High Biobased Content Latexes for Development of Sustainable Pressure Sensitive Adhesives

Waterborne pressure sensitive adhesives with biobased contents up to 72% and adhesive performance comparable to pure oil-based formulations have been developed. For that, partially biobased commercial 2-octyl acrylate and isobornyl methacrylate monomers (derived from castor oil and pine resin, respectively) are copolymerized by emulsion polymerization, an environmentally friendly procedure which allows fine-tuning the microstructure of the copolymer at high solids content as well as notably reducing the VOCs in the final product. Formulations with well balance adhesiveness and cohesiveness are achieved, and the reasons are thoroughly discussed. Furthermore, the moderate reduction of the biocontent by the substitution of part of 2-octyl acrylate by the oil-based 2-ethylhexyl acrylate provides trade off waterborne formulations with very promising adhesive properties.