US 5,290,820 A · Process for preparing low density porous crosslinked polymeric materials · patentgrep

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Abstract

In a process for the preparation of a low density porous crosslinked polymeric material by polymerizing a water-in-oil high internal phase emulsion, curing time of the monomers in the emulsion can be reduced without adversely affecting polymer properties by first advancing one or more of the monomers. All or a portion of the monomers are advanced in the presence of an advancement initiator or a free-radical-producing radiation source for about 5% to about 95% of the time effective to form a solid. Then, a water-in-oil high internal phase emulsion is formed with the advanced monomers and optionally additional monomers or the advanced monomers are added to a water-in-oil high internal phase emulsion containing other monomers. The emulsions containing the advanced monomers are cured. The process provides an improved method to incorporate volatile monomers in the porous polymeric material. The curing time is further reduced by carrying out the polymerization and crosslinking in the presence of a alkylperoxycarbonate or a alkylperoxycarboxylate polymerization initiator that is branched at the 1-position and/or the .alpha.-position.

Claims43

Dependent claims

A process for the production of a porous crosslinked polymeric material comprising:

(a) providing an aqueous mixture comprising water an electorlyte;
(b) advancing one or more vinyl monomers in the presence of an effective amount of an advancement initiator or by a free-radical-producing radiation source to produce an advanced monomer component having a viscosity ratio of advanced monomer component to the non-advanced monomer of greater than 1.00;
(c) adding one or more multifunctional unsaturated crosslinking monomers (i) to the one or more vinyl monomers prior to advancing in step (b), (ii) to the advanced monomer component prior to emulsion forming step (e), or to both (i) and (ii) to form an advanced monomer mixture;
(d) providing a surfactant to the aqueous mixture, the vinyl monomer, the advanced monomer component, the advanced monomer mixture, or any combinations of the aqueous mixture, vinyl monomer, advanced monomer component and advanced monomer mixture;
(e) combining and mixing said aqueous mixture and said advanced monomer mixture in a mixing vessel under conditions effective to produce a water-in-oil emulsion having at least 90 weight percent, based on the emulsion, of water as the internal phase;
(f) heating the emulsion at a temperature of at least about 25.degree. C. to polymerize and crosslink the advanced monomers;
and
(g) removing at least a portion of water from said cross-linked emulsion thereby producing a porous cross-linked polymeric material.

5 more elements

A process for the production of a porous crosslinked polymeric material comprising:

(a) providing an aqueous mixture comprising water and an electrolyte;
(b) advancing one or more vinyl monomers in the presence of an effective amount of an advancement initiator or by a free-radical-producing radiation source for about 5% to about 95% of the time effective to form a solid thereby producing an advanced monomer component;
(c) adding one or more multifunctional unsaturated crosslinking monomers (i) to the one or more vinyl monomers prior to advancing in step (b), (ii) to the advanced monomer component prior to emulsion forming step (e), or to both (i) and (ii) to form an advanced monomer mixture;
(d) providing a surfactant to the aqueous mixture, the vinyl monomer, the advanced monomer component, the advanced monomer mixture, or any combinations of the aqueous mixture, vinyl monomer, advanced monomer component and advanced monomer mixture;
(e) combining and mixing said aqueous mixture and said advanced monomer mixture in a mixing vessel under conditions effective to produce a water-in-oil emulsion having at least 90 weight percent, based on the emulsion, of water as the internal phase;
(f) heating the emulsion at a temperature of at least about 25.degree. C. to polymerize and crosslink the advanced monomers;
and
(g) removing at least a portion of water from said cross-linked emulsion thereby producing a porous cross-linked polymeric material.

