176 results about "Initial strength" patented technology

The invention provides single-component t high-performance mortar for repairing and reinforcing concrete, which comprises the following components in part by mass: 200g of sand, 55 to 75 parts of ordinary portland cement, 10 to 30 parts of sulphate aluminium cement, 3 to 7 parts of siliceous dust, 8 to 12 parts of flyash, 0.18 to 0.22 part of water reducing agent, 2 to 4 parts of flexibilizer, 0.04 to 0.06 part of water-retaining agent, 1.0 to 2.0 parts of swelling agent and 0.1 to 0.2 part of polymer synthetic fiber. The single-component t high-performance mortar has the advantages of high initial strength, good adhesion, excellent cracking resistance, low ratio of compressive strength to flexural strength, excellent toughness, simple and convenient construction, single component, no toxin or smell, no harm to human bodies, and environmental protection without pollution.

The present invention is directed to crystalline copolymers of l-lactide and a minor portion of a cyclic monomer, preferably epsi-caprolactone or trimethylene carbonate or both. The present copolymers have a melting temperature of at least 150° C. and a crystallinity of at least 25%. Preferred are high molecular weight copolymers having an inherent viscosity of at least 1.4 dl/g. A variety of surgical constructs may be formed from the present copolymers. Surgical sutures made of mono- or multifilament yarns of the present copolymers will bioabsorb in less than three years and will maintain at least 50% of their initial strength three weeks post-operatively.

The invention relates to a laser sintering sand, a preparation method thereof, a sand core and the preparation method thereof. The laser sintering sand consists of a first component and a second component which are evenly mixed, the first component consists of a first type of raw sand with the coefficient of angularity of less than 1.3, thermosetting resin and additives, wherein the thermosetting resin and the additives are coated on the surface of the first type of the raw sand; and the second component consists of a second type of raw sand with the coefficient of angularity of less than 1.1, a thermoplastic material and the additives, wherein the thermoplastic material and the additives are coated on the surface of the second type of the raw sand. The adoption of the laser sintering sand does not need to add an auxiliary support structure during the laser sintering process, thereby improving the molding efficiency and reducing the manual intervention; and the any complex sand core can be manufactured without using a mold, and the sand core simultaneously has high sintering initial strength and can meet the requirements on the thermal strength and the gas-generating capacity of the sand core during the metal casting process.

The invention discloses an aqueous acrylic emulsion, an aqueous adhesive for pearlized film composite materials and a preparation method thereof, and belongs to the field of preparation of adhesive. The acrylic emulsion is polymerized from 20-40 wt% of acrylic acid hard monomer and 55-70 wt% of acrylic acid soft monomer and 1-5 wt% of acrylic acid functional monomer under the action of water, an emulsifying agent, an initiator, a buffering agent and a pH regulator. The invention also provides an aqueous adhesive and a preparation method thereof. The molecule segment of the film forming matter (acrylate copolymer) in the aqueous acrylic emulsion has various chemical groups, such as -OH, -COOH, -NH and the like; and the chemical groups can form various chemical bonds and hydrogen bonding acting force, and thereby having favorable adhering force for various composite substrates (plastic films, aluminum plating films, metal foils and the like). The polymer obtained by polymerization has higher molecular weight, lower coating viscosity and favorable levelling property; and thus, the polymer has high shear strength and initial strength and can achieve the best bonding strength without curing for a long time.

The invention relates to a preparation method of a photo-moisture dual cured hot melt polyurethane sealant. The preparation method comprises following steps: firstly, an HDI (hexamethylene diisocyanate) trimer reacts with a hydroxyl acrylate monomer, after the reaction, polyether polyol is added for continuous reaction, and a prepolymer A is obtained; bifunctional isocyanate reacts with crystalline polyester polyol and non-crystalline polyester polyol, and a prepolymer B is obtained; the prepolymer A and the prepolymer B are mixed in a certain ratio, then a photoinitiator, a catalyst, a coupling agent and the like are added, and the photo-moisture dual cured hot melt polyurethane sealant is obtained. The preparation method improves the defects of failure in rapid positioning of UV glue, low initial strength of the hot melt polyurethane sealant and the like, rapid positioning can be realized, the hot melt polyurethane sealant can achieve higher strength in a short time, and the hot melt polyurethane sealant can be used for bonding of appliances, furniture, electronic components and the like.

