Effects of maleated ethylene propylene diene rubber (EPDM) on the thermal stability of pure polyamides, and polyamide/EPDM and polyamide/poly(ethylene terephthalate) blends: kinetic parameters and reaction mechanism

Abstract

The effects of maleated ethylene propylene diene (EPDM-g-MA) on the thermal stability of polyamide/EPDM and polyamide/poly(ethylene terephthalate) (PET) systems were studied by thermogravimetric analysis and infrared spectroscopy in nitrogen. Based on the activation energy ( E) and reaction products, it is suggested that the thermal degradation of pure polyamide 12.10 (PA-12.10) and polyamide 6.10 (PA-6.10) occurred firstly by chain scission of the weakest C–N and –C(O)–NH bonds. The average value of E for pure PA-12.10 was ca. 280 kJ mol −1. In the binary and ternary blends, the decrease of E to ca. 180–200 kJ mol −1 indicated a more favourable degradation. For the systems containing PA-6.10, E decreased from ca. 210 kJ mol −1 (pure PA-6.10) to ca. 160 kJ mol −1 in the ternary blends. The results suggest that the presence of EPDM-g-MA in the blend decreased the thermal stability of the polyamides.