Thermal degradation of vinylidene chloride/butyl acrylate copolymers

摘要

Vinylidene chloride/acrylate copolymers display good barrier to the transport6 of small molecules (oxygen, cargon dioxide, water, etc.) as well as to flavor and aroma constituents of food items. For this reason, they occupy a place of prominence in the barrier plastic packaging industry. However, at process temperatures, these materials tend to undergo degradative dehydrochlorination. This is a typical radical chain process with distinct initiation, propagation, and termination phase and if unchecked can lead to the development fo coloration which may be objectionable in some applications. To examine the influence of an aliphatic sidechain on this process, a series of vinylidene chloride/butyl acrylate (4, 8, 12, 18, 20 wt. percent) copolymers have been sythesized, fully characterized by chromatographic, thermal, and spectroscopic methods and subjected to examination by thermogravimetry. INcreasing levels of butyl acrylate in the copolymer have little impact on the rate of initiation of degradation but do modestly decrease the propagation rate for the degradation.