Heterocyclic Ylide-Initiated Polymerization of Methyl Acrylate |
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Authors: | Sujata Saini A K Shukla P Kumar A K Srivastava |
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Institution: | Department of Chemistry , Harcourt Butler Technological Institute , Kanpur, 208002, India |
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Abstract: | β-Picolinium-p-chlorophenacylide initiates radical polymerization of methyl acrylate (MA) up to 19.5% conversion without gelation due to autoacceleration. The average rate of polymerization (Rp) increases as ylide] is raised from 1.02 to 3.06 mmol/L, the order of reaction being 0.5 ± 0.02. However, at higher concentrations (>3.06 mmol/L), Rp decreases. The monomer exponent is 1.40 when benzene is used as diluent. The overall energy of activation is computed to be 28.8 kJ/mol. A polar solvent like dimethyl-sulfoxide and a radical scavenger like hydroquinone retard the reaction. The kinetic data and ESR studies indicate that the polymerization proceeds via a free-radical mechanism. Chain termination by degradative chain (initiator) transfer appears to be significant. |
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