Cure Studies

摘要

A two step method is involved to study the post effects of methyl methacrylate polymerisation at low monomer conversions.The method consists in a short initial photo-induced polymerisation period and subsequent registering of the evolution of monomer concentration in the dark.It has been found that after the light is switched off,the free radical concentration drastically drops,but a certain concentration is still present,capable of continuing the polymerisation for a long time period.The process in the dark is controlled by the transfer to the monomer and initiator.The polymers obtained in the dark using the persistent radicals after the short photo-inducing polymerisation,have very high molecular weights.