5 more elements

A process for the production of a porous crosslinked polymeric material comprising:

(a) providing an aqueous mixture comprising water and an electrolyte;
(b) providing a monomer component comprising at least one vinyl monomer and from about 2 to about 70 weight percent, based on the mixture, of at least one multifunctional unsaturated crosslinking monomer;
(c) advancing at least a portion of said monomer component in the presence of an effective amount of an advancement initiator or by a free-radical-producing radiation source to produce an advanced monomer component having a viscosity ratio of advanced monomer component to the non-advanced monomer component of greater than 1.00;
(d) combining said advanced monomer component and any remaining monomer component if any to provide an advanced monomer mixture;
(e) providing a surfactant to the aqueous mixture, the monomer component, the advanced monomer component, the advanced monomer mixture or any combinations of the aqueous mixture, monomer component, advanced monomer component and advanced monomer mixture;
(f) combining and mixing said aqueous mixture and said advanced monomer mixture in a mixing vessel under conditions effective to produce a water-in-oil emulsion having at least 90 weight percent, based on the emulsion of water as the internal phase;
(g) heating the emulsion at a temperature of at lest about 25.degree. C. to polymerize and crosslink the advanced monomers;
and
(h) removing at least a portion of water from said cross-linked emulsion thereby producing a porous cross-linked polymeric material.

6 more elements

A process for the production of a porous crosslinked polymeric material comprising:

(a) providing an aqueous mixture comprising water and an electrolyte;
(b) providing a monomer component comprising one or more vinyl monomer, multifunctional unsaturated crosslinking monomer, or a mixture thereof;
(c) providing a surfactant to the aqueous mixture, the monomer component, or to the aqueous mixture and monomer component;
(d) combining and mixing said aqueous mixture and said monomer component in a mixing vessel under conditions effective to produce a water-in-oil emulsion having at least 90 weight percent, based on the emulsion, of water as the internal phase;
(e) advancing one or more vinyl monomers in the presence of an effective amount of an advancement initiator or by a free-radical-producing radiation source to produce an advanced monomer component having a viscosity ratio of advanced monomer component to the non-advanced monomer of greater than 1.00;
(f) adding and mixing the advanced monomer component to the emulsion to form an advanced monomer emulsion;
(g) adding at least one multifunctional unsaturated crosslinking monomer (i) to the one or more vinyl monomers in step (e) prior to advancing, (ii) to the advanced monomer component, (iii) to the advanced monomer emulsion, or to any combination of (i), (ii) and (iii) provided that no multifunctional unsaturated crosslinking monomer is present in step (b);
(h) heating the emulsion at a temperature of at least about 25.degree. C. to polymerize and crosslink the advanced monomers;
and
(i) removing at least a portion of water from said cross-linked emulsion thereby producing a porous cross-linked polymeric material.

7 more elements

A process for the production of a porous crosslinked polymeric material comprising:

(a) providing an aqueous mixture comprising water and an electrolyte;
(b) providing a monomer component comprising one or more vinyl monomer, multifunctional unsaturated crosslinking monomer, or a mixture thereof;
(c) providing a surfactant to the aqueous mixture, the monomer component, or to the aqueous mixture and monomer component;
(d) combining and mixing said aqueous mixture and said monomer component in a mixing vessel under conditions effective to produce a water-in-oil emulsion having at least 90 weight percent, based on the emulsion, of water as the internal phase;
(e) advancing one or more vinyl monomers in the presence of an effective amount of an advancement initiator or by a free-radical-producing radiation source for about 5% to about 95% of the time effective to form a solid thereby producing an advanced monomer component;
(f) adding and mixing the advanced monomer component to the emulsion to form an advanced monomer emulsion;
(g) adding at least on multifunctional unsaturated crosslinking monomer (i) to the one or more vinyl monomers in step (e) prior to advancing, (ii) to the advanced monomer component, (iii) to the advanced monomer emulsion, or to any combination of (i), (ii) and (iii) provided that no multifunctional unsaturated crosslinking monomer is present in step (b);
(h) heating the emulsion at a temperature of at least about 25.degree. C. to polymerize and crosslink the advanced monomers;
and
(i) removing at least a portion of water from said cross-linked emulsion thereby producing a porous cross-linked polymeric material.

7 more elements

Dependencies are inferred from the claim text.