Pyolysis Characteristics And Kinetics Of Printed Circuit Boards Made With Anti-BR Type Epoxy Resin

As the rapid development of electrical and electronic equipment industry, the frequency of replacement electronic products is accelerated, the amount of waste Electrical and Electronic Equipment (WEEE) is rapidly increasing in China. As the key component of WEEE, waste printed circuit board (wPCB) has become an important kind of WEEE. Because of instruction of WEEE, ROHS, EUP and Regulation on contamination control and management of IT products, issued by the Ministry of Information Industry coming into effect, the amount of Anti-Br type epoxy resin printed circuit boards becomes larger. Therefore, it is of great significant to explore comprehensive utilization techniques of waste Anti-Br type epoxy resin printed circuit boards.Based on the National Science and Technology Support Program sub-project, "recycling technology technology and industry chain linking technology", Pyrolysis recycling technology of wPCB was researched in the paper. As the single nonmetal recycling technology, pyrolysis recycling technology was integrated with many metal recycling technology. This can achieve good results. The anti-Br type epoxy resin printed circuit boards were investigated by pyrolysis experiment. This paper focuses on three aspects, including the influencing factors of pyrolysis, the analysing of the pyrolysis product and the pyrolysis kinetics.Firstly, the effects of pyrolysis temperature (300℃-900℃), heating rate(10℃/min-40℃/min) and holding time (30 min-60min) on the yield of pyrolysis products in nitrogen were analyzed. Results show that solid residues account for about 61.74-71.08wt.%, liquid yields about 22.52-28.44wt.%and gas yields about 5.86-12.81wt.%. To get more pyrolysis oil, the optimal condition was obtained as follows:pyrolysis temperature at 700℃, heating rate of 20℃/min, holding time of 40 min.Secondly, pyrolysis oil and residue were analyzed by Infrared spectroscopy, gas chromatography and mass spectroscopy (GC/MS), element analysis and scanning electron microscope. The main components of pyrolysis oil are phenol, 2-methylphenol,2,6-diisopropyl phenol, and bisphenol A,etc. In the process of pyrolysis, fibreglass appears unchanged.In the end, pyrolysis kinetics of anti-Br type epoxy resin printed circuit boards was investigated with thermo gravimetric (TG) analysis in atmosphere of argon. The pyrolysis characteristics, stability analyses of anti-Br type epoxy resin printed circuit boards and the influence on pyrolysis were researched under various hearting rates(5,10,20,30℃·min-1). The pyrolysis activation energy E and other kinetic parameters were determined by Kissinger differentiation and Flynn-Wall-Ozawa integration. The reaction kinetics equation and the thermal decomposition mechanism function were investigated by Coats-Redfern method, the study shows that the proximal reaction kinetic equation is Valensi equation, and the reaction order is 2, and the thermal decomposition mechanism function isα+(1-α)·ln(1-α).