Examination of a Biobased Carbon Nucleating Agent on Poly(lactic acid) Crystallization

This article assesses the performance of a biobased carbon as a nucleator using common techniques to stimulate poly(lactic acid) crystallization and enhance the thermal stability of PLA during injection molding. The combination of a biodegradable plasticizer, poly(ethylene glycol) (PEG), along with biobased carbon-rich pyrolyzed biomass char residue and an industrially available microcrystalline talc, were tested for nucleating agent capabilities at additions of 10 wt%. Differential scanning calorimetry (DSC) data demonstrated that the inclusion of the plasticizer could increase the PLA crystalline content with further improvements when nucleating agent was present. With a higher mold temperature, the PLA crystallinity surpassed 40% for the multicomponent formulations. The thermomechanical properties including heat deflection temperature exhibited performance above 100 degrees C, while the coefficient of thermal expansion was lowered. Optical analysis of the crystal structure showed increased crystallization rate with plasticizer and nucleating agents. The mechanical properties and morphology characteristics are also presented.