Effect of bismaleimide reactive extrusion on the crystallinity and mechanical performance of poly(lactic acid) green composites

摘要

Poly(D-,L-lactic acid) (PDLA) and PDLA-wood pulp fiber injection molded composites were modified with very small amounts (< 1 wt %) of N′-(o-phenylene)dimalemide and 2,2′-dithiobis(benzothiazole) by reactive extrusion and their resulting mechanical and thermal properties characterized. The modification produced an increase in the percent crystallinity (X _c), heat deflection temperature (HDT), impact energy, tensile strength, and modulus in PDLA. A significant reduction in the melting temperature (T _m) and an increase in the thermal resistance (T _(max)) were also found. Fourier-Transform infrared spectroscopy (FTIR) suggests the creation of hydrogen bonds, a thiol ester and/or ester bond during the modification. Reactive extrusion of commercially available poly(lactic acid) (PLA) by means of N′-(o-phenylene)dimalemide and 2,2′- dithiobis(benzothiazole) provides a low cost and simple processing method for the enhancement of the properties of this biopolymer.