37results about How to "Low percolation value" patented technology

The invention belongs to the field of conductive polymer composites pressure-sensitive materials and particularly relates to a preparation method of a porous conductive polymer material with pressure-sensitive property and an application thereof. The preparation method of the porous conductive polymer material with pressure-sensitive property comprises the following steps: a) suspension preparation; b) unidirectional freezing; and c) low-temperature low-pressure drying. The porous conductive polymer composite with pressure-sensitive property prepared in the invention has excellent stability and resilience and can be used for preparing a light polymer-based strain sensor; and by combining the obtained conductive polymer composite with the circuit board and semiconductor technology, various pressure-sensitive sensors with good stability and long service life can be made.

The invention discloses a preparation method for a polymer material with a continuously-alternating layer structure. The preparation method comprises the following steps of step 1, premixing 30-70 parts of first resin or a first resin compound and 70-30 parts of second resin or a second resin compound, adding the premix in a double-screw extruder, performing melt blending and extrusion at a temperature of 100-300 DEG C, cooling, and slicing to obtain blend grains; and step 2, performing high-speed thin-wall injection forming on the obtained blend grains at an injection temperature of 100-300 DEG C and an injection speed of 50-1200 mm/s, so as to obtain the polymer material with a continuously-alternating layer structure. The preparation method disclosed by the invention is simple in the whole operation process, low in production cost, suitable for large-scale industrialized production, capable of regulating and controlling the thickness of the continuously-alternating layer structure by adjusting the component proportioning ratio of the blend, and suitable for various blend systems.

The invention relates to a preparation method of a low-percolation graphene/macromolecule electromagnetism shielding material. The composite material comprises the following main raw materials by weight percent: 94-99.7wt% of ultra-high molecular weight polyethylene (UHMWPE) and 0.3-6wt% of graphene oxide GONS. The preparation process comprises the following steps: (1) drying the raw materials; (2) preparing GONS/UHMWPE conductive particles; and (3) pressing and forming at high temperatures. According to the invention, the graphene oxide is reduced in situ at high temperatures in a hot pressing preparation process, so that the agglomeration of the graphene oxide in a chemical reduction process is avoided, the composite material has lower conductive percolation value, higher conductivity and higher electromagnetism shielding performance; and the preparation process is simple and low in production cost, the process is easy to master and mass production is easy to achieve.

The invention belongs to the technical field of manufacturing of conductive polymer composites, and in particular relates to a preparation method of a conductive polymer composite with negative temperature coefficient (NTC) characteristics. The invention discloses a polymer based temperature-sensitive resistance material with a NTC effect, and the polymer based temperature-sensitive resistance material comprises the following raw materials in parts by weight: 88.5-96.9 parts of a polymer 1 and a polymer 2, 0.1-1.5 parts of a conductive filler and 3-10 parts of a compatilizer; moreover, the conductive filler is selectively distributed in the polymer 2; the MFI of the polymer 1 is less than or equal to 7g/10 minutes, and the MFI of the polymer 2 is more than or equal to 12g/10 minutes; the thermal expansion coefficient of the polymer 2 is greater than that of the polymer 1, and the conductive filler is a two-dimensional conductive filler; and the mass ratio of the polymer 1 to the polymer 2 is (3:7)-(7:3). The resistance material prepared by the method disclosed by the invention is low in percolation threshold, the NTC characteristic repeatability of the obtained resistance material is good, and the resistance material is convenient to use for a long time.

The invention belongs to the technical field of conductive macromolecular materials and particularly relates to a method for preparing a conductive macromolecular composite material with an isolation structure. The invention provides the method for preparing the conductive macromolecular composite material with the isolation structure. The preparation method comprises the following steps: uniformly mixing two macromolecular materials and conductive particles by adopting a mechanical blending method to obtain a macromolecular material/conductive particle blending material, wherein the conductive particles are selectively distributed between interfaces of the two macromolecular materials to form a conductive network; and then, injection moulding the macromolecular material/conductive particle blending material by adopting a plunger injection moulding device to prepare the conductive macromolecular composite material with the isolation structure. According to the method provided by the invention, the conductive particles are selectively distributed between the two macromolecules to form the conductive network so as to form the so-called isolation structure, thus the percolation threshold of the material is reduced to a great extent. The invention provides a new concept for preparing the conductive macromolecular composite material which is low in percolation threshold, good in processing performance and extremely high in moulding efficiency.

