Butyl Acrylate/2-Methylene-1,3-Dioxepane/Vinyl Acetate Emulsion Terpolymerization: Incorporating Backbone Degradable Linkages into Adhesive Applications.

Abstract

The ring-opening polymerization of bio-based monomer 2-methylene-1,3-dioxepane (MDO) can reportedly enhance polymer degradability. Butyl acrylate (BA)/MDO/vinyl acetate (VAc) terpolymers were synthesized via emulsion polymerization for their eventual application as pressure-sensitive adhesives (PSAs). While using MDO in emulsion polymerization leads to a more sustainable process, it also presents challenges such as MDO hydrolysis, MDO ring retention, and inadequate MDO distribution. By carefully selecting reaction conditions such as pH and temperature, MDO hydrolysis and MDO ring retention were mitigated, and a uniform distribution of MDO throughout the terpolymer was confirmed. In addition, carboxylated cellulose nanocrystals (cCNCs) were incorporated into the final formulation to enhance the PSA properties.