Study on the photocrosslinking of the photocrosslinkable system based on epoxy resin modified by Tung oil. III - Study on the influence of the mass ratio ETT 39/BCDE and the film thickness on the photocrosslinking reaction of the system ETT 39-BCDE-TAS.

Abstract

The photopolvmerization of epoxy group in the 20 µm thick fihn of the system containing 5% triarylsulfonium salt (TAS) and epoxy resin modified by tung oil (ETT39), monome epoxy cyracure 6105 (BCDE) with different mass ratios ETT 39-BCDE 10/90, 30/70. 50/50. 70/30 have been studied. The fastest rate of the reaction was observed in the system with the weight ratio ETT 39-BCDE = 50/50 leading to epoxy conversion of lite EIT39 and BCDE 82% and 98% respectively after 8.4 seconds exposure under 250 mW/cm² intensity UV-lamp. The influence of the film thickness studied in range from 10 µm to 50 µm showed the decrease of the photocrosslinking rate with the increase of the film thickness.