Study On UV-curing Epoxy Resin And Its Composites

The UV curing technology is a environmentally friendly green technology.It is completely in conformity with 4E principle,that is Energy saving,Environmentally friendly,Economy,Excellent finishing of radiation curing,so the research and application for it change quickly.Now,the UV curing technology has been widely used in coating,ink,adhesive,printing board,electronic industry,micromachining and rapid prototyping,etc.Used in curing of resin matrix composites is a new direction recently.In this thesis,the UV absorption spectrum of three kinds of cationic photoinitiators,the curing-velocity of three different types of epoxy resins,the effect of attenuant and accelerant on the curing-velocity and curing-degree,the curing characteristics and post-curing characteristics of photopolymer system in different concentration of photoinitiator,irradiation time and temperature UV intensity have been studied.To analysis the variation of epoxy group in the course of UV curing,the FTIR spectrometry was used to track the conversion rate of epoxy group.The mechanical properties of UV curing epoxy resin and thermal curing epoxy resin and composite have been discussed also.It is shown that:the photopolymer system using triarylsulfonium salt 831 and glycidol ether epoxy CYD-128 as photoinitiator and photopolymer has the highest photocuring rate.The concentration of photoinitiator has a optimum value for both the curing-velocity and the thickness.High photoinitiator concentration could increase the curing rate,but higher concentration would lead to an insufficient cure of the thick sample.Prolonging the irradiation time and increasing the incident intensity can improve the curing-degree and thickness of sample.According to the curve line of Barcol hardness which agree with the Beer-Lambert law.Improving the concentration of photoinitiator,prolonging the irradiation time and increasing the environmental temperature are conducive to the process of the post-curing.The UV cured sample which initiated by 831 has the similar mechanical properties with thermo-cured sample,and the interlaminar shear strength of UV cured composite is less than the interlaminar shear strength of thermo-cured composite.At last,the UV radical-cationic hybrid curing resins system has been preliminarily studied.