464 results about "Polytetrafluoroethylene sheet" patented technology

This invention concerns a method of manufacturing a highly conductive polytetrafluoroethylene sheet; a method of manufacturing a highly conductive unsintered polytetrafluoroethylene sheet: and a method of manufacturing a highly conductive sintered sheet. In the first method, a paste of polytetrafluoroethylene powder admixed with conductive substance and extrusion lubricant is extruded to preform an unsintered tube-like material, and at least one place on the circumference of this extruded material, the material is cut open longitudinally and the resulting sheet is calendered if necessary. The second method includes a sintering process for the sheet. This invention also concerns a highly conductive polytetrafluoroethylene sheet having a wide-width and long-length, which is obtained by the above-mentioned method. This sheet is not less than 170 mm in width and has variance of volume resistivity (conductivity) in the longitudinal direction, 10% or less, preferably 7% or less in the cross direction. This invention can provide a highly conductive wide-type PTFE sheet whose conductivity in the longitudinal direction is nearly uniform in the cross direction.

The invention belongs to the technical field of crystal growth and relates to a growth method of organic nonlinear optical crystal. The growth method comprises the following steps of: firstly, drying a DAST (sulfur trifluoride) crystal growth raw material, dissolving the DAST crystal growth raw material in an absolute methanol solution to prepare a DAST methanol solution; then, heating and filtering the DAST methanol solution, and transferring the DAST methanol solution into a wild-mouth bottle; putting a polyfluortetraethylene plate in the wild-mouth bottle, and sealing the wild-mouth bottle; putting the wild-mouth bottle in a sealed water bath heating device to be thermally insulated, and cooling the wild-mouth bottle until the DAST crystal stops growing, taking out the crystal DAST crystal, namely, obtaining the DAST crystal with large surface area and thickness. The growth method is simple, the principle is scientific, the growth environmental is friendly, the cost is low, and the grown DAST crystal is large in geometric dimension, high in transmittance and convenient to be further processed and utilized.

The present invention discloses a compounded full-solid polymer electrolyte for secondary lithium cell and its preparation method. The described polymer electrolyte contains 2%-30% of inorganic oxide, and the matching ratio of polyethylene glycol and alkali metal salt O/Li is 8-16. Its preparation method includes: dissolving polyethylene glycol and LiClO4 in acetionitrile, adding inorganic oxide,pouring the mixed solution onto teflon plate, evaporating solvent and drying at 50-100 deg.C in vacuum drying box. The described inorganic oxide also can be modified inorganic oxide. Said prepared material can be extensively used in the fields of handset, domestic appliances and electric car.

The invention discloses a polyurethane elastomer material with the wide temperature range and the high damping capacity and a preparation method thereof. The preparation method comprises the steps that polyester diol and a diisocyanato raw material are adopted to react with each other to prepare a polyurethane prepolymer, the polyurethane prepolymer is poured into a polytetrafluoroethylene plate mold by taking an HDI trimer as a cross-linking agent and taking a raw material containing dynamic reversible disulfide bonds as a chain extender to remove bubbles, and heat preservation and curing molding are conducted. According to the polyurethane elastomer designed and synthesized based on the molecular structure, the damping factor tan<delta> is larger than 0.3 when the temperature of the damping material exceeds the temperature range of 220 DEG C (minus 50 DEG C-178 DEG C), and the damping factor tan<delta> is larger than 0.4 when the temperature of the damping material exceeds the temperature range of 200 DEG C (minus 44 DEG C-165 DEG C); the polyurethane elastomer material has the good high-low temperature damping property and can be expected to be widely applied to the damping and noise reducing aspects in the fields of building materials, automobiles, national defense, aerospace and the like.

A method for manufacturing an expanded polytetrafluoroethylene (PTFE) plate comprises the following steps: sieving PTFE dispersion resins, adding a propellant and mixing the two materials, placing the mixed materials for 24h and then carrying out aging treatment, then carrying out pre-press shaping and extruding blanks, carrying out calendaring with two rollers, removing the propellant, carrying out composite shaping after biaxial tension and carrying out reshaping and trimming to finally manufacture the expanded PTFE plate. The expanded PTFE plate is a great breakthrough in the manufacturingprocess of molded plates and turning plates. The compression resilience, the tensile strength and the low stress relaxation rate of the expanded PTFE plate are obviously increased and the expanded PTFE plate obviously improves the performance defects of the fluoroplastics, thus meeting the demand of the use functions of the sealing elements and propelling the fluoroplastics to be one of the substitutes of the asbestos materials widely used at present in the sealing material field.

