Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
Acetone-soluble and -insoluble fractions were obtained from two different PVC samples: a polymer prepared in our laboratory at 60°C using 2,2′-azoisobutyronitrile (AIBN) as initiator (sample A) and a commercial polymer prepared at 70°C (sample B). The content of isotactic, syndiotactic and heterotactic traids was accurately measured by high resolution 13C NMR. From the obtained data it follows that the isotactic triads accumulate preferably in the soluble fraction, the amount of which depends on the type of polymer. In agreement with earlier results, the soluble fraction is about 40% less stable than the insoluble fraction. The reasons for this behaviour are discussed in the light of the higher content of both isotactic triads and some defect structures, as found in the low molecular weight soluble extracts of PVC.
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