478 results about "Crosslinking reagent" patented technology

The invention relates to the technical field of fracturing fluids, and discloses a preparation method of a temperature-resistant and salt-resistant fracturing fluid, which comprises the following steps: carrying out polymerization reaction on acrylamide, acrylic acid and an acrylamide sulfonic acid monomer to obtain a polymer thickening agent, and compounding the polymer thickening agent with a cross-linking agent, a clay stabilizer and the like to obtain the temperature-resistant and salt-resistant fracturing fluid. The polymer thickening agent contains long-chain alkyl, a physical cross-linked spatial network structure can be formed through a hydrophobic association effect, the hydrodynamic volume is increased, a good tackifying effect is achieved, and after high-speed shearing, the long-chain alkyl can be cross-linked again to form a spatial network structure, so that a solution still keeps very high apparent viscosity, and the viscosity of the solution is improved. Good anti-shearing performance is realized. The acrylamide sulfonic acid monomer contains a sulfonate group and is used as a temperature-resistant and salt-resistant monomer, so that the polymer thickening agent has good temperature resistance and salt resistance, and the fracturing fluid still keeps relatively high apparent viscosity after being subjected to high-temperature heat treatment and in formation water with high salinity.

The invention discloses a porous tantalum and hydrogel combined integrated bionic bone cartilage scaffold as well as preparation and application thereof, and belongs to the field of biomedical materials. According to the invention, a porous tantalum metal scaffold and a polysaccharide hydrogel scaffold are combined to construct the porous tantalum hydrogel biphase scaffold. Wherein the porous tantalum is used as an osteogenesis layer, and the polysaccharide hydrogel is used as a cartilage regeneration layer. The porous tantalum and the hydrogel are tightly combined in a physical cross interlocking mode and cannot fall off, and the thickness size of the two layers can be directionally regulated and controlled according to actual needs. The preparation method provided by the invention is simple and easy to implement, does not use additional chemical cross-linking agents, adhesives and the like, and is greener and safer. The biphasic stent provided by the invention has the characteristics similar to bone cartilage, and has the potential of guiding synchronous regeneration of bone and cartilage.

The invention provides an embolism microsphere capable of slowly releasing drugs and controlling degradation speed and a preparation method thereof, the method comprises the following steps: dissolving a dispersant in an oil phase liquid, and stirring at a first preset temperature to obtain a dispersion liquid; dissolving gelatin in water at a second preset temperature to obtain a gelatin solution; the preparation method comprises the following steps: dissolving a compound with negative electricity groups in water, and adding alkali liquor and an initiator in an ice bath to obtain a modified solution; adding the modified solution into a gelatin solution, stirring to obtain a water-phase pre-polymerized solution, dropwise adding the water-phase pre-polymerized solution into the dispersion solution, premixing, adding a cross-linking agent and a catalyst, and directly grafting negative electricity groups onto gelatin molecules in a low-temperature free radical polymerization manner to obtain an intermediate product; and performing post-treatment to obtain the embolism microspheres. According to the preparation method disclosed by the invention, a non-degradable material is not needed, negative electricity groups can be directly grafted on the surface of gelatin, so that the embolism microspheres have efficient drug loading performance and good long-period drug sustained release, and the degradation speed of the embolism microspheres is controlled.

The present invention relates to a kind of silk fibroin hydrogel and preparation method thereof, silkworm raw silk is degummed, sol, dialyzed, filtered, freeze-dried to obtain silk fibroin freeze-dried powder, then redissolved into high concentration silk fibroin solution, filtered and spray-dried into silk fibroin microspheres; silk fibroin microspheres are slowly added to a phosphate buffered saline solution containing γ-polyglutamic acid and glutaraldehyde, stirred and ultrasonically carried out the first cross-linking, then a cross-linking agent solution is added, stirred evenly and ultrasonically, and the second cross-linking is carried out, and the silk fibroin hydrogel is obtained after being rinsed with pure water after being placed for a period of time. In the preparation method of the present invention, a phosphate buffered saline solution containing γ-polyglutamic acid and glutaraldehyde is used as a cross-linking agent and secondary cross-linking is carried out, and the prepared silk fibroin hydrogel silk fibroin has a long retention time, good stability and mechanical strength, and the cross-linking method is simple, and it is suitable for large-scale industrial production.

