Abstract: A method for producing a powder comprises the steps of: charging a vessel with a mixture of at least two solid components. At least one of the solid components comprises a polymeric resin. The vessel with charged with a fluid in which the polymeric resin, and preferably the other components of the mixture, are not substantially soluble. The fluid is selected such that the density of the fluid can be adjusted upon adjustment of temperature and pressure in the vessel to enable creation of a suspension of the mixture within the vessel upon agitation of the contents of the vessel. The temperature is maintained above the glass transition temperature of the polymeric resin in the fluid. The pressure of the fluid is adjusted such that the density of the fluid enables creation of the suspension of the mixture within the vessel upon agitation of the contents of the vessel. The contents of the vessel is agitated to create the suspension.

Abstract: The present invention provides crosslinked polymeric networks that are reversibly crosslinked upon exposure to light of a suitable wavelength. In one embodiment photocrosslinkable branched hydrophilic polymers containing photochromic groups are synthesized. Cinnamylidene groups and derivatives of cinnamylidene are preferably used as the photochromic agents or photocrosslinking agents.

Abstract: The present invention provides crosslinked polymeric networks that are reversibly crosslinked upon exposure to light of a suitable wavelength. In one embodiment photocrosslinkable branched hydrophilic polymers containing photochromic groups are synthesized. Cinnamylidene groups and derivatives of cinnamylidene are preferably used as the photochromic agents or photocrosslinking agents.

Abstract: Described herein is a technique for covalently modifying tissue and cellular surfaces to inhibit cell adhesion. The process described herein is conducted under conditions tolerable in vivo and employs a biocompatible polymer having a reactive group attached to at least one end that reacts with groups present or on tissue and cellular surfaces under aqueous and mild conditions and thereby covalently attaches the polymer to the tissue or cellular surface. Preferably, the reactive group attached to the polymer reacts with amines and hydroxyls present on tissue and cellular surfaces. In one preferred embodiment, the methods described herein provide for the covalent modification of tissue and cellular surfaces using a PEG-diisocyanate solution. The methods described herein are particularly useful in impairing platelet and leukocyte deposition in blood vessels and thereby thwarting thrombosis and restenosis, a common complication of vascular procedures including PTCA and vascular surgery.

Abstract: Polymers capable of reversibly complexing carbon dioxide and other acid gases and a method of producing such polymers are disclosed. In a preferred embodiment, the present polymers incorporate amine groups capable of reversibly complexing carbon dioxide to produce an environmentally safe foamed polymer product. Because the reaction of an amine and CO.sub.2 is a reversible reaction, and because the amines are incorporated into the polymer backbone, the foamed polymers can be reverted to foamable polymers simply by collection, washing, granulating, and re-exposure to CO.sub.2. The polymers are environmentally desirable as carbon dioxide is non-toxic and is easily isolated from the atmosphere. Moreover, the process recycles the gas continually, rather than generating new gases.

Abstract: The present invention provides a chelating agent suitable for forming coordinated complexes with a metal in liquid and supercritical carbon dioxide of covalently bonded (i) a chelating group selected from the group consisting of a dithio carbamate, a thiol group, and a picolyl amine group, (ii) a non-electron withdrawing spacer group selected from (CH.sub.2).sub.x ; and (iii) a CO.sub.2 -soluble functional group selected from (CF.sub.2 CF.sub.2 O).sub.X, (CF.sub.2 O).sub.X, (CF.sub.2).sub.X, and ?CF.sub.2 (CF.sub.3 FO)!.sub.x. X is selected to be greater or equal to 3 and to minimize the electron withdrawing effect of the CO.sub.2 -soluble functional group and to achieve a chelating agent solubility of at least a 10.sup.-3 gm/gm CO.sub.2. A solubility of at least 10.sup.-2 gm/gm CO.sub.2 is attained at a temperature in the range of approximately 0.degree. to 100.degree. C. and a pressure of approximately 500 to 5000 psi.

Abstract: The present invention provides a chelating agent suitable for chelating metals metals in liquid or supercritical carbon dioxide. The chelating agent comprises generally a conventional chelating group and a CO.sub.2 -soluble functional group covalently attached to the chelating group. Examples of suitable CO.sub.2 -soluble functional groups include fluorinated polyether groups, silicone groups, fluorinated polyalkyl groups, phosphazene groups and fluorinated polyacrylate groups. The present invention also provides a method of extracting a metal from a matrix containing at least one other material and the metal using such CO.sub.2 -soluble chelating agents.

Abstract: Aminated polymers capable of reversibly complexing carbon dioxide and other acid gases including CO.sub.2, SO.sub.2, NO.sub.x and H.sub.2 S, a method of using such polymers and an operational unit including such polymers are disclosed. The polymers incorporate amine group which reversibly complex acid gases. Such polymers provide a significant advantages over presently used sorbents used to remove acid gas.

Abstract: Aminated polymers capable of reversibly complexing carbon dioxide and other acid gases including CO.sub.2, SO.sub.2, NO.sub.x and H.sub.2 S, a method of using such polymers and an operational unit including such polymers are disclosed. The polymers incorporate amine group which reversibly complex acid gases. Such polymers provide a significant advantages over presently used sorbents used to remove acid gas.

Abstract: The present invention provides protein-containing polymers and a general method of incorporating biologically active proteins into a polymer matrix via copolymerization in organic solvents. Preferably, the protein is an active enzyme which maintains its activity in the polymeric matrix. The proteins are first solubilized in organic solvents by covalent attachment of a modifying moiety such as a polyalkylene oxide. The polyalkylene oxide is functionalized with a functional group enabling copolymerization in organic solvents with an organic-soluble comonomer.

Abstract: A process of preparing a polyester by reacting a diol with an acid or acid ester in the presence of a solid enzyme and in a supercritical fluid is described.

Abstract: The present invention provides a method for selectively separating co-mingled materials of different densities by selective density flotation of the materials in a fluid in the vicinity of its critical point. The extermely high compressibility of a fluid in the vicinity of its critical point allows continuous variations over the maximum density range to be accomplished using minimal changes in temperature and pressure. Materials exhibiting similar densities can thus be separated by adjusting the fluid density to a point between the two materials.

Abstract: This invention is directed to a microemulsion system comprising a first phase including a low-polarity fluid material which is a gas at standard temperature and pressure, and which has a cloud-point density. It also includes a second phase including a polar fluid, typically water, a monomer, preferably a monomer soluble in the polar fluid, and a microemulsion promoter for facilitating the formation of micelles including the monomer in the system. In the subject process, micelles including the monomer are formed in the first phase. A polymerization initiator is introduced into the micelles in the microemulsion system. The monomer is then polymerized in the micelles, preferably in the core of the micelle, to produce a polymeric material having a relatively high molecular weight.