| Abstract: | Synthesis and radical crosslinking reaction of poly (vinylcyclopropanone acetal)s ( 4 ), volume change on the crosslinking, and thermal analysis of 4 and the crosslinked polymers were carried out. 4 was prepared by the reaction of 1,1-dichloro-2-vinylcyclopropane with sodium dialkoxides. Radical crosslinking of 4a was carried out in the presence of AIBN, BPO, or DTBP at 60, 80, or 120°C, respectively. 4a afforded no dichloromethane-insoluble part in the crosslinking in chlorobenzene but afforded in 37% yield in bulk at 120°C. On the other hand, 4b afforded dichloromethane-insoluble part in 33% yield in the crosslinking in chlorobenzene at 120°C. Volume shrinkage of 4a and 4b on crosslinking at 120°C was 4.11 and 3.55%, respectively. Glass transition temperatures of the crosslinked polymers obtained from 4a and 4b were 28 and 163°C, respectively, which were 32 ～ 49°C higher than those before crosslinking. © 1994 John Wiley & Sons, Inc. |
