Preparation and characterization of long carbon chain based polyacrylate latexes and their pressure sensitive adhesive application

Aqueous emulsion homo- and co-polymerization of lauryl methacrylate (LMA), a strong hydrophobic monomer with long carbon chain, is quite challenging. In this study, a long carbon chain emulsifier N-390 was used as the primary emulsifier to facilitate the emulsion copolymerization of LMA with other acrylate monomers through the mutual hydrophobic interaction between N-390 and LMA, and ultimately polyacrylate latex pressure sensitive adhesives modified by LMA via pre-emulsified semi-continuous seeded emulsion polymerization process were synthesized. The effects of LMA on the resulting latex and PSA properties was comprehensively examined. Both FTIR and 1H NMR spectra indicated that LMA has been successfully introduced into copolymer chain with the aid of long carbon chain emulsifier N-390. The results also showed that the introduction of LMA will contribute to decrease in particle size and zeta potential, while increase viscosity and gel content of the acrylate PSA latex. Moreover, as the LMA content increased, the latex PSA films demonstrated gradual improvements in both water resistance and thermal stability. Finally, for the long carbon chains adhesive film, the shear strength was improved greatly while at the sacrifice of loop tack and peel strength, when compared to counterparts without LMA.