16530 results about "Prepolymer" patented technology

Fast curing surgical adhesives and sealants contain an NCO-terminated hydrophilic urethane prepolymer derived from an aromatic diisocyanate and a polyol. Substantially all the aromatic diisocyanate used to prepare the NCO-terminated hydrophilic urethane prepolymer is in the para form. Optionally, the aromatic diisocyanate is substituted with at least one electron withdrawing group, such as, for example, a fluorine group.

An extrusion-based freeform fabrication method for making a three-dimensional object from a design created on a computer, including (a) providing a support member; (b) operating a dispensing head having at least one dispensing nozzle with a discharge orifice for dispensing continuous strands of a material composition in a fluent state at a first temperature onto the support member, the material composition including a reactive prepolymer with a melting point above 23° C. and the first temperature being greater than the prepolymer melting point; (c) operating material treatment devices for causing the dispensed strands of material composition to rapidly achieve a rigid state in which the material composition is substantially solidified to build up the 3-D object, the material treatment devices also working to convert the reactive prepolymer to a higher molecular weight thermoplastic resin; and (d) operating control devices for generating control signals in response to coordinates of the object design to control the movement of the dispensing nozzle relative to the support member and for controlling the strand dispensing of the material composition to construct the 3-D object.

The invention provide a new class of silicone-containing prepolymers containing dangling polysiloxane-containing polymer chains. This class of silicone-containing prepolymer is capable of being actinically crosslinked to form a silicone hydrogel material with a relatively high oxygen permeability, a reduced elastic modulus, and a relatively high ion permeability. The present invention is also related to silicone hydrogel contact lenses made from this class of silicone-containing prepolymers and to methods for making the silicone hydrogel contact lenses.

The invention provide a new lens curing method for making hydrogel contact lenses. The new lens curing method is based on actinically-induced step-growth polymerization. The invention also provides hydrogel contact lenses prepared from the method of the invention and fluid compositions for making hydrogel contact lenses based on the new lens curing method. In addition, the invention provide prepolymers capable of undergoing actinically-induced step-growth polymerization to form hydrogel contact lenses.

The invention is a composition comprising applying to a substrate a stream of an adhesive comprising: one or more epoxy resins; one or more rubber modified epoxy resins; one or more toughening compositions comprising the reaction product of one or more isocyanate terminated prepolymers and one or more capping compounds having one or more phenolic, benzyl alcohol, aminophenyl, or, benzylamino groups wherein the reaction product is terminated with the capping compounds; one or more curing agents for epoxy resins and one or more catalysts which initiate cure at a temperature of about 100° C. or greater; and optionally; fillers adhesion promoters, wetting agents or rheological additives useful in epoxy adhesive compositions; wherein the adhesive composition has a viscosity at 45° C. of about 20 Pa.s to about 400 Pa.s. The composition can be used as an adhesive and applied as a stream using a high speed streaming process.

The invention provide a new class of silicone-containing prepolymers containing dangling hydrophilic polymer chains. This class of silicone-containing prepolymer is capable of being actinically crosslinked to form a silicone hydrogel material with a hydrophilic surface without post curing surface treatment. The present invention is also related to silicone hydrogel contact lenses made from this class of silicone-containing prepolymers and to methods for making the silicone hydrogel contact lenses.

Methods for preparing a biochip are provided herein wherein the biomolecular probe to be used with the biochip is alternatively bound to a hydrogel prepolymer prior to or simultaneously with polymerization of the prepolymer. In particularly preferred embodiments, a polyurethane-based hydrogel prepolymer is derivatized with an organic solvent soluble biomolecule, such as a peptide nucleic acid probe in aprotic, organic solvent. Following derivatization of the prepolymer, an aqueous solution, for example sodium bicarbonate, preferably buffered to a pH of about 7.2 to about 9.5, is added to the derivatized prepolymer solution to initiate polymerization of the hydrogel. Alternatively, a water soluble biomolecule, such as DNA or other oligonucleotide, is prepared in an aqueous solution and added to the polyurethane-based hydrogel prepolymer such that derivatization and polymerization occur, essentially, simultaneously. While the hydrogel is polymerizing, it is microspotted onto a solid substrate, preferably a silanated glass substrate, to which the hydrogel microdroplet becomes covalently bound. Most preferably the hydrogel microdroplets are at least about 30 mum thick, for example about 50 mum to about 100 mum thick. The resulting biochips are particularly useful for gene discovery, gene characterization, functional gene analysis and related studies.

