Effects of temperature and strain amplitude on dynamic mechanical properties of EPDM gum and its carbon black compounds

Abstract

SYNOPSISThe effects of carbon black loadings cp, temperature T, and shear frequency w on dynamic mechanical properties of EPDM gum elastomer and its carbon black compounds were investigated under sinusoidal shear flows. The region of shear flows where the gum elastomer and its carbon black compounds exhibited characteristic plateau in viscoelastic properties were established and found to directly depend on temperature but were inversely proportional to carbon black loading. The gum rubber and its 20% carbon black compound showed rather unusual similar dynamic flow behaviors a t 50 and 100°C attributed to the possible presence of crystallinity from the fractional ethylene components in the gum. This fraction could act as nucleation sites for macrogels that required higher temperatures than 50 and 100°C for melting, particularly in the presence of carbon black particles. Dynamic properties were amplified due to carbon black filler. This effect was more pronounced at low frequencies and at 50 and 15OoC, respectively. At 100°C, amplifications appeared to have been attenuated by the hydrodynamics of the continuum elastomer matrix. This observation helps the further understanding of the filler-elastomer interactions and the critical role played by temperature, particularly as it affects rubber processors. 0

Comparative study on mechanical, thermal, viscoelastic and rheological properties of vulcanised EPDM rubber

“…The effects of carbon black filler, temperature and shear frequency on dynamic mechanical properties of EPDM elastomer and its carbon black compounds were investigated under sinusoidal shear flows by Osanaiye. 4 Huang et al 5 prepared thermoplastic elastomer of EPDM and nylon by dynamic vulcanisation, and the effects of the curing systems, compatibiliser, nylon content and reprocessing on the mechanical properties of EPDM/nylon thermoplastic elastomer were investigated. Ghosh and Chakrabarti 6 studied the effect of incorporation of different doses of conducting carbon black filler on melt rheology and relaxation behaviour of curative free elastomer from EPDM system via cone plate viscometer.…”