摘要:
A method of synthesizing a compound having the formula: comprising the step of: reacting a N-vinylformamide salt having the formula with a compound having the formula XR1R2; wherein X is Br, Cl or I, M is an alkali metal or an alkali earth metal, R1 is a C0–C25 alkylene group, a C0–C25 fluroalkylene group or a C0–C25 perfluoro alkylene group, R2 is H, provided R1 is not absent, an alkyl group, a fluroalkyl group, a perfluoroalkyl group, an aryl group, a hydroxy group, a polyether group, a heterocyclic group of 5 or 6 atoms wherein at least one of the atoms is not a carbon and is N, O, or S, —OR3, wherein, R3 is an alkyl group, a fluoroalkyl group, a perfluoroalkyl group, or an aryl group, —C(O)R4, —C(O)OR4, —OC(O)R4, —OC(O)R4, wherein R4 is an H, an alkyl group, a fluoroalkyl group, a perfluoroalkyl group, or an aryl group, a phthalimide group or NR5 R5 wherein R5 and R5 are independently H, —C(O)R4, an alkyl, a fluoroalkyl group, a perfluoroalkyl group or an aryl group.
摘要:
A method is provided for the extraction of water soluble biomaterials such as enzymes or proteins into carbon dioxide utilizing certain carbon dioxide soluble surfactants. The extraction can be performed on an aqueous solution, a fermentation broth or a fluid. The method includes the process steps of forming a carbon dioxide/surfactant mixture which involves dissolving carbon dioxide soluble surfactant(s) in carbon dioxide. The carbon dioxide can be in a liquid or supercritical form and the surfactant includes tail and head groups that interact with the biomaterials. Further, the mixture is added to the aqueous solution, fermentation broth or liquid under conditions to allow for extraction of the biomaterials. The method further includes depressurizing and/or temperature adjusting to remove the water soluble biomaterials. The surfactants include fluroethers, oligomers of propylene-oxide, siloxanes, etc. The biomaterials include proteins or enzymes. The carbon dioxide is suberitical or supercritical.
摘要:
A composition comprising the reaction product of (a) an isocyanate group-containing component having an average functionality of at least 2; and (b) an active hydrogen group-containing component having an average functionality of at least 2. The composition is biodegradable, a solid at 22° C. and below, and has pressure sensitive adhesive properties at a temperature of 37° C. and relative humidity of 100%. The composition may be used to adhere polymer meshes or films to biological tissue.
摘要:
A composition includes water having a salinity of at least 1 ppt, at least one hydrophilic polymer containing primary (—NH2) and/or secondary (—NHR) amine groups and at least one saccharide containing a reducible function. A method of changing the permeability of a subterranean formation includes the step of injecting into a subterranean formation a composition comprising water, at least one hydrophilic polymer containing at least two groups which are independently the same or different a primary amine group or a secondary amine group and at least one saccharide containing a reducible function.
摘要:
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. The temperature is then reduced to a temperature below the glass transition temperature of the polymeric resin component in the fluid.
摘要:
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. Furthermore, by masking the tissue surface proteins from blood elements, the methods described herein are useful in decreasing graft thrombogenicity and reducing the complications of vascular surgery. Finally the methods described herein reduce the immunogenicity of transplanted tissues and cells and thereby reduce the need for immunosuppressive therapy.
摘要:
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.
摘要:
A tissue sealant is described that includes the reaction product of (a) a polyol having at least two groups capable of reacting with an alkoxy silane and (b) an alkoxy silane having the formula: (R1R2R3)—Si—CH2—Z where (i) Z is an —OH, —SH, —NCO, or —NHR4 group, where R4 is hydrogen or an alkyl group; and (ii) each R1, R2, and R3, independently, is H, an alkoxy group, an alkyl group, a heteroalkyl group other than an alkoxy group, an aryl group, or a heteroaryl group, with the proviso that at least two of R1, R2, and R3 are alkoxy groups. The tissue sealant is moisture-curable and biodegradable in a physiological environment.
摘要:
A composition includes at least one hydrophilic polymer containing primary (—NH2) and/or secondary (—NHR) amine groups and at least one saccharide containing a reducible function. A method of increasing the strength of paper includes the step of contacting the paper with a composition comprising (i) at least one hydrophilic polymer containing at least two groups which are independently the same or different a primary amine group or a secondary amine group and at least one saccharide containing a reducible function. A hydrogel composition is formed from a mixture of at least one hydrophilic polymer containing at least two groups which are independently the same or different a primary amine group or a secondary amine group and at least one saccharide containing a reducible function.
摘要:
A composition includes water; at least one hydrophilic polymer containing at least two groups which are independently the same or different a primary amine group or a secondary amine group and at least one saccharide containing a reducible function as described above. The hydrophilic polymer and the saccharide are mixed to form a reaction mixture and reacted to increase the viscosity of the reaction mixture. The reaction is then substantially terminated by reducing the pH of the composition. A method of increasing the strength of a cellulosic pulp product includes the steps of: contacting wet cellulosic pulp with a composition comprising (i) at least one hydrophilic polymer containing at least two groups which are independently the same or different a primary amine group or a secondary amine group and at least one saccharide containing a reducible function, the hydrophilic polymer and the saccharide of the composition having been reacted in a crosslinking reaction prior to contacting the composition with the cellulosic pulp product to increase the viscosity the composition; and, after contacting the cellulosic pulp with the composition, causing the crosslinking reaction between the hydrophilic polymer and the saccharide of the composition to proceed further.