The invention relates to the technical field of rubber compounds, and particularly discloses a bio-based and circulating material synergistically modified EPDM rubber compound and a preparation method thereof. The invention discloses a bio-based and circulating material synergistically modified EPDM rubber compound. The rubber compound is prepared from the following components: 100 parts of bio-based EPDM rubber, 100 to 130 parts of a reinforcing agent, 40 to 60 parts of paraffin oil, 5 to 7 parts of magnesium oxide, 0.5 to 1.5 parts of stearic acid, 6 to 8 parts of BIPB-40 peroxide, 2 to 5 parts of a Si-69 silane coupling agent, 1 to 3 parts of a dispersing agent and 1 to 3 parts of an assistant crosslinking agent, the reinforcing agent is composed of fast extruding furnace black N550, rice hull ash white carbon black and thermal cracking carbon black; and the assistant cross-linking agent is prepared from diallyl terephthalate and triallyl isocyanurate. The rubber compound prepared by utilizing the technical scheme provided by the invention can meet and maintain the mechanical property requirements, and meanwhile, carbon emission of the product in the whole life cycle is reduced from the aspects of formula and process.

The invention relates to the technical field of soil remediation, in particular to a charcoal-fungus symbiont for a freeze-thaw environment and a preparation method and application of the charcoal-fungus symbiont. The preparation method of the charcoal-fungus symbiont comprises the following steps: crushing a biomass raw material, and carrying out pyrolysis to prepare basic charcoal; placing the basic biochar in an iron oxide solution, and carrying out an iron oxide loading reaction to obtain iron oxide biochar; the preparation method comprises the following steps: dipping iron oxide biochar in a chitosan solution for coating modification, then continuously adding a cross-linking agent for cross-linking solidification, and freeze-drying to obtain chitosan-iron oxide composite modified biochar; and immersing the chitosan-iron oxide composite modified biochar into a bacterial suspension of functional microorganisms, oscillating and adsorbing, and freeze-drying to obtain the carbon-bacteria symbiont. The invention aims to improve the heavy metal pollution phenomenon of soil and the soybean root rot disaster in the freezing and thawing cycle environment at the same time.

The invention relates to a temperature-resistant and salt-resistant gel for deep plugging and a preparation method thereof. The gel comprises a main agent, a cross-linking agent, a cross-linking promoting agent, a reinforcing agent, a stabilizing agent and water. The main agent is an acrylamide / 2-acrylamide-2-methylpropanesulfonic acid / N-vinyl pyrrolidone (AM / AMPS / NVP) terpolymer, the temperature-resistant and salt-resistant gel for deep plugging control is suitable for oil reservoirs with the temperature of 110-130 DEG C and the formation water mineralization degree of 5 * 10 < 5 >-10 * 10 < 5 > mg / L, the gelling time is controllable within 73-98 hours, the gel strength after gelling is high, the thermal stability is good, and the temperature-resistant and salt-resistant gel for deep plugging control is suitable for the oil reservoirs with the temperature of 110-130 DEG C and the formation water mineralization degree of 5 * 10 < 5 >-10 * 10 < 5 > mg / L. And long-time deep effective plugging of high-temperature and high-salt oil reservoirs can be realized.

The invention relates to the field of medical materials and medical instruments, and discloses a dry bioprosthetic valve and a preparation method thereof.The preparation method comprises the following steps that S1, pericardium and a cross-linking agent solution are mixed for a cross-linking reaction; s2, carrying out first dehydration treatment on the crosslinked pericardium by adopting a first dehydration solution with gradually increased concentration gradient under an ultrasonic condition; and S3, carrying out second dehydration treatment on the pericardium subjected to the first dehydration treatment by adopting a second dehydration solvent, so as to obtain the dried bioprosthetic valve. According to the preparation method provided by the invention, ethanol, isopropanol and water in a specific proportion are adopted to prepare a dehydration solution with gradient concentration, and two-step dehydration drying is carried out in combination with the physical effect of an ultrasonic technology and glycerol, so that rapid rehydration of the bioprosthetic valve is realized, and the original shape and mechanical property of the bioprosthetic valve can be better recovered after rehydration; and the immediate hemodynamic stability of the valve is improved.

