Process for the preparation of porous polymer beads
First Claim
1. A process for the preparation of porous polymer beads with controllable surface porosity wherein said beads are substantially nonswellable in water and have substantially uniform pores of not substantially greater than about 5 microns in diameter, said process comprising(i) heating and mixing an acrylonitrile homopolymer or copolymer thereof with a mixture comprising a solvent and a non-solvent for the polymer to form a homogeneous solution having a polymer solids concentration range of from 0.5 to less than 20 percent:
- (ii) breaking the homogeneous solution into droplets using a high shearing technique;
(iii) cooling the droplets, optionally in the presence of an inert liquid, to bring about phase separation and solidification of the polymer in the droplets;
(iv) separating the solidified droplets from any inert liquid and removing the solvent non-solvent mixture from the solidified droplets to produce porous beads.
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Abstract
Isotropic porous polymer beads having controllable surface porosity and large pore diameters from about 0.002 to about 5 microns are produced from solutions of an acrylonitrile polymer or a copolymer by a thermally-induced phase separation process including intensively shearing the polymer solution into small droplets. The use of mixed solvent non-solvent combinations as solvents for the polymers, and preferably reducing the polymer content in solution to below 10 percent 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.
78 Citations
20 Claims
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1. A process for the preparation of porous polymer beads with controllable surface porosity wherein said beads are substantially nonswellable in water and have substantially uniform pores of not substantially greater than about 5 microns in diameter, said process comprising
(i) heating and mixing an acrylonitrile homopolymer or copolymer thereof with a mixture comprising a solvent and a non-solvent for the polymer to form a homogeneous solution having a polymer solids concentration range of from 0.5 to less than 20 percent: -
(ii) breaking the homogeneous solution into droplets using a high shearing technique; (iii) cooling the droplets, optionally in the presence of an inert liquid, to bring about phase separation and solidification of the polymer in the droplets; (iv) separating the solidified droplets from any inert liquid and removing the solvent non-solvent mixture from the solidified droplets to produce porous beads. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification