Poly(vinyl chloride) Dechlorination Catalyzed by Zirconium

Poly(vinyl chloride) undergoes dechlorination in the presence of triethylsilane (Et3SiH) and a catalytic amount of [Cp2Zr(NPh2)][CH3B(C6F5)3] (1 b) at 40–80 °C, with up to 91 % efficiency. Stoichiometric reactivity studies conducted on cyclohexyl chloride as a model suggest that 1 b dechlorinates PVC by initial chloride ion, followed by hydride transfer to the cationic PVC chain from Et3SiH. Consumer items such as pipe fitting, vinyl disc or electric cable insulation undergo either dechlorination or hydrosilylation of the carbonyl‐containing copolymer (polyvinyl acetate) or plasticizer (phthalate). A cationic amidozirconocene catalyst is shown to dechlorinate poly(vinyl chloride) (PVC) under mild conditions in the presence of triethylsilane as a hydrogen donor. PVC additives containing carbonyl functional groups (e. g. phthalates, poly(vinyl acetate)) underwent complete hydrosilylation. A procedure is reported for the deconvolution of catalyst poisoning effects by PVC additives.