The invention belongs to the technical field of preparation of high molecular materials, and particularly relates to a low-percolation polyester/carbon nanotube conductive composite material and a preparation method thereof. The composite material comprises the following components in parts by weight: 0.05-5 parts of modified carbon nanotube, 78 parts of dimethyl terephthalate, 50-100 parts of aliphatic diol, 0.0078-0.78 part of ester exchange catalyst and 0.0078-0.78 part of polymerization catalyst. The invention also provides a preparation method of the low-percolation polyester/carbon nanotube conductive composite material. The method comprises the following two core steps: surface polymerization of carbon nanotubes and in-situ polymerization. Compared with the prior art, the specially modified carbon nanotubes in the polyester/carbon nanotube conductive composite material provided by the invention have high similarity with polyester, and thus, can be chemically combined with the polyester, and the system viscosity is very low in the in-situ polymerization process, so that the carbon nanotubes are highly dispersed in the substrate, thereby greatly lowing the conductive percolation value of the carbon nanotubes in the composite material.

The invention discloses a formula for producing conductive fiber through graphene. The formula for producing conductive fiber through graphene comprises the following components: (1) graphene with the addition amount of 0.1-5% vol; (2) a solvent; (3) polyphenylene sulfide with the addition amount of 5-20% in percent by mass. According to the formula for producing conductive fiber through graphene, through addition of the graphene, the influence on the conductivity of a nonconductive composite material is eliminated.

The invention relates to a pipeline, in particular to a polypropylene (PP) pipeline, which comprises a pipe. The technical scheme includes that a pipe wall has three layers, an inner layer and an outer layer are antistatic polypropylene layers, namely conductive carbon fiber materials with the weight ratio ranging from 1% to 5% and conducting carbon black with the weight ratio ranging from 2% to 8% are mixed in polypropylene materials to form each polypropylene layer, and an intermediate layer is a glass fiber reinforced polypropylene layer, namely glass fibers with the weight ratio ranging from 25% to 45% and amine beta nucleating agent with the weight ratio ranging from 0.1% to 0.5% are mixed in polypropylene materials to form the glass fiber reinforced polypropylene layer. The polypropylene pipeline has the advantages that the polypropylene pipeline is high in corrosion resistance and physical properties and excellent in antistatic performance, the quality of a product can be guaranteed, maintenance cost of equipment is low, resources can be greatly saved, production cost of the product is greatly lowered, and the polypropylene pipeline is a product with excellent economic and social benefits.

The invention discloses a low-percolation-threshold polypropylene-based composite electroconductive high polymer material which is composed of, by weight, 40-50 parts of polypropylene, 1-2 parts of carbon nano tube, 20-30 parts of electroconductive carbon black, 5-12 parts of glass fiber, 5-10 parts of titanium-magnesium alloy, 5-8 parts of calcium powder, 5-10 parts of decabromodiphenyl ether and 1-2 parts of silicone oil.The invention further discloses a preparation method of the material.The silicone oil is adopted as a phase solvent, so that dispersity of the electroconductive carbon black in polypropylene is improved, percolation value of the composite material is lowered, and electroconductivity of the material is improved greatly; various fillers are compounded and added, overall mechanical performance of the material is improved, and the material has better properties.

The invention relates to a strong-basicity graphene composite ion exchange resin material and a preparation method thereof. A matrix and graphene in the strong-basicity graphene composite ion exchangeresin material are combined in a covalent bond form. The technical scheme adopted by the invention is as follows: the strong-basicity graphene composite ion exchange resin material comprises the following components in parts by weight: (a) 75-90 parts of a polymeric monomer; (b) 5-15 parts of a comonomer; and (c) 0.1 to 10 parts of a graphene-styrene derivative compound. According to the technical scheme, the thermal decomposition temperature and the swelling resistance of the composite ion exchange resin are well improved, and the method can be applied to industrial production and application of strong-basicity composite ion exchange resin materials in the future.