The invention discloses a biomass-inorganic-organic ternary composite flocculant and a preparation method and application thereof, and belongs to the field of coking wastewater treatment.The preparation method comprises the steps that chitosan serves as a substrate material, glutaraldehyde serves as a cross-linking agent, and polyferric sulfate (PFS) and chitosan are subjected to chemical cross-linking to generate an intermediate product PFS and chitosan composite particles; then potassium persulfate is used as an initiator, graft copolymerization of acrylamide and methacryloyloxyethyl trimethyl ammonium chloride is initiated through hydroxyl on the surface of PFS-chitosan, a cationic branched chain is introduced, and a final product is obtained. Through multi-component cooperation and structural design, the defects that a traditional flocculating agent is not thorough in demulsification, large in sludge amount, unstable in floc combination and the like in coking wastewater treatment are overcome, and the flocculating agent is particularly suitable for treating oil pollutants in coking wastewater.

The present invention provides a preparation method of high-viscosity hydroxypropyl methylcellulose. A preparation method of high-viscosity hydroxypropyl methylcellulose comprises the following steps: grinding and alkalizing refined cotton cellulose; adding methyl chloride and propylene oxide for etherification reaction; successively adding a crosslinking agent and an aqueous fulvic acid solution for reaction; adding potassium naphthylacetate, sodium sulfite and sodium molybdate and then drying. In the present invention, during the etherification reaction of alkalized cellulose, a crosslinking agent prepared by mixing sodium tetraborate and sodium tripolyphosphate is added for crosslinking reaction, which can reduce the content of water-soluble groups of the prepared hydroxypropyl methylcellulose, achieving the effect of increasing the viscosity of hydroxypropyl methylcellulose. Coating the crop surface with the high-viscosity hydroxypropyl methylcellulose not only has a better surface glazing effect, but also can increase its sugar content.

The invention provides glycosaminoglycan hydrogel with a physical and chemical double crosslinking mechanism as well as a preparation method and application thereof, and relates to the technical field of biological materials. The glycosaminoglycan hydrogel is prepared from the following raw materials: oxidized sodium hyaluronate, chondroitin sulfate, epsilon-polylysine hydrochloride, a polydopamine-titanium dioxide compound and a stabilizer. The glycosaminoglycan hydrogel is prepared through a physical and chemical double-crosslinking mechanism under the specific raw materials and proportion, the problems of cytotoxicity and the like caused by use of a crosslinking agent or introduction of other solvents are avoided, a stable covalent network is constructed through chemical crosslinking, the gel is endowed with the self-repairing characteristic through physical crosslinking, and the self-repairing performance of the hydrogel is improved. And the viscosity of the product is remarkably improved, so that the hydrogel has stronger mechanical support performance, is suitable for wound repair, wound healing and the like, and has good antibacterial activity and stability.

The present invention provides a chitosan recombinant humanized collagen gel, comprising the following components in mass percentage: 0.08-0.30% of type III recombinant humanized collagen; 0.20-0.45% of chitosan or its derivatives; 0.05-0.13% of a cross-linking agent; 0.10-0.20% of a moisturizing agent; and the balance is water. The dressing provided by the present invention can slowly release humanized collagen, is non-toxic, non-irritating, has high biocompatibility, good stability, and can continuously promote the healing of uterine incisions.

Functionalized and crosslinked material, which may optionally be employed as a sorbent, as well as methods of making such materials and systems of using such materials are provided. The processes, methods, systems and materials herein can be used for the separation of carbon dioxide from fluid streams. In one aspect, a method of forming functionalized crosslinked particles comprises introducing at least a portion of a surface of each porous particle in at least a subset of a plurality of porous particles to a crosslinking agent and a first reagent comprising at least one adsorbing moiety. Examples of adsorbing moiety include silane-functionalized amines, amino-functionalized silanes (aminosilane), and polyamines. In some aspects the method further comprises introducing the porous particles to a second reagent comprising at least one interaction moiety such as a silane-functionalized amine, amino-functionalized silane (aminosilane), or polyamine. Examples of crosslinking agent include dialdehyde, diisocyanates, dihaloalkane, diepoxide and dianhydrides.

