CONVERSION-DEPENDENT MOLECULAR-WEIGHT OF THE POLYMER IN FREE-RADICAL POLYMERIZATION OF CAPTODATIVE SUBSTITUTED (ACYLOXY)ACRYLATES

The radical homopolymerization of captodatively substituted methyl alp ha-acetoxyacrylate (MAA) is studied by comparing it with that of the a lpha-trifluoroacetoxy, the alpha-butyryloxy, and the ethyl ester analo gs at 40 degrees C. The yield of the polymer is much influenced by the acyloxy substituents, and the polymer molecular weight increases with conversion in bulk MAA and ethyl ester polymerizations in contrast to other polymerizations, Dilution of the MAA polymerization system, how ever, results in no increase in the polymer molecular weight during th e polymerization. Some polymer-polymer interactions between captive an d dative moieties in MAA polymer are discussed on the basis of the mea surement of the viscosity of the polymerization system and the polymer solution.