膜分离法精制低不饱和度聚醚多元醇

Experimental study on the purification of low unsaturated degree polyether polyols with membrane separation

采用聚醚砜超滤膜对ZSN-330低不饱和度聚醚多元醇进行精制,粗聚醚多元醇由正己烷1∶1体积比稀释,精制效果很好,大部分检测时间下锌、钴离子截留率高达90%以上,含量低于1μg/g。采用红外分析并验证了截留物中含有双金属氰化络合物催化剂(DMC)成分。考察了膜截留分子量、料液黏度、操作压力、料液流速等对膜通量的影响,确定了较佳的超滤条件为膜截留分子量为150 kDa、由正己烷1∶1稀释、操作压力0.5 MPa、料液流速40 L/h。分别采用去离子水、2‰氢氧化钠溶液、正己烷溶剂超声清洗污染的膜,2‰氢氧化钠溶液的清洗效果较好,膜通量恢复率达66.4%。

Purification of polyether polyols,ZSN-330,with low unsaturated degree was studied by using ultrafiltration membrane prepared from polyethersulphone（PES）.Crude polyether polyols were used as polyols/hexane miscella in a 1∶1 proportion.The intercepting rate of zinc and cobalt ions were more than 90% and the content of zinc and cobalt ions were less than 1 ？g/g among most tests.The double metal cyanide catalysts（DMC）was found in the residue by IR test.The effects of molecular weight cut-off,feed liquid viscosity,operating pressure,flow speed on permeate flux were investigated.The optimal operating condition of ultrafiltration were determined as molecular weight cut-off 150 kDa,diluting by hexane in a 1∶1 proportion,operating pressure 0.5 MPa,flow speed 40 L/h.The contaminated membrane was ultrasonic cleaned by deionized water,2‰ sodium hydroxide solution,hexane,respectively.The one cleaned by 2‰ sodium hydroxide solution,can recover up to 66.4% permeate flux,better than other two solutions.