The invention relates to the technical field of wound care, in particular to a responsive release microcapsule as well as a preparation method and application thereof. The preparation method comprises the following steps: S1, dissolving a polylactic acid-glycolic acid copolymer in an organic solvent, adding an emulsifier, and carrying out ultrasonic emulsification to form a water-in-oil emulsion; s2, mixing a polyphenol compound, elastin, vegetable fat and probiotic suspension to form a quaternary mixed solution, slowly dropwise adding the quaternary mixed solution into the water-in-oil emulsion, continuing ultrasonic emulsification to form multiple emulsion, and evaporating to remove an organic solvent to obtain a quaternary system active component mixed solution; and S3, dissolving PDMAEMA in deionized water, adding a cross-linking agent, stirring, slowly dropwise adding the quaternary system active component mixed solution, carrying out a cross-linking reaction, and freeze-drying to obtain the responsive release microcapsule. The microcapsule can accurately release corresponding active ingredients according to pH value changes in different stages of wound healing, effectively shorten the wound healing time, improve the healing quality and reduce scar formation.

The invention belongs to the technical field of water treatment agents, and particularly relates to a solid slow-release scale inhibition material with an antibacterial function and a preparation method of the solid slow-release scale inhibition material. According to the preparation method of the solid slow-release scale inhibition material with the antibacterial function, provided by the invention, formylated starch without biotoxicity is taken as a cross-linking agent, chitosan quaternary ammonium salt is taken as a cross-linking matrix, the formylated starch and the chitosan quaternary ammonium salt are simultaneously mixed with scale inhibition and bacteriostasis components, and a cross-linking material is prepared through a Schiff base reaction between formyl groups and amino groups; and coating of the scale inhibition and bacteriostasis component by the crosslinking material is synchronously realized. Further, curdlan is adopted to carry out secondary coating on the scale inhibition and bacteriostasis component, so that the solid slow-release scale inhibition material with the antibacterial function is prepared. The preparation method disclosed by the invention is simple in process operation and mild in condition, and through twice coating treatment, the structural stability of the scale inhibition material can be effectively improved, the long-acting antibacterial performance and the scale inhibition slow release effect of the scale inhibition material can be remarkably improved, and the scale inhibition material is suitable for being used in a water treatment environment.

The invention discloses a wear-resistant composite rubber packing sealing material for an oil pumping unit and a preparation method, and the sealing material is prepared from the following raw materials in parts by weight: a main body rubber material, which comprises 70-90 parts by weight of nitrile rubber and 10-30 parts by weight of polyurethane rubber, based on the total weight of 100 parts; 3-5 parts of zinc oxide; 2-3 parts of stearic acid; 30 to 60 parts of carbon black; 5 to 15 parts of graphite; 20-40 parts of an inorganic nano wear-resistant filler; 3-6 parts of an active agent; 5-10 parts of a softening agent; 2-3 parts of an anti-aging agent; 2-6 parts of an effective vulcanization cross-linking agent and 2-5 parts of a peroxide cross-linking agent; wherein the effective vulcanization cross-linking agent is a mixture of an accelerant and sulfur, and the peroxide cross-linking agent is dicumyl peroxide. According to the wear-resistant composite rubber packing sealing material for the oil pumping unit provided by the invention, by balancing the tensile strength, tearing strength, oil resistance and wear resistance of the material, the comprehensive performance of the material is remarkably improved, and the service life of the material is prolonged.

The invention relates to the technical field of eye medical instruments, in particular to an adsorption fixing device for corneal cross-linking and a using method.The adsorption fixing device comprises an adsorption fixing device body, a cross-linking cavity is formed in the center of the adsorption fixing device body, a transparent cover plate is arranged at the top of the cross-linking cavity, and a negative pressure adsorption cavity is coaxially formed outside the cross-linking cavity; the adsorption fixing device is provided with an adsorption skirt outside the negative pressure adsorption cavity, a cross-linking through hole of the cross-linking cavity is communicated with a cross-linking agent pipeline, a pressure applying through hole of the cross-linking cavity is communicated with a pressure applying pipeline, a cleaning through hole of the cross-linking cavity is communicated with a cleaning pipeline, and a negative pressure through hole of the negative pressure adsorption cavity is communicated with an air exhaust pipeline. According to the adsorption fixing device for cornea cross-linking and the use method, the tensile strain of the cornea which is in a tensile state under the action of intraocular pressure originally is reduced or even inverted into compressive strain, so that the non-deformability of the cornea is improved through cross-linking, and the curvature of the cornea can be reduced.