A process for preparing a polymer having a 2,5-furandicarboxylate moiety within the polymer backbone and having a number average molecular weight of at least 10,000 (as determined by GPC based on polystyrene standards) includes a first step where a prepolymer is made having the 2,5-furandicarboxylate moiety within the polymer backbone, followed in a second step by a polycondensation reaction. In the first step a 2,5-furandicarboxylate ester is transesterified with a compound or mixture of compounds containing two or more hydroxyl groups, in the presence of a tin(IV) based transesterification catalyst. In the second step at reduced pressure and under melt conditions the prepolymer prepared in the first step is polycondensed in the presence of a tin (II) based polycondensation catalyst until the polymer is obtained. This polymer may then be subjected to Solid State Polycondensation. Polymers so produced may have a 2,5-furandicarboxylate moiety within the polymer backbone, and having a number average molecular weight of at least 20,000 (as determined by GPC based on styrene standards), and an absorbance as a 5 mg/mL solution in a dichloromethane:hexafluoroisopropanol 8:2 at 400 nm of below 0.05.

A process for the manufacture of polytrimethylene ether glycol comprising the steps of: (a) providing (1) 1,3-propanediol reactant selected from the group consisting of 1,3-propanediol and/or oligomers or prepolymers of 1,3-propanediol having a degree of polymerization of 2-9 and mixtures thereof, and (2) a polycondensation catalyst; and (b) polycondensing the 1,3-propanediol reactant to form a polytrimethylene ether glycol at less than one atmosphere pressure, and the product of the process. In addition, polytrimethylene ether glycol has a number average molecular weight greater than 1,500, an APHA color of less than 120, an unsaturation of less than 20 meq/kg, and a content of cyclic ether oligomers of less than 2%.

The invention is an epoxy resin based adhesive composition comprising an epoxy resin and a compound comprising an elastomeric prepolymer residue selected from the group of a polyurethane, a polyurea and a polyurea polyurethane having isocyanate end groups, the isocyanate end groups of said prepolymer residue being capped by a capping compound selected from the group consisting of a primary aliphatic, cycloaliphatic, heteroaromatic and araliphatic amine, a secondary aliphatic, cycloaliphatic, aromatic, heteroaromatic and araliphatic amine, a thiol and an alkyl amide, said capping compound being bound to the end of the polymer chain of the elastomeric prepolymer in a manner such that the end to which it is bonded no longer has a reactive group. In addition to the capping compound defined above above, a capping compound selected from the group consisting of a phenol and a polyphenol can be used for capping the isocyanate end groups of the prepolymer residue

In one embodiment the invention is a polymerizable composition comprising a) an organoborane amine complex; b) one or more of monomers, oligomers or polymers having olefinic unsaturation which is capable of polymerization by free radical polymerization; c) one or more compounds, oligomers or prepolymers having a siloxane backbone and reactive moieties capable of polymerization; and d) a catalyst for the polymerization of the one or more compounds, oligomers or prepolymers having a siloxane backbone and reactive moieties capable of polymerization. This composition may further comprise a compound which causes the organoborane amine complex to disassociate. In a preferred embodiment, the two part composition further comprises a compound which is reactive with both the b) one or more of monomers, oligomers or polymers having olefinic unsaturation which is capable of polymerization by free radical polymerization; and the c) one or more compounds, oligomers or prepolymers having a siloxane backbone and reactive moieties capable of polymerization. This composition can be polymerized by contacting the two parts of the composition. In another embodiment the invention is an organoborane amine complex comprising an alkyl borane having ligands which are alkyl, cycloalkyl or both and an amino siloxane.

A polyurethane based prepolymer is provided and useful in biomedical devices which provides high oxygen permeability and superior physical properties. A hydrogel is produced from a comonomer mixture containing a polysiloxane-containing urethane prepolymer, tris(trimethylsiloxy)-silylpropyl methacrylate and a hydrophilic comonomer. The hydrogel is especially useful for biomedical materials such as contact lenses and implants.

The present invention relates to biocompatible, biodegradable polyurethane/urea polymeric compositions that are capable of in-vivo curing with low heat generation to form materials suitable for use in scaffolds in tissue engineering applications such as bone and cartilage repair. The polymers are desirably flowable and injectable and can support living biological components to aid in the healing process. They may be cured ex-vivo for invasive surgical repair methods, or alternatively utilized for relatively non-invasive surgical repair methods such as by arthroscope. The invention also relates to prepolymers useful in the preparation of the polymeric compositions, and to methods of treatment of damaged tissue using the polymers of the invention.

The invention provide a class of actinically-crosslinkable silicone-containing prepolymers which comprise dangling polysiloxane chains each having a terminal ethylenically-unsaturated group and are obtained in a one-step of RAFT polymerization of a reactive mixture comprising a polysiloxane crosslinker, a hydrophilic vinylic monomer, a RAFT agent, and a free-radical initiator. The present invention is also related to silicone hydrogel contact lenses made from a prepolymer of the invention and methods for making the contact lenses in a cost-effective way and with high consistency and high fidelity to the original lens design.

