Toughening of polylactide by in-situ reactive compatibilization with an isosorbide-containing copolyester

Abstract

Polylactide (PLA)/poly(1,4-cyclohexanedimethylene isosorbide terephthalate) (PEICT) blends were prepared by melt processing. Oligomer, with multiple epoxy functional groups, were introduced as a reactive compatibilizer to enhance interfacial adhesion of the two blend components. The reaction between the reactive compatibilizer and blend components was confirmed by infrared spectroscopy and rheological analysis. The improved compatibility of the blends reduced interfacial tension between polymer components, yielding a co-continuous phase morphology from a sea-island morphology. The added PEICT improved the impact strength of PLA to 22.5 kJ/m(2) at 40% loading. After compatibilization and the impact strength of PLA/PEICT blends increased to 44.1 kJ/m(2), showing that increased interfacial adhesion improved energy transfer between the polymers.