Heat-resistant adhesion performance of acrylic latex PSAs using reactive surfactants and a novel methacrylate with ethylene-urea heterocyclic group

Abstract

Most acrylate latex pressure-sensitive adhesives (PSAs) possess very low shear strength under high temperature environment and will leave a large amount of adhesive residue on the surface of the adherend when they are peeled off. To improve its heat-resistant adhesion performance, reactive anionic/nonionic surfactants SL- 900/ER- 10 and a novel ethylene-urea ethyl methacrylate (UMA) monomer were utilized to prepare a series of acrylate latexes via seeded semi-continuous emulsion polymerization containing butyl acrylate, methacrylate, acrylic acid and 2-hydroxyethyl acrylate. The results showed that the particle size and its distribution of latexes prepared with SL- 900/ER- 10 were smaller and narrower compared to SDS/O- 10, respectively. The introduction of UMA monomer made the latex particle size and its distribution become larger. It was also found that gel content, glass transition temperature (T_g) and thermal stability of the PSA film were all increased with the using of reactive surfactants and UMA monomer. Besides, water contact angle of the latex film increased gradually when fully reactive surfactants were employed, while decreased with the increment in UMA content. Furthermore, the latex film with fully reactive surfactants exhibited obvious improvement on initial tack and shear strength at room temperature, while a slight decrease in peel strength. Especially, when UMA content was 4wt%, the temperature of PSAs film leaving no residue after 2 h treatment increased to 160℃. The shear strength at 150 °C increased significantly and a balanced adhesion performance among initial tack, peel strength, and shear strength at high temperature was obtained by fully using reactive surfactants and UMA monomer.