128results about How to "Improved thermal dimensional stability" patented technology

The invention relates to a composite nanofiber lithium battery diaphragm and a making method thereof. The composite nanofiber lithium battery diaphragm is obtained by compounding at least one layer of an aramid 1313 nanofiber film containing nanoparticles with at least one layer of a low-melting-point polymer nanofiber film containing nanoparticles, and nanofibers in the fiber films containing nanoparticles are mutually interlaced and are bonded and connected with each other at interlaced points. The aperture range and the pore closing temperature of the surface layer of the fibers in the composite nanofiber lithium battery diaphragm are 100-400nm and 130-170DEG C respectively, the fiber film does not shrink after the pore closure, the heat shrinkage is less than 2% after the fiber film is heated at 250DEG C for 1h, and the tensile strength is 100-1000MPa, so the composite nanofiber lithium battery diaphragm has the characteristics of heat closing effect, good heat dimension stability and high strength. The making method has the advantages of simple process and low cost, and the obtained composite nanofiber lithium battery diaphragm has a wide application prospect in energy storage fields of supercapacitors, sodium ion batteries and the like.

The invention relates to a composite diaphragm. The composite diaphragm comprises a non-woven fabric-organic polymer composite base material, and a composite gel compounded with the non-woven fabric-organic polymer composite base material, wherein the non-woven fabric-organic polymer composite base material comprises a non-woven fabric and a cross-linked polymer, and the cross-linked polymer is formed by copolymerization of a polymer monomer containing alkenyl and alkoxy silane containing alkenyl in the presence of a catalyst and a cross-linking agent; the composite gel comprises a gel polymer and inorganic modified nano powder, and the inorganic modified nano-powder comprises a polymer formed by copolymerization of methyl methacrylate and a silane coupling agent containing C=C groups, and further comprises a nano-sol connected with the alkoxy silane by virtue of condensation reaction. The invention also relates to a preparation method of the composite diaphragm and a lithium ion battery.

This invention relates to a formulation with the addition of low density additives of volcanic ash, hollow ceramic microspheres or a combination of microspheres and volcanic ash or other low density additives into cementitious cellulose fiber reinforced building materials. This formulation is advantageously lightweight or low density compared as compared to current fiber cement products without the increased moisture expansion and freeze-thaw degradation usually associated with the addition of lightweight inorganic materials to fiber cement mixes. The low density additives also give the material improved thermal dimensional stability.

The invention provides a preparation method for a polyimide nanofiber membrane with a cross-linked structure and application of the polyimide nanofiber membrane in a lithium battery diaphragm, belonging to the field of high polymer materials. The preparation method comprises the following steps: subjecting a polyamide acid solution to electrostatic spinning to prepare a polyamide acid nanofiber membrane; etching the polyamide acid nanofiber membrane in an aqueous ammonia solution with a pH value of 8 to 10 for 60 s to form the cross-linked structure; and carrying out washing, drying and imidization at a temperature of 300 DEG C so as to prepare the polyimide nanofiber membrane. The lithium ion battery diaphragm provided by the invention has high mechanical properties, heat stability, high porosity and excellent electrochemical performance. The battery diaphragm has the cross-linked structure and high mechanical properties, thereby overcoming the problems of low strength and an over-open pore structure of a nonwoven polyimide nanofiber membrane. Meanwhile, the diaphragm has porosity of about 80% and can resist a high temperature of 300 DEG C without any deformation, thereby overcoming the disadvantages of low porosity and poor temperature resistance of a polyolefin microporous diaphragm. In particular, the diaphragm provided in the invention has specific capacity substantially better than that of the traditional polyolefin microporous diaphragm under the conditions of high-rate rapid charging and discharging.

The filter material is characterized by satisfying the following (1) and (2) in the filter material containing polyphenylene sulfide fibers, thereby providing a filter material with excellent dust collection efficiency and high mechanical strength and its composition The bag filter, (1) contains at least 2 layers of fiber webs, the fiber web on the side of the air inflow side contains 50% by weight or more of heat-resistant fibers with a fiber diameter of 15 μm or less, and the fibers on the side of the air outlet side The web contains 50wt% or more of heat-resistant fibers with a fiber diameter greater than or equal to 20 μm; (2) contains a fiber web containing polyphenylene sulfide short fibers with a denier of 1 to 3 decitex and a denier of at least 20 μm; Short fibers of fluorine-based fibers in the range of 2 to 4 decitex.

The present invention discloses discloses a supporting device for a space optical remote sensor. The supporting device comprises two external frames disposed oppositely, and an internal frame disposed between the two external frames. The internal frame is connected to the two external frames by means of a plurality of truss rods, respectively. The external frames are connected to the plurality of truss rods by means of a plurality of external joint assemblies. The internal frame is connected to the plurality of truss rods by means of a plurality of internal joint assemblies. By means of the split frames and the truss rods and using the joint assemblies for connection, the rigidity and strength of the supporting device are effectively improved with good structural stability, thereby meeting the requirements of large aperture and long focal length. The present invention also discloses a space optical remote sensor comprising the supporting device.

