Accession Number : AD0250735

Title :   STRESS RELAXATION AND STRUCTURE OF HIGH TEMPERATURE ELASTOMERS

Descriptive Note : Final rept.

Corporate Author : AKRON UNIV OH INST OF RUBBER RESEARCH

Personal Author(s) : SCOTT, K.W. ; ALLEN, V.R.

Report Date : 31 MAY 1960

Pagination or Media Count : 1

Abstract : Sol-gel relations in natural rubber vulcanizates have been studied both during network formation and degradation. The experimental values obtained during network formation, deviated markedly from theory, both as to magnitude and by showing an unexpected dependence on the primary chain length. It was shown that this deviation could be attributed to physical crosslinks, resulting from chain entanglements trapped during network formation. The total number of elastically effective chain entanglements per unit volume was found to be a function of the concentration of chemical crosslinks. The effectiveness of a chain entanglement was also found to be a function of the concentration of chemical crosslinks. The theoretical expressions of Horikx (J. Polymer Sci. 19:445, 1956) for network degradation were modified to include the effect of chain entanglements. (Author)

Descriptors :   *ELASTOMERS, DEGRADATION, GELS, MOLECULAR STRUCTURE, MOLECULAR WEIGHT, RUBBER, STRESSES.

Distribution Statement : APPROVED FOR PUBLIC RELEASE