9318 results about "Condensation reaction" patented technology

Polymer blends are disclosed that comprise one or more unsaturated olefinic homopolymers or copolymers having at least one functionality capable of entering into condensation reactions; one or more polyamide homopolymers or copolymers; one or more polyethylene terephthalate homopolymers or copolymers obtained using a catalyst system comprising antimony atoms; and one or more transition metal atoms. The inventive blends are useful for packaging, and exhibit improved oxygen-scavenging activity and lower haze compared with blends made using polyethylene terephthalate polymers prepared with antimony catalyst and either the olefinic or the polyamide homopolymers or copolymers, individually.

A novel environmentally responsive polymeric system is provided for biomedical applications, comprising silicon-containing reactive groups which undergo a hydrolysis-condensation reaction at a predetermined body site and thereby change rheological and mechanical properties of the polymeric system. The polymeric system is useful, for example, as a sealant, as a matrix for drug delivery, in the prevention of post-surgical adhesions, and in gene therapy.

The invention relates to a novel preparing method for an in-situ nitrogen-doped porous carbon material, the application of the in-situ nitrogen-doped porous carbon material serving as a carrier of a load type catalyst, the load type catalyst comprising the in-situ nitrogen-doped porous carbon material, and the application of the load type catalyst in the water phase alcohol condensation reaction. Cheap micromolecule nitrogen substances serve as a nitrogen source of the in-situ nitrogen-doped porous carbon material, nitrogen atom in-situ doping is achieved in the carbon material preparing process, the doping content of the in-situ nitrogen-doped porous carbon material is controllable, the in-situ nitrogen-doped porous carbon material is distributed evenly, the dispersity of metal in the carrier and the combining strength with the carrier can be improved through doping of nitrogen atoms, and therefore the catalytic activity of the nitrogen-doped porous carbon material can be improved, and the service life of the nitrogen-doped porous carbon material can be prolonged.

A water-base resin has both excellent storage stability and excellent curability at room temperature, the water base resin being obtained by mixing a composite resin (C) and a polysiloxane (D), bringing about a condensation reaction partially between them if necessary, and thereafter dispersing or dissolving the resulting mixture or partially condensed product into a water-base medium, wherein the composite resin (C) comprises a polysiloxane segment (A) and a polymer segment (B), the polysiloxane segment (A) having at least one silicon atom selected from the group consisting of a silicon atom bearing at least one organic group having a total carbon number of at least 3 together with at least one hydrolyzable group and/or at least one hydroxyl group, a silicon atom bearing one hydrolyzable group or one hydroxyl group together with two groups selected from the group consisting of methyl groups and ethyl groups, and a silicon atom bearing at least one triorganosiloxy group together with at least one hydrolyzable group and/or at least one hydroxyl group, and the polymer segment (B) having at least one type of hydrophilic group selected from the group consisting of an anionic group, a cationic group, and a non-ionic group, and wherein the polysiloxane (D) has a hydrolyzable group bonded to a silicon atom and/or a hydroxyl group bonded to a silicon atom, the polysiloxane (D) having a structure represented by the following structural formula (S-I) as an essential structural unit:(wherein R1 in the formula denotes a methyl group or an ethyl group). A water-base curable resin composition comprising the water-base resin as an essential component produces a cured material which possesses excellent resistance stain during outdoor exposure as well as excellent durability such as acid rain resistance and gloss retention during outdoor exposure.

The object of the present invention is to provide a method for producing a polyether polyol which is little colored and has a high degree of polymerization in high yield by a dehydration-condensation of a polyol. In the present invention, a dehydration-condensation reaction is carried out in the presence of a catalyst composed of an acid and a base.

The present invention provides a curable polysiloxane composition which is excellent in light resistance (particularly ultraviolet resistance) and adhesion and has a sufficient heat resistance/hydrothermal resistance and film-forming property and which generates little foaming at curing and does not generate cracks, peeling, coloring, and foaming even when used for a long period of time. A curable polysiloxane composition which comprises a specific hydrosilyl group-containing polysiloxane compound, a specific polysiloxane compound comprising two or more silanol groups in one molecule, and a dehydrogenative condensation reaction catalyst.

