Polymerization kinetics of boron carbide/epoxy composites

• Conversion degree and rate reaction of the curing reaction increase with temperature.
• At low temperature, the particles exhibit catalytic effect, similar to the OH groups.
• At high temperature, B4C micro-particles increase the n-order rate reaction.
• The diffusion constant diminishes with temperature for all the studied materials.
• The autocatalytic reaction is favored by the effect of 6% nanoparticles.

This study employs Differential Scanning Calorimetry (DSC) technique and focuses on the curing kinetics and the activation energy of the commercial epoxy resin (which cures at room temperature for 12 h) filled with boron carbide particles (B4C) in different amount (6 and 12 wt%) and particle size (60 nm, 7 and 23 μm). An isothermal dwell at different temperatures (25, 35 and 50 °C) was used for 180 min. Thereafter, the temperature is increased by 5 °C min−1 up to 200 °C to complete the curing process. Conversion degree is calculated by combining both methods.The kinetic constant and the reaction order are calculated using Kamal's equation with diffusion control. Consequently, the activation energy is computed assuming Arrhenius’ equation.The results show a significant influence of the temperature on the reaction mechanism. Furthermore, polymerization kinetics is affected by B4C additions depending on the amount and size of the added particles.

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