(56d) New Biocomposite Materials from Poly(lactic acid) Blended with Poly(ethylene glycol) and Biobased Carbon

Biobased and biodegradable polymeric materials continue to be a fundamental step towards achieving an environmentally-friendly society. Therefore, poly(lactic acid) (PLA) being the most common biopolymer in the marketplace today is useful as the base component in the formation of future compostable consumer products. The current downsides of PLA being its toughness and low thermal stability are the key reason for its limited applications and a major focus for research and optimization.

In this study, poly(lactic acid) based composites prepared through melt blending with poly(ethylene glycol) (PEG) and biobased carbon were tested for their thermal and mechanical properties. The addition of poly(ethylene glycol) acted as a plasticizer, via greater chain mobility and as a crystallization promoter, by the reduction in energy necessary for chain folding during spherulite formation. The biobased carbon was beneficial in establishing nucleation sites for the poly(lactic acid) upon cooling, increasing the crystallization relative to the neat material. The poly(D-lactic acid) (PDLA) was essential in the development of the PLA stereocomplex between the L- and D- enantiomers. The crystallinity of the polymeric composites was elevated when PEG was included in the system. The heat deflection temperature of the poly(lactic acid) with PEG and PDLA was hindered by the low glass transition temperature of the samples. The mechanical properties of the composites samples are still under characterization and will be incorporated into the results prior to event. It is expected that the tensile strength and Youngâ??s modulus will be lowered with the inclusion of poly(ethylene glycol), while the elongation at break will be increased. Further investigation of the nothched Izod impact strength will be conducted and optical microscopy for visual representations of the crystallization of the composites. Also, scanning electron microscopy (SEM) will be used to determine the morphology and dispersion of the components throughout the composite in order to correlate all findings.

Acknowledgment: This research is financially supported by (1) the Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA)-New Directions Research Program (Project # 049528) and (2)  the Ontario Ministry of Economic Development and Innovation (MEDI), Canada, Ontario Research Fund, Research Excellence Round 4 program (ORF-RE04) (Project # 050231 and 050289).