A POLYVINYLIDENE FLUORIDE POROUS MEMBRANE AND A METHOD FOR PRODUCING THE SAME

摘要

A polyvinylidene fluoride porous membrane, the cross-section of the porous membrane has uniform perforate spongy structure; the surface of the porous membrane has no obvious cortex structure. The breakdown strength is 2MPa~15MPa, the flux of pure water is 700L/(m2 h 0.1MPa)~3000L/(m2 h 0.1MPa). A method for producing the porous membrane comprises: adding 30wt%~60wt% polyvinylidene fluoride and 40wt%~70wt% diphenyl carbonate or composite diluents comprising diphenyl carbonate into a high temperature agitator tank, elevated-temperature heating and mixing uniformly, then standing and defoaming, producing polymer solution in homogeneous phase; scraping the solution on the support web directly to form a flat membrane or spray spinning by spinneret to form a hollow fiber, then immersing into cooling liquid to solidify out into membrane; putting the membrane produced into extract solvent to extract the diluents, and then forming the polyvinylidene fluoride porous membrane.