Modified Acrylate Pressure-Sensitive Adhesives for Low-Surface-Energy Substrate and Adhesion Mechanism Models

Most acrylate adhesives do not bond well to low-surface-energy substrates (e.g., polyethylene and polypropylene) due to the weak interaction force between the polar adhesive molecules and the substrate. To enhance the adhesion performance on low-surface-energy substrates and investigate the effects of substrate surface energy, roughness, pressure-sensitive adhesive (PSA) surface energy, viscosity, and modulus on adhesion performance, this study modifies the acrylate adhesive by incorporating a hydrogenated-terminated hydroxylated polybutadiene (HHTPB) structure with a double bond at one end. The results demonstrate an enhancement in the adhesion performance of the modified PSAs on High-Density Polyethylene (HDPE). The 24 h peel strength and loop tack increase to 4.88 N/25 mm and 8.14 N/25 mm at 20 °C, respectively, with the failure modes remaining adhesive failure. However, as the temperature increases, the peel strength decreases. The high-temperature resistance of the adhesive improves. Based on the experimental data, a mathematical model is proposed that incorporates both the wetting area and loss factor to predict peel strength. The influence of these two factors on the peel strength of the PSA is dependent on the application temperature of the adhesive.