Synthesis of dodecanedioic dihydrazide derivative to enhance the crystallization properties and fluidity of PLLA Available to Purchase

This study investigated the effect of a new organic nucleating agent, N,N′-dodecanedioic bis(4-phenylbutyric acid) dihydrazide (BPADH), on the crystallization and melting behavior, thermal stability and fluidity of poly(l-lactic acid) (PLLA). The melt crystallization demonstrated that BPADH could serve as a heterogeneous nucleating agent for improving the crystallization of PLLA, and 0·5 wt% BPADH caused PLLA to exhibit the sharpest non-isothermal crystallization peak and the highest crystallization peak temperature. Additionally, an increase in the cooling rate was found not to be beneficial for the melt crystallization of PLLA. Isothermal crystallization measurement showed that the crystallization half-time (t _1/2) of PLLA/BPADH significantly decreased compared with that of virgin PLLA, and PLLA/2% BPADH had the minimum t _1/2 value of 69·6 s. The difference in melting behavior between PLLA/BPADH samples further confirmed the promoting role of BPADH in the crystallization of PLLA, and the melting behavior was affected by the heating rate and crystallization temperature, and the double-melting peaks were attributed to the melting recrystallization. Although BPADH had a minimal effect on the thermal decomposition profile of PLLA, the presence of BPADH led to a drop in its thermal stability. Furthermore, the increasing addition of BPADH to the PLLA matrix significantly improved the fluidity of PLLA.