Adhesion performance of highly biobased latex copolymers from isobornyl methacrylate and plant oil-based acrylic monomers

A range of cross-linkable latex copolymers with up to 90% biobased content was synthesized from isobornyl methacrylate combined with acrylic monomers based on high-oleic soybean (HO-SBM) or camelina (CMM) oil in miniemulsion polymerization. By varying HO-SBM and CMM macromolecular fraction, the cross-link density of resulted materials can be altered due to differences in the fatty acid profile of plant oil-based monomers. The glass transition temperature of the synthesized copolymers correlates very well with calculated Flory-Fox values. Higher cross-link density of the biobased copolymer films leads to a notable growth in materials modulus, while elongation at break decreases due to more restricted macromolecular mobility. Remarkably, the copolymer with the highest in a range unsaturation (based on CMM) shows an increase of both the modulus and elongation at break owned, perhaps to extended entanglements of fatty acids-based side chains. The adhesion performance of the cross-linked biobased copolymers was evaluated using shear and peel strength measurements on steel and polypropylene. Based on the obtained results, the amount of unsaturation in CMM and HO-SBM (determined by plant oil composition) can be applied as a criterion to adjust adhesion by choosing plant oil-based monomers (or their mixtures) with different unsaturation and provide properties and performance required for specific applications.