The invention discloses a multiplex composite engineering scaffold material capable of gradually decomposing bone tissue and a preparation method thereof. The composite scaffold material consists of calcium phosphate bone cement, biological compatible degradable synthetic high polymer and biological compatible degradable natural high polymer, has better mechanical property and gradient degradation characteristic, and can achieve the aim of regenerating and repairing bone tissue defect by implanting a bone growth factor to induce in-vivo stem cells to be differentiated into bone cells, thereby obviously improving initial strength and toughness of the scaffold material, and ensuring enough strength and toughness of the scaffold material during operating and implanting. After compounded with the high polymer material, the scaffold has excellent flexibility, so that the scaffold can be subjected to certain machining, such as cutting and the like.

The invention relates to a liquid cement grinding aid which can obviously reduce the dosage of trolamine and does not contain urea. The grinding aid comprises the following compositions in weight percentage: 1 to 10 percent of trolamine, 5 to 10 percent of diglycol, 1 to 10 percent of trimeric sodium phosphate, 10 to 30 percent of molasses, 0 to 20 percent of sodium thiosulfate, 0 to 10 percent of air entraining component and the balance being water, wherein the air entraining compositions are triterpenoid saponin air entraining agent, sodium lignin sulfonate or a mixture of the triterpenoid saponin air entraining agent and the sodium lignin sulfonate at any proportion. The invention obviously reduces the dosage of the trolamine, does not contain the urea, lowers product cost and simultaneously facilitates the environmental protection. The sodium thiosulfate has the function of exciting mixed materials of cement and can improve the initial strength and the later strength of the cement, thereby effectively improving the service performance of the cement grinding aid. The triterpenoid saponin air entraining agent and the sodium lignin sulfonate have the action of the auxiliary aided grinding and simultaneously properly entrain air to reduce the water consumption of the cement standard consistence.

The invention relates to a preparation method of low-alkaline liquid accelerating agent, comprising the following steps: 1) preparing sodium aluminate liquid; 2) modifying sodium aluminate liquid; 3)carrying out a reaction between the modified sodium aluminate and the aluminum sulfate; and 4) adding hydramine and hydroxycarboxylic acid and stirring evenly to prepare the finished product. The low-alkaline liquid accelerating agent prepared by the invention has low alkali content, namely, the sum of Na2O and K2O is less than 5%, low preparation cost, is suitable for cement such as ordinary Portland cement, moderate-heat cement, low-heat cement and other brands and types, is applicable to the sprayed concrete construction, can significantly improve initial strength and ensure later strength.

The invention discloses water-based composite adhesive, which contains acrylate emulsion and a cross-linking agent, wherein the weight of the cross-linking agent is 0.1-6 percent of the weight of the acrylate emulsion; the cross-linking agent is any one or a mixture of hexamethylenediamine and adipic acid dihydrazide; and the acrylate emulsion is formed by copolymerizing a terpenes hard monomer, a terpenes soft monomer, a terpenes carboxylic acid monomer, a terpenes functional monomer, a dual-vinyl monomer and a terpenes cross-linking monomer through nuclear shells under an emulsion system. The adhesive is particularly suitable for dry-type composite adhesion between flexible package composite base materials such as a plastic film and a vacuum aluminized film which are processed through corona; has good leveling, fast drying, high transparency, capability of curing at room temperature, high initial strength, excellent peel strength, difficulty in mesh clogging and skinning, wide adaptability and low cost; and can be applied to various machine types, does not contain any organic solvent, can replace solvent adhesive at present completely, and belongs to environment friendly adhesive.

