Role of Bis‐Amide Nucleator in Enhancing the Crystallization and Mechanical Properties of Polylactide/Poly(Vinyl Acetate) Blends

ABSTRACT The impact of the nucleating agent N ‐(3‐(hydrazyl) benzoyl)‐1‐naphthylhydrazide (HBNA) on the crystallization behavior, optical characteristics, mechanical and shape memory properties of polylactide (PLA)/polyvinyl acetate (PVAc) blends was systematically investigated. The addition of HBNA maintained the homogeneity of PLA/PVAc blends, resulting in an evident glass transition temperature ( T g ) between PLA and PVAc. Both non‐isothermal and isothermal crystallization rates were accelerated, accompanied by a consistent Avrami index of approximately 3, indicative of three‐dimensional crystal growth. The existence of HBNA reduced the dimension of PLA crystals and increased nucleation density by initiating crystal bundle formation. As a result, the transmittance was increased, and thus the haze of annealed samples was decreased, with the optimal performance at 0.5 wt% HBNA content after annealing at 120°C. The addition of PVAc contributed to both the tensile strength and modulus of PLA, which were further bolstered by the incorporation of HBNA. Moreover, the shape memory performance of PVAc20 was well modified by HBNA, particularly for the sample with 0.5 wt% HBNA, where the recovery ratio and fixation ratio peaked at 98.7% and 97.0%, respectively. The mechanisms underlying the influence of HBNA on the microstructure and performance of PLA/PVAc blends were thoroughly analyzed.