The embodiment of the invention relates to a conductive composite material with an isolation and double-percolation structure and high PTC strength, and a preparation method and application of the conductive composite material. The conductive composite material is prepared from raw materials comprising following components: linear low-density polyethylene, polyvinylidene fluoride, a conductive filler and an antioxidant. The preparation method of the conductive composite material comprises the following steps that the linear low-density polyethylene, the conductive filler and the antioxidant are fused and blended in an internal mixer, the temperature of the internal mixer is set to be 130-160 DEG C, and a clad master batch is prepared; then the polyvinylidene fluoride is added into the internal mixer, the temperature of the internal mixer is set to be 130-150 DEG C, and the clad master batch and the polyvinylidene fluoride are fused, blended and then taken out; and hot pressing is conduced to obtain the conductive composite material. The prepared CB/LLDPE/PVDF conductive composite material has the isolation and double-percolation structure, is low in conductive content, high in PTCstrength and high in stability, and can be used as a temperature-sensitive material.

The invention relates to a composite wave-absorbing material and a preparation method thereof, in particular to an iron oxide nanotube@polyaniline/silicon tungsten nickel polyoxometallate composite wave-absorbing material prepared by adopting a hydrothermal-supramolecular self-assembly method. According to the prepared composite wave-absorbing material, on the basis of magnetic loss, conductive and dielectric materials are introduced, the impedance matching characteristic of the material is improved, the wave-absorbing performance of the material is enhanced, and the defects that an existing composite wave-absorbing material is large in density, poor in impedance matching characteristic, narrow in absorption bandwidth, poor in absorption performance and the like are overcome.

The invention discloses a flexible polyurethane-based composite material with excellent flame retardance and electromagnetic shielding performance and a preparation method thereof, the material prepared by the method is composed of a conductive composite material and a flame-retardant composite material, and a sample with an isolation structure is obtained by melt blending and hot press molding. Wherein the conductive composite material is a polymer-based composite material filled with conductive filler, and the flame-retardant composite material is a polymer-based composite material filled with flame retardant particles. The mass ratio of the conductive phase to the flame-retardant phase, the sample thickness and the performance of the composite material with the isolation structure prepared by the preparation method provided by the invention are controllable, and the raw material formula is adjustable; the electromagnetic shielding performance and the flame retardant performance areexcellent; the used raw materials are commercially available, wide in source and low in cost, no chemical reaction or organic solvent is involved in the preparation process, and the preparation process is simple, safe, environmentally friendly and suitable for industrial production.

The invention relates to a strong-basicity carbon nano tube-graphene composite ion exchange resin material and a preparation method thereof. In the strong-basicity carbon nano tube-graphene compositeion exchange resin material, a matrix and carbon nanotubes/graphene are combined in a covalent bond form, and the strong-basicity carbon nano tube-graphene composite ion exchange resin material comprises the following components in parts by weight: (a) 75-90 parts of a polymeric monomer; (b) 5-15 parts of a comonomer; (c) 0.1 to 10 parts of carbon nanotubes; and (d) 0.1 to 10 parts of graphene. According to the technical scheme, the thermal decomposition temperature and the swelling resistance of the composite ion exchange resin are well improved, and the method can be applied to industrial production and application of strong-basicity composite ion exchange resin materials in the future.

The invention relates to the technical field of button switches, in particular to a non-metal conductor used for button switches. The non-metal conductor comprises the following raw materials in partsby weight: 75-85 parts of polymer elastic particles, 23-31 parts of polydodecalactam, 2-8 parts of an alkali metal salt, 85-105 parts of a conductive material, 15-20 parts of carbon black and 2-4 parts of an active agent. The polymer elastic particles enable the conductor to have good elasticity, and the surfaces of the polymer elastic particles are coated with a vulcanizing agent, so that the conductive elastomer has a low percolation value. An organic polymer polyelectrolyte is prepared by complexing and coordinating alkali metal ions with a polydodecactam polyether block, and the polyetherblock (C-O-C) generally have flexibility and can form an associated matter with an electron acceptor or certain inorganic electrolytes. Through addition of an auxiliary conductive agent, surface activity of the polymer elastic particles can be improved and conductivity is improved. The non-metal conductor has outstanding substantive characteristics and remarkable progress.

The present invention relates to an electroconductive high-molecular composite material composition which has gas-sensing response characteristics and its made by using amorphous polystyrene matrix filled up with electroconductive filler and its preparation method. Said material is made up by using amorphous polystyrene as matrix and combining it with electroconductive filler, and has higher gas-sensing response characteristics for organic solvent steam having a certain compatibility with said matrix, so that when it is met with several organic solvent gases, the electric resistance of said composite material can be quickly changed.