P.M. Visakh

Thermal Degradation of Polymer Blends, Composites and Nanocomposites

This chapter deals with a brief account of thermal degradation of polymer-based blends, composites and nanocomposites. Different synthesising, preparation and characterisation methods of thermal degradation of polymer-based blends, composites and nanocomposites are discussed. Finally the applications, new challenges and opportunities for these thermal degradation of polymer-based blends, composites and nanocomposites are discussed.

Thermal and Mechanical Characteristics of Polymer Composites Based on Epoxy Resin, Aluminium Nanopowders and Boric Acid

The epoxy polymers are characterized by low thermal stability and high flammability. Nanoparticles are considered to be effective fillers of polymer composites for improving their thermal and functional properties. In this work, the epoxy composites were prepared using epoxy resin ED-20, polyethylene polyamine as a hardener, aluminum nanopowder and boric acid fine powder as flame-retardant filler. The thermal characteristics of the obtained samples were studied using thermogravimetric analysis and differential scanning calorimetry. The mechanical characteristics of epoxy composites were also studied. It was found that an addition of all fillers enhances the thermal stability and mechanical characteristics of the epoxy composites. The best thermal stability showed the epoxy composite filled with boric acid. The highest flexural properties showed the epoxy composite based on the combination of boric acid and aluminum nanopowder.

Effect of Boric Acid on Volatile Products of Thermooxidative Degradation of Epoxy Polymers

The polymeric materials are characterized by high flammability. The use of flame retardants in order to reduce the flammability of polymers can lead to the formation of toxic gaseous products under fire conditions. In this work we studied the effect of boric acid on the volatile products of thermooxidative degradation of epoxy polymers. The comparative investigations were carried out on the samples of the unfilled epoxy resin and epoxy resin filled with a boric acid at percentage 10 wt. %. The analysis of the volatile decomposition products and thermal stability of the samples under heating in an oxidizing medium was performed using a thermal mass-spectrometric analysis. It is found that the incorporation of boric acid into the polymer matrix increases the thermal stability of epoxy composites and leads to a reduction in the 2-2.7 times of toxic gaseous products

Effect of electron beam irradiation on thermal and mechanical properties of epoxy polymer

This study investigates the thermal and mechanical properties of epoxy polymer after exposure to different doses of electron beam irradiation. The epoxy polymer was prepared using epoxy-diane resin ED-20 cured by polyethylenepolyamine. The irradiation of the samples was carried out with doses of 30, 100 and 300 kGy. The effects of doses on thermal and mechanical properties of the epoxy polymer were investigated by the methods of thermal gravimetric analysis, tensile test, and dynamic mechanical analysis. The thermal properties of the epoxy polymer slightly increased after irradiation at the heating in air. The tensile strength and Youngs modulus of the epoxy polymer increased by the action of electron beam up to dose of 100 kGy and then decreased. The elongation at break decreased with increasing the irradiation dose.

Effect of zeolite modification on mechanical properties of epoxy composites

The epoxy composites filled with unmodified zeolite of 5 and 10 wt. % and modified natural zeolite of 10 wt. % were prepared. The modification of zeolite with nanofibers of aluminum oxyhydroxide was carried out. Aluminum oxyhydroxide nanofibers were produced at the heating and oxidation of aluminum powder with water. The tensile properties of all the samples were studied. The mechanical properties of modified zeolite based composite were significantly increased compared with that of unmodified zeolite based composite.

Characterization of copper nanopowders after natural aging

Copper nanopowders after storage under natural conditions can oxidize and change their properties. In this work, the phase composition, morphology and thermal properties of copper nanopowders after natural aging of 10 years were studied. The copper nanopowders were produced by the method of electrical explosion of wires in different gaseous ambient: argon and carbon dioxide. The nanopowders were characterized by X-ray diffraction, thermal analysis, scanning electron microscopy, Fourier transform infrared spectroscopy. The content of copper oxides phases was found to be increased in comparison with freshly synthesized powders. This transformation results in the change of the thermal characteristics of the nanopowders. The effect of the synthesis conditions on the composition and thermal characteristics was shown.