Accession Number : AD0715010

Title :   Chemorheological Study on Natural Rubber Vulcanizates.

Descriptive Note : Technical rept.,

Corporate Author : PRINCETON UNIV N J FRICK CHEMICAL LAB

Personal Author(s) : Takahashi,Yuzo ; Tobolsky,Arthur V.

Report Date : SEP 1970

Pagination or Media Count : 20

Abstract : Chemical stress relaxation studies were carried out in air and in vacuum (0.001 mm Hg) on two natural rubber vulcanizates, one curved by dicumyl peroxide and one by tetramethyl thiuram disulfide. These are believed to produce carbon-carbon crosslinks and monosulfide crosslinks, respectively. Chemical stress relaxation in air showed that oxidative scission along the main chain was the major cause of stress decay for each vulcanizate. The stress decay curves for both vulcanizates were nearly the same. Chemical stress decay in vacuum for the two samples were slower than the decay in air. The network with monosulfide crosslinks showed more rapid decay in vacuum than the network with peroxide crosslinks. Analysis of the effedt of crosslink density on the decay curves in vacuum indicate tat the cleavage was at the network junctures for the network with monosulfide crosslinks; the cleavage was along the main chain for the network with carbon-carbon crosslinks. (Author)

Descriptors :   (*RUBBER, STRESSES), (*VULCANIZATES, STRESSES), TEST METHODS, CURING AGENTS, PEROXIDES, SULFIDES, OXIDATION, CROSSLINKING(CHEMISTRY)

Subject Categories : Elastomers and Rubber

Distribution Statement : APPROVED FOR PUBLIC RELEASE