Enhanced microwave processing of epoxy nanocomposites using carbon black powders

Flexural strength and thermal properties of carbon black nanoparticle reinforced epoxy composites obtained from waste tires

In this study, both mechanical and thermal properties of epoxy@carbon black nanocomposite (EP@CB-NC) produced by adding 0.3, 0.6, and 1% by weight carbon black nanoparticle obtained from waste automobile tires to epoxy were investigated. The chemical and structural composition of EP@CB-NC was characterized by Fourier transform infrared spectroscopy (FTIR) in scanning electron microscopy (SEM). In addition, simultaneous thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC) experiments, and thermal conductivity measurements were performed to determine the thermal stability of the prepared EP@CB-NC. Increasing the strength of modified epoxy composites by means of nanoparticles obtained with waste may pave the way for obtaining new materials with clean environment and superior properties. The mechanical and thermal properties were improved by adding carbon black to the bare samples.

Quantitative evaluation of the non-thermal effect in microwave induced polymer curing

Microwave irradiation is one of the most effective strategies to accelerate the curing of resin. However, the mechanism is still unclear. The debates mainly focus on how to quantitatively evaluate the ‘non-thermal’ effect of the microwave. In this work, the non-thermal effect on DGEBA with amine (D230) and anhydride (MHHPA) hardeners respectively was evaluated via an isothermal microwave curing reactor. The ‘thermal effect’ caused by the microwave was peeled off accurately. Iso-conversional kinetic analysis was performed based on the reaction extent from the real time FTIR spectrum, and the apparent activation energy (E_a) was calculated for the quantitative evaluation of the microwave non-thermal effect. The influence caused by the polarized functional groups, reaction temperature and the transition state were explored, and the microwave non-thermal effect on the mechanical performance of the cured thermosets was evaluated. Results indicated that the microwave non-thermal effect was able to reduce the E_a and accelerate the curing speed of epoxy resin. At the same time, the final curing extent was increased when the non-thermal effect of microwave was induced leading to enhanced mechanical and thermal performance.

The non-thermal effect of microwave was evaluated quantitatively by the calculation of activation energy and pre-exponential factors with an isothermal microwave.