Polyvinyl chloride tacticity

Extensive dynamic viscoelastic measurements on polyvinyl chloride gels with well-defined tacticities and thermal histories have revealed changes in aging which affect the plateau zone as some crystallites melt and others are formed. The appearance of secondary loss mechanisms is attributed to the formation of entan-gelments during the aging process. 

An excellent demonstration of the power of 2D heteronuclear chemical-shift correlations to determine tacticity has been given for polyvinyl chloride (PVC) [65]. The 500-MHz H and 125-MHz spectra of PVC at 65 C are shown in Fig. 6.22. 

Tacticity studies have been conducted on poly(3-methyl-l-butene) [120], poly(p-isopropyl-a-methyl styrene) [121], a-methyl styrene [122], polytetrafluoroethylene [123], polyacrylic acid [124], polymethylvinyl ethers [125], polyacrylonitrile [126, 127], polyvinyltrifluoro acetate [128], polyvinyl alcohol and its ethers [129, 130], isobutene-maleic anhydride [111], isobutene dimethyl fumerate [131], isobutene dimethyl maleate [131], polyacrylonitrile [127], ethylene - vinyl acetate [132-135], polyalkyl vinyl ethers [136, 137], ethyl-2-chloroacetate [133], poly-trans-1,3-pentadiene [138], isotactic-l-butene - propylene [139], butadiene - propylene [140], polybutene [141], polychloroprene [142], ethylene - vinyl chloride [143], chlorinated polyethylene [144, 145], poly-a-methyl styrene [146], styrene acrylic acid [147], a-methyl styrene - methacylonitrile [148], styrene acrylonitrile [149], styrene isobutene [150], poly(p-fluoro-a-methyl styrene) [151], polyarylamide-6 [152], PP - polyamide-6 [152], polystyrene oxide [153], polybutene [154], atraconic anhydride - p-chlorostyrene [155], styrene - maleic anhydride [156, 157], ethylene - vinyl acetate [158], polymethyl vinyl ether [159], propene - carbon monoxide [160], methyl(3,3,3-trifluoropropyl)siloxane [161], poly(diallyldimethyl ammonium chloride) [162], polypropene [163, 164], polyepichlorohydrin [165], maleic anhydride-p-chlorostyrene [166], polymethacrylonitrile [167] and polyvinyl acetate [168]. 

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