Influence of Hydrogen Bonding on the Adhesive Properties of Photo-Curable Acrylics

摘要

Novel hot melt pressure sensitive adhesives (HMPSAs) were developed from acrylic terpolymers of 2-ethylhexyl acry late (EHA), hydroxyethyl acrylate (HEA), and methyl acrylate (MA) functionalized with hydrogen bonding and photo-reactive functionalities. The hydrogen bonding and photo-reactive sites were introduced from the reaction of HEA repeat units with cyclohexyl isocyanate and cinnamoyl chloride, respectively. The functionalization reaction conditions were optimized to tailor the degree of urethane and cinnamate groups in order to examine the influence of hydrogen bonding and photo-active groups in low T_g acrylics. The synergy of hydrogen bonding and photo-reactivity resulted in higher peel values and rates of cinnamate photo-reactivity with increasing urethane concentration. The increase in cinnamate photo-reactivity with increasing urethane concentration provides evidence that hydrogen bond associations can promote cinnamate dimerization. Isothermal rheological experiments conducted at 150°C confirmed the melt stability of the cyclohexyl urethane linkage, cinnamate, and the acrylic composition indicating the potential for hot melt adhesive applications.