The present invention provides a water-soluble crosslinkable polyurea prepolymer. The crosslinkable polyurea prepolymer of the invention is prepared by reacting an amine- or isocyanate-capped polyurea with a multifunctional compound having at least one one ethylenically unsaturated group and a function group coreactive with the capping amine or isocyanate groups of the amine- or isocyanate-capped polyurea. The amine- or isocyanate-capped polyurea is a copolymerization production of: (a) at least one poly(oxyalkylene)diamine, (b) optionally at least one organic di- or poly-amine, (c) optionally at least one diisocyanate, and (d) at least one polyisocyanate. The crosslinkable polyurea prepolymer of the invention can find use in economically producing contact lenses which have durable, highly elastic soft contact lenses with desired physical properties. In addition, the present invention provides method for making a medical device, preferably an ophthalmic device, more preferably a contact lens.

This invention relates to a process for producing a polyester comprising the steps of:

• • (g) obtaining an aqueous homogenous solution of isosorbide;
  • (h) feeding the aqueous homogenous solution of step (a) into a reactor;
  • (i) feeding one or more glycols and one or more dicarboxylic acids either into the aqueous solution of step (a) or into the reactor of step (b) either prior to, during and/or subsequent to step (b);
  • (j) esterifying the reactor contents at sufficient temperatures and pressures, and optionally in the presence of suitable catalysts, to effect esterification;
  • (k) forming a prepolymer; and
  • (l) polycondensing the prepolymer at sufficient temperatures and pressures in the presence of a suitable catalyst to effect polycondensation to form a polyester.

A biodegradable polymer is provided for use in providing syringeable, in-situ forming, solid biodegradable implants for animals. The polymer is placed into the animal in liquid form and cures to form the implant in-situ. A thermoplastic system to form said implant comprises the steps of dissolving a non-reactive polymer in biocompatible solvent to form a liquid, placing the liquid within the animal, and allowing the solvent to dissipate to produce the implant. An alternative, thermosetting system comprises mixing together effective amounts of a liquid acrylic ester terminated, biodegradable prepolymer and a curing agent, placing the liquid mixture within an animal and allowing the prepolymer to cure to form the implant. Both systems provide a syringeable, solid biodegradable delivery system by the addition of an effective level of biologically active agent to the liquid before injection into the body.

The invention relates to an immobilized microorganism preparation method in biochemical technical field, comprising the following steps: step 1, preparing a solution of which preparation method per 100ml comprises the following steps: (1) dissolving 12-18g of polyethylene glycol prepolymer in water to obtain a solution A; (2) adding microorganism in the solution A, then adding 0.5-1g of N,N-dimethylbisacrylamide and 0.05-0.1g of silicon dioxide, then adding 0.05-0.2g of diethoxyacetophenone and obtaining a solution B; (3) adding water in the solution B to ensure the volume of the obtained solution is 100ml, mixing evenly and obtaining the desired solution; step 2, placing the solution obtained in the step 1 under a ultraviolet lamp for curing, cutting, and washing to obtain the immobilized microorganism. The method of the invention can be performed at room temperature, the reaction process is easy to control and the prepared embedded bacteria particles have longer service life.

A polyurethane adhesive which is useful in bonding porous and non-porous surfaces is provided. The adhesive is especially useful in bonding windshield glass into automotive frames under a variety of environmental conditions, particularly in after market windshield replacement applications. The polyurethane includes at least one urethane prepolymer which is based on at least one thermoplastic polyol. In one embodiment, the urethane prepolymer may be formed from one or more polyisocyanates, one or more polyetherpolyols and one or more thermoplastic polyesterpolyols, wherein the prepolymer has a free isocyanate content of from about 0.6 to about 3.5 % by weight, based on the weight of the polyurethane. In another embodiment, a one-part adhesive composition is provided which includes an isocyanate-functional and thermoplastic polyurethane prepolymer having a free isocyanate content of from about 0.6 to about 3.5 % by weight, based on the weight of the polyurethane, and a combination of several catalysts which are capable of catalyzing the reaction of isocyanate moieties with isocyanate-reactive moieties while providing less temperature dependent catalyzing of the reaction between isocyanate moieties and water. Also provided is a process for bonding two or more substrates together utilizing the polyurethane adhesive. In automotive windshield replacement applications, the polyurethane adhesive allows for a sufficient working time and development of green strength to provide a safe drive-away time within 1 hour at a temperature from about 0 to about 100° C.