Toughening of poly(lactic acid) with the renewable bioplastic poly(trimethylene malonate)
ABSTRACT
The aim of this work was to enhance poly(lactic acid)'s (PLA) flexibility and ductility by blending it with another bioplastic. Poly(trimethylene malonate) (PTM), developed as part of this study, was synthesized from 1,3-propane diol and malonic acid via melt polycondensation. Blend films of PLA and PTM were prepared by solvent casting from chloroform. Differential scanning calorimetry and thermogravimetric analysis were used to show shifted phase transitions and a single glass-transition temperature, indicating miscibility of PTM in the blend films. Morphology and mechanical characterizations of the PLA/PTM blend films were performed by atomic force microscopy using a quantitative nanomechanical property mapping mode, tensile testing, and scanning electron microscopy. Miscible blends exhibited Young's modulus and elongation at break values that can significantly extend the usefulness of PLA in commercial applications. The blending of PTM with PLA resulted in films with a 27-fold increase in toughness compared with neat PLA film. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40888.




