Preparation And UV Curing Properties Of Functional Acrylates

With the rapid development of China’s economy,the waste of resources,environmental pollution and other problems are increasingly concerned.The photocuring technology,which enjoys the reputation of"5E",is widely used in coatings,ink,3D printing and many other fields with the advantages of less environmental pollution,low economic cost and high production efficiency.The composition of the photocurable system is the key factor to determine the quality of the photocurable products.Therefore,the design and synthesis of new photocurable materials has always been the research focus of high performance photocurable products.Based on the review of the main components of the photocuring system and its research progress,oxazolidinone-based acrylate and rosin-based oligomer resin were designed and synthesized,and their photopolymerization properties were studied.The main contents are as follows:Oxazolidinone-based acrylate derivatives were prepared by two-step reaction.The molecular structure of the product was characterized by FT-IR,~1H NMR and HRMS-ESI.The photocuring kinetics of oxazolidinone-based acrylate was studied by FT-IR.The double bond conversion of oxazolidinone-based acrylate system was 92%after 30 s under LED lamp radiation with 1 wt%2-isopropyl-9H-thioxanthen-9-one(ITX)as initiator.The double bond conversion of oxazolidinone-based acrylate system was 97.9%under mercury lamp radiation with 1 wt%2-hydroxy-2-methyl-1-phenylpropan-1-one(Da-1173)as initiator.The order of photopolymerization activity is in the order as follow:oxazolidinone-based acrylate>conventional acrylate with 3 wt%ethyl 4-(dimethylamino)-benzoate(EDB)>conventional acrylate.The results of photocuring kinetics of oxazolidinone-based acrylate showed that oxazolidinone group could be used as hydrogen donor in the curing process,and the chain transfer reaction between polymer radical and oxazolidinone group was the rate-determining step of polymerization,showing a first-order kinetic relationship.The role of oxazolidinone group as hydrogen donor was further confirmed by HRMS-ESI analysis of oligomers extracted from UV-curable butyl acrylate film.And a possible UV polymerization mechanism was proposed.The compound of prepared oxazolidinone-based acrylate system and epoxy acrylate was 3D printed to obtain a model with hardness of 5H and gel fraction of88.5%.Three kinds of rosin-based acrylates were synthesized by Diels-Alder addition reaction of rosin-based pentaerythritol polyester(SX1)and neopentyl glycol diacrylate(NPGDA),ring-opening reaction of residual acid in polyester with glycidyl methacrylate(GMA)and ethylene glycol diglycidyl ether(EGDE).The photopolymerization properties of rosin-based system were investigated.Under UV radiation and initiated by 1wt%ITX,the double bond conversion of SX1-GMA/NPGDA,SX1-EGDE-AA/NPGDA and SX1-NPGDA/NPGDA of equal mass were 49.6%,65.4%and 63.7%,respectively,and the gel fraction of cured films were 98%,87.7%and 83.8%,respectively.The double bond conversion of SX1-GMA/NPGDA and SX1-NPGDA/NPGDA of equal mass initiated by 1 wt%Da-1173 under light were 98.3%and 97.3%,respectively,and the gel fraction of SX1-GMA/NPGDA cured film was 86%.