Poly(lactic acid)/natural rubber/cellulose nanocrystal bionanocomposites. Part II: Properties evaluation

•The localization of the nanocrystals in the blend was controlled as a function of their modification.•The location and affinity of the fillers play a vital role on the composite properties.•“Taylor-made” properties were obtained by choosing the processing and chemical modification.•The nanomaterials completely disintegrated after one month in compost. The crystallization, mechanical and biodegradation properties of poly(lactic acid)/natural rubber/cellulose nanocrystals (CNC) bionanocomposites were evaluated. Three types of CNC were used in this study, one unmodified (CNC), long alkyl chain grafted CNC (C18-g-CNC) and PLA grafted CNC (PLA-g-CNC). The CNC modifications determined the affinity of the nanocrystals toward the polymers and reflected on the ultimate properties. Interestingly, PLA-g-CNC acted as a nucleating agent for the PLA matrix in the bio-based PLA/NR blend. Good mechanical properties were reported, as the bionanocomposites maintained a high elongation at break for a concentration up to 3wt.% of cellulose nanocrystals. Moreover, the disintegration study confirmed that the materials completely disintegrated after one month in compost.