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Poly(furfuryl alcohol) bioresin (PFA) was synthesized and utilized through two distinct alloying strategies. It was crosslinked by a bismaleimide (BMI) via a Diels-Alder (DA) reaction. The novel PFA-BMI polyadduct network was spectrally, thermally, and thermo-mechanically characterized and its thermally repeatable self-healing behavior was visually established. The network showed a high pyrolytic thermostability (char yield 51% at 600 8C). PFA was also used for modification of epoxy-novolac resin (EP). EP hybrid resins containing 5, 10, and 15 wt % of PFA were cured by a polyamine hardener. Despite of different curing mechanisms of the two resins, PFA had no effect on EP curing behavior as revealed by differential scanning calorimetry, which proved homogeneous formation of the thermosets. PFA at the composition of 15 wt % improved tensile properties and toughness of EP, so that it almost doubled tensile modulus and elongation at break. However, PFA slightly deteriorated flexural properties of EP. PFA also decreased T g of EP, with a maximum decrease of 22 8C. Besides, PFA disfavored initial thermostability of EP, but improved its pyrolytic char yield. In conclusion, PFA can be beneficial from smart materials to toughen hybrid epoxy thermosets with potential applications in composites, adhesives, and surface coatings.

This article presents a method for the electrochemical preparation of a coating of nickel-silica nanocomposites on a carbon steel substrate. The incorporation of hydrophilic silica particles into the Ni composite coating during co-electrodeposition is so difficult due to the small size and the hydrophilicity of SiO 2 particle, generally less than 2 v% of silica is incorporated into the composite at different current densities, agitation speeds and silica concentrations. The effect of the presence of four surfactants, namely cocamidopropyl betaine (CAPB), decylglycoside (DG), cetyltrimethyl ammonium chloride (CTAC) and ammonium lauryl ether sulfate (ALES), on overcoming this problem was investigated in this research, and the surfactants were found to greatly influence the surface charge of silica, silica incorporation percentage and the microstructure of the composite. In fact, upon increasing the internal stresses, the products prepared in the presence of CAPB and DG were found to crack to some degree. CTAC was found to lead to entrapment mode silica co-deposition in the Ni coating. Furthermore, the addition of ALES into an electrolyte bath negatively supercharged silica surfaces and increased silica dispersion, which led to a dramatic increase in the silica incorporation percentages to around 14 v%. The results showed that Ni-SiO 2 composites prepared in the presence of ALES had better corrosion resistance, hardness and wear properties.

Polystyrene/polyolefin elastomer (PS/POE) (90/10 and 80/20 wt/wt) blends containing 1, 3, and 5 phr halloysite nanotubes (HNTs) in the presence and absence of a compatibilizer (polypropylene-graft-maleic anhydride) were prepared using the meltmixing technique. Scanning electron microscopic studies confirmed a matrix-droplet morphology. Energy dispersive spectroscopy (EDS) mapping indicated that the blends containing 5 phr HNTs possessed aggregates, while no agglomeration was observed after incorporating 5 phr compatibilizer. Thermal stability and thermal degradation kinetics were investigated using thermogravimetry analysis (TGA). The results demonstrated that the PS/POE blend (90/10) containing 5 phr HNTs and compatibilizer (90/10/5/5) has the best thermal stability. Different methods such as Friedman, Flynn-Ozawa-Wall, and Kissinger-Akahira-Sunose were applied to calculate the degradation activation energy. The 90/10/5/5 nanocomposite exhibited the highest degradation activation energy, indicating that this sample is more difficult to degrade thermally than other samples. A correlation was obtained between the activation energy and the intensity of the TGA-fourier-transform infrared spectroscopy (TGA/FTIR) peaks of the evolved products. The Criado method was used to determine the changes in the thermal degradation mechanism of the samples.

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Effects of multi-walled carbon nanotubes (MWNTs) on flame retardation as well as thermal stabilization efficiency of two phosphorus-containing flame retardant systems i.e., ammonium polyphosphate/pentaerythritol (APP/PER) and red phosphorus (RP) in polypropylene (PP) have been investigated. Limiting oxygen index, thermo-gravimetric analysis, melt flow index, and tensile tests have been performed in this study. Moreover, the structure of the nanocomposites was characterized by scanning electron microscopy (SEM). SEM images revealed good dispersion of fillers in the polymer matrix. Furthermore, it was shown that the addition of MWNTs alone at a minimum loading level of 4 wt% improves thermal stability of PP considerably without any undesirable effect on its flow-ability and mechanical properties. Moreover, addition of MWNTs alone resulted in a slight improvement of flammability of the polymer. However, comparison between thermal stability and flame retardancy of PP samples containing a combination of MWNTs and APP/PER or RP and those of the samples containing APP/PER or RP alone proved that MWNTs interfere with thermal stabilization and flame retardation efficiency of both APP/PER and RP in the polymer.

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