The invention relates to the technical field of extraordinary film preparation, and especially relates to a preparation method of a biaxially oriented polyphenylene sulfide composite film with good toughness and excellent heat resistance. The preparation method comprises the steps of master batch preparation, sheet casting and stretching film formation. The biaxially oriented polyphenylene sulfide composite film prepared by adopting a technical scheme in the invention has the advantages of excellent heat resistance, excellent dimensional stability, excellent heat formability and excellent toughness, can be applied the fields of electric insulation materials or forming materials of motors, transformers and insulation cables, the field of circuit substrate materials, and the field of loudspeaker vibration plates for mobile phones.

The invention provides a polyimide film with ultralow dielectric loss and a preparation method thereof, the polyimide film is capable of being directly adhered to a copper foil, the polyimide film comprises a core layer and a surface layer, or the polyimide film comprises two surface layers and a core layer which is sandwiched between the two surface layers, the dielectric loss factor of the polyimide film at 10GHz test frequency is 0.0030-0.0060, and the dielectric constant is less than 3.0.

The invention discloses composite lithium-sulfur battery diaphragm, a preparation method thereof and application. The method comprises the steps of impregnating porous substrate membrane into reactionprecursor solution composed of reaction monomers, cross-linking agent, initiator and solvent; and carrying out in situ polymerization and cross-linking reaction under certain condition, thereby acquiring gel electrolyte filled composite lithium-sulfur battery diaphragm with nanoscale pore diameters. According to the lithium-sulfur battery diaphragm, the porous substrate membrane is taken as a framework material, so the good mechanical property and excellent thermal dimension stability are endowed to the diaphragm; the filled gel electrolyte has a great number of lithium conduction functionalgroups, so channels for lithium ions to shuttle are provided, and the problem that the ionic conductivity is relatively low due to reduction of the pore diameters of the diaphragm is avoided; and according to the prepared nanoscale pore diameter composite diaphragm, migration of polysulfide can be inhibited through physical range limitation and chemical absorption effect, so the coulombic efficiency and cycling stability of the lithium-sulfur battery are improved. The composite lithium-sulfur battery diaphragm, the preparation method thereof and the application are simple in technology and high in practicability, are easy to popularize and are beneficial for accelerating industrial application of a lithium-sulfur battery.

It is provided that a polyester film excellent in heat resistant dimension stability, impact-resistant strength properties, easy-slipping properties, mechanical properties, transparency, and gas barrier performance, and a film roll obtained by winding up this polyester film. A polyester film includes at least one layer mainly including a polyester resin containing a dicarboxylic acid component including furandicarboxylic acid as a main component and a glycol component including ethylene glycol as a main component; and the polyester film has a plane orientation coefficient ΔP of not less than 0.005 and not more than 0.200, a thickness of not less than 1 μm and not more than 300 μm, a heat shrinkage rate of 3.2% or less in each of the MD direction and the TD direction at 150° C. for 30 minutes, and a layer containing at least one additive.

The invention relates to a high-temperature-resistant multi-layer composite diaphragm for a lithium ion battery and a preparation method thereof. The diaphragm is of an A1/B/A2 three-layer structure or an A1/B two-layer structure, wherein A1 and A2 are high-temperature-resistant polymer porous membranes prepared by applying an electrostatic spinning process; the middle layer B is a polyolefin diaphragm, A1/B/A2 or A1/B is compounded through a compounding process, and a three-layer or two-layer composite diaphragm is obtained. The lithium battery diaphragm prepared by the invention has the characteristics of lower closed pore temperature of the middle layer and high temperature resistance of the porous diaphragm on the surface layer, the preparation process is simple and feasible, the adhesive force between different diaphragms is strong, the thermal dimensional stability is excellent, and the dimensional stability, the integrity and the electrolyte wettability of the diaphragm under the condition of extremely high temperature of the lithium ion battery can be improved; therefore, the safety of the battery is improved and the application prospect is good.

This film provides a polyethylene terephthalate film whereby dimensional variation in various steps can be reduced, particularly when the film is used as a substrate film for a flexible device, and that is suitable as a substrate film having minimal curl and excellent appropriateness for processing. This biaxially oriented polyethylene terephthalate film has a degree of crystallinity (Xc) of 0.35 to 0.50, the intrinsic viscosity (IV) of the resin constituting the film is 0.66-1.0 dl/g, the coefficient of thermal expansion at a temperature of 50-170° C. in each of the machine direction and transverse direction of the film is 0.29 ppm/° C., and the degree of thermal shrinkage at 180° C. in each of the machine direction and transverse direction of the film is 0.5%-1.0%.

The invention discloses a filter material and the application thereof. The filter material has a three-layer structure including a filter layer, a non-filter layer and an intermediate fabric strengthened layer, wherein, the filter layer is a fibre net which consists of 10wt percent to 90wt percent of glass fiber with the average diameter of being smaller than 10microns and 90wt percent to 10wt percent of heat resistant fibre with the average diameter of 10 microns to 20microns, the non-filter layer is a fibre net which consists of heat resistant fibre with the average diameter of 20microns to 200microns, and the intermediate layer is the fibre strengthened layer. The filter material has high dust trapping efficiency; the increase of the pressure loss after the removal of dusts from the surface of the filter material is low, and since that the increase of the dust removal period reduces the damage to the filter material caused by the excessive blowing by compressed air, the service life of the filter material is prolonged and the cost is reduced.

The invention discloses polyimide with high thermal dimensional stability, a preparation method therefor and an application of the polyimide. The polyimide disclosed