Preparation, characterization and properties of PMMA/NiO polymer nanocomposites

Abstract

PMMA/NiO polymer nanocomposites (PNCs) were prepared. NiO nanoparticles (NPs) were prepared from reaction of NiCl2·6H2O with caustic soda, and then calcination of the precipitate obtained at 300 °C for 2 h. Surface of NiO NPs was modified by oleic acid and confirmed through lipophilic degree (LD). The results revealed that LD increased with the rising amount of modifier up to 5 wt% Optimum modification was obtained in 65 °C and 2 h for reaction time. The modified NPs were dispersed in methylmethacrylate (MMA), and PMMA/NiO PNCs were prepared via emulsion polymerization. The NiO NPs, modified NPs and PMMA/NiO PNCs were characterized by XRD, FT-IR, SEM and EDX. The average crystallite sizes of NiO were calculated 35 nm from XRD patterns. The results of EDX analysis and FT-IR spectra showed that chains of oleic acid have been successfully grafted on surface of NiO NPs. Morphological observation revealed that NiO NPs were embedded homogeneously in the inner part of PMMA. Thermal stability of PMMA/NiO PNCs was studied using techniques of TGA and DSC. Compared to PMMA, PMMA/NiO PNCs prepared by this method display glass transition temperature that are up to 10 °C higher and thermal degradation temperature that are up to 30 °C higher. The photocatalytic activity of NiO NPs, modified NPs and PMMa/NiO PNCs was investigated in the degradation of methyl orange under UV radiation. The results showed that photocatalytic degradation percentage (PDP) of methyl orange decreases when NiO NPs modified by oleic acid and/ or grafted on PMMA.