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US 5,314,923 AGranted
Porous polymer beads and process
AssigneeCytec Technology Corp.
InventorsMichael T. Cooke, Laura J. Hiscock
Life of this patent
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Abstract
Isotropic porous polymer beads having a high surface porosity and large pore diameters from about 0.002 to about 5 microns are produced from solutions of a polymer or a copolymer by a thermally-induced phase separation process. The use of mixed solvent-non-solvent combinations as solvents for the polymers, produces high pore content, substantially spherical beads having a morphology ideally suited to the chromatography of large molecules, such as proteins, and for enzyme-binding.
Claims14
A process for the preparation of isotropic polymer beads, said process comprising:
- (i) heating and mixing a polymer or copolymer selected from the group consisting of vinyl addition polymers, condensation polymers and oxidation polymers which are soluble in a liquid medium and form rigid structures at the temperatures at which said beads will be used with a mixture comprising an organic or inorganic liquid solvent capable of dissolving said polymer or copolymer without permanent chemical transformation and a liquid non-solvent which is immiscible with said polymer or copolymer to form a homogeneous solution:
- (ii) breaking said homogenous solution into droplets;
- (iii) cooling said droplets, optionally in the presence of an inert liquid, to bring about phase separation and solidification of the polyerm or copolymer in the droplets;
- and
- (iv) separating the droplets from any inert liquid and the solvent-non-solvent mixture to produce isotropic porous beads.
2 more elements
Dependencies are inferred from the claim text.