Abstract: Photocuring is an effective way to achieve solvent-free and high-performance acrylate pressure-sensitive adhesives. With ethynyl cyclohexyl acrylate (ECA) as the alkyne functional monomer and using its photopolymerization characteristics, solvent-free and gel-free syrup and their final acrylate pressure-sensitive adhesive are prepared in two steps by photocuring the syrup prepared by bulk photopolymerization. With the increase of ECA addition (0~3 mol%), the molecular weights of the polymers containing the retained acetylene groups in the precursors decreased from 55.59×10⁴ Da to 14.12×10⁴ Da and molecular weight distribution slightly increased. Comparative studies have shown that acetylene groups improve the dynamic and static shear properties of the photocured pressure-sensitive adhesives, but have no or minimal effect on the peeling and tack forces. The acetylene group participates in photocuring, which increases the cohesion strength of the pressure-sensitive adhesive and will be a new means for pressure-sensitive adhesives modification.

Key words: acetylene functionalization, photocuring, pressure sensitive adhesives, polyacrylates