Stress relaxation in rubbers containing reinforced fillers

✍ Scribed by G. R. Cotten; B. B. Boonstra

• Book ID: 102732735
• Publisher: John Wiley and Sons
• Year: 1965
• Tongue: English
• Weight: 727 KB
• Volume: 9
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1965.070091017

✦ Synopsis

Stress relaxation in rubber stocks containing various fillers was measured at room temperature, and an empirical equation found for relating decredse in tension, ft, over a period of time from 0.1 sec. to 6 months, namely:

where fi.o is force after 1 min. of relaxation, n is the relaxation rate of m a t e h l (by definition) and t is time in minutes. Raw rubbers were examined under compression, and cured rubbers were tested under tension. In both cured and raw butadiene rubbers, stress relaxation was found to be a viscous-controlled process. In raw rubbera, reinforcing carbon blacks decrease the rate of relaxation, while in cured rubbers the effect of carbon black is very small. However, in swollen (to V X = 0.25), cured rubbers, the rate of relaxation increases with increasing carbon black loading, indicating a slippage and/or breakage of some carbon black-polymer attachments.