Synthesis and characterization of water-borne vanillin derived copolymers containing dynamic imine cross-links

In the effort toward the production of circular plastics, the use of lignin-derived aromatic building blocks such as vanillin is interesting due to their functionality. Nonetheless, the water-borne emulsion polymerization of acrylic monomers derived from vanillin is still lacking. Vanillin can be readily functionalized with a methacrylate group for the radical polymerization to yield polymers containing functional aldehyde side groups. The functionality can be exploited via imine formation to produce vitrimers, a class of cross-linked recyclable polymers. Besides recycling, synthesis via a water-borne emulsion polymerization is desired to reduce the negative contribution of solvents on the environment and health. In the present work, polymethacrylates based on 2-(methacryloyloxy)ethyl vanillin and 2-octyl acrylate were synthesized via a emulsion polymerization approach to produce a water-borne latex. A latex with a small particle size (49 nm) and solid content of 31 wt% was obtained. For comparative purposes, a similar polymer was synthesized via solution polymerization. Both polymers were cross-linked using a multifunctional amine to produce recyclable imine vitrimers. This research investigates the unique combination of water-borne synthesis and vitrimer polymers, and therefore contributes to future development of vitrimer latex products such as coatings and films.