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Anionic synthesis of poly(epichlorohydrin-g-styrene) and chemical modification of polyepichlorohydrin
Authors:MA Majid  MH George  JA Barrie
Affiliation:Department of Chemistry, Imperial College of Science and Technology, London SW7 2AY, UK
Abstract:Poly(epichlorohydrin-g-styrene) copolymers, P(ECH-g-S)s, have been prepared in solution by two different methods of coupling polyepichlorohydrin, PECH, with polystyrene, PS, containing a functional end group. In the first method, polystyryl carboxylic acid, PSCOOH, prepared from living polystyrene, was converted to the corresponding potassium salt which was coupled with PECH in dimethyl formamide solution usually at 60°C. In the second method, polystyryl potassium, PS?K+, in tetrahydrofuran solution was end-capped with propylene sulphide to form PSCH2CH(CH3)S?K+ which was coupled directly with PECH in tetrahydrofuran at 40°C. Grafting by the first reaction was relatively slow but occurred without significant adverse side reactions. The grafting by the second reaction was relatively fast, but side reactions occurred resulting in a cleavage of the graft copolymer. The graft copolymers were purified by fractional precipitation and extraction procedures and were characterized by infra-red and ultra-violet spectroscopy, microanalysis, gel permeation chromatography, differential scanning calorimetry, solution viscometry, dynamic mechanical testing, and electron microscopy. Solution properties of the graft copolymers in benzene-carbon tetrachloride and toluene-cyclohexane mixtures were studied. There was evidence of micelle formation in dilute solutions of the mixed solvents and microphase separation of components in the solid state. Nucleophilic substitution of chlorine atoms in PECH by phenyl acetate (C6H5 CH2COO-) and thiophenoxide (C6H5S-) groups was performed.
Keywords:Characterization  synthesis  copolymers  modification  polyepichlorohydrin  functional group
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