The invention discloses a medical catheter surface strong interface bonding hydrogel coating method based on subsurface initiated polymerization. The method comprises the steps that firstly, a mixed solvent of an organic solvent and water is adopted for conducting swelling pretreatment on the surface of a catheter base material, so that polymer chains on the surface layer of the base material are relaxed; a solution containing initiator molecules is injected into the inner cavity of the catheter, so that the initiator is diffused and anchored in the subsurface area of the base material; preparing a hydrogel monomer solution containing a hydrophilic monomer, a cross-linking agent and a catalyst, and pouring the hydrogel monomer solution into the inner cavity of the catheter; and finally, sealing the two ends of the conduit, and initiating polymerization reaction under a specific temperature condition, so that the initiator anchored on the subsurface is decomposed to generate free radicals. The hydrogel coating and the catheter base material form a double combination effect of physical interlocking and chemical bonding through a subsurface initiated polymerization mechanism, the firmness and stability of the coating are remarkably improved, and the method is particularly suitable for modification of the inner surfaces of various medical catheters with complex structures.

This invention discloses a method for preparing a pH / glucose dual-responsive chronic wound dressing containing frankincense essential oil, comprising: (1) using 4-formaldehyde phenylboronic acid as a crosslinking agent to form Schiff base and borate ester bonds with carboxymethyl chitosan and two different molecular weight hyaluronic acids, respectively, to prepare a hydrogel capable of filling skin surface wounds and performing dual dynamic covalent crosslinking adhesion, and freeze-drying for later use; (2) preparing frankincense essential oil into microcapsules by emulsification coagulation method, and freeze-drying for later use; (3) mixing the hydrogel with the freeze-dried powder of frankincense essential oil microcapsules, adding deionized water or PBS and stirring to reconstitute to form a pH / glucose dual-responsive hybrid hydrogel dressing coated with frankincense essential oil microcapsules. The composite dressing prepared by this invention has anti-inflammatory, antioxidant, antibacterial, and healing-promoting effects, is quick and easy to prepare, and has the ability to respond to the acidic / high-glucose microenvironment of diabetic wounds, and has important practical application value.

The invention discloses a vaginal repair hydrogel dressing based on microsphere-matrix synergistic response and a preparation method, the vaginal repair hydrogel dressing comprises a GA (at) CC microsphere and an SA-CC dynamic crosslinking matrix, the GA (at) CC microsphere takes glycyrrhizic acid as an active core and takes aldehyde chitosan as a shell layer; the SA-CC dynamic crosslinking matrix is used as a supporting frame, is of a porous honeycomb network structure and is formed by an SA solution, a CC solution and a calcium ion crosslinking agent in a synergistic mode. The GA (at) CC microspheres and the SA-CC dynamic crosslinking matrix are fixed through ionic bonds formed by bridging SA carboxyl and Ca < 2 + > of hydroxyl groups on the surfaces of the GA (at) CC microspheres. Through molecular design of a double-response gating mechanism, multi-network construction of a dynamic crosslinking matrix and space-time collaborative loading of functional components, the bottleneck of the traditional technology in response mechanism compatibility, mechanical-response balance and time-space drug release control is broken through, and comprehensive improvement of double-response accuracy, mechanical stability and function collaboration is achieved.

The invention discloses high-strength deformable porous hydrogel for postoperative abdominal cavity tissue effusion drainage, belongs to the technical field of medical porous hydrogel, and particularly relates to a temperature-sensitive hydrogel reaction solution obtained by adding a monomer, a cross-linking agent and an initiator into water and mixing, and freezing and polymerizing to obtain ice gel; treating the ice gel in a salting-out solution to obtain porous hydrogel; the cross-linking agent is prepared from at least one of N, N-methylene bisacrylamide, N, N-methylene bisacrylamide and polyethylene glycol diacrylate. The invention provides the high-strength deformable porous hydrogel for postoperative abdominal cavity tissue effusion drainage, which has a temperature-sensitive effect, can be dynamically controlled through electric heating, and has good mechanical properties and a good drainage effect.

A process for producing a crosslinked cellulose ether including contacting an activated cellulose material with (i) an aqueous crosslinking agent emulsion, wherein the aqueous crosslinking agent emulsion is a mixture of (ia) at least one crosslinking agent; (ib) water; and (ic) any other optional components desired; and (ii) at least one etherification reagent; wherein the aqueous crosslinking agent emulsion (i) and the at least one etherification reagent (ii) react with the activated cellulose material to form the crosslinked cellulose ether; and a crosslinked cellulose ether produced by the above process.

