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

✍ Scribed by Gabriel J. Osanaiye

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 707 KB
• Volume: 59
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19960124)59:4<567::aid-app1>3.0.co;2-r

✦ Synopsis

The 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.