A kinetic study of thermal degradation of non-metallic part of printed circuit boards for the combined effect of particle size and catalyst

Abstract

ABSTRACT After the successful removal of metals from printed circuit boards either through a physical or chemical process, epoxy resins are thermosetting plastics left over for landfilling. To overcome landfilling, thermal degradation of this resin was done under different particle sizes with varying catalyst concentrations. A series of thermogravimetric experiments were carried out using ZSM-5 as the catalyst. To study kinetics parameters’ mass loss with temperature was divided into 3 zones 120–240°C, 240–360°C and 360–650°C. To determine activation energy and the order of reaction, the Coats and Redfern method was used. Experimental data in all three zones were found in agreement with the Coats and Redfern method. ZSM-5 was found to be reducing activation energy and the order of reaction in zone 2. The average activation energy was in the range of 150–200 kJ/mol and the order of reaction was 1.5–2 in zone 2 for different experiments. Coarser particles were found to have less decomposition than finer particles due to heat transfer limitation within the particle. However, the effect of increasing catalyst concentration was found ineffective in the mass transfer of more volatiles from PCB.