A green physical approach to compatibilize a bio-based poly (lactic acid)/lignin blend for better mechanical, thermal and degradation properties

The poly (lactic acid) (PLA) and lignin (LG) are promising candidates to develop green plastic. However, the blending of lignin with PLA leads to incompatible blend with poor mechanical and thermal properties. Hence, in the present work, a green and simple approach was employed to make PLA/LG compatible blend with high lignin percentage (5 and 20%). The E-beam irradiated lignins having different absorbed dosages were blended with two different percentages 5 and 20 with PLA in the presence of 3 phr triallyl isocyanurate (TAIC). FTIR and DSC studies have confirmed the formation of PLA-TAIC-Lignin crosslinked structures which act as an interface between the dispersed lignin phase and PLA matrix and hence improved their compatibility in the resulting blend. The compatibility of resulting blends was further validated by the morphology study, Glass transition temperature (Tg) behavior of PLA/LG blends and by observing the significant improvement in the mechanical, thermal and hydrolytic degradation properties. [Display omitted] •The in-situ formed PLA-TAIC-Lignin crosslinked structures act as an interface between dispersed lignin phase and PLA matrix.•PLA/E-beam irradiated lignin blends show significant improvement in the mechanical properties as compared to PLA/LG blends.•The blending of E-beam irradiated lignin also restricts the hydrolytic degradation of PLA.•The low E-beam irradiation dose (i.e. 30 kGy) is suitable to improve the compatibility of PLA/LG blend.