Efficient Miniemulsion Polymerization of Plant Oil-Based Acrylate Monomer toward Waterborne Epoxy Resins
Wei Liu, Mei Wu, Chuqing Ma, Cheng Liu, Xiaoying Zhang, Zhong Wang, Zhongkai Wang
Abstract
Synthesis of waterborne polymers from biomass via emulsion polymerization has gained more and more interest. Plant oils are one of the most abundant renewable resources. However, in most cases, plant oil-derived monomers are difficult to polymerize through emulsion polymerization due to the existence of hydrophobic and unsaturated fatty acids. Herein, plant oil-acrylate epoxy monomers were synthesized efficiently. Miniemulsion polymerization was applied to obtain plant oil-acrylate epoxy latexes. Stable latexes containing epoxy moieties with monomer conversion rate exceeding 99% were successfully obtained and characterized. By taking advantages of the epoxy groups presented in the latexes, excellent adhesion properties were obtained (1.5 MPa shear strength). These plant oil-acrylate epoxy monomers were also copolymerized with vinyl acetate (VAc) to modify the commercial PVAc latexes. Waterborne latexes with better adhesion properties, water resistance, and tensile strength were obtained, compared with PVAc latex. Furthermore, the fully biobased waterborne epoxy resin was prepared by using citric acid as the cross-linking agent. The existing dynamic β-hydroxyl ester chemical networks enable great potential as a reconfigurable and recyclable coating.