The invention discloses a chitosan-furfural residue nano-fiber composite membrane preparation method mainly comprising the following steps: furfural residue nano-cellulose is prepared, and a 1-10% nano-cellulose suspension liquid and a 1wt% chitosan acetic acid solution are prepared; the nano-cellulose suspension liquid is added into the chitosan acetic acid solution, and magnetic stirring is carried out for 1.5h; when the material is dissolved, ultrasonic dispersion is carried out for 30min; after vacuum degassing, the mixed solution is spread on a polytetrafluoroethylene plate with a flat surface; the solution is dried for 72h under vacuum and under a temperature of 45 DEG C; an obtained membrane is soaked in a 0.5mol/L NaOH solution for further neutralization; deionized water is used for washing; and the membrane is dried, such that the chitosan-furfural residue nano-fiber composite membrane is obtained. The method has the advantages that: no expensive equipment such as high-pressure homogenization equipment is needed, such that production cost is reduced; problems such as low mechanical strength and poor water resistance of chitosan membrane are solved; no complicated modification operation upon chitosan is needed, and the composite material with excellent performance can be obtained by simply adding natural high-molecular fiber.

The invention discloses edible composite cling film, and a preparation method and application thereof. The composite film is prepared by the following steps: adding a polyvinyl alcohol solution, a chitosan solution, a phenolic acid substance and a plasticizer in an edible polysaccharide Curdlan suspension, adjusting the pH value of the mixed solution to 3-5, carrying out ultrasonic degassing to obtain a film-forming liquid, pouring the film-forming liquid into a polytetrafluoroethylene plate, carrying out heat preservation for carrying out a reaction for 8-10 minutes at a temperature of 90-120DEG C, carrying out sizing, carrying out sterilization treatment, carrying out ultraviolet irradiation treatment for 5-10 minutes, carrying out hot-air circulating drying treatment at a temperature of 90-120 DEG C for 30-60 minutes, and carrying out cooling at a temperature of 4 DEG C to obtain the edible composite cling film. The edible composite film provided by the invention has the advantagesof high tensile strength and high extensibility, has excellent integrity, tensile strength and extensibility after being stewed in boiling water for 1 hour, and can effectively prolong the shelf lifeof fruits, vegetables and the meat products.

The invention relates to a steel structure hoisting slide support seat with large span and a construction process thereof. The steel structure hoisting slide support seat with large span comprises a support boss surface steel plate platform, wherein the support boss surface steel plate platform is welded and fixed with a lower pre-embedded steel column angle groove by a high-strength bolt; a slide steel plate base is arranged on the support boss surface steel plate platform and connected and fixed with the support boss surface steel plate platform through steel columns; a gap between the support boss surface steel plate platform and the slide steel plate base is filled by high-strength grouting materials; an upper slide steel plate is arranged on the slide steel plate base; the top of theupper slide steel plate is provided with a polytetrafluoroethylene plate; the top of the polytetrafluoroethylene plate is provided with a reinforcing steel plate, and one side of the reinforcing steel plate is provided with a slide steel plate. The invention has reasonable design, safety, reliability and high construction speed and successfully solves the problem of hoisting of a steel truss structure with large span under the condition of unstable deviation of a support boss.

A solid polymer electrolyte composite for an electrochemical reaction apparatus that possesses satisfactory ion conduction properties and has excellent mechanical strength and heat resistance, is provided. the solid polymer electrolyte composite is characterized in that a solid polymer electrolyte is contained in the continuous pores of an expanded porous polytetrafluoroethylene sheet which has continuous pores and in which the inner surfaces defining the pores are covered with a functional material such as a metal oxide. An electrochemical reaction apparatus containing an electrolyte, wherein said electrochemical reaction apparatus is characterized in that the aforementioned solid polymer electrolyte composite is used as this electrolyte is also provided.

The invention relates to a preparation method of a novel polyether copolyamide gel membrane, belonging to the field of membrane separation technologies. The preparation method of the gel membrane comprises the following steps of mixing and stirring polyether copolyamide, surfactant and solvent at a certain temperature so as to obtain casting film liquor, coating the casting film liquor on a teflon plate, standing in air for a while, then drying in a vacuum drying oven for several hours, and obtaining the polyether copolyamide gel membrane. The polyether copolyamide gel membrane prepared by the method not only has excellent tensile strength and elongation at break, but also has high permeation flux and separation factor, and is especially suitable for separation of carbon dioxide and hydrogen and recycling of organic steam such as benzene and methane.

The utility model relates to a multifunctional bridge shock-absorbing and isolating support, which is composed of upper and lower parts. The upper part is composed of PTFE plate sliding bearings, which can realize the free expansion and displacement of the main beam structure under conventional loads, and thus have all the characteristics of conventional sliding bearings. The lower part is a combined shock-absorbing and isolating device with multi-level shock-absorbing and isolating functions, which is composed of a lead rubber pad in the middle part and an elastic-plastic energy-dissipating soft steel plate in the peripheral part. A lead core is arranged in the middle of the lead core rubber pad. Under earthquake action, lead rubber pads and elastic-plastic energy-dissipating steel plates are used to jointly dissipate energy to effectively limit the relative displacement between beams and piers. A rigid connection is made between the sliding support of the polytetrafluoroethylene plate and the combined shock-absorbing and isolating device to ensure the joint work of the upper and lower parts of the device. With the worldwide emphasis on the anti-seismic fortification of engineering structures and the continuous development of the economic level, this new type of bridge anti-seismic bearing will have a wide range of engineering application prospects.

The invention discloses a preparation method of a polyurethane pervaporation phenol/water separating membrane compounded by inorganic particles, and belongs to the field of pervaporation membrane separation. The polyurethane membrane basic material is obtained by polymerizing and mixing monomer hydroxyl-terminated polybutadiene, toluene diisocynate, 4,4'-diamine diphenylmethane solution, cyclodextrin and silica or carbon fiber powder. The preparation method comprises the following steps: reacting hydroxyl-terminated polybutadiene with toluene diisocynate to obtain blocked prepolymer, then adding 4,4'-diamine diphenylmethane solution and cyclodextrin as chain extenders to perform the chain extension, and adding inorganic modified particle silica or carbon fiber powder (using N,N-dimethylacetamide as solvent) to obtain prepolymer solution of polyurethane; casting the solution on a polyfluortetraethylene plate to form a membrane, solidifying for 1-1.5 hours at room temperature, and moving the membrane to an oven at 80 DEG C to thermally treat to obtain the polyurethane membrane compounded by inorganic particles. The preparation method disclosed by the invention is simple in process, and the prepared membrane has good heat and chemical stability and mechanical property.

The invention relates to a damper with vibration energy dissipated through a soft steel surface internal yield deformation mechanism. The damper is used for energy dissipation and vibration reduction of a house building. An assembly type soft steel damper optimized through an equal-stress line comprises a soft steel energy dissipation piece, an anti-buckling clamping plate, L-shaped connecting plates, anchoring steel plates, a polyfluortetraethylene plate, pre-pressing fastening bolts, friction type high-strength connecting bolts, a limiting bolt, embedded anchoring steel bars and flexible filling materials. The assembly type soft steel damper optimized through the equal-stress line can serve as a dividing element of a building to be installed in a structure and does not bear a vertical load; when the assembly type soft steel damper bears a wind load or an earthquake load, the elastic-plastic hysteretic behavior generated when the soft steel energy dissipation piece deforms dissipates the energy input by the wind load or the earthquake load, and thus main components of the structure are protected; the soft steel energy dissipation piece is optimized through the equal-stress line, so that accumulated plastic deformation of the energy dissipation piece is greatly reduced, and the low cycle fatigue performance of the energy dissipation piece is enhanced.

Belonging to the technical field of pervaporation membrane separation, the invention relates to a preparation method of a modified polyurethane pervaporation phenol/water separation membrane. The preparation method of the membrane consists of: reacting hydroxyl-terminated polybutadiene with diisocyanate to obtain a terminated prepolymer, adding diamine and cyclodextrin as a chain extender for chain extension, and taking N, N-dimethyl acetamide as a solvent to obtain a modified polyurethane solution, carrying out membrane casting on the solution on a polyfluortetraethylene plate, and conducting curing at room temperature for 1 to 1.5 hours, then moving the obtained membrane into an oven at a temperature of 80DEG C for 10-15 hours of heat treatment, thus obtaining the modified polyurethane membrane. The material synthesis and membrane preparation process of the invention is simple, and the prepared membrane has good thermal and chemical stability as well as mechanical properties. Moreover, compared with traditional unmodified polyurethane separation membranes, the membrane prepared in the invention, due to the existence of the modifier cyclodextrin, has a better comprehensive separation effect on phenol in a phenol/water mixed solution, and has a great practical value.

The invention discloses a fluorescent sensor for measuring the picric acid content. A fluorescent carrier in a film substrate monomer is an allyl four iodine fluorescein. 15mg of fluorescent carrier allyl four iodine fluorescein is dissolved in 0.2ml of N, N-dimethylformamide for sufficient dissolution, 200mg of acrylamide, 0.4ml of hydroxyethyl methylacrylate, 0.15ml of cross-linking agent triethoxy trimethyl acrylate and 0.2ml of triethanolamine are added, finally 0.25ml of 1-oxhydryl cyclohexyl phenyl ketone is added for even mixing; and a solution is removed to drop on a Teflon plate, a quartz slide subjected to silanization is covered on the Teflon plate, an ultraviolet lamp is used for irradiating for 20 minutes, and drying is carried out at a room temperature. The sensor has the advantages of simple preparation, good stability, short response time, good reproducibility and the like, and can continuously and timely measure the picric acid content on line.

