溴化环氧树脂印刷线路板的中温热解实验

Experimental Research on Pyrolysis of Brominated Epoxy Resin Printed Circuit Boards at Medium-Level Temperature

利用热重法进行了溴化环氧树脂(FR4)印刷线路板不同升温速率的热解特性试验研究,并利用热重和热重微分曲线的信息计算了动力学三参数.利用固定床热解试验装置进行了大颗粒FR4型线路板中温热解实验,并利用GC-MS,FT-IR和SEM检测了热解产物.结果表明:①FR4型线路板热解温度区间为300,℃～400,℃,热解反应活化能107.70 kJ/mol,指前因子为2.22×109/s,反应级数为1;②热解气体产物主要为CO、CO2、溴甲烷及少量的丙酮和C1～C3卤代烷烃;热解液体产物主要为苯酚和烷基苯酚,还有其他C6～C17芳香族如苯、烷基苯等成分;③固体产物包括金属片和含碳的玻璃纤维,可手动实现金属和玻璃纤维的分离富集,富集的金属包含大量的铜和少量的金、镍等贵重金属,富集的玻璃纤维包含碳、硅、氧、钙和铝等元素.

Pyrolysis characteristics of brominated epoxy resin printed circuit boards （ FR4 PCBs ） were investigated under different heating rates with thermogravimetry（TG）. The kinetic parameter（activation energy,pre-exponential factor, reaction order） were determined from the information of TG and DTG curves. A fixed-bed experimental apparatus was used to pyrolyze FR4 PCBs at medium-level temperature and the products were detected by using GC-MS, FT-IR and SEM. The results indicated thatthe pyrolysis temperature zone of FR4 PCBs was 300 ℃--400 ℃, the activation energy of the pyrolysis reaction was 107.70 kJ/mol, the pre-exponential factor was 2.22 × 10^9/s, and the pyrolysis reaction was one-order reaction. It was also shown that gas products mainly consisted of CO, CO2, propylene, bromomethane, and a small amount of acetone, C1-C3 halogenation alkyls, and liquid products contained high concentration of phenol,alkyl phenols and significantly quantitative other C3-C17 aroma chemicals, as well as low concentration of bromides. Solid products included sheet metals and glassfiber, which were separated manually and enriched easily. Gathering metals consisted of abundant copper and a bit gold and nickel. Accumulating glassfibre contained carbon, silicon, oxygen, calcium and aluminium.