2271 results about "Endcapping" patented technology

Sealant and potting formulations are provided which are prepared from components including ungelled mercapto-terminated polymer(s) prepared by reacting reactants comprising polyvinyl ether monomer(s) and polythiol material(s); curing agent(s) reactive with a mercapto group of the mercapto-terminated polymer; and additive(s) selected from the group consisting of fillers, adhesion promoters, plasticizers and catalysts.

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

The present invention relates to polymeric compositions useful in the manufacture of biocompatible medical devices. More particularly, the present invention relates to certain cationic monomers capable of polymerization to form polymeric compositions having desirable physical characteristics useful in the manufacture of ophthalmic devices. Such properties include the ability to extract the polymerized medical devices with water. This avoids the use of organic solvents as is typical in the art. The polymer compositions comprise polymerized silicon-containing monomers end-capped with polymerizable cationic hydrophilic groups.

A nanostructure composed of a plurality of peptides, each peptide containing at least one aromatic amino acid, whereby one or more of these peptides is end-capping modified, is disclosed. The nanostructure can take a tubular, fibrillar, planar or spherical shape, and can encapsulate, entrap or be coated by other materials. Methods of preparing the nanostructure, and devices and methods utilizing same are also disclosed.

Acrylate-terminated poly(beta-amino esters) are cross-linked to form materials useful in the medical as well as non-medical field. The polymeric starting material is combined with a free radical initiator, either a thermal initiator or a photoinitiator, and the mixture for cross-linking is heated or exposed to light depending on the initiator used. The resulting materials due to the hydrolysable ester bond in the polymer backbone are biodegradable under physiological conditions. These cross-linked materials are particular useful as drug delivery vehicles, tissue engineering scaffolds, and in fabricating microdevices. The materials may also be used as plastics, coating, adhesives, inks, etc. The cross-linked materials prepared exhibit a wide range of degradation times, mass loss profiles, and mechanical properties. Therefore, the properties of the material may be tuned for the desired use. The high-throughput approach to preparing a library of cross-linked poly(beta-amino esters) allows for the rapid screening and design of degradable polymers for a variety of applications.

A polymerizable liquid, or resin, useful for the production by additive manufacturing of a three-dimensional object of polyurethane, polyurea, or a copolymer thereof, is described. The resin includes at least one of (i) a blocked or reactive blocked prepolymer, (ii) a blocked or reactive blocked diisocyanate, or (iii) a blocked or reactive blocked diisocyanate chain extender.

A method of forming a three-dimensional object of polyurethane, polyurea, or copolymer thereof is carried out by: (a) providing a carrier and an optically transparent member having a build surface, the carrier and the build surface defining a build region therebetween; (b) filling the build region with a polymerizable liquid, the polymerizable liquid including at least one of: (i) a blocked or reactive blocked prepolymer, (ii) a blocked or reactive blocked diisocyanate, or (iii) a blocked or reactive blocked diisocyanate chain extender; (c) irradiating the build region with light through the optically transparent member to form a solid blocked polymer scaffold and advancing the carrier away from the build surface to form a three-dimensional intermediate having the same shape as, or a shape to be imparted to, the three-dimensional object, with the intermediate containing the chain extender; and then (d) heating or microwave irradiating the three-dimensional intermediate sufficiently to form from the three-dimensional intermediate the three-dimensional object of polyurethane, polyurea, or copolymer thereof.

A hot melt adhesive composition, comprising a blend of components including about 10% to about 40% by weight of an elastomeric block copolymer, preferably styrene-isoprene-styrene (SIS) or styrene-butadiene-styrene (SBS), about 15% to about 70% by weight of a first midblock tackifying resin having a softening point of at least about 110° C. and having an aromatic content of at least about 1.5% by weight; about 0 to 55% of second midblock tackifying resin, about 5% to about 35% by weight of a plasticizer; and about 0% to about 20% by weight of an end block resin having a softening point lower than 125° C.; wherein the components total 100% by weight of the composition, the viscosity of the composition is equal to or less than about 20,000 mPa.s at 120° C., and is applied at a temperature lower that 150° C. and initial bond retention of the composition on elastic strands is at least about 60%. Also, the elastic modulus G′ of the composition is higher than about 5000 Pa, the vicous modules G″ is higher than about 50 Pa, and the tan delta value is between about 0.5 and about 60. Laminates, especially those used in disposable soft goods, and methods of making such laminates are also described. The adhesive composition and/or laminate may be used in making a variety of end products such as a disposable diaper, a sanitary napkin, a bed pad, a bandage, a surgical drape, a tape, a label, a plastic sheet, a nonwoven sheet, a paper sheet, a cardboard, a book, a filter, or a package.