The invention discloses an industrial production process for tenofovir disoproxil fumarate represented by a structural formula (II). The production process comprises the following steps of: (1) preparing R-9-(2-hydroxypropyl)adenine by taking adenine and R-propylene carbonate as initial raw materials; (2) performing a condensation reaction on the obtained R-9-(2-hydroxypropyl)adenine and diethyl(tosyloxy)methylphosphonate under the catalytic action of magnesium alkoxide to prepare R-9[2-(diethyl-phosphonic acid methoxy)propyl]adenine; (3) hydrolyzing R-9[2-(diethyl-phosphonic acid methoxy)propyl]adenine to obtain tenofovir; and (4) performing condensation on the tenofovir and the chloromethyl isopropyl carbonate under the catalytic action of triethylamine to prepare the tenofovir disoproxil fumarate. The process of the invention has the characteristics of low cost, safe process, high product quality and suitability for industrial production.

A curable composition comprising (A) an organopolysiloxane having functional groups capable of condensation reaction at both molecular terminals thereof and (B-1) a hydrophobic silica and a hydrophilic silica. A curable composition comprising (A) an organopolysiloxane having functional groups capable of condensation reaction at both molecular terminals thereof and (B-2) a hydrophobic silica, wherein the hydrophobic silica (B-2) is thermally treated together with the organopolysiloxane (A).

A method preparing controlled release nitrogen in particulate fertilizers which exhibit single growing season availabilities to plants of about 80 percent or higher. The method utilizes relatively low urea and ammonia to formaldehyde mol ratios of about 1.7 urea to 0.1 ammonia to 1 formaldehyde to assure high conversions to controlled release nitrogen with low free ureas, and carefully controlled elevated temperatures, acid dehydration condensation catalyst concentrations and short dehydration reaction times of about 2-4 minutes to provide effective conversion of hydroxymethyl nitrogen compounds by dehydration condensation reaction to controlled release methylene nitrogen compounds. Quick neutralization of the dehydration catalyst in a turbulent mixing reactor minimizes the formation of undesirable methylene nitrogen polymers which are hot water insoluble and unavailable to plants in a single growing season.

The invention provides a process for producing a modified conjugated diene based polymer which attains favorable interaction between a rubber component and carbon black and/or silica, thereby improving dispersibility of the fillers, and which exhibits excellent properties such as heat-buildup-suppressing performance, fracture characteristics, and wear resistance; a modified conjugated diene based polymer produced through the process; a rubber composition containing the diene polymer; and a tire produced from the rubber composition and exhibiting the above properties. The process for producing a modified conjugated diene based polymer includes a step (a) of reacting a silicon compound with a conjugated diene based polymer having an active end so that the reaction takes place at the active end, the silicon compound having a protected primary amino group in the molecule thereof and a bi-functional silicon atom to which a hydrocarbyloxy group and a reactive group including a hydrocarbyloxy group are bonded, to thereby modify the active end, and a step (b) of performing condensation reaction which involves the compound having a bi-functional silicon atom, in the presence of a titanium compound serving as a titanium-based condensation-accelerating agent.

A full fill trench structure comprising a microelectronic device substrate having a high aspect ratio trench therein and a full filled mass of silicon dioxide in the trench, wherein the silicon dioxide is of a substantially void-free character and has a substantially uniform density throughout its bulk mass. A corresponding method of manufacturing a semiconductor product is described, involving use of specific silicon precursor compositions for use in full filling a trench of a microelectronic device substrate, in which the silicon dioxide precursor composition is processed to conduct hydrolysis and condensation reactions for forming the substantially void-free and substantially uniform density silicon dioxide material in the trench. The fill process may be carried out with a precursor fill composition including silicon and germanium, to produce a microelectronic device structure including a GeO₂/SiO₂ trench fill material. A suppressor component, e.g., methanol, may be employed in the precursor fill composition, to eliminate or minimize seam formation in the cured trench fill material.

