Physicochemical Properties of Polylactide/Delta-Valerolactone/Organosolv Lignin Atactic Terpolymers

Compostable graft terpolymers of stereotactic lactide, delta-valerolactone, and switchgrass organosolv lignin were synthesized via ring-opening polymerization to improve on polylactide homopolymer properties for commercial applications. Organosolv lignin from swtichgrass has been shown to have properties that improve some of the deficiencies of polylactide, including polylactide’s limited use in food, beverage and medical applications due to its ease to degrade hydrolytically. Delta-valerolactone has been shown to add flexibility to copolymers. It was found that controlling the ratios of the stereoisomers of lactide had significant effects the tensile properties of the resultant terpolymers. Terpolymers containing various ratios of L(-) lactide to D(+) lactide showed greatly increased elasticity and lower Young’s modulus compared to terpolymers containing only L(-) lactide.