Effect of the network structure on the flammability ofcis-1,4-polyisoprene vulcanizates
Tóm tắt
The combustibilities ofcis-1,4-polyisoprene and its peroxide and sulphur vulcanizates have been investigated by means of the oxygen index method. The temperature distribution in the sample and the molecular weight of the liquid products formed as a result of elastomer destruction in the combustion zone have been measured. It has been found that the combustibility ofcis- 1,4-polyisoprene diminishes as its cross-link density increases. This effect is much stronger for sulphur than for peroxide vulcanizates. The investigations lead to the conclusion that a mechanism of network degradation and volatile sulphur compounds penetrating to the flame are responsible for this difference.
Tài liệu tham khảo
L. Ślusarski and G. Janowska, J. Thermal Anal., 29 (1984) 95.
P. J. Flory and J. Rehner, J. Chem. Phys., 11 (1943) 512, 521.
P. J. Flory, J. Chem. Phys., 18 (1950) 108.
A. F. Blanchard and P. M. Wootton, J. Polym. Sci., 34 (1959) 627.
C. P. Fenimore and F. J. Martin, Modern Plastics, 44 (1966) 141.
E. S. Freeman and B. Carrol, J. Phys. Chem., 62 (1958) 394.
D. W. Van Krevelen, Elsevier, Amsterdam (1972) 235.
D. Hands and F. Horsfall, Rubber Chem. Tenol., 50 (1977) 253.
W. A. Pryor, Mechanisms of Sulphur Reactions, McGraw-Hill, New York, 1962.
F. Fairbrother, G. Gee and G. T. Merral, J. Polym. Sci., 16 (1955) 459.
D. M. Gardner and G. K. Fraenkel, J. Am. Chem. Soc., 78 (1956) 3279.