The invention provides a preparation method and application of cystamine modified hyaluronic acid hydrogel. The preparation method comprises the step of synthesizing hydrogel with a three-dimensional network structure by taking hyaluronic acid as a carrier and cystamine as a cross-linking agent. The insoluble drug is entrapped by the hydrogel, so that the solubility of the insoluble drug is effectively improved. The preparation method disclosed by the invention is simple in process, the prepared hydrogel has excellent performance and has the characteristics of uniform pores, good hydrophilicity, high drug loading capacity and high encapsulation efficiency, and the prepared drug-loaded hydrogel can slowly and continuously release drugs and has good antioxidant and antibacterial properties.

The invention relates to the technical field of gel material preparation, in particular to a bio-based gel material for dangerous chemical leakage disposal and a preparation method thereof.The preparation method comprises the steps that gelatin and deionized water are added into a reaction container, a gelatin solution is obtained under the preset dissolution condition, alkaline protease is added into the gelatin solution for an enzymolysis reaction, and a gelatin solution is obtained; a modified gelatin solution is obtained; the preparation method comprises the following steps: adding a phytic acid-chitosan compound and magnesium-aluminum layered double hydroxide into dispersion equipment, and obtaining a composite inorganic matter dispersion liquid under a preset dispersion condition; adding the modified gelatin solution, the composite inorganic substance dispersion liquid, polyethylene glycol and phase change microcapsules into a mixing reactor, and obtaining a premixed solution under a preset mixing condition; sequentially adding an initiator, a cross-linking agent and tetramethylethylenediamine into the premixed liquid, and performing cross-linking reaction under preset cross-linking conditions to obtain a bio-based gel initial product. The plugging efficiency of the bio-based gel material on dangerous chemical leakage is improved.

The invention discloses an expandable rubber cable pipe plugging device and a preparation method thereof.The expandable rubber cable pipe plugging device is prepared from, by weight, 100 parts of EPDM rubber, 0.5-1.0 part of graphene, 0.2 part of silane coupling agent KH550, 10 parts of sodium carboxymethyl cellulose, 15 parts of sodium acrylate-acrylamide copolymer, 5 parts of polyvinyl alcohol, 8 parts of bentonite, 5 parts of expandable graphite and 3 parts of 4, 4 '-oxybisbenzenesulfonyl hydrazide foaming agent. The anti-aging coating is prepared from the following components in parts by weight: 1 part of zinc stearate, 2.5 parts of peroxide DCP, 2 parts of assistant crosslinker TAIC, 5 parts of zinc oxide, 1 part of stearic acid, 30 parts of fumed silica, 5 parts of modified nano montmorillonite, 20 parts of light calcium carbonate, 1.5 parts of anti-aging agent TMQ, 1 part of anti-aging agent 6PPD, 0.5 part of hindered phenol antioxidant 1076, 2 parts of UV absorbent UV-3292, 8 parts of naphthenic oil, 10 parts of microcapsules and 0.5 part of boron trifluoride diethyl etherate complex catalyst.

The invention discloses a nitrogen-doped porous carbon material and a preparation method thereof, and belongs to the technical field of porous carbon materials, and the preparation method comprises the following steps: adding an amino monomer and a carboxyl monomer into an organic solvent, carrying out a preliminary amidation reaction, further promoting the amidation reaction through heating, then adding an epoxy group cross-linking agent, and carrying out a reaction to obtain the nitrogen-doped porous carbon material. The preparation method comprises the following steps: carrying out amino-epoxy cross-linking reaction on an amino-epoxy resin, carrying out hydrolysis reaction on amide under an alkaline condition, mixing with a chemical activator to obtain a mixed material, putting the mixed material into a high-temperature furnace, carrying out high-temperature carbonization, and finally washing, pickling, filtering and drying the carbonized material to obtain the product. The nitrogen-doped porous carbon material with the nitrogen-doped characteristic, high pore volume, high specific surface area and high micropore rate is obtained by adopting a dual pore-forming strategy of internal nitrogen atom self-doping and chemical activation assisted chemical bond pore-forming, and the nitrogen-doped porous carbon material has the advantages of easily available raw materials, low cost, simple operation process, continuous production and the like, and has practical value and industrial prospect.

