ETHYLENIC OXYGEN SCAVENGING COMPOSITIONS AND PROCESS FOR MAKING SAME BY ESTERIFICATION OR TRANSESTERIFICATION IN A REACTIVE EXTRUDER

摘要

Disclosed is a process for transesterifying a polymer having a polyethylenic backbone and pendant ester moieties comprising contacting a melt of the polymer in a reactive extruder with a transesterifying compound so that the polymer undergoes transesterification but not alcoholysis. The transesterified polymer also has pendant ester moieties which differ in kind and/or number from the unreacted polymer. In one embodiment, the process also comprises adding an amount of a transition metal salt that is effective to promote oxygen scavenging. Also in a further embodiment, the process comprises irradiating the transesterified polymer with actinic radiation to reduce the induction period before oxygen scavenging commences. Also disclosed are compositions comprising a component which comprises an ethylenic backbone and a pendant or terminal moiety comprising a benzyl radical are disclosed. The invention also embodies new polyethylenic oxygen scavenging compositions comprising a transition-metal salt and a component which comprises a polyethylenic backbone and a pendant or terminal moiety comprising a benzyl radical. Methods of making the compositions, and methods and compositions using the ethylenic compositions, are disclosed.