There is a method for producing plastic which can be degraded by visible light catalyzing, it uses TiO2/organic dye as catalyzer, TiO2/organic dye and plastic are blended and dissolved in four hydrogen furan, following the liquid is dropped onto poly-tetrafluoro ethylene board, it is taken off after it is air-dried naturally, and then the visible light catalyzer degraded plastic is obtained.

The invention discloses a polyvinyl alcohol/xylan biodegradable composite membrane and a preparation method and an application thereof. The preparation method comprises the following steps: adding polyvinyl alcohol into water, dissolving for 1-4 hours at a temperature of 80-100 DEG C, adding and uniformly mixing xylan and citric acid and controlling the mass ratio of the xylan to the citric acid to be 1:1-4:1; and agitating obtained mixed solution for 2-6 hours at a temperature of 50-80 DEG C, standing, casting on a horizontally-arranged clean polyfluortetraethylene plate and vacuum-drying to obtain the polyvinyl alcohol/xylan biodegradable composite membrane. The polyvinyl alcohol/xylan biodegradable composite membrane and the preparation method and the application thereof have the benefits that the composite membrane has a tensile strength of 7.58-37.42 MPa and an elongation at break of 13.67-249.50 percent; the process is simple, the reaction conditions are easy to control, no environmental pollution is generated in the production process, and the industrialization is easy; and the composite membrane is innocuous, has good biodegradability and higher strength and can be applied to food packaging materials.

The invention belongs to the technical field of electrochemistry power supply, and more specifically relates to a preparation method of a three-dimensional composite metal lithium anode all-solid-state lithium ion battery. According to the preparation method, metal lithium is loaded onto a carrier material through chemical methods including electrochemical deposition or fusion penetration or physical methods so as to obtain a three-dimensional composite metal lithium anode; the carrier material is active carbon fiber cloth; a PMMA-PEI based all-solid-state polymer electrolyte membrane is prepared, is peeled off from the surface of a polyfluortetraethylene plate, and is cut into pieces of appropriate sizes for further processing; LiFePO4 is taken as a cathode, assembling is carried out based on a cathode-PMMA-PEI based all-solid-state polymer electrolyte membrane-three-dimensional composite metal lithium anode sequence so as to obtain all-solid-state lithium ion button cells. The three-dimensional composite metal lithium anode is high in specific energy, coulombic efficiency, safety performance, is table in electrode interfaces, assembling process of the all-solid-state lithium ionbatteries is simple, and is convenient to control.

The invention discloses a method for preparing a polytetrafluoroethylene super-hydrophobic coating. According to the super-hydrophobic coating, in actual application, the contact angles between water drops and the surface are 150-165 degrees, the rolling angles of the water drops on the surface of a material are smaller than 10 degrees, and the polytetrafluoroethylene super-hydrophobic coating has good hydrophobicity. The method for preparing the polytetrafluoroethylene super-hydrophobic coating comprises the steps of adopting a supercritical method, placing a polytetrafluoroethylene plate and a substrate in a reaction kettle with a heating device, leading gas into the kettle, controlling temperature and pressure, causing the led-in gas to be in a super-critical state, maintaining pressure for 12-120 h, performing decompression cooling, and obtaining a super-hydrophobic polytetrafluoroethylene plate and a super-hydrophobic substrate. The inner wall of a metal pipe connected with a pressure release valve and the inner wall of a container are also super-hydrophobic. The method for preparing the super-hydrophobic coating is simple, practical and free of solvent in preparation process and facilitates large-scale production.

The invention discloses a self-balancing test device and a method for directly testing axial tensile strength of early-age concrete. The testing device consists of an outer framework, an inner template, a dowel bar, a hydraulic hollow jack, a hollow load sensor, a ball hinge, a lock nut, a polyfluortetraethylene plate, a hydraulic oil pump and a resistance strain gauge. When testing, a side template in the inner template is removed, and an end template in the inner template and a side plate in the outer framework which are fixed are loosened; the dowel bar is fixed in the center of the end template in the inner template; the hydraulic oil pump drives the hydraulic hollow jack; and the end template and the hydraulic hollow jack move together to break a concrete test piece to test the axial tensile strength of the early-age concrete. The testing device has simple structure, convenient assembly and disassembly and less required materials and equipment, and is suitable for scientific research and testing the axial tensile strength of the early-age concrete in construction site.