Adhesion properties of a polyurethane-acrylic hybrid adhesive synthesized through modification of polyol with a silane coupling agent

To simultaneously take advantage of the properties of polyurethanes and acrylic polymers, the synthesis of their hybrid polymer has been proposed. In this research, to use this method for preparation of a pressure-sensitive adhesive (PSA), a silane coupling agent was used to modify a polyol, followed by synthesis of a silanized polyurethane (SPU). Subsequently, free radical polymerization of acrylic comonomers was performed on C=C present in the chemical structure of the silane coupling agent. Compared to the acrylic PSA, the presence of 10 and 20 wt. % of SPU in the system decreased the glass transition temperature by 11.1 and 14.6 °C, and increased tack by 2.3 and 1.8 times, respectively. The peel force of the PSA containing 10 wt. % SPU was almost the same as that of the acrylic PSA. However, further increase in the amount of SPU resulted in a decrease in the peel force.