Evaluation of poly(lactic acid) and sugar beet pulp green composites

Poly(lactic acid) (PLA) and sugar beet pulp (SBP) were compounded by twin-screw extrusion and injection molded into composite forms. Specific mechanical energy decreased with the addition of SBP during processing. PLA-SBP composites retained more tensile strength than expected based on the Nicolais-Narkis model especially at high levels of SBP suggesting adhesion between SBP and PLA. The thermal characteristics of PLA were not affected by thermo-mechanical processing or by the incorporation of SBP up to 30% weight basis. PLA and PLA-SBP composites had similar tensile properties to other thermoplastic resins and may be used as a cost-competitive replacement.