Composite membranes based on interpenetrating polymer networks

Claim 2

A composite membrane which comprises an interpenetrating polymer network of: (1) an isocyanate-capped polyether which is obtained by reacting a polyether with a diisocyanate, said isocyanate-capped polyether being physically entwined with (2) a copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds, said composite membrane being supported on a porous backing support material; and (3) said component (1) being physically entwined with compound (2) by means of a generated polyurethane, said polyurethane being formed by the curing of said membrane at a temperature in the range of from about ambient to about 100° C. in an atmosphere which possesses a relative humidity in the range of from about 20% to about 100% for a period of time sufficient to generate an amine-capped polymer by the hydrolysis of a portion of said isocyanate-capped polyether, with said amine-capped polymer subsequently reacitng with a portion of the isocyanate groups present in said membrane to form a polyurethane which serves to physically entwine said component (2) in said membrane.

Claim 3

The composite membrane as set forth in claim 1 in which said polyether is selected from the group consisting of polyethylene glycol, polypropylene glycol and block copolymers of ethylene glycol and propylene glycol, having an average molecular weight of 100 to 450.

Claim 4

The composite membrane as set forth in claim 1 in which said diisocyanate is selected from the group consisting of toluene diisocyanate, methylene diphenyldiisocyanate, ethylene diphenylisocyanate, and propylene diphenylisocyante.

Claim 5

The composite membrane as set forth in claim 1 in which said isocyanate-capped polymer and said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds are present in a weight ratio in the range of from about 1:1 to about 8:1 weight percent of isocyanate-capped polymer to copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds.

Claim 6

The composite membrane as set forth in claim 1 in which said isocyanate-capped polymer is the reaction product obtained by reacting toluene diisocyanate with polypropylene glycol and said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylpyridine-N-vinylpyrrolidinone].

Claim 7

The composite membrane as set forth in claim 1 in which said isocyanate-capped polymer is the reaction product obtained by reacting toluene diisocyanate with polyethylene glycol and said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly [N-vinylimidazole-N-vinylpyrrolidinone].

Claim 8

The composite membrane as set forth in claim 1 in which said isocyanate-capped polymer is the reaction product obtained by reacting toluene diisocyanate with polyethylene glycol and said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylimidazole-N-vinylpyrrolidinone].

Claim 9

The composite membrane as set forth in claim 1 in which said isocyanate-capped polymer is the reaction product obtained by reacting toluene diisocyanate with polyethylene glycol and said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylimidazole-N-vinylpiperidine].

Claim 10

The composite membrane as set forth in claim 1 in which said porous support backing material is polysulfone.

Claim 11

The composite membrane as set forth in claim 1 in which said porous support backing material is polyethylene.

Claim 12

A process for the production of a composite interpenetrating polymer network membrane which comprises reacting a polyether with a diisocyanate to form an isocyanate-capped polyether, admixing said isocyanate-capped polyether with a copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds, casting said membrane on a porous backing support material, curing the resultant composite at a temperature in the range of from about ambient to about 100° C. in an atmosphere which possesses a relative humidity in the range of from about 20% to about 100% for a period of time sufficient to generate an amine-capped polymer by the hydrolysis of a portion of said isocyanate-capped polyether, with said amine-capped polymer subsequently reacting with a portion of the isocyanate groups present in said membrane to form a polyurethane which serves to physically entwine said component (2) in said membrane, and recovering the resultant composite interpenetrating network membrane.

Claim 13

A process for the production of a composite interpenetrating polymer network membrane which comprises reacting a polyether with a diisocyanate to form an isocyanate-capped polyether, admixing said isocyanate-capped polyether with a copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds, casting said membrane on a porous backing support material, curing the resultant composite at a temperature in the range of from about ambient to about 100° C. in an atmosphere which possesses a relative humidity in the range of from about 20% to about 100% for a period of time sufficient to generate an amine-capped polymer by the hydrolysis of a portion of said isocyanate-capped polyether, with said amine-capped polymer subsequently reacting with a portion of the isocyanate groups present in said membrane to form a polyurethane which serves to physically entwine said component (2) in said membrane, and recovering the resultant composite interpenetrating network membrane.

Claim 14

The process as set forth in claim 11 in which said polyether is selected from the group consisting of polyethylene glycol, polypropylene glycol and block copolymers of ethylene glycol and propylene glycol having an average molecular weight in the range of from about 100 to about 450.

Claim 15

The process as set forth in claim 11 in which said diisocyanate is selected from the group consisting of toluene diisocyanate, methylene diphenylisocyanate, ethylene diphenylisocyanate, and propylene diphenylisocyanate.

Claim 16

The process as set forth in claim 11 in which the isocyanate-capped polymer of the interpenetrating polymer network membrane is the reaction product obtained by reacting toluene diisocyanate with a block copolymer of ethylene glycol and propylene glycol, said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylpyridine-N-vinylpyrrolidinone] and said porous support backing material is polysulfone.

Claim 17

The process as set forth in claim 11 in which said isocyanate-capped polymer of the interpenetrating polymer network membrane is the reaction product obtained by reacting toluene diisocyanate with polypropylene glycol, said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylimidazole-N-vinylpyrrolidinone] and said porous support backing material is polysulfone.

