Study On Functionalized Photo-induced Thermal Frontal Polymerization System

Photopolymerization is widely used in coatings,adhesives,micro-electronics,dental restorations and biomaterials due to it's "5E" advantage.Especially,the patterning on the micro and nano-scales,as well as the application of photo curing systems with pigments and functional fillers such as printing inks,color photo resists and 3D printing,have become a hot topic in the field of science and technology.However,photopolymerization technology has the problem of limited light penetration,which limits the thickness of the sample polymerization.Generally,the thickness of polymerization does not exceed 100 ?m,photopolymerization is more difficult to achieve deep curing for thick coatings or bulk materials with pigments and functional fillers.In the free radical photo-induced thermal frontal polymerization system,selective exposure of photo-mask and surface temperature control technology were used to obtain thick structural materials with patterns on the surface.Further,cationic photo-induced thermal frontal polymerization system was also studied.On the basis of the influencing factors and the mechanical properties of the product,the thick colored samples were realized by photo-induced thermal frontal polymerization;then the photo-induced thermal frontal polymerization of montmorillonite composite was realized,and the products with better performance than pure epoxy system were prepared.In addition,the thermal stability and impact strength of the solid samples using this technology are better than the traditional thermal curing technology.The main research contents and results are as follows:1.Adjusting the concentration of photoinitiator,thermal initiator,light intensity and surface cooling temperature of the polymerization process,using 385 nm-LED and mask by photo-induced thermal frontal polymerization technology to prepare the thick structure material with surface pattern in situ.2.Studying the effect of the kinds of cationic photo-initiator,the concentration of cationic photoinitiator,photo-sensitizer,thermal initiator and monomer ratio on the epoxy conversion rate,conversion rate and temperature of the polymerization system.Based on the above factors,the thickness of cured sample in the optimized experimental conditions was up to 6.02 mm3.Analysing of thermodynamic properties between cationic photo-induced thermal frontal polymerization and conventional thermal curing technology.It was found that the thermal stability,solvent resistance,shore hardness(HA)and impact mechanical properties of the epoxy resin samples of the former were all better than the latter.4.Cationic photo-induced thermal frontal polymerization with different pigments is achieved.When the content of the black paste was 0.5 wt%,the cured thickness of the sample could reach 3.86 mm.5.The montmorillonite/epoxy composites were prepared by photo-induced thermal frontal polymerization.The thermal stability and impact resistance of the cured products were better than those of epoxy.In addition,the thermal stability and impact strength of samples made by using of this technology was better than conventional thermal curing technology.