The present invention is directed to crystalline copolymers of l-lactide and a minor portion of a cyclic monomer, preferably epsi-caprolactone or trimethylene carbonate or both. The present copolymers have a melting temperature of at least 150° C. and a crystallinity of at least 20%. Preferred are high molecular weight copolymers having an inherent viscosity of at least 1.1 dl/g. A variety of surgical constructs may be formed from the present copolymers. Disclosed are coated surgical constructs including sutures made of multifilament yarns of the present copolymers and coated with nitrogenous copolyesters which will bioabsorb in less than three years and will maintain at least 50% of their initial strength three weeks post-operatively.

Interposition and augmentation devices for tendon and ligament repair, including rotator cuff repair, have been developed as well as methods for their delivery using arthroscopic methods. The devices are preferably derived from biocompatible polyhydroxyalkanoates, and preferably from copolymers or homopolymers of 4-hydroxybutyrate. The devices may be delivered arthroscipiclly, and offer additional benefits such as support for the surgical repair, high initial strength, prolonged strength retention in vivo, flexibility, anti-adhesion properties, improved biocompatibility, an ability to remodel in vivo to healthy tissue, minimal risk for disease transmission or to potentiate infection, options for fixation including sufficiently high strength to prevent suture pull out or other detachment of the implanted device, eventual absorption eliminating future risk of foreign body reactions or interference with subsequent procedures, competitive cost, and long-term mechanical stability. The device are also particularly suitable for use in pediatric populations where their eventual absorption should not hinder growth.

Disclosed is a method for manufacture and application of a polymeric papermaking additive, which can be used in paper manufacture as an agent for improving retention, drainage, product strength and paper machine operation. The additive according to this disclosure is a polymer of epichlorohydrin and contains primary amino groups. Under neutral or acidic conditions these primary amino groups become cationic, which assures good adsorption of the polymer onto anionic fibres and fines of pulps used for production of paper or paperboard. By adsorbing on several fibres or fines, the polymer can increase the retention of fines and fillers. Primary amino groups of this polymer can also form chemical bonds with carbonyl groups of cellulose, lignin and hemicellulose, which are especially abundant in the fibres and fines of mechanical pulps. The cross-linking of fibres and fines by chemical bonds can increase the initial strength of wet web and the strength of rewetted paper. Mechanical pulps contain high negative charge and tend to deactivate many conventional cationic polymers. Because of its high cationic charge and the ability to form chemical bonds with mechanical pulp, novel papermaking additive according to this invention is particularly suitable for improving the retention and the strength of paper made from fibrous pulp suspensions that contain at least a portion of mechanical pulp. If the polymer has a high molecular weight it can be use as a single component retention and strength additive. If the polymer has a relatively low molecular weight, it can be conveniently used as coagulant and can be combined with a high-molecular-weight, low-charge-density polymer that serves as a flocculent.

To provide a spraying material having an excellent quick-setting property and excellent adherability, a small alkali amount and excellent initial strength development, and a spraying method using it. The spraying material comprises a liquid quick-setting admixture containing an aluminum source, a sulfur source and a fluorine source, one or more quick-setting aids selected from the group consisting of calcium aluminate, calcium sulfoaluminate, calcium aluminosilicate, an alkali metal-containing substance, calcium hydroxide and aluminum hydroxide, and a cement concrete, and the method is to spray this spraying material.

The invention discloses a modified phosphogypsum cement retarder and the preparation method thereof, comprising the following steps: performing composite modification to the industrial residue phosphogypsum by using acetylene sludge and fly ash which are also industrial residues, meanwhile, adding the glauber-salt powder used as a cement excitant and/or triethanolamine scrap used as a cement grinding aid, wherein the weight percentage of the components thereof is: 90 percent to 95 percent of phosphogypsum, 3 percent to 7 percent of acetylene sludge, 1 percent to 5 percent of fly ash, 1 percent to 3 percent of glauber-salt powder and/or the triethanolamine scrap; the materials are put into a storage hopper, then crushed, balled by a telescopic pelletizer and dried so as to finally obtain the product. The cement retarder prepared through the adoption of the invention can accelerate the hydration, promote the condensation of the cement, improve the initial strength of the cement and eliminate the influence of the soluble minor components upon the hydration of the cement; moreover, the cement retarder contains little moisture in the obtained balls, is stored for a short time, not only utilizes the waste but also is environment friendly, thereby achieving the aims of comprehensively using the waste residue resources and saving resources,; and the cement retarder has low cost, thereby enhancing economic returns for enterprises.

