31results about How to "Raise the initial decomposition temperature" patented technology

The invention relates to a polyurethane sealant. The polyurethane sealant comprises a component A and a component B, wherein the component A adopts a formula as follows: 20-30 parts of a TDI prepolymer, 30-50 parts of an NDI prepolymer, 20-30 parts of hydroxyl-terminated polybutadiene, 60-90 parts of polyether 220 and 10-20 parts of a plasticizer; the component B adopts a formula as follows: 30-50parts of a filler, 10-20 parts of a chain extender, 1-3 parts of a dispersant, 2-5 parts of a heat stabilizer, 0.5-1 part of a light stabilizer, 0.2-0.5 part of a catalyst and 1-3 parts of A-151. Inthe polyurethane sealant, the polyether 220 and the hydroxyl-terminated polybutadiene form a soft segment to improve the elasticity of the sealant; the small molecular chain extender is added and reacts with the TDI prepolymer and the NDI prepolymer to produce an oligomer of carbamate, so that the hardness is achieved, the initial decomposition temperature is increased, and the heat stability of the polyurethane sealant is improved; the polyurethane sealant has the advantages of good water resistance, long service life and high strength.

This invention relates to a method for preparing and modifying Al (OH) 3 flame retardant. The method adopts rare earth coupler as the modifier, or rare earth coupler and phosphate compounds as the composite modifier, and utilizes wet or dry technique to prepare and modify Al (OH) 3 flame retardant. The method can largely improve heat resistance of Al (OH) 3 as well as raise its initial decomposing temperature, and the obtained Al (OH) 3 flame retardant can be widely used in rubber and plastic industiries. The method utilizes one-time surface modification instead of multi-step organic/inorganic modification, thus simplifying the modification process. Besides, the method also raises the activity index of the obtained Al (OH) 3 flame retardant, and reduces its oil-aborbency.

The invention discloses a method for preparing core-shell type silicon dioxide coated ammonium phosphate based on a reversed-phase micro-emulsion method. The method comprises the following steps: (1) preparing reversed-phase micro-emulsion A of non-ionic surfactant/n-hexane/phosphoric acid; (2) preparing reversed-phase micro-emulsion B of non-ionic surfactant/n-hexane/ammonia water; (3) mixing the reversed-phase micro-emulsion A and the reversed-phase micro-emulsion B to obtain dispersion liquid of nano-particles; (4) dropwise adding a n-hexane solution of tetraethyl orthosilicate into the dispersion liquid of the nano-particles to obtain dispersion liquid of core-shell type silicon dioxide coated ammonium phosphate; and (4) dropwise adding a n-hexane solution of a silane coupling agent into the dispersion liquid of the core-shell type silicon dioxide coated ammonium phosphate, and then carrying out emulsion breaking, separation and drying treatments to obtain surface modified core-shell type silicon dioxide coated ammonium phosphate. The particle size of the core-shell type silicon dioxide coated ammonium phosphate prepared by the method disclosed by the invention can be controlled to be 100-800nm, and the core-shell type silicon dioxide coated ammonium phosphate is relatively small in particle size, narrow in distribution and good in dispersity.

The invention relates to the technical field of nano antibacterial materials, in particular to a silver-loaded polyphosphazene microsphere with a mesoporous core-shell structure and a preparation method and an application thereof. The preparation method comprises the following steps that 1, a protective agent and a dispersing agent are added into a silver nitrate solution and stirred to be uniform, heating is conducted to 30-90 DEG C, then a reducing agent is dropwise added, a reaction is conducted in a dark place, centrifugal separation is conducted, obtained sediment is washed with a washing agent, and drying is carried out in vacuum to obtain hard template single-phase nano silver particles; and (2) the hard template single-phase nano-silver particles are ultrasonically dispersed in an organic solvent, a dispersing agent, hexachlorocyclotriphosphazene and resveratrol are sequentially added, uniformly stirred, then an acid-binding agent is added, ultrasonic reaction and centrifugal separation are carried out, the obtained precipitate is washed with a detergent, and vacuum drying is carried out to obtain the silver-loaded polyphosphazene microsphere with the mesoporous core-shell structure. The prepared silver-loaded polyphosphazene microsphere with the mesoporous core-shell structure can achieve a long-acting sterilization effect, can improve the dispersibility of a nano material and reduce the biotoxicity of a silver-series antibacterial material, and can be applied as an antibacterial material.

