Rubber-like materials prepared from copolymerization of tannin fatty acid conjugates and vegetable oils

Novel bio-based rubber-like materials are prepared from the oxidative copolymerization of tannin oleate esters and vegetable oils. The copolymer materials are prepared as solvent-cast films. Analysis reveals the reactivity and amount of vegetable oil employed has the greatest influence on copolymer crosslinking and mechanical properties. Copolymer film stiffness values range between 6 and 300 MPa and crosslink densities are 661-15 800 mol · m ^-3. Glass transition temperature (T_g) and Soxhlet insolubles (>80%) are relatively similar when forming copolymers with tung oil. In contrast, both T_g and degree of crosslinking decrease significantly with use of linseed stand oil. Thermogravimetric analysis indicates that the copolymers are thermally stable up to 200 °C. Oxidation copolymerization of tannin oleate esters and vegetable oils provides a route to novel materials comprising relatively rigid and soft domains. These rubber-like materials are considered totally bio-based exhibiting a range of mechanical properties with thermal stability up to 200 °C.