废旧电视机外壳塑料中十溴联苯醚的溶剂法分离

Removal of Decabromodiphenyl Ether from TV Set Housing Plastic Waste by Solvolysis Process

以d-柠檬烯为溶剂、正丙醇为沉淀剂建立了溶剂法再生废旧电视机外壳塑料(主要成分为高抗冲聚苯乙烯,HIPS)的新工艺,考察了外壳塑料溶液中十溴联苯醚在固液两相的分布特征及影响因素,探讨了反溶剂沉淀过程中十溴联苯醚的转移机制,提出了减少十溴联苯醚进入再生HIPS产品的措施,通过实验确立了从废旧电视机外壳塑料中分离十溴联苯醚的工艺条件.当电视机外壳塑料浓度为20%,使用管式离心分离机,在温度30℃、转速12000r/min下能去除溶液中87.7%的十溴联苯醚;每100mL离心液补加40mL柠檬烯溶解十溴联苯醚颗粒后,再用等体积正丙醇在50℃下沉淀HIPS,所得再生塑料的多溴联苯醚总含量低于0.1%,十溴联苯醚的脱除率超过99%.

A solvolysis recycling process of waste TV set housing plastic with d-limonene and propanol was developed, the phase distribution characteristics of decabromodiphenyl ether and its influential factors were investigated, the transfer mechanism of decabromodiphenyl ether into the recycled high-impact polystyrene （HIPS） in the course of antisolvent precipitation was analyzed, the measures for reducing the amount of decabromodiphenyl ether to move into recycled HIPS were proposed, the optimum process conditions to separate decabromodiphenyl ether from waste housing plastic were determined by experiments. 87.7% of decabromodiphenyl ether was removed by a tubular centrifuge at 12 000 r/min rotation speed and 30℃, when the solution was adjusted to be 20% of TV set housing plastic. After decabromodiphenyl ether particles were dissolved by adding 40 mL d-limonene per 100 mL centrifugate, recycled HIPS particles were precipitated with the same volume of propanol at 50 ℃. The total polybrominated diphenyl ether concentration of recycled HIPS was reduced to lower than 0.1% and over 99% of decabromodiphenyl ether input successfully removed by this recycling process.