The invention discloses a method for preparing a compound of a formula (I) or pharmaceutically acceptable salts thereof. The method is characterized by comprising the following steps of: (1) using a compound of a formula (II) as a raw material and carrying out a reduction and amination reaction with an appropriate reducing agent to obtain a compound of a formula (III); (2) using 2-quinary heterocyclic substituted ethanol as a raw material and reacting to obtain a compound of a formula (IV) under the conditions of appropriate reagent, temperature and solvent; (3) after carrying out chiral separation on the compound of the formula (III), carrying out a condensation reaction with the compound of the formula (I) under an alkaline condition to obtain a compound of a formula (V); and (4) carrying out demethylation protection on the compound of the formula (V) under the condition of appropriate temperature and solvent to obtain the compound of the formula (I), wherein R1 in each formula is selected from C1-8 alkyl groups or aromatic bases which can be arbitrarily substituted, X is selected from halogen atoms or p-toluenesulfonic acid groups and methanesulfonic acid groups for protecting alcoholic extract hydroxyl groups, and Y is selected from O, S and N. A target product obtained by the method has high optical purity, convenient operation, lower cost, higher yield and less pollution and is suitable for industrialized production.

Provided is a film having a low refractive index, which can be formed under normal temperature and pressure while obtaining a lower refractive index, has excellent adhesion with a solid substrate, and does not lose geometric optical properties, such as the diffusibility or light-harvesting capability attributed to the microstructure. Also disclosed is a method for producing the same. The film having a low refractive index is obtained by causing an electrolyte polymer and microparticles to be alternately adsorbed on the surface of a solid substrate and bringing the resulting microparticle-laminated film into contact with a silicon compound solution in order to bond the solid substrate with microparticles and microparticles with microparticles. The silicon compound solution is selected from (1) the hydrolysis product of alkoxysilane (I) wherein the functional groups are formed from hydrolyzable groups and non-hydrolyzable organic groups, and the condensation reaction product thereof, (2) the hydrolysis product of a mixture of alkoxysilane (I) and alkoxysilane (II) wherein the functional groups are formed from hydrolyzable groups alone, and the condensation reaction product thereof; and (3) a mixture of hydrolysis product and condensation product thereof according to (1) and alkoxysilane (II).

The invention discloses a polyester resin with a high acid value and a low acid value for an environment-friendly dry blended low-gloss weather-resistant powder coating. The polyester resin is made from the following raw materials by weight percentages by virtue of esterification and condensation reaction: 15%-60% of polyol, 30%-65% of polyacid, 0%-5% of a branching agent, 5%-15% of an acidolysis agent and 0.01%-0.15% of an esterification catalyst. The invention further discloses a preparation method of the polyester resin with the high acid value and the low acid value for the environment-friendly dry blended low-gloss weather-resistant powder coating. Thepolyester resin with the high acid value and the polyester resin with the low acid value have the characteristics of proper glass transition temperature, proper softening point and good storage stability. A powder coating made by curing beta-hydroxyalkyl amide with the polyester resin has the advantages of excellent deglossing effect and good mechanical properties.

The invention provides an imine coupled covalent organic framework material and a preparation method and application thereof and belongs to the technical field of porous materials. The structural formula of the imine coupled covalent organic framework material is shown in the description, and the material can be prepared by triazinyl aromatic polyamine A and alkoxy substituted aromatic aldehyde B through simple Schiff base condensation reaction. Under visible light excitation condition, the prepared imine coupled covalent organic framework material can catalyze multiple types of organic reactions, specifically for example reaction for photocatalysis of N-aryl tetrahydroisoquinoline and nucleophilic reagent. The prepared covalent organic framework material has very good chemical stability and heat stability, high specific surface area and high crystallinity, has strong visible light absorption properties, can serve as an excellent heterogeneous photocatalyst and has good industrial application prospect.

The invention belongs to the technical field of friction material, and in particular relates to a graphene-nano polytetrafluoroethylene composite filler with a function of reducing friction, as well as a preparation method and the application of the composite filler. The composite filler comprises the following main components in parts by weight: 1 part of modified graphene and 1-20 parts of modified nano polytetrafluoroethylene; the preparation method of the composite filler comprises the following steps: separately reacting graphene and nano polytetrafluoroethylene with amination reagent and carboxylation reagent to obtain the modified graphene and the modified nano polytetrafluoroethylene; carrying condensation reaction so that the modified graphene and the modified nano polytetrafluoroethylene are connected with each other by a covalent bond to obtain the graphene-nano polytetrafluoroethylene composite filler. The function of friction reduction of the graphene and the function of lubrication of the nano polytetrafluoroethylene are utilized at the same time; after the composite filler is added to a polymer material, the friction coefficient and the wear rate of the material can be reduced, and the mechanical property of the material can be improved.

