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.

Growing environmental concerns are enforcing sustainable recycling processes for glass substrates, especially bottles, where a fast cleaning and minimization of the use of solvents is desired. In this process, labels and adhesives are mostly removed by the addition of harsh reagents, alkaline solutions, or high temperature, increasing economic costs and harming the environment. Herein, high performance and biobased waterborne pressure-sensitive adhesives with fast removability in water have been developed using small percentages of isosorbide (derived from glucose)-based methacrylate monomers. Formulations containing 2-octyl acrylate and isobornyl methacrylate and small amounts (1 wt %) of these monomers not only yield stronger adhesive fibrils, but also promote a removability in water 6× faster than that of nonisosorbide-based counterparts. This waterborne isosorbide containing PSAs represents an alternative to current PSA formulations toward more sustainable glass recycling and reusing processes.

Novel waterborne pressure-sensitive adhesives (PSAs) with biobased contents up to 71% and UV-light-tunable features have been developed using piperonyl methacrylate (PIPEMA) as a hard monomer. The biobased monomer was synthesized from piperonyl alcohol (derived from black pepper), and its homopolymer was fully characterized. Emulsion polymerization was chosen as a sustainable strategy to copolymerize piperonyl methacrylate together with biobased 2-octyl acrylate to produce high-solid-content latexes for pressure-sensitive adhesive applications. The UV light curing ability of the piperonyl methacrylate moieties in the copolymer backbone yielded PSAs with excellent shear resistance and reasonable adhesive properties (tack and peel).

No abstract

No abstract