Vinyl carbonate endcapped polysiloxanes containing a fluorinated side chain are useful as biomaterials, especially hydrogel biomaterials, including contact lens materials.

A method of synthesizing an endcapped polymer, comprising reacting in a solvent a cationic living polymer with an optionally substituted conjugated diene as an endcapping reagent, whereby the solvent causes termination by halogenation to be faster than the addition of additional molecules of the conjugated diene, thereby producing an endcapped polymer having a halogenated endcap group.

The present invention relates to a process for preparing organyloxysilyl-terminated polymers which have increased stability toward atmospheric moisture, by reacting hydroxy-terminated organic polymers with isocyanato-functional silanes in the presence of at least one catalyst selected from the group consisting of bismuth and zinc compounds, and to crosslinkable compositions comprising such polymers.

Free flowing filler composition based on organofunctional silane and/or mixtures of organofunctional silanes possessing mercaptan and blocked mercaptan functionality. The invention also relates to articles of manufacture, particularly tires, made from the elastomer compositions described herein.

The present invention relates to reactive compositions containing A) one or more blocked polyurethane prepolymers which have a content of blocked isocyanate groups (calculated as NCO) of 0.1 to 20 wt. % and are prepared from i) at least one aromatic, aliphatic, araliphatic and/or cycloaliphatic diisocyanate having a content of free NCO groups of 5 to 60 wt. %, ii) a polyol component containing at least one polyester polyol, and/or at least one polyether polyol and/or at least one polycarbonate polyol,

iii) CH-acidic cyclic ketones corresponding to formula (I) as blocking agents

wherein X represents an electron-attracting group,

• R¹ and R² independently of one another represent the radicals H,
• C₁-C₂₀ (cyclo)alkyl, C₆-C₂₄ aryl, C₁-C₂₀ (cyclo)alkyl ester or amide, C₆-C₂₄ aryl ester or amide, mixed aliphatic/aromatic radicals with 1 to 24 carbon atoms that can also be part of a 4- to 8-membered ring, n is an integer from 0 to 5, and B) one or more OH-functional compounds in which the OH component undergoes activation by a deposition amine component. The present invention also relates to a composite system containing two adherends bonded together with the reactive composition according to the invention.

The invention provides a sulfur vulcanizable silica-reinforced elastomeric compound having improved tensile mechanical and dynamic viscoelastic properties. The compounds are formed by mixing an elastomer optionally having an alkoxysilane terminal group, with silica in the presence of an alkyl alkoxysilane and a blocked mercaptosilane. In particular, the mercaptosilane moiety of the blocked mercaptosilane and the alkyl alkoxysilane are present in a weight ratio of about 0.001:1 to about 0.20:1. Preferably, the blocked mercaptosilane and the alkyl alkoxysilane are compounded with the elastomer and the silica at high temperature to facilitate the silica-silane reaction. A deblocking agent is added at any desired mixing stage, optionally with the cure package, to allow binding of the mercaptosilane to the polymer.

The invention provides an article comprising, a mesoporous silicate matrix, such as a particle, having one or more pores; and one or more releasable caps obstructing one or more of the pores. The articles are useful as delivery vehicles for encapsulated agents such as therapeutic agents, polynucleotides, polypeptides and the like.

The polishing pad is suitable for planarizing at least one of semiconductor, optical and magnetic substrates. The polishing pad includes a cast polyurethane polymeric material formed with an isocyanate-terminated reaction product formed from a prepolymer reaction of a prepolymer polyol and a polyfunctional isocyanate. The isocyanate-terminated reaction product has 4.5 to 8.7 weight percent NCO reaction group; and the isocyanate-terminated reaction product is cured with a curative agent selected from the group comprising curative polyamines, curative polyols, curative alcoholamines and mixtures thereof. The polishing pad contains at least 0.1 volume percent filler or porosity.

Epoxy-capped polythioethers, amine/hydroxy-capped polythioethers, and curable compositions of epoxy-capped polythioethers are disclosed.