Effect of hydroxyl and carboxyl-functionalized carbon nanotubes on phase morphology, mechanical and dielectric properties of poly(lactide)/poly (butylene adipate-co-terephthalate) composites

Authors：Wang, Ping^*; Gao, Shang; Chen, Xinliang; Yang, Li; Wu, Xiusheng; Feng, Shaojie; Hu, Xianhai; Liu, Jin; Xu, Pei^*; Ding, Yunsheng

Source：International Journal of Biological Macromolecules, 2022, 206: 661-669.

DOI：10.1016/j.ijbiomac.2022.02.183

• Poly(lactide)
• Carbon nanotubes
• Dielectric properties

A series of poly(lactide)/poly(butylene adipate-co-terephthalate) (PLA/PBAT) composites containing different types of multi-walled carbon nanotubes (CNTs) such as hydroxyl and carboxyl-functionalized CNTs were fabricated using the melt blending method. The multifunctional epoxy oligomer (ADR) was selected as a chain extender in order to enhance the compatibility between PBAT and PLA. It was revealed that the addition of ADR could induce CNTs-OH to locate at the PLA/PBAT interface. But the inhibition effect of CNTs-COOH on chain extension reaction in PLA/PBAT blend system led to a decrease in the interaction force between PLA and PBAT owing to the high efficiency of the reaction between CNTs-COOH and ADR. The epsilon' of PLA/PBAT/4CNTs-OH composite was greater than that of PLA/PBAT/4CNTs-COOH composite because of the strong interaction between fillers and polymer matrix in PLA/PBAT/4CNTs-OH composite. The PLA/PBAT/4CNTs-OH composite showed a high epsilon' (24.9) and a low tan delta (0.23), respectively. The adjacent CNTs-OH could act as assemble microcapacitors electrodes and the polymer acted as a dielectric to, which greatly increased the interfacial polarization. The PLA/PBAT/4CNTs-OH composite has excellent mechanical and dielectric properties.