Introduction to Living Polymerization. Living and/or Controlled Polymerization

摘要

The effect of various imperfections such as slow initiation, termination,transfer, and slow exchange on kinetics, molecular weights, and polydispersities in chain growth polymerizations are simulated. Simulations demonstrate that well defined polymers can be prepared in systems with chain breaking reactions. Thus, under carefully selected conditions, non-living polymerizations may provide controlled polymers. On the other hand, polymers with unpredictable molecular weights, broad and even polymodal molecular weight distributions can be formed in living systems without irreversible transfer and termination. In some living systems, molecular weights may stay constant or even decrease with conversion. Therefore, a clear distinction should be made between living and controlled polymerizations. jg p.2.