Cyclopolymerization, 30 - Design of an unconjugated diene with high polymerizability using functional groups with no homopolymerization tendency, and synthesis of completely cyclized polymers therefrom: Radical polymerizations of N-phenyl-N-2(methoxy

摘要

Cyclopolymerizabilities of N-pently-N-2-(methoxycarbonyl)allylmethacrylamide (1a) and N-phenyl-N-2-(methoxycarbonyl)allylacrylamide (1b) were compared to see the validity of the concept proposed previously for the design of 1,6-dienes with both a cyclization tendency and a high polymerizanbility. It states that the use of functional groups with a higher conjugative nature together with a no homopolymerization tendency is essential for the purpose. Of the four monofunctional counterparts of these dienes, only N-phenyl-N-2-(methoxycarbonyl)propylacrylamide, one of the monoene counterparts of 1b, is assumed to have high polymerizabilities of compounds with similar structure. alpha- substituted acryloyl groups of 1a and 1b have higher conjugative natures. This indicates that both the dienes have high polymerizability but their cyclization tendency is essentially different; i.e., 1a yields highly cyclized polymers, while polymers with lower degrees of cyclization are obtained from 1b. The results obtained were in good accordance with this consideration. Repeat cyclic units of poly(1a) and poly(1b) consist mainly of five-membered rings. Both the double bonds of 1b were pendant unsaturations in poly(1b). Mechanism of the polymerizations was discussed based on the results obtained. References: 18