The invention discloses flame-retardant nano cellulose containing a phosphazene group, a preparation method of the flame-retardant nano cellulose and flame-retardant polylactic acid of the flame-retardant nano cellulose. A phosphazene modifier is chemically grafted on the surface of nanocellulose to obtain the novel flame-retardant nanocellulose containing the phosphazene group. The flame-retardant nano cellulose obtained by the invention has excellent thermal stability and charring ability. The flame-retardant polylactic acid is compounded with a phosphorus-containing flame retardant, so that the flame retardant property of the material can be remarkably improved, and the mechanical property of the material can also be improved.

The invention discloses a nanometer laminated boron nitride reinforced carbon fiber sizing agent, and a preparation method thereof, and belongs to the technical field of composite material. The preparation method is capable of solving problems in the prior art that at humid hot environment, humidity hot aging is caused by resin chemical degradation and fiber/resin interface cracking. The nanometerlaminated boron nitride reinforced carbon fiber sizing agent comprises 100 parts of an organic resin, 0.3 to 6 parts of an emulsifier, 0.05 to 0.6 part of a dispersant, 0.05 to 1 part of a compatiblymodified nanometer laminated boron nitride dispersion liquid, 20 to 200 parts of an organic solvent, and 20 to 40 parts of deionized water; the compatibly modified nanometer laminated boron nitride dispersion liquid is a dispersion liquid of nanometer laminated boron nitride dispersion liquid processed through polyacrylic acid in-suit polymerization modification. According to the preparation method, raw materials are mixed and stirred until phase transferring is achieved; the compatibly modified nanometer laminated boron nitride dispersion liquid is mixed with the organic resin emulsion, deionized water is added for dilution so as to obtain the nanometer laminated boron nitride reinforced carbon fiber sizing agent. The nanometer laminated boron nitride reinforced carbon fiber sizing agentcan be used for carbon fiber sizing.

The invention discloses a high flame-retardant material for a mobile phone shell. The high flame-retardant material is prepared from the following raw materials in parts by weight: 65 to 75 parts of PC (polycarbonate), 27 to 33 parts of ABS (acrylonitrile butadiene styrene), 4 to 7 parts of compound compatilizer, 13 to 17 parts of compound flame retardant, 0.2 to 0.7 part of polytetrafluoroethylene, 0.5 to 1.2 parts of diisobutyl phthalate, 0.3 to 0.7 part of pentaerythritol stearate, 0.4 to 1 part of zinc stearate, 0.2 to 0.8 part of phosphate, and 0.3 to 0.8 part of 2,6-ditert butyl-4-methylphenol. The prepared high flame-retardant material has excellent flame-retardant property and flowing property.

The invention discloses perdeuterated ammonium dinitramide and a preparation method thereof, belonging to the technical field of synthesis of deuterated energetic materials. According to the invention, purification is simple, and a high-purity product can be obtained without adsorption and solvent elution; the product does not contain metal ions such as potassium ions, does not cause catalyst poisoning in the use process, and is widened in application range; reaction process is judged by measuring the pH value of a solution, and the reaction endpoint judgment method is simple; and deuterated ammonia gas can be recycled after being collected, so the waste of deuteration raw materials is reduced, and production cost is reduced. Compared with common ammonium dinitramide, the initial decomposition temperature of the perdeuterated ammonium dinitramide is increased to about 150 DEG C, and the thermal stability of the perdeuterated ammonium dinitramide is obviously improved; and crystalline density is increased, and meanwhile, energy characteristic is obviously improved. According to the preparation method disclosed by the invention, the preparation of the perdeuterated ammonium dinitramide can be realized, and a reference is provided for industrially producing the perdeuterated ammonium dinitramide.

