Abstract
A photosensitive polymer, poly [p-(3-butoxy-2-cinnamoyloxypropoxy) styrene] (PBCS) was synthesized by the condensation reaction of cinnamoyl chloride and a reactive polymer, poly [p-(3-butoxy-2-hydroxypropoxy) styrene] (PBHS) in pyridine. The reactive polymer PBHS was synthesized from poly (p-hydroxy-styrene) and n-butyl glycidyl ether in the presence of a basic catalyst, benzil trimethylamine. Under the influence of the basic catalyst, n-butyl glycidyl ether reacts only on the phenolic hydroxyl groups, but not on the secondary ones produced by the reaction. It was confirmed by NMR spectra of trimethylsilylated PBHS and the related compounds that the catalyst played an inportant role. The photosensitive polymer, PBCS became insoluble to solvents by UV-irradiation. The rate of the insolubilization by the irradiation increased with the increase of the content of cinnamoyl groups of the polymer. The photosensitivity of PBCS (cinnamolized; 85%) varied with the thickness of the film coated and with the amount of exposure energy. The sensitivity relative to poly (p-vinyl phenetyl cinnamate) was about 0.7 when the film thickness was 2-2.5μm and the time of the irradiation by 500W high pressure mercury lamp was 15 minutes.
