Model systems for the study of poly(vinylidene chloride) degradation

Poly(vinylidene chloride) and copolymers which contain vinylidene chloride (VDC) as a major component undergo thermal degradative dehydrochlorination. Previous work has demonstrated that random double bonds introduced during polymerization/processing serve as the principal defect sites responsible for initiation of the dehydrochlorination reaction. However, residues from degradation of polymers of relatively high molecular weight tend to be crosslinked and relatively insoluble in most solvents. This prohibits the examination by instrumental techniques of these “products” of the degradation reaction. Low‐molecular‐weight model compounds prepared from appropriate multifunctional ketones or by telomerization of VDC monomer in carbon tetrachloride provide materials which upon degradation afford soluble residues which may be characterized by nmr spectroscopy. Initial results suggest that depolymerization/fragmentation can be a major degradation process for these materials.