The influence of monobutyl itaconate and β-carboxyethyl acrylate on acrylic latex pressure sensitive adhesives

The application of two different kinds of carboxylic monomers, monobutyl itaconate (MBI) and beta-carboxyethyl acrylate (beta-CEA), in acrylic pressure sensitive adhesive (PSA) latexes is presented in this article. The hydrophilic-lipophilic balance (HLB) values of carboxylic monomers were calculated to determine their water solubility, which was further confirmed by their partition coefficients between organic and water phases. Influences of the functional monomers on particle size and zeta potential of the latexes, as well as on water resistance, thermal stability, gel content, sol molecular weight (M-w, M-n) and adhesive properties of the polymer were investigated in this work. In addition, the application of commonly used methacrylic acid (MAA) was also determined as a benchmark. The results indicated that for equiweight amounts of acid comonomer, latex particle sizes fall in the order: MBI > MAA > beta-CEA, depending on water solubility of the corresponding monomer. Besides, the latex film prepared with MBI showed the best water resistance when compared with other two counterparts. Results also indicated that the PSA prepared with beta-CEA exhibited the highest gel content among the three acid monomers. Moreover, the thermal stability of the three carboxylated polymers follow the order P(n-BA + MAA) > P(n-BA +beta-CEA) > P(n-BA + MBI). Finally, the effects of carboxylic monomers on the adhesive properties of the PSAs were also evaluated.