The invention discloses a three-source one-body intumescent flame retardant, a hybrid intumescent flame retardant grafted by using the three-source one-body intumescent flame retardant as well as a preparation method and application of the three-source one-body intumescent flame retardant and the hybrid intumescent flame retardant, wherein the structural general formulas of the three-source one-body intumescent flame retardant and the hybrid intumescent flame retardant are respectively as shown in the specification, and the three-source one-body intumescent flame retardant or the hybrid intumescent flame retardant is used for a thermoplastic elastomer, rubber, polyolefin plastic and aliphatic polyester, the epoxy resin and the unsaturated resin are not required to be compounded when used in flame retardancy, the proportion of phosphorus, nitrogen and carbon elements is appropriate, the flame-retardant efficiency is high, the addition amount of the flame retardant can be greatly reduced, the cost is reduced, the influence on the mechanical property of the base material is small, the water resistance is better, and the initial decomposition temperature is higher.

The invention discloses an LCP/HBN composite material and a preparation method thereof. The heat-conducting polymer composite material is prepared by compounding and filling the heat-conducting fillers, compounding of the heat-conducting fillers with different particle sizes has a heat-conducting synergistic effect, and the heat conductivity coefficient of the composite material is improved. Meanwhile, high polymer material plasticizing and transporting equipment based on extensional rheology is used for processing, and the composite material has better dispersing and mixing efficiency in a flow field dominated by extensional deformation than in a flow field dominated by shear deformation. The preparation method of the LCP/HBN composite material is simple, additives and chemical reagents do not need to be added, and pollution to the environment can be reduced while the cost is reduced. The heat conductivity of the composite material is improved, the heat stability of the composite material is also improved, the mechanical property of the material can be maintained, the use scene of the material is greatly widened, and the composite material has wide application prospects in the fields of packaging materials, electronic substrates and the like.

The invention belongs to the technical field of pyrolysis instruments, and particularly relates to a low-pressure flash pyrolysis flow tube reaction device based on a continuous molecular beam source. The device comprises a test bed, a mounting mechanism, a flash pyrolysis mechanism and a vacuum box; the flash pyrolysis mechanism comprises a cylindrical cavity horizontally arranged in the vacuum box, and a sample injection pipe, a water inlet pipe and a water outlet pipe which are arranged in the cylindrical cavity, the water cooling cavity is slidably arranged in a cavity body at the other end of the cylindrical cavity, the other end of the sample injection pipe penetrates through the water cooling cavity, the extending end of the sample injection pipe is connected with a silicon carbide pipe, and the silicon carbide pipe is sleeved with a pair of graphite electrodes; and a sliding table is arranged in the cylindrical cavity corresponding to the extension end of a push rod of the linear introducer, the extension end of the push rod is fixedly connected with a sliding block, and the upper end of the sliding block is fixedly connected with a corresponding sample injection pipe. The silicon carbide tube is used as a reactor, the graphite electrode is used for heating, rapid heating is achieved, secondary reaction is reduced, annihilation of active and important reaction intermediates such as free radicals can be reduced under low pressure, continuous sampling can be achieved, and reaction kinetics research of pyrolysis samples can be perfected.

The invention relates to the technical field of preparation of epoxy foam materials, and mainly relates to a preparation method of high-pressure-resistant fire-resistant composite epoxy foam. On the basis of the controllable benzyl hydroxyl activity principle, the benzyl hydroxyl activity in the boron novolac epoxy resin synthesis process is reduced by taking ammonia water as a catalyst and adopting a stepped heating method, so that the problems of epoxy value reduction and boric acid residue caused by over-high benzyl hydroxyl activity in resin synthesis are solved; the boron-containing high-temperature-resistant foaming resin matrix is successfully prepared; a bifunctional foaming agent with a synergistic curing effect is added in the foaming process, so that the problem that resin gel and foaming agent decomposition are not matched is solved; boron novolac epoxy resin grafted and modified graphene oxide is added into epoxy foam, so that the size of a foam hole is reduced, the wall of the foam hole is enhanced, the surface of the epoxy foam is promoted to form a stable graphitized carbon layer in flame, the heat conductivity is reduced, and finally the epoxy foam material integrating compression resistance, heat insulation and flame resistance functions is prepared.