tion of dibasic acids and dihydric alcohols, rings Mould not form if the number of atoms in the structural unit was 7 or more. Under the conditions employed in the present investigation any rings formed as a result of esterification would have to contain a t least eight atoms. More recently Jacobson and Stockmayer (7) concerned themselves with the presence of very large rings (15 skeletal atoms and up) in the reaction between adipic acid and decamethylene glycol. They concluded that such rings could form and the amount would increase with the degree of polymerization but that their Lveight average degree of polymerization was generally negligible compared to those of the chain fractions. A4dipostearin products 3, 3C. and 6 show the effect of substituting hydroxyl groups for half of the stearoyl groups. Product 6. which contains a n excess of glycerol has a loiver number-average molecular weight yet is more viscous. T h e increase in viscosity cannot be attributed to the presence of monostearin because the latter has a viscosity of about 45 cs. a t 70’ C. T h e substitution of the oleoyl group for part or all of the stearoyl group in a polyester product definitely lowers the viscosity. T h e viscosity of succinostearin 2 is higher than that of succino-olein 1: while that of adipostearin 4 is higher than that of adipo-oleostearin 1. This observation agrees with the pattern for vegetable oils (Figure 2). I n appearance and certain other characteristics the solid polyester products tvere wax-like. Solidification of the melt generally produced a fine-grained crystal structure a n d a glossy surface. T h e solids were not brittle like tristearin; instead they possessed a degree of toughness and resilience. T h e actual hardness of well-tempered and aged samples ranged from about that of beeswax (hardness index! 17) to that of completely hydrogenated cottonseed oil (hardness index, 140) (Figure 3). I n color the solids ranged from light brown to very light brown for those products made with acid chlorides, but those made by direct esterification were practically colorless. Hydroxyl and acid values for some of the polyester products resembled those for natural waxes. Beeswax has a n acid value of 18 to 22 and a hydroxyl value of about 15, while these same values for carnauba wax are 4 to 10 and about 57. With one exception, the stearic acidcontaining products appeared to melt over a short temperature interval, generally one or two degrees. T h e one exception was adipo-oleostearin 1, which behaved like a plastic fat; that is, a t lower temperatures it seemed to contain both liquid and solid components. T h e solids were so finely divided that they formed a gel-like structure, which made it impossible to determine the melting point by the capillary tube method.
1022
Conclusions
literature Cited
Mixtures of fatty acids, short-chain dibasic acids, and glycerol when combined in such proportions that the mole ratio of fatty acid to dibasic acid is one or more yield on esterification polyesters which are much more viscous than are edible oils and fats. T h e viscosity can be controlled by varying the composition of the polyester. L’iscosities above 2000 cs. a t 50” C. are artainable. T h e melting points of the polyester products ivhich contain stearic acid as the only fatty acid and in which the dibasic acid is fumaric, succinic or adipic have melting points ranging from about 33.7’ to 67” C. T h e apparent range of melting is short, generally l o or 2” C. When oleic acid is substituted for the stearic acid in these polyesters, the melting point drops sharply and in some instances the products do not appear to crystallize on cooling. but instead become highly viscous. O n crystallization of the melt. the polyesters containing stearic acid form a fine-grained crystal structure and possess a hardness a t 30” C. Lvhich ranges from that of beesivax to that of completely hydrogenated cottonseed oil. T h e products prepared had properties that indicated potential use of them as coating materials by the food industry.
(1) Cannon, hf. R., Fenske, M. R., I N D . ENG. CHEM., . h ” L . ED. 10, 297-301 11938’1. - - - , (2) Carothers, W.H., Arvin, G. J . Am. Chem. Sac. 51, 2560-70 (1929). (3) Carothers, W. H., Hill, I. N’.,Ibid., 54, 1559-60 (1932). (4) Feuee, R. 0..Kraemer, E. X.. Bailrv. A. E.,-O;l Sou$122,202-7 (19451. (5) Feuge, R. O., Ward, T. L., J . A m . Chem. Sac. 80, 6338-41 (1958). (6) Handschumaker. E., Linteris, L.? J . A m . 011 Chemists’ Sac. 24, 1 4 3 ~ (1947). 5 (7) Jacobson, H., Stockmayer, W. H., J . Chem. Phys. 18, 1600-6 (1950). ( 8 ) Koroly, J. E., Beavers, E. M., IND. ENG.CHEM. 45. 1060-3 11953). (91 Lovegren, N.’V., Guice, W.A , , Feuge, R. O., J . Am. Oil Chemisls‘ Sac. 35, 327-31 (,1958). ((10) Menzies, .A. W. C., Wright, S. L.. Jr., J . .47li. Chern. SOC. 43, 2314-23 (1921). (11 Uspensky, J. V.: “Introduction to Mathematical Probability,” p. 41 1, McGraw-Hill, ;leu, York, 1937. ! l Z i \.Vest, E. S.: Hoagland, C . L., Curtis, G. H., J . Bid. Chern. 1C4,627-34 (19341. \
RECEIVED for review August 1 2 , 1957 ACCEPTEDSeptember 5, 1958 Division of Agricultural and Food Chemistry, 131st Meeting, XCS, Miami, Fla., April 7-12, 1957. It is not the policy of the L . S.Department of Agriculture to recommend or endorse the products of one firm over those of other firms. Trade names and firms are mentioned merrly as part of the exact experimental conditions.
Corrections Correlating Vapor Pressures and Other Physical Properties I n the article “Correlating Vapor Pressures and Other Physical Properties” [D. F. Othmer. P. W. Maurer, C. J. Molinary, and R . C. Kowalski, IND. 1,2-Dichloroethane
C2H.Clz
0.812
ESG. CHEM.49, 125 (1957)]. the 15th compound listed under Halogenated Hydrocarbons in Table 11, page 129, should be: $0.7770
f0.235
+0.4542
Correlating latent Heats and Entropies of Vaporization with Temperature I n the article on “Correlating Latent Heats and Entropies of T’aporization with Temperature” [D. F. Othmer and David Zudkevitch, IND.ENG.CHEM.51, 791 (1959)] the second = sign should be deleted and Equation 3 should read: dlnP =
d?’
L
RF
(ZGTZLj
-
(3)
O n page 792, the heading of the numerical column of the table should be:
O n page 793>the first line of the center column should read: Diisoamyl oxalate
0.1903
O n page 794, column 3, the third line under Properties of Reference Substance, the value should be: 1’ (26
- z;)
m’ = ( 1 8 m / X )
T h e last line of the middle column should read: Dichloroethyl ether
INDUSTRIAL AND ENGINEERING CHEMISTRY
0.1495
O n page 796, the second listing of column 3 under P R in the table should be: 0.02090
