Study On Modification And Mechanism Of 3D Printing Of UV Curable Material By Expansion Monomer

Shringkage is a phenomenon to all types of polymerization.It is defined as the reduction in volume caused by an increase in density,by pasing from the liquid or viscous state of the monomer to the solid state of the final polymer.Until 1970s,studies have first found a class of cyclic compounds that expand in the polymerization process,called swelling monomers.This kind of expansion monomer was introduced into acrylate free radical curing system and cationic photocurable photosensitive resin system to make copolymerization with double bond.That is,the Hybrid Polymerization consisting of cationic ring opening polymerization of acrylate compounds and radical polymerization of acrylate monomers can control the volume change during curing and reduce the volume shrinkage.The main purpose of this paper is a spiro orthocarbonate expanding monomer 3,9-hydroxymethyl-2-3,9-two--1,5,7,11-four oxaspiro ring[5.5]eleven alkyl for 3D printing UV light curing hybrid system,study its effect on the light curing material shrinkage and evaluate 3D printing UV light curing material performance.The main content of this study is divided into three parts:the expansion of different content of monomer on the 3D printing UV light curing material properties;different content of photoinitiator on adding expansion effect of 3D printing UV light curing material properties of monomers;influence of expansive monomer and epoxy resin ratio on 3D printing UV light the curing properties of materials.The double bond conversion rate and relative reaction rate of the system during the curing process were analyzed by real-time infrared spectroscopy.According to the above analysis results,when the amount of expansion monomer is 2%,the content of photoinitiator is 7%,and the ratio of expansion monomer to epoxy resin is 1/3,the volume shrinkage of the cured material is the smallest.When the light intensity is 100mw/cm~2,the double bond conversion rate reaches the maximum,and the relative reaction rate reaches the maximum value.The induction time is shortened and can be cured quickly.