Study on gel weight fraction of ultraviolet-cured acrylic adhesives

Abstract Ultraviolet (UV)-cured adhesives have attracted plenty of attention in the fields of health care and electronic components thanks to low energy loss and environment pollution. UV-cured adhesives bearing epoxy acrylate prepolymers have been extensively utilized, ascribed to low cost and high stability. However, the gel content of UV-cured adhesives has hardly been investigated in detail. The gel content has been found to strongly affect the mechanical properties and serving life of adhesives. We have found the strong composition dependence of adhesive performances of UV-cured adhesives before. To clarify the influencing factors of gel content in UV-cured adhesives containing epoxy acrylate prepolymers, in this work, a family of UV-cured adhesives with epoxy acrylate constituents have been elaborately designed and further fabricated. The influences of prepolymer kind, UV photoinitiator kind, UV photoinitiator concentration, reactive diluent concentration, feed style during preparing prepolymers and film thickness on gel weight fraction of cured adhesive films were deeply researched. This work might open the door to the large-scale preparation of promising high-performance UV-cured adhesives with a higher gel weight fraction based on regulating the formula. Graphical Abstract