Physical and mechanical properties of poly(L-lactic acid) nucleated by dibenzoylhydrazide compound

Benzoylhydrazide compounds were evaluated as a nucleating agent for poly((L)-lactic acid) (PLA). From the results of the differential scanning calorimetry, octamethylenedicarboxylic dibenzoylhydrazide (OMBH) was found to be most effective for acceleration of PLA crystallization under higher cooling rate of -50 degrees C min(-1). PLA with OMBH of 1 wt % exhibited very short crystallization half-time with wide range of isothermal temperature from 90 to 130 degrees C. The molding cycle time of PLA with OMBH in injection molding was less than 3 min, and the cooling time was one-third of ethylenebis(12-hydroxystearylamide) /talc system as a nucleating agent. Physical and mechanical properties improved extremely, and the heat distortion temperature of 124 degrees C, flexural modulus of 4.1 GPa, and Izod impact strength of 7.9 kJ m(-2) were achieved. This indicates that the utilization of OMBH makes it possible to extend the application range of PLA as automotive parts and electric appliances, which require higher heat resistance and stiffness. (C) 2006 Wiley Periodicals, Inc. J Appl Polyrn Sci 103: 244-250, 2007