Morphology of photodegraded heterophasic ethylene-propylene copolymers

The morphology of photooxidative degraded films of heterophasic ethylene-pr opylene copolymer (EPQ-30R) was investigated and compared with isotactic po lypropylene and linear low-density polyethylene by scanning electron micros copy. Surface damage caused by polychromatic ultraviolet irradiation (lambd a greater than or equal to 290 nm) at 55 degrees C in air is presented in d ifferent micrographs. Changes occurring due to the formation of polar group s during photooxidative degradation are discussed. Morphological study of t hese photodegraded polymer samples show very good correlation with the phot odegradation results. The rate of photooxidation is very fast in case of is otactic polypropylene, compared with polyethylene and ethylene-propylene co polymers. (C) 1999 John Wiley & Sons, Inc.