Abstract:

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 mg/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.