English Abstract
Influences of the Residual Peroxide on Degradation of Crosslinked EPDM
Yoshito OHTAKE
Chemicals Evaluation and Research Institute, Japan, Kitakatusika-Gun, Saitama, Japan
Nippon Gomu Kyokaishi,(2007),80(5),165-171 Original Paper in Japanese

The influences of residual peroxide on degradation and the detection methods for under-crosslinking were investigated.
The under-crosslinking of peroxide-crosslinked EPDM can be detected by differential scanning calorimetry (DSC) measurement of heat of residual crosslinking reaction, which was found to correlate with the amount of remaining dicumyl peroxide(DCP) and triallyl isocyanurate, without determination of their amounts. For the DCP-crosslinked EPDM in under-crosslinking state, it was considered that softening degradation occurs more remarkably than hardening degradation as long as the crosslinking agent remains. By surface analysis of aged DCP-crosslinked EPDM with FT-IR, it turned out that oxidative degradation of the EPDM in under-crosslinking state occurs faster than the EPDM without crosslinking agent remaining.

(Received on August 30, 2006)

(Accepted on February 22, 2007)

Peroxide-crosslinked EPDM, Residual Peroxide, Degradation, Detection Methods for Under-crosslinking, FT-IR, DSC