The prdducts softened and could be molded upon heating t o 160" C. but did not melt. Other natural oils were tried, but none of them gave products as tough as the ones mentioned in Table 111. Dicyclopentadiene could be added to either the sulfur polymer or the sulfur polymernatural oil mixture to cut down sulfur blooming and to give the products a more lustrous surface. Both the binary and the ternary reactions have been run on pilot plant scale with few difficulties encountered. Although the structure of the reaction product was not investigated, certain related properties were determined (Table IV). The final product has much less unsaturation than the starting material but the molecular weight was increased by only 45 units. Since the original polymer was a mixture, it is quite probable that
27.5 30.6 26.8 29 30
31.5 30.2 31.8 20 20
Castor Perilla Linseed Linseed Rapeseed
1 2 2 2S/, 41/1
100-160 115-148 141-146 140-152 140-162
Stiff, rubbery Rubberlike, unmeltable Tough a n d elastic Tough a n d elastic Tough, plastic
TABLE IV. CHEMICAL PROPERTIES OF SULFURIZED PETROLEUM POLYMER (70% polymer, 30% sulfur; 5.5 hours a t 90-135' C.; softening point, 62.6' C.) Mo!. wt. a t freezing point of benzene 470 Iodine No. 26 Sulfur content analysis 28.8 Sulfur oontent'used in reaction mixture 30.0
Various methods of modifying the mastic to obtain an inexpensive molding composition were inconclusive. Although the products have low tensile and impact strengths, the addition of cyclopentadiene to the original reaction mixture gave a product with both properties improved. ACKNOWLEDGMENT
The authors arc indebted to the Texas Gulf Sulphur Company, Inc., for permission to publish this work, and to W. A. Hamor of Mellon Institute and W. W. Duecker of the Texas Gulf Sulphur Company, Inc., for their advice and criticism in the research. LITERATURE CITED
(1) Chittick and McKinney, U. S. Patent 2,309,692 (1943). (2) Chittick and Schlandt, Ibid., 2,330,798 (1943). (3) Egloff, Ibid., 1,896,227 (1933). (4) Ellis, "The Chemistry of Synthetic Resins", Chap. 60, New York, R e i n h o l d Pub. Corp., 1936. (5) McKinney and Mayberry, U. S. Patent 2,316,964 (1943). (6) Snelling, Ibid., 1,635,740 (1925). (7) Thomas, Ibid., 2,078,353 (1937). CONTRIBUTION from the Multiple Fellowship of the Texm Gulf Sulphur Company at Mellon Institute.
