Effect of polyethylene glycol modified MWCNTs-OH on the crystallization of PLLA and its stereocomplex

Poly (L-Lactide) (PLLA) and PLLA/Poly (D-Lactide) (PLLA/PDLA) blends were blended with different contents of multi-walled carbon nanotubes-graft-polyethylene glycol (PEG) (MWCNTs- g -PEG), which was synthesized by esterifying. The infrared peak of MWCNTs- g -PEG at 1730 cm −1 is caused by the carbonyl (C = O) stretching vibration, and the peak at 1109 cm −1 is attributed to the stretching vibration of C–O–C, confirming that the grafted product is successfully synthesized. When compared to MWCNTs-OH, the synergistically effects of heterogeneous nucleation of MWCNTs- g -PEG and plasticizing of PEG in MWCNTs- g -PEG strengthen the crystallization ability of PLLA matrix much more effectively. Furthermore, the addition of MWCNTs- g -PEG to PLLA/PDLA inhibits the formation of homopolymer crystals (HC), while promoting the formation of stereocomplex (SC).