The invention discloses a cold patch asphalt mixture and a preparation method thereof. The preparation method comprises the following steps: heating and dewatering petroleum asphalt, then adding a diluent, a tackifier and an anti-stripping agent in sequence according to weight parts, uniformly mixing, and then adding waterborne epoxy emulsion and a waterborne epoxy curing agent, and uniformly mixing, thus obtaining cold patch asphalt liquid; uniformly mixing the cold patch asphalt liquid with an aggregate at 60 to 70 DEG C, thus obtaining a mixture A; and finally, adding mineral powder into the mixture A, uniformly stirring, thus obtaining the cold patch asphalt mixture which is used for repairing recesses in a pavement. By the adding of epoxy components, curing reaction of the epoxy components increases the strength increase speed of the mixture; and particularly, by the use of initial strength formation, after the cold patch asphalt mixture is paved, the load bearing capacity is relatively high, and the traffic can be quickly opened. The water stability and the high temperature stability of the cold patch asphalt mixture are improved to a certain extent; by high pavement performance, the service life of a novel cold patch material can be prolonged; and therefore, the pavement repair quality is improved, and occurrence of secondary damage to the pavement is reduced.

Resorbable multifilament yarns and monofilament fibers including poly-4-hydroxybutyrate and copolymers thereof with high tenacity or high tensile strength have been developed. The yarns and fibers are produced by cold drawing the multifilament yarns and monofilament fibers before hot drawing the yarns and fibers under tension at temperatures above the melt temperature of the polymer or copolymer. These yarns and fibers have prolonged strength retention in vivo making them suitable for soft tissue repairs where high strength and strength retention is required. The multifilament yarns have tenacities higher than 8.1 grams per denier, and in vivo, retain at least 65% of their initial strength at 2 weeks. The monofilament fibers retain at least 50% of their initial strength at 4 weeks in vivo. The monofilament fibers have tensile strengths higher than 500 MPa. These yarns and fibers may be used to make various medical devices for various applications.

The invention relates to a refractory material and particularly relates to a gunning mix for a blast furnace tapping channel, which aims at solving the problems that a channel lining is easily cracked and dropped in the prior art. The gunning mix for the blast furnace tapping channel comprises the following components in parts by mass: 35-45 parts of mullite of which the granularity is 3-5mm, 25-35 parts of corundum of which the granularity is 1-3mm, 12-25 parts of silicon carbide of which the granularity is 0-1mm, 8-12 parts of alumina powder, 6-10 parts of cement, 0.1-0.3 part of explosion-proof fiber, 1-3 parts of graphite and 3-5 parts of iron silicon nitride. According to the gunning mix disclosed by the invention, by adding the explosion-proof agent, the adhesion rate can be increased and the cracking and dropping are prevented, and especially when the high-temperature gunning is carried out, since voids are formed by melting fibers, the porosity is increased to provide a passage for the rapid exhaust of the steam; the gunning mix contains relatively high content of Al2O3 and is suitable for a part with a serious melting loss need to be repaired on the main channel; cement is conductive to improving the initial strength of the gunning mix and thus the gunning mix can withstand relatively high vapor pressure and thus the burst is avoided and the gunning mix has relatively high adhesion force and durability; by adding iron silicon nitride, bonding strength between the oxide and non-oxide is improved; by virtue of the gunning mix disclosed by the invention, the service life of the main channel is prolonged.

The invention provides a semi-flexible base material and a production method thereof, which belong to the technical field of modification and emulsification engineering, and comprises the following components by weight percent: 90-95% of aggregate, 3-8% of cement and 2-16% of SBS modified and emulsified asphalt. The production method comprises the following steps of: after firstly dry mixing the cement and stones uniformly, adding water and SBS modified and emulsified asphalt to stir, and after uniform mixing, obtaining the semi-flexible base material. The invention is better than rigid base material and flexible base material, compound produced by the using the semi-flexible base material has good permanent deformation resistance, improves the initial strength of semi-rigid base material and shortens the time for forming the strength, simultaneously increases the flexibility through adding emulsified asphalt, takes the advantage of asphalt and cement base stabilizing performance to make up the shortage, has appropriate rigidity, higher strength, smaller temperature sensitivity and better low temperature crack resistance, and decreases and prevents the base from cracking, and thereby preventing roads from reflection crack, playing good road use performance, and prolonging the service lives of the roads.

