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Mixed metal vinyl stabilizer synergism—reactions with model compounds
Author(s) -
Grossman Richard F.
Publication year - 1990
Publication title -
journal of vinyl technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 35
eISSN - 1548-0585
pISSN - 0193-7197
DOI - 10.1002/vnl.730120108
Subject(s) - barium , chemistry , carboxylate , allylic rearrangement , barium chloride , reaction rate constant , chloride , inorganic chemistry , metal , cadmium , organic chemistry , kinetics , catalysis , physics , quantum mechanics
An allylic model compound for degrading PVC, cinnamyl chloride, was found to react with metal carboxylates in n‐butyl acetate at 50°C with rates first order in each component. The corresponding metal chlorides and a mixture of rearranged and unrearranged allyl esters were isolated. With cadmium carboxylates, the rate constant is of the order of 300 × 10 −5 sec −1 ; with barium carboxylates, two orders of magnitude slower. In the presence of excess barium carboxylate, the rate of reaction is first order in cadmium and independent of barium concentration; the product is, however, barium chloride. Under such conditions, only unrearranged allyl ester is recovered. These observations are interpreted in terms of a rapid step leading to formation of a carboxylate‐bridged barium/cadmium intermediate. It is proposed that such intermediates displace chloride from allylic carbon by a concerted mechanism, generating chloride‐bridged reaction products that collapse exclusively to barium chloride.