Effect of new phenylalanine monomer and molecular structure on water and heat resistance of pressure-sensitive adhesive

Abstract

Acrylate pressure-sensitive adhesives (PSA) have been widely used in daily life and industrial manufacturing. However, its inherent hydrophilicity and low cohesive strength severely limit its application under harsh conditions such as underwater and high temperature. In this study, the molecular structure of PSA was carefully designed to take advantage of the structurally advantageous strategy of N-acryloylphenylalanine (ACP), and PSA was prepared by copolymerization of ACP with commonly used acrylic monomers. The rigid benzene ring of ACP facilitates the breaking of the hydration layer on the surface of the PSA-substrate underwater, and the carboxylic acid facilitates the establishment of an effective physical interaction between PSA and substrate. As a result, compared with the conventional acrylic ABP_0.1-AA₁₀, the ABP_0.1-ACP₁₀ exhibited excellent adhesion properties underwater and at high temperature, with an underwater peel strength of 3.1 N and a high-temperature peel strength of 8.7 N, which were increased by 181.1 % and 234.6 %, respectively. Notably, the UV-induced cross-linking and rigid benzene ring restricted the movement of molecular chains, giving ABP_0.1-ACP₁₀ good heat resistance (T_HRI: 178.3 °C) and water resistance. Our work may provide a promising solution for designing PSA with good water resistance, heat resistance and high cohesion.