Core-shell structure of carbon nanotube nanocapsules reinforced poly(lactic acid) composites

In this study “core-shell” structure of carbon nanotube (CNT) nanocapsules, which aimed at toughening poly(lactic acid) (PLA) were designed by a synthetic strategy consisting of two reaction steps. The first step was to produce reactive chemical bond to bridge CNTs and PLA. So coupling agent KH570 was used to modify CNTs (CNTs-KH570). The second step involved ring open polymerization of lactide (LA). Lactide polymerized into PLA under catalysis and meanwhile grafted onto CNTs via KH570 (CNTs-KH570-PLA). Thus, the CNTs nanocapsules were constructed. Fourier transform infrared spectroscopy (FTIR) showed coupling agent KH570 succeeded in linking CNTs and PLA during LA polymerization. In addition, scanning electron microscopy (SEM) and transmission electron microscope (TEM) indicated CNTs dispersed homogeneous in PLA matrix and the compatibility between them was excellent. The mechanical test also suggested the designed nanocapsules had good effect on toughening PLA composites. This research found one economical and simple way to improve PLA mechanical properties and further broaden its application in many fields. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44919.