Development of bio-acrylic polymers from Cyrene™: transforming a green solvent to a green polymer
In this work, Cyrene™, a bio-based green solvent, has been transformed into its methacrylic derivative (m-Cyrene) for the first time. Polymerization of the newly-synthesized monomer was studied using different polymerization techniques such as bulk, solution and emulsion polymerization. Compared to solution polymerization, emulsion polymerization was found to produce higher yields and molecular weights. Cyrene™, along with other green solvents, was used as a polymerization solvent and was found to be the most effective (as a solvent) with the highest yield and molecular weight. The new Cyrene™ monomer was found to undergo rapid polymerization compared to isobornyl methacrylate (IBMA), another bio-derived monomer with a close structural similarity, and the highest polymerization rate was obtained in Cyrene™ as the polymerization solvent media. A reactivity ratio calculation also showed m-Cyrene to be more reactive than IBMA. The homopolymer derived from emulsion polymerization showed high glass transition temperature (192 °C) and thermal stability (up to ca. 266 °C). Cytotoxicity testing confirmed the non-toxic nature of the bio-derived monomer, making it a green bio-derived methacrylic monomer for synthesizing polymers, where high thermal stability and mechanical properties are required.