| With the innovating of information technology and the continuous expansing of market demand, the upgrading of electronic products is accelerated, as a result, it creats a large number of WEEE, and printed circuit board is the indispensable part in WEEE, However, people focus on the recycling valuable metals from waste printed circuit board, non-metallic residue of PCB is discarded at random without environmental friendly processing, it is a threat to ecological environment.This paper researched on the recycling process of non-metallic waste printed circuit board and degradation and transformation process of bromide combination. Regarded non-metallicmaterials of wasteprinted circuit board and TBBPA as the research object, investigated the effect of degradation of bromide combination through the treating of synergistic effect of microwave and ultrasonic, andcleared the optimal conditions within the experimental range, and preliminary discussed the mechanism of the degradation of brominated flame retardants through the treating of synergistic effect of microwave and ultrasonic.This paper firstly based on the infrared analysis, SEM analysis.thermal analysis of initial material, Investigated its main components, resin category, combining state and thermal degradationcharacteristics, and further determined the temperature conditions of the reaction.The ultrasonic and microwave synergistic degradation of non-metallic powder in waste printed circuit board was researched in a closed and relatively mild aqueous system. The influences of temperature and time on the characteristics of degradation were investigated under different effects of single hydrothermal, single microwave, single ultrasound and the synergistic effects of microwave and ultrasonic through the analysis of the liquid products. The results showed that in the range of 200℃ to 280℃, the degradation rate tend to be stableafter the reaction time to 40min; thedegradation rate of organic components in non-metallic waste printed circuit board could be up to 74.11% under the synergistic effects of microwave and ultrasonic in 280℃. In the degradation products,the main solid product was the highly purity of glass fiber, while the liquid organic product was phenol.To further explore the mechanism of degradation of bromide flame retardant resinsin waste printed circuit board, this paper choosed TBBPA as a model compound, this experiment was done under the different conditions of single hydrothermal, single ultrasonic, single microwave and the synergistic effects of ultrasonic and microwave, the experiment reseached the degradation rate of TBBPA with different temperature、different reaction time and reaction conditions through the analysis of the liquid products. The result showed that the experiment could realize the degradation of TBBPA at lower temperature and shorter time through the treating with the synergistic effects of microwave and ultrasonic.the degradation rate can reach 95% and 95.9% respectively when the experimental condition seted in 180℃、4h and230 ℃、1h, the degradation products primarily were non-bromobenzenephenolics and there could be two degradation pathways. |
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