US EPA

5700531 

Journal Article 

Recovery behaviors of silica-reinforced SBR vulcanizates using circular deformation test 

Choi, SS; Lee, H; Ko, J; Kim, M 

2007 

Yes 

Journal of Industrial and Engineering Chemistry
ISSN: 1226-086X 

ELSEVIER SCIENCE INC 

NEW YORK 

13 

7 

1169-1173 

WOS:000252451500019 

We introduced a new test method, the circular deformation method which changing a linear sample to a circular form by fixing the both ends with a pin, to investigate recovery behaviors and level of the permanent set of a rubber vulcanizate by thermal aging. The pin was removed after the thermal aging, and the gap distance between both ends of the sample was measured. The recovery increased as the measuring time elapsed. The instantaneous recovery less than 0.1 s could be obtained from the extrapolation method. Influence of the 1,2-unit content on the recovery behaviors of silica-filled SBR vulcanizates was also investigated. The SBR specimen with the higher 1,2-unit content had faster recovery behaviors than that with lower one. The silica-filled SBR vulcanizates containing the silane coupling agent had higher recoveries than those without the coupling agent irrespective of the 1,2-unit contents. The experimental results were explained with the crosslink density and the filler-polymer interactions. The instantaneous recovery at 0.09 s became larger as the crosslink density of the sample increased. 

circular deformation; recovery; thermal aging; crosslink density; SBR vulcanizate