INVESTIGATION OF STATISTICAL, BLOCK AND GRAFT COPOLYMERIZATIONS USINGNMR-SENSITIVE INITIATORS AND MACROINITIATORS

C-13- and P-31-NMR studies on polymers and copolymers derived from C-1 3-enriched AIBN, C-13-enriched dibenzyl ketone and diphenyl-2,4,6-trim ethylbenzoylphosphine oxide (Lucrin TPO) are reported. They provide in formation about the influence of solvent on the initiation step in cop olymerization reactions, the selectivity of diphenylphosphinyl radical s and the chemical behavior of radicals derived from dibenzyl ketone. In addition, NMR, molecular weight and molecular weight distribution m easurements on polymers obtained from polymerizations of methyl methac rylate conducted in the presence of stilbene indicate that stilbene or radicals derived from it may be able to moderate MMA polymerizations.