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US 5,431,817 AGranted
Bleach resistant polysulfone/polyurethane composite membranes
AssigneeW. R. Grace & Co.-Conn.
InventorsJames A. Braatz, Denise A. Miller
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Abstract
The resistance to an oxidizer of a biocompatible polysulfone membrane can be enhanced by the incorporation of a specific hydrophilic polyurethane polymer.
Claims11
A substantially protein non-adsorptive polysulfone membrane having enhanced resistance to an oxidizer comprising:
- (a) a polysulfone polymer;
- (b) a polyurethane polymer prepared by reacting water with a prepolymer prepared from
- (i) a polyoxyethylene containing diol consisting essentially of polyoxyethylene, having a molecular weight of about 2500 or less, and containing at least about 50% by weight of oxyethylene units;
- (ii) a crosslinking agent comprising a low molecular weight polyol having 3 or 4 hydroxyl equivalents per mole;
- and
- (iii) methylene bis (4,4'cyclohexyl isocyanate);
- and
- (c) a pore-forming agent.
5 more elements
A method of improving the oxidative degradation resistance of a substantially protein non-adsorptive polysulfone membrane, by incorporating into the membrane a prepolymer prepared from
- (i) a polyoxyethylene containing diol consisting essentially of polyoxyethylene, having a molecular weight of about 2500 or less, and containing at least about 50% by weight of oxyethylene units;
- (ii) a crosslinking agent comprising a low molecular weight polyol having 3 or 4 hydroxyl equivalents per mole;
- and
- (iii) methylene bis(4,4'cyclohexyl isocyanate), and reacting said prepolymer with water to form a polyurethane polymer.
1 more element
Dependencies are inferred from the claim text.