Polyaniline stabilized magnetite nanoparticles reinforced epoxy nanocomposites and flame retardant epoxy resin nanocomposites

Magnetic epoxy polymer nanocomposites (PNCs) reinforced with magnetite (Fe3O4) nanoparticles (NPs) have been prepared at different particle loading levels. The particle surface functionality tuned by conductive polyaniline (PANI) is achieved via a surface initiated polymerization (SIP) approach. The effects of nanoparticle loading, surface functionality and temperature on both the viscosity and storage/loss modulus of liquid epoxy resin suspensions and the physicochemical properties of the cured solid PNCs are systematically investigated. The glass transition temperature (Tg) of the cured epoxy filled with the functionalized NPs has shifted to the higher temperature in the dynamic mechanical analysis (DMA) compared with that of the cured pure epoxy. Enhanced mechanical properties of the cured epoxy PNCs filled with the functionalized NPs are observed in the tensile test compared with that of the cured pure epoxy and cured epoxy PNCs filled with as-received NPs. The uniform NP distribution in the cured epoxy PNCs filled with functionalized NPs is observed by scanning electron microscope (SEM). These magnetic epoxy PNCs show the good magnetic properties and can be attached by a permanent magnet. Enhanced interfacial interaction between NPs and epoxy is revealed in the fracture surface analysis. The PNCs formation mechanism is also interpreted from the comprehensive analysis based on the TgA, DSC and FTIR in this work.;Untreated epoxy is highly inflammable, which significantly limits its applications. Therefore, the modification of epoxy in order to improve its flame retardancy is an important issue and needs be addressed. Epoxy resin nanocomposites reinforced with silica nanoparticles have been prepared at different nanoparticle loading levels. The surface functionality of the silica nanoparticles is manipulated by the phosphoric acid (H3PO4) doped conductive polyaniline (PANI) via a surface initiated polymerization (SIP) method. The improved glass transition temperature (T g) and enhanced mechanical properties of the cured epoxy resin nanocomposites filled with the functionalized silica nanoparticles are observed compared with those of the cured pure epoxy resin. The flammability and thermal stability behaviors of these nanocomposites are evaluated using microscale combustion calorimeter (MCC) and thermogravimetric analysis (T gA). The heat release rate (HRR) peak of the epoxy filled with functionalized silica nanoparticles is observed to decrease dramatically with increasing functionalized silica particle loadings, indicating a flame retardant performance from the phosphoric acid doped PANI.