The invention discloses a high-temperature-resistant toughened light-cured resin composition and a preparation method thereof. The composition contains the following raw materials: acrylic resin, epoxy resin, an active diluent, a free radical initiator 1, a free radical initiator 2, a cationic initiator, polyol, a leveling agent, an antifoaming agent, a wetting dispersing agent, nano-core-shell rubber, nano-silicon oxide and a pigment. According to the resin composition, the curing rate of high-temperature-resistant light-cured resin can be effectively increased, and the initial strength of a product is greatly enhanced; furthermore, the material further has relatively high tenacity, so that the operations of punching, screw drilling and the like can be realized on a sample. Therefore, the high-temperature-resistant toughened light-cured resin composition has the characteristics of high curing efficiency and initial strength, excellent high temperature resistance, good tenacity and stable dimension.

The invention provides a flame-retardant single-component moisture-curable silicone rubber and a preparation method and application thereof and belongs to the field of organic silicon rubber materials. The preparation method of the flame-retardant single-component moisture-curable silicone rubber is characterized in that alpha,omega-hydroxyl-terminated polydimethylsiloxane serves as a basic resin, alkoxy silane serves as a cross-linking agent, organic tin serves as a catalyst, meanwhile reinforcing filler, increment filler, a fire retardant, hydroxyl scavenging agent and other components are adopted for matching, and the silicone rubber is obtained through vacuum kneading and mixing, extrusion and lamination and vacuum package. The silicone rubber is a single-component band-shaped or flaky material, is stable in appearance, has a certain initial strength and flexibility, and has good insulativity, weather resistance, heat resistance, acid-base resistance and flame retardant properties after moisture curing. The silicone rubber has good appearance and plasticity, can be attached in a planar mode, wound and bound, or be plugged, blocked and filled in joints and has the wide application prospect in the fields of cable damage repairing, insulated protection of exposed electrical connecting points and the like. The flame-retardant single-component moisture-curable silicone rubber is simple in preparation process and is especially suitable for industrial production, and the raw materials are wide in source.

The invention relates to a high initial strength filling mining method. The method includes the following steps: crushing municipal garbage, mixing the garbage with a proportional curing agent and pressing the garbage into a filling material; transporting the prepared sealed filling material from the ground to the bottom of the well, and then shipping the filling material to a working face; after coal cutting, support advancing and pushing on the working face, sending the filling material from a gate top by using a mining flatbed truck, sending the filling material into a flexible rail behind a support through a rotating switch of an upper end, unloading the filling material to a goaf area, stacking regularly, and filling the remaining gap with a rapid hardening cement paste material to ensure complete roof contact; and after mining, sealing the goaf area again through boundary coal pillars and stop line coal pillars to ensure zero gas and liquid exchange between the filled area and the unfilled area. The method of the invention solves the problems of municipal garbage disposal and the sources for mining coal filling material, and the filling material has high initial strength and can effectively control the surface subsidence.

The invention provides a colored asphalt mixture, which is characterized in that raw materials comprise a colored asphalt binder, a pigment and aggregates; the aggregates comprise coarse aggregates, fine aggregates and mineral powder; and the colored asphalt binder comprises the following components by weight portion: 100 portions of petroleum resin, 80-120 portions of extracted oil, 5-10 portions of polyethylene wax and 0.1-2 portions of thermoplastic acrylic resin. Since the polyethylene wax and the thermoplastic acrylic resin are simultaneously added into the colored asphalt binder, the dispersion and the durability of the pigment can be improved. Moreover, the performance of the colored asphalt binder is the same as or superior to the performance of black asphalt mixture in the looseness, compactness and initial strength, the strength of the formed mixture, water damage resistance and the like.