PHOTO-TRANSFORMATION OF PENDANT ACYLOXYIMINO GROUPS INTO VINYLIDENE-TYPE DOUBLE-BONDS IN COPOLYMERS OF O-METHACRYLOYL ACETOPHENONE OXIME AND STYRENE - STRUCTURAL-ANALYSIS BY H-1-NMR AND C-13-NMR

The structural changes in copolymers of 0-methacryloyl acetophenone ox ime and styrene upon UV irradiation were followed by NMR. After irradi ation, the disappearance of pendant methyl groups and the appearance o f terminal olefinic carbon were observed in H-1- and C-13-NMR spectra. These facts show that the pendant methyl groups were converted to vin ylidene-type double bonds. The pendant methyl group in the photoreacti on of this copolymer was proved to play a very important role.