聚醚酮不同结晶温度对其精制的影响

为了更有利于聚醚酮从结晶混合物中分离出来,探索了其结晶条件对其结晶物形态及精制时间的影响。采用特制的恒温制片板,在不同温度、不同恒温时间下获得聚醚酮结晶物,用液泛提取器对其进行精制。结果表明:聚醚酮产物在速冷时晶体类似层岩状,晶体间隙小,精制时间长;在130—155℃及165—190℃,晶体为球形,晶体间有小的孔洞;在160℃左右时,聚醚酮在混合物中的晶型类似海绵状,晶体间孔隙较大,空隙率高,形成均匀纳微结构界面,更有利于精制过程的传质,其精制时间是12.6 h.为速冷精制时间的69.3%。对同批次不同温度下结晶的聚醚酮进行物性检测,其性能未发生变化。此结果对聚醚酮结晶工艺的设计、达到节能降耗、提高生产效益具有指导意义。

Effect of different crystallization temperatures on polyether ketone refining

In order to better separate polyether ketone(PEK) from the crystallization mixture,the effect of crystallization conditions on its crystal shape and refining time was explored.The PEK crystals were gained using the special thermostatic production plate at different constant temperatures and different time,and were refined with flooding extractor.The results show that the PEK products by rapid cooling are similar in shape to rock,with small crystal gap and long refining time;at 130-155 ℃ and 165-190 ℃,the crystals are in spherical shape,with small holes among crystals;at about 160 ℃,the PEK crystal in the mixture is shaped like the sponge,with larger crystal gap,high voidage,and uniform nano/micro-structured interface,which is easier for mass transfer of refined process.The refining time at about 160 ℃ is 12.6 h,69.3% of that of rapid cooling.For the PEK crystals of the same batch at different temperatures,the property detection shows that there is no change in the performance.The results have guiding significance to the process design of PEK crystallization,the goal of saving energy and improving production efficiency.