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