本研究探討以植物油溶解回收廢聚苯乙烯之處理方法的可行性。使用樟腦白油、桔子油以及松節油，溶解通用級（GPS）及發泡（EPS）聚苯乙烯，再以蒸發法或用沈澱法回收聚苯乙烯。三種植物油溶解聚苯乙烯的快慢次序是桔子油＞樟腦白油＞松節油。提高溫度及加快攪拌速率，可以加快GPS及EPS之溶解速率。EPS與GPS之溶解皆為質傳速率控制，其質傳係數在桔子油中為最高，松節油中為最低。以蒸發法回收聚苯乙烯，會因高溫而破壞聚苯乙烯的分子結構，使再生聚苯乙烯之分子量及玻璃轉化溫度較原先稍低，其回收率約為85%。以沈澱法所得再生聚乙烯，其分子量及玻璃轉化溫度與原先的幾無差異。使用乙醇或丙酮為沈澱劑，回收率沒有差距，其回收率會依乙醇或丙酮的使用量增加而增加，在用量為溶液體積50倍下，約為95%。本研究結果有助於聚苯乙烯的環保溶劑溶解回收與再生程序之開發，並可作為後續的設備和程序設計之基礎資料。
The polystyrene (PS) materials were dissolved in plant-derived oil, and then the solution was subjoted to evaporation or a precipitation to recover the PS. The ranking of the measured dissolution rates of PS in oils was: citrus peel oil＞camphor white oil＞ turpentine oil. The dissolution rate was increased with the increaing temperature and stir ring speed. The dissolution of expanded PS (EPS) and general PS (GPS) were both controlled by mass transfer; and the mass transfer coefficient was the highest in citrus peel oil and the lowest in turpentine oil. The average molecular weight (Mw) and glass transition temperature (Tg) of the PS regenerated by evaporation method were lower than those of the original PS, probably due to the damage of molecular structures by higher evaporation temperature. Recovery of PS by the evaporation method was about 85%. The PS regenerated by precipitation in ethanol or acetone had the Mw and Tg similar to those of the original PS. Increasing the quantity of ethanol or acetone increased the recovery of PS, which was about 95% when the volume of ethanol or acetone was fifty times that of the PS solution. These results may contribute to development of environmentally-friendly solvents for the PS dissolution, and could be the basic data for further design of the recovery process.
