Covalent functionalization of MWCNT with PHBV chains: Evaluation of the functionalization and production of nanocomposites

Abstract

Multi-walled carbon nanotubes (MWCNT) were covalently functionalized with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) chains, through esterification reaction. Thereunto, pristine MWCNT (P-MWCNT) were oxidized (MWCNT-COOH) and posteriorly reduced (MWCNT-OH). MWCNT-OH were used to produce MWCNT functionalized with PHBV chains (MWCNT-PHBV). All functionalized MWCNT were used to produce PHBV nanocomposites films with 0.5 wt% by solution casting. Functionalization was evaluated by Raman spectroscopy and thermogravimetry (TGA), and nanocomposites were characterized by X-Ray Diffraction and contact angle measurements. Results showed that functionalization with PHBV chains was successfully performed and that the polymer chains were attached to MWCNT surface, as expected. IG/ID ratio obtained from Raman curves was reduced from 1.34 to P-MWCNT to 0.90 to MWCNT-PHBV. TGA confirmed the presence of PHBV on MWCNT surface, showing a peak at 236°C on the first derivative curve. Crystallite size of PHBV on 020 plane was 11% larger with introduction of MWCNT in nanocomposites. Contact angle was increased with the introduction and functionalization of MWCNT. POLYM. COMPOS., 40:288–295, 2019. © 2017 Society of Plastics Engineers.