Effect of aliphatic diacyl adipic dihydrazides on the crystallization of poly(lactic acid)

A series of aliphatic diacyl adipic dihydrazides (ADHs) with different alkyl moieties were synthesized by the reaction between adipic dihydrazide and acyl chloride. Then these ADHs were solution blended with PLA respectively and were evaluated as nucleating agents. Through the investigation of nonisothermal and isothermal crystallization, it was found that both the crystallization rate and the crystallinity of PLA could be enhanced by adding only 1 wt % of ADHs. Especially for ADH-Oc (ADH-Octyl), the crystallization rate of PLA increased about 4 times at 105°C. Optical morphology showed that and the size of PLA spherulites decreased and the nucleation density increased with the existence of ADH-Oc. Meanwhile, the crystal structure of PLA were not discerniblly affected after the addition of ADHs as found by wide-angle X-ray diffraction. Thus, this study suggested these ADHs compounds are simple and potential nucleating agents to enhance crystallization ability of PLA. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42028.