Effects of Amino Hyperbranched Polymer-Modified Carbon Nanotubes on the Crystallization Behavior of Poly (L-Lactic Acid) (PLLA)

Bofan Shen; Shulai Lu; Chunfu Sun; Zhenbiao Song; Fuyi Zhang; Jian Kang; Ya Cao; Ming Xiang

doi:10.3390/polym14112188

Effects of Amino Hyperbranched Polymer-Modified Carbon Nanotubes on the Crystallization Behavior of Poly (L-Lactic Acid) (PLLA)

Polymers (Basel). 2022 May 28;14(11):2188. doi: 10.3390/polym14112188.

Authors

Bofan Shen¹, Shulai Lu^{2

3}, Chunfu Sun^{2

3}, Zhenbiao Song^{2

3}, Fuyi Zhang¹, Jian Kang¹, Ya Cao¹, Ming Xiang¹

Affiliations

¹ State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu 610065, China.
² Synthetic Resin Factory of Jilin Petrochemical Company, PetroChina, Jilin 132021, China.
³ PetroChina ABS Resin Technology Center, Jilin 132021, China.

Abstract

Poly-L-lactic acid (PLLA) is an environmentally friendly and renewable polymer material with excellent prospects, but its low crystallization rate greatly limits its application. Through the amidation reaction between amino hyperbranched polymer (HBP N103) and carboxylated carbon nanotubes (CNTs), CNTs-N103 was obtained. The modification was confirmed by Fourier-transform infrared (FTIR) spectroscopy, X-ray electron spectroscopy (XPS) and thermogravimetric analysis (TGA). Using transmission electron microscopy (TEM), we observed the changes on the surface of modified CNTs. PLLA/CNT composites were prepared, and differential scanning calorimetry (DSC) was used to investigate the crystallization behavior of the composites. The results showed that the addition of CNTs could greatly improve the crystallization properties of PLLA; at the same concentration, the modified CNTs had better regulation ability in PLLA crystallization than the unmodified CNTs. Moreover, in the concentration range of 0.1-1%, with the increase in HBP concentration, the ability of CNTs-N103 to regulate the crystallization of PLLA increased as well. Wide-angle X-ray diffraction (WAXD) once again proved the improvement of the crystallization ability. The results of polarized optical microscopy (PLOM) showed that the number of nucleation points increased and the crystal became smaller.

Keywords: PLLA; carbon nanotubes; crystallization behavior; hyperbranched polymer; surface modification.

Grants and funding

This research was funded by National Natural Science Foundation of China (NSFC, Grant Nos. 51503134, 51702282) and State Key Laboratory of Polymer Materials Engineering (Grant No. SKLPME 2017-3-02), and the APC was funded by National Natural Science Foundation of China (NSFC, Grant No. 51702282).