Synthesis and characterization of poly(3-hexylthiophene)-grafted polyvinyl alcohol

Abstract

Poly(3-hexylthiophene) (P3HT) was grafted onto the surface of polyvinyl alcohol (PVA) through simple chemical oxidative polymerization with FeCl3 in three different solvents, namely acetonitrile, chloroform, and hexane. Among these solvents, hexane best stimulated the grafting of P3HT to PVA; the modified PVA was obtained with a high grafting ratio and molecular weight. The resultant modified PVA was characterized by Fourier-transform infrared (FT-IR), ultraviolet visible (UV–vis), fluorescence spectroscopies, X-ray diffraction (XRD), as well as thermo gravimetric analysis (TGA), contact angle and field emission scanning electron microscopy (FE SEM) coupled with energy dispersive X-ray (EDX) analysis. The presence of P3HT on the PVA surface imparted hydrophobic character, and the PVA modified with P3HT exhibited enhanced electrical conductivity compared to PVA. The peaks in the XRD spectrum of PVA were less intense following P3HT grafting to the PVA surface, and the build-up of P3HT on the PVA surface led to the appearance of absorption and emission peaks in the visible wavelength range. PVA was less stable following grafting by P3HT and the existence of elemental sulfur originating from P3HT was detected on the modified PVA by FE-SEM elemental mapping.