The invention relates to a method for preparing a nanocomposite and particularly relates to a method for modifying a halloysite nanotube with a silane coupling agent and an epoxy resin nanocomposite prepared by mixing the modified halloysite nanotube obtained by the method and epoxy resin. The surface modification treatment method of the halloysite nanotube, which is disclosed by the invention comprises the following steps of adding the silane coupling agent into a suspension containing the acidified halloysite nanotube and carrying out condensation reaction on a hydrolyzable X group on the silane coupling agent and a hydroxy group on the lamella on the surface of the halloysite nanotube to obtain the halloysite nanotube which is modified by the silane coupling agent and of which an inner cavity and the outer surface are grafted by the silane coupling agent, and mixing the modified halloysite nanotube and epoxy resin to prepare the epoxy resin nanocomposite. The epoxy resin nanocomposite can obtain the desired mechanical properties and thermal properties.

Problem: To provide a silicone-based releasable adhesive composition that is capable of easily controlling peeling force of a releasable adhesive layer by the composition, and whereby the silicone-based releasable adhesive composition has excellent attachment characteristics and releasability characteristics. A further object is to provide a sheet-form substrate and a releasable adhesive sheet that have a releasable adhesive layer formed by curing this composition.

Resolution Means: The silicone-based releasable adhesive composition includes an organopolysiloxane resin-organopolysiloxane condensation reaction product obtained by condensation reaction between (a1) 100 weight parts of an MQ type organopolysiloxane resin containing hydroxyl groups or alkoxy groups in a range of 0.3 to 2.0 weight % and having an M unit to Q unit molar ratio of 0.6 to 1.0, and (a2) 20 to 150 weight parts of a chain-like diorganopolysiloxane having an average degree of polymerization of 100 to 1,000 and having at least one hydroxyl group or alkoxy group, wherein the organopolysiloxane resin-organopolysiloxane condensation reaction product preferably includes a certain hydroxyl group content.

The invention discloses a preparation method of a stable superhydrophobic hot liquid coating, and belongs to the technical field of surface coating preparation. According to the preparation method, in an acetone-water mixed system, in the catalytic effect of acid or base, organic silane and nano particles carry out hydrolysis and condensation reactions to obtain organic silane polymer/nano particle compound suspension; then organic resin adhesive is added into the compound suspension, the mixture is evenly mixed and evenly sprayed on the surface of a substrate material, and finally a thermal curing treatment is performed to obtain the stable superhydrophobic hot liquid coating. The prepared coating has an excellent superhydrophobic hot liquid performance, has the advantages of good mechanical stability, chemical stability, and environmental stability, and thus has a good application prospect.

The invention relates to a preparation method of injectable natural polysaccharide self-healing hydrogel. The preparation method of the injectable natural polysaccharide self-healing hydrogel comprises the following steps: firstly synthesizing water soluble N-carboxyethyl chitosan by carrying out a Michael addition reaction on acrylic acid and chitosan, carrying out an oxidization reaction on sodium periodate and sodium alginate to obtain oxidized sodium alginate, then carrying out a dehydration condensation reaction on N-carboxyethyl chitosan and oxidized sodium alginate and on adipic dihydrazide and oxidized sodium alginate in a phosphate buffer liquid at the temperature of 37 DEG C, so as to respectively generate invertible imine bond and acylhydrazone bond, and finally preparing injectable natural polysaccharide macromolecular hydrogel with self-healing property. The preparation method of the injectable natural polysaccharide self-healing hydrogel has the advantages that a synthetic process of the injectable self-healing hydrogel is simple and green, reaction conditions are mild, the injectable self-healing hydrogel can form gel in a physiological environment and has self-healing capability, and the injectable self-healing hydrogel has a good application prospect in the fields of drug sustained release and the like.