| 主权项 |
1. A caustic-resistant membrane comprising a homogeneous polymer blend consisting of:
a) 75 to 90 percent by weight of at least one polyvinylidene fluoride (PVDF) polymer or copolymer; and b) 10 to 25 percent by weight of at least one acrylic polymer, wherein said acrylic polymer is selected from the group consisting of
1) a terpolymer consisting of from 90 to 99 weight percent of methyl methacrylate monomer units, from 0.5 to 9.5 weight percent of one or more C1-4 alkyl acrylates monomer units and 0.5 to 5 weight percent of (meth)acrylic acid monomer units, wherein the total of these acrylic monomers adds to 100%, and2) an acrylic block copolymer consisting of all acrylic monomers units wherein at least one end block consists of 75-100 percent by weight of methyl methacrylate units, and from 0 to 25 weight percent of one or more C1-4 alkyl acrylates and/or (meth)acrylic acid,wherein said membrane is microporous, having a pore size of from 0.01 to 10 microns. |