Claim 18

The process as set forth in claim 11 in which said isocyanate-capped polymer of the interpenetrating polymer network membrane is the reaction product obtained by reacting toluene diisocyanate with polyethylene glycol, and said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylimidazole-N-vinylpyrrolidinone] and said porous support backing material is polyethylene.

Claim 19

The process as set forth in claim 11 in which said isocyanate-capped polymer of the interpenetrating polymer network membrane is the reaction product obtained by reacting toluene diisocyanate with polyethylene glycol, said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylimidazole-N-vinylpyrrolidinone] and said porous support backing material is polysulfone.

Claim 20

The process as set forth in claim 11 in which said isocyanate-capped polymer of the interpenetrating polymer network membrane is the reaction product obtained by reacting toluene diisocyanate with polyethylene glycol, said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylimidazole-N-vinylpiperidine] and said porous support backing material is polysulfone.

Claim 21

A process for the separation of a saccharide from a mixture of mono- and polysaccharides which comprises passing said mixture across a composite membrane comprising an interpenetrating polymer network at separation conditions to form a retentate and a permeate, and recovering said permeate consisting mainly of a monosaccharide, said interpenetrating polymer network being comprised of: () an isocyanate-capped polymer which is obtained by reacting a polyether with a diisocyanate, said isocyanate-capped polyether being physically entwined with (2) a copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds, said composite membrane being supported on a porous backing support material; and (3) said component (1) being physically entwined with component (2) by means of a generated polyurethane, said polyurethane being formed by the curing of said membrane at a temperature in the range of from about ambient to about 100° C. in an atmosphere which possesses a relative humidity in the range of from about 20% to about 100% for a period of time sufficient to generate an amine-capped polymer by the hydrolysis of a portion of said isocyanate-capped polyether, with said amine-capped polymer subsequently reacting with a portion of the isocyanate groups present in said membrane to form a polyurethane which serves to physically entwine said component (2) in said membrane.

Claim 22

A process for the separation of a saccharide from a mixture of mono- and polysaccharides which comprises passing said mixture across a composite membrane comprising an interpenetrating polymer network at separation conditions to form a retentate and a permeate, and recovering said permeate consisting mainly of a monosaccharide, said interpenetrating polymer network being comprised of: () an isocyanate-capped polymer which is obtained by reacting a polyether with a diisocyanate, said isocyanate-capped polyether being physically entwined with (2) a copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds, said composite membrane being supported on a porous backing support material; and (3) said component (1) being physically entwined with component (2) by means of a generated polyurethane, said polyurethane being formed by the curing of said membrane at a temperature in the range of from about ambient to about 100° C. in an atmosphere which possesses a relative humidity in the range of from about 20% to about 100% for a period of time sufficient to generate an amine-capped polymer by the hydrolysis of a portion of said isocyanate-capped polyether, with said amine-capped polymer subsequently reacting with a portion of the isocyanate groups present in said membrane to form a polyurethane which serves to physically entwine said component (2) in said membrane.

Claim 23

The process as set forth in claim 19 in which said separation conditions include a temperature in the range of from about ambient to about 70° C. and a pressure in the range of from about 25 to about 1500 pounds per square inch.

Claim 24

The process as set forth in claim 19 in which said composite membrane comprises an interpenetrating polymer network in which the isocyanate-capped polymer is the reaction product obtained by reacting toluene diisocyanate with a block copolymer of ethylene glycol and propylene glycol, said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylpyridine-N-vinylpyrrolidinone] and said porous support backing material is polysulfone.

Claim 25

The process as set forth in claim 19 in which said composite membrane comprises an interpenetrating polymer network in which the isocyanate-capped polymer is the reaction product obtained by reacting toluene diisocyanate with polypropylene glycol, said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylimidazole-N-vinylpyrrolidinone] and said porous support backing material is polysulfone.

Claim 26

The process as set forth in claim 19 in which said composite membrane comprises an interpenetrating polymer network in which the isocyanate-capped polymer is the reaction product obtained by reacting toluene diisocyanate with polyethylene glycol and said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylimidazole-N-vinylpyrrolidinone] and said porous support backing material is polyethylene.

Claim 27

The process as set forth in claim 19 in which said composite membrane comprises an interpenetrating polymer network in which the isocyanate-capped polymer is the reaction product obtained by reacting toluene diisocyanate with polyethylene glycol and said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylimidazole-N-vinylpiperidine] and said porous support backing material is polysulfone.

Claim 28

The process as set forth in claim 19 in which said composite membrane comprises an interpenetrating polymer network in which the isocyanate-capped polymer is the reaction product obtained by reacting toluene diisocyanate with polyethylene glycol, said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylimidazole-N-vinylpyrrolidinone] and said porous support backing material is polysulfone.

Claim 29

The process as set forth in claim 19 in which said composite membrane comprises an interpenetrating polymer network in which the isocyanate-capped polymer is the reaction product obtained by reacting toluene diisocyanate with polyethylene glycol, said copolymer of at least two saturated or unsaturated heterocyclic nitrogen-containing compounds is poly[N-vinylimidazole-N-vinylpiperdine] and said porous support backing material is polysulfone.

Claim 30

The process as set forth in claim 19 in which said monosaccharide comprises glucose.