Removal of decabromodibenzyl (DDB) from high impact polystyrene (HIPS), using a solution of NaOH in ethylene glycol (EG)

本研究的目的是在NaOH/乙二醇溶液中对高冲击聚苯乙烯（HIPS）阻燃剂进行脱溴化。使用球磨机在最有效的反应条件下，190摄氏度，NaOH浓度为0.5 M，反应24小时，可将残留HIPS中的溴含量降低至0.02% （200 mg/kg）。虽然在没有球磨的情况下，只有大约一半的脱溴得以实现，但在两种情况下，反应都是通过扩散进行的，活化能约为200 kJ/mol。尽管大部分阻燃剂在脱溴后仍留在HIPS中产生交联，但发现酚类是阻燃剂的降解产物。脱溴后的HIPS具有较高的热稳定性，可通过机械循环利用。

The purpose of this research was the debromination of high-impact polystyrene (HIPS) flame retarded with decabromodiphenylethane in NaOH/ethylene glycol solution.Using a ball-mill at the most efficient reaction conditions, 190 degree celsius for 24 h at a NaOH concentration of 0.5 M, resulted in a reduction of the bromine content to 0.02% (200 mg/kg) in the residual HIPS. Although without ball-milling only about the half of the debromination was achieved, the reaction proceeded in both cases by diffusion with an activation energy of about 200 kJ/mol. Even though the most of the flame retardant remained in the HIPS causing cross-linking after debromination, phenols were observed as degradation products of the flame retardant.The debrominated HIPS showed high thermal stability and might be reused by mechanical recycling.