Heterophasic Ethylene-propylene Research Articles

Photoinitiated oxidation of heterophasic ethylene–propylene copolymers. I. Comparison of oxidation products

AbstractDetailed photoproducts from photoirradiation of heterophasic ethylene‐propylene copolymers and their fractions have been compared by infrared spectroscopy combined with chemical derivatization. The oxidized films were treated with gaseous NH3, SF4, and NO for the rapid identification and resolution of the various carbonyl species, alcohols, and hydroperoxides. The photoproduct formation depends upon the composition of the sample. The heterogeneities in thin films were also determined by micro FTIR spectroscopy. © 1993 John Wiley & Sons, Inc.

Photodegradation of Heterophasic Ethylene-Propylene Copolymers in the Solid State

Abstract The photodegradations of various heterophasic ethylene-propylene (E-P) copolymer films were studied at 30 and 55°C in air for varying time intervals. The photochemical behavior of E-P copolymers is quite different from amorphous polypropylene and polyethylene homopolymers but resembles that of isotactic polypropylene. The nonvolatile products in photooxidized copolymer films have been quantitatively identified by infrared analysis. The kinetics and general oxidation mechanism scheme for E-P copolymer are presented. The identification of γ-lactone is an indication of the importance of an intramolecular back-biting process. The overall functional group distribution is found to differ from that in polyethylene and E-P copolymers.