97 results about "Hydrolytic degradation" patented technology

There is provided a backside protective sheet for a solar battery module that is excellent in strength as well as in various properties such as weathering resistance, heat resistance, water resistance, light resistance, wind pressure resistance, hailstorm resistance, chemical resistance, moisture resistance, antifouling properties, light reflectivity, light diffusivity, and design, and is particularly excellent in the so-called “moisture resistance,” which is the ability to prevent the entry of moisture, oxygen and the like, and durability against performance degradation with time, particularly against hydrolytic degradation and the like, and is also excellent in protective capability. There is also provided a backside protective sheet for a solar battery module, which can facilitate inventory control by properly using the front side and back side of the protective sheet depending upon applications and is excellent in cost performance, and a solar battery module using the same. The backside protective sheet for a solar battery module comprises: a deposited assembly comprising a vapor-deposited film of an inorganic oxide provided on at least one side of a substrate; and a transparent or translucent heat-resistant polyolefin resin layer provided on both sides of the deposited assembly.

A method for forming a biodegradable polylactic acid suitable for use in fibers is provided. Specifically, a polylactic acid is melt processed at a controlled water content to initiate a hydrolysis reaction. Without intending to be limited by theory, it is believed that the hydroxyl groups present in water are capable of attacking the ester linkage of polylactic acids, thereby leading to chain scission or “depolymerization” of the polylactic acid molecule into one or more shorter ester chains. The shorter chains may include polylactic acids, as well as minor portions of lactic acid monomers or oligomers, and combinations of any of the foregoing. By selectively controlling the hydrolysis conditions (e.g., moisture and polymer concentrations, temperature, shear rate, etc.), a hydrolytically degraded polylactic acid may be achieved that has a molecular weight lower than the starting polymer. Such lower molecular weight polymers have a higher melt flow rate and lower apparent viscosity, which are useful in a wide variety of fiber forming applications, such as in the meltblowing of nonwoven webs.

An ionic liquid according to the invention is substantially halogen-free, has a low viscosity and is stable to hydrolytic degradation under test conditions. The ionic liquid is a compound of the formula (cation) (R′—O—SO₃), (cation) (R′—SO₃), or a mixture of the two compounds. It can be used in processes for the chemical conversion and separation of materials by employing the ionic liquid as a solvent, solvent additive, extraction agent or phase-transfer catalyst. It can also be used in a heat exchange device wherein the ionic liquid serves as a heat carrier or heat carrier additive.

A resorbable interbody fusion device for use in spinal fixation is disclosed. The device is composed of 25–100% bioresorbable or resorbable material. The interbody fusion device of the invention can be in any convenient form, such as a wedge, screw or cage. Preferably, the resorbable device of the invention is in the shape of a tapered wedge or cone, which further desirably incorporates structural features such as serrations or threads better to anchor the device in the adjoining vertebrae. The preferred device further comprises a plurality of peripheral voids and more desirably a central void space therein, which may desirably be filled with a grafting material for facilitating bony development and/or spinal fusion, such as an autologous grafting material. As the preferred material from which the resorbable interbody fusion device is manufactured is most likely to be a polymer that can produce acidic products upon hydrolytic degradation, the device preferably further includes a neutralization compound, or buffer, in sufficiently high concentration to decrease the rate of pH change as the device degrades, in order to prevent sterile abscess formation caused by the accumulation of unbuffered acidic products in the area of the implant.

The invention provides a carrier-linked prodrugs, wherein the biologically active moieties comprise at least one carboxylic acid and wherein the linkage between the drug moiety and linker is in the form of an ester wherein the hydroxyl group required for ester formation is provided by the linker moiety and the carboxyl group required for ester formation is provided by the drug moiety. The hydroxyl group of the linker is sterically hindered by the presence of an alkyl or aryl group on the carbon directly bound to or adjacent to the carbon carrying the hydroxyl group (α-carbon). The steric effect of the alkyl or aryl group enables greater control of the rate of hydrolytic degradation of such carrier-linked prodrugs.

Novel bioabsorbable and/or biocompatible polyurethanes, polyureas, polyamideurethanes and polyureaurethanes with tunable physical, mechanical properties and hydrolytic degradation profiles are provided for use in biomedical applications such as stents, stent coatings, scaffolds, foams, and films. The disclosed polymers may be derived from biocompatible and/or bioabsorbable polyisocyanates. The present invention also relates to new and improved methods for the preparation of the biocompatible and/or bioabsorbable polyisocyanates.