The invention provides a macromolecular phosphorus-nitrogen flame-retardant composite material as well as a preparation method and application thereof, and belongs to the technical field of flame retardants. The novel weather-resistant intumescent flame retardant is synthesized by introducing a metal catalyst, a polyfunctional group cross-linking agent and a synergist into a piperazine pyrophosphate and melamine phosphate system. A new method and a new formula are provided for an intumescent flame retardant system, the flame retardant effect of the phosphorus-nitrogen intumescent flame retardant in a polypropylene material is improved, the dispersity and the water resistance of the flame retardant in a base material are improved, the addition amount of the flame retardant is reduced, and the flame retardant efficiency is improved. And the migration resistance of the white powdery phosphorus-nitrogen intumescent flame retardant in a dark polypropylene material is also improved. The invention has important application prospects in the field of flame-retardant materials, and can promote the development and innovation of the industry.

The invention discloses hydrogel for preventing postoperative tissue adhesion and a preparation method thereof, and belongs to the field of medical biological materials. The hydrogel is formed by taking a carboxylated chitin / chitosan derivative with the percentage concentration of 0.5-7% or a low-crosslinking-degree supramolecular derivative of a hydroxyalkylated chitin / chitosan derivative and collagen or gelatin as a solute and water, normal saline, a physiological equilibrium solution, a phosphate buffer solution or a Green's solution as a solvent, the crosslinking degree of the low-crosslinking-degree supramolecular crosslinking derivative is 0.1 to 6 mol percent. The molar ratio of the raw materials to the cross-linking agent is controlled, a small amount of cross-linking agent is used for micro-crosslinking, the prepared low-crosslinking-degree supramolecular derivative can form hydrogel in an aqueous solvent, and the hydrogel has adhesiveness and self-repairing performance, can effectively prolong the residence time and physical barrier time of the hydrogel on the surface of an operative wound, and can be used for preparing the hydrogel. Therefore, the effect of preventing postoperative combined adhesion of the hydrogel is improved, and the hydrogel is an ideal hydrogel material for preventing postoperative abdominal cavity and uterine cavity tissue adhesion.

Provided in the present invention is a radiation-aging-resistant phenyl silicone rubber compound, which is prepared from the following components in parts by weight: 100 parts of a phenyl silicone rubber premix, 1-3 parts of a processing aid, 20-30 parts of a radiation-resistant additive, and 0.5-2 parts of a peroxide crosslinking agent. The preparation method specifically comprises the following steps: weighing the following components according to the following parts by weight: 100 parts of the phenyl silicone rubber premix, 1-3 parts of the processing aid, 20-30 parts of the radiation-resistant additive and 0.5-2 parts of the peroxide crosslinking agent; performing first mixing on the phenyl silicone rubber premix, the processing aid and the radiation-resistant additive by using an open mill, and carrying out first tight milling to obtain a masterbatch; performing second mixing on the masterbatch and the peroxide crosslinking agent by using the open mill, and performing second tight milling to obtain a final batch; and vulcanizing the final batch to obtain the radiation-aging-resistant phenyl silicone rubber compound. The present invention solves the problem of the reduction of mechanical properties of rubber undergone ray irradiation aging in the prior art.

The invention discloses a curcumin-containing polyurethane hydrogel for promoting healing of scalded wounds. The hydrogel is prepared by a one-step method under the condition of no solvent and no catalyst. The raw materials comprise biodegradable polyester polyol, polyethylene glycol, bio-based diisocyanate, an acidic response chain extender, a zwitterionic chain extender, curcumin, a biodegradable cross-linking agent and a notoginsenoside aqueous solution. The hydrogel disclosed by the invention has the effect of promoting healing of scalded wounds; in a hemostasis stage, the hydrogel can quickly stop bleeding and construct a physical barrier; in the inflammation stage, the quaternary ammonium salt in the hydrogel and the physically loaded curcumin have a synergistic effect to effectively kill bacteria; in wound remodeling and hyperplasia stages, notoginsenoside slowly released by the hydrogel can regulate inflammatory response, improve collagen deposition and promote granulation tissue hyperplasia and neovascularization. The hydrogel has good biocompatibility, controllable degradation performance and multifunctional biological activity, and can be used as an efficient special dressing for scalded wounds.