The present invention provides NO and, optionally, drug releasing macromers and oligomers wherein the drug molecule and NO releasing moiety are linked an absorbable macromer or oligomeric chain susceptible to hydrolytic degradation and wherein the macromer or oligomer comprises of repeat units derived from safe and biocompatible molecules such as glycolic acid, lactic acid, caprolactone and p-dioxanone. Furthermore, the present invention relates to controlled release of nitric oxide (NO) and/or drug molecule from a NO and drug releasing macromer or oligomer. Moreover, the present invention also relates to medical devices, medical device coatings and therapeutic formulations comprising of nitric oxide and drug releasing macromers and oligomers of the present invention.

The invention provides new aliphatic diester-di-acid-containing PEA polymer compositions with significant improvement in hydrolytic degradation rates as compared to aliphatic di-acid-containing PEA polymers. The di-acids used in the invention PEA compositions include non-toxic fatty aliphatic homologs. These molecules inherently contain two-ester groups, which easily can be cleaved by biotic (enzymatic) and abiotic hydrolysis. Additional di-acid-type compounds useful for active polycondensation are α,ω-alkylene dicarboxylates composed of short aliphatic non toxic diols and di-acids. In addition, the invention PEA polymer compositions optionally can include a second monomer, such as a C-protected L-lysine-based monomer, to introduce additional chain flexibility into the polymer. The invention PEA polymer compositions are useful for delivery of bioactive agents when administered internally.

Poly(ethylene glycol) carbamate derivatives useful as water-soluble prodrugs are disclosed. These degradable poly(ethylene glycol) carbamate derivatives also have potential applications in controlled hydrolytic degradation of hydrogels. In such degradable hydrogels, drugs may be trapped in the gel and released by diffusion as the gel degrades, or they may be covalently bound through hydrolyzable carbamate linkages. Hydrolysis of these carbamate linkages releases the drug at a controllable rate as the gel degrades.

The invention discloses a dual-carbodiimide class compound and preparation as well as anti-hydrolysis application thereof. The invention relates to a dual-carbodiimide class compound and a preparation method thereof in a general formula (I), wherein R1, R2, R3, R4 and R5 are defined as in claim 1. The dual-carbodiimide class compound can be used as an anti-hydrolysis stabilizing agent to be added to polyurethane and polyester elastomers so as to prevent the hydrolytic degradation aging of the polyurethane and polyester elastomers with ester structures.

The invention relates to an antifouling hydrolysis degradation resin and a preparation method and application thereof. The antifouling hydrolysis degradation resin is prepared from the following raw materials in percent by weight: 15-100 percent of degradable polyols and 0-85 percent of diisocyanate and chain extender, wherein a molar ratio of the diisocyanate to the degradable polyols and the chain extender is 1.0-1.3. According to the invention, excellent hydrolysis property of a side chain silane ester and degradation property of a main chain are combined, a new surface can be updated through a hydrolysis degradation function without seawater flushing, the dependence of the traditional self-polishing material on the navigational speed is overcome, and antifouling requirements of a low-speed ship, a submarine and an offshore production platform are well met. In addition, due to the introduction of the diisocyanate and the chain extender, on the premise that the hydrolysis degradation property is controllable, excellent mechanical property and adhesive force of polyurethane are combined. The preparation method is simple in process and low in cost, is suitable for industrial production, and has a good application prospect in the field of preparation of sea antifouling coatings.

Among other aspects, provided herein is a mixed-acid salt of a water-soluble polymer-drug conjugate, along with related methods of making and using the same. The mixed-salt acid salt is stably formed, and appears to be more resistant to hydrolytic degradation than the corresponding predominantly pure acid salt or free base forms of the polymer-drug conjugate. The mixed acid salt is reproducibly prepared and recovered, and provides surprising advantages over non-mixed acid salt forms of the water-soluble polymer drug conjugate.

Solid oral dosage forms that include melt granules of a moisture-sensitive therapeutic compound and a hydrophobic melt component. The melt granules better protect the therapeutic compound from hydrolytic degradation. Such solid oral dosage forms also possess immediate-release characteristics rather than that associated with extended-release or controlled-release drug products.

A non-blooming plasticizer composition and methods of using the composition are described herein. The composition is a mixture of sorbitol and sorbitan wherein the ratio of sorbitan and sorbitol is between about 0.40 and about 1.2 by weight, more preferably from about 0.45-0.50 to about 0.70 by weight, wherein the composition contains less than 20% of other dextrose hydrolytic degradation products. The non-blooming plasticizer compositions can be mixed, alone or in combination with other shell additives, with gelatin or non-gelatin materials to prepare soft capsules for the delivery of pharmaceutical, nutritional and personal care products, such as bath oils, shampoos and conditioners, and skin lotions.

The invention discloses a bi-metal water-cooling casting mold for preparing aluminum alloy capable of achieving hydrolytic degradation. The bi-metal water-cooling casting mold comprises an internal mold casting cavity (4), casting mold external metal (3), a water inlet flow regulating valve (5) and a water outlet flow regulating valve (6). A metal ring (2) is in sealing connection with the internal mold casting cavity (4) and the casting mold external metal (3) by means of welding or interference fit so that an annular water-cooling cavity (1) can be formed. The water outlet flow regulating valve (6) and the water inlet flow regulating valve (5) communicating with the annular water-cooling cavity (1) are arranged at the upper end and the lower end of the casting mold external metal (3) separately. The water flow velocity and water flow rate can be controlled through the water inlet flow regulating valve (5) and the water outlet flow regulating valve (6), the internal mold casting cavity (4) is provided with an upper end mold casting chamfer (alpha), and the internal mold casting cavity (4) has a tilting angle (beta) in an outward mode relative to the vertical plane.

The invention belongs to the field of preparation of nanomaterials and particularly relates to a preparation method of a degradable silicon dioxide particle internally doped with a polyphenol-metal mesh. According to the preparation method, a silicon dioxide polycondensation network system is doped with a metal-polyphenol coordinated and complexed network structure, so that porosity of silicon dioxide is increased; and the polycondensation degree of silicon dioxide is further weakened by virtue of a hydrogen-bond interaction between hydroxyl and silanol, so that the hydrolytic degradation of silicon dioxide is accelerated. The metal-polyphenol coordinated and complexed network structure can be dissociated under faintly-acid and high-glutathione environments so as to induce the collapse of a silicon dioxide skeleton structure, nano-particles are degraded into smaller fragments, and then silicic acid molecules, polyphenol molecules and metal ions are further degraded and extracted, so that the self-degradation of a drug carrier in a tumor microenvironment is realized.

The invention discloses a production technology for a heat shrinkable polyester film and relates to the package material field. The production technology comprises the following technologies: slicing, vacuum drying, melt extrusion, quenching slice casting, biaxial tension, cooling and rolling slitting. Amorphous polyethylene glycol terephthalate is selected as a raw material, amorphous polyethylene glycol terephthalate is easy to recycle, nontoxic and odourless, has good mechanical properties, and meets environment protection requirements. Heat is transferred to materials to be dried through a drier shell under the vacuum environment, and therefore the purpose of drying reinforcement is achieved. The softening point of polymers is raised effectively, adhesion and agglomeration of resin particles are avoided during the drying and melt extrusion processes, moisture in resins can be removed, and hydrolytic degradation and bubble generation of polymers containing ester groups are prevented during the melt extrusion process. The ways of segmented heating and segmented processing are beneficial for fusion of molecules, and avoid material deterioration caused by too fast heating. the intensity of the produced shrinkable film is raised, and the shrinkable film has impact resistance.

This invention relates to hydrolytically degradable gels of crosslinked poly(ethylene) glycol (PEG) structures. Addition of water causes these crosslinked structures to swell and become hydrogels. The hydrogels can be prepared by reacting two different PEG derivatives containing functional moieties at the chain ends that react with each other to form new covalent linkages between polymer chains. The PEG derivatives are chosen to provide covalent linkages within the crosslinked structure that are hydrolytically degradable. Hydrolytic degradation can provide for dissolution of the gel components and for controlled release of trapped molecules, including drugs. Reagents other than PEG can be avoided. The hydrolysis rates can be controlled by varying atoms adjacent to the hydrolytically degradable functional groups to provide substantially precise control for drug delivery in vivo.

A method for forming a biodegradable polyester suitable for use in fibers is provided. Specifically, a biodegradable polyester is melt processed at a controlled water content to initiate a hydrolysis reaction. Without intending to be limited by theory, it is believed that the hydroxyl groups present in water are capable of attacking the ester linkage of the polyester, thereby leading to chain scission or “depolymerization” of the polyester molecule into one or more shorter ester chains. By selectively controlling the reaction conditions (e.g., water content, temperature, shear rate, etc.), a hydrolytically degraded polyester may be achieved that has a molecular weight lower than the starting polymer. Such lower molecular weight polymers have a higher melt flow rate and lower apparent viscosity, which are useful in a wide variety of fiber forming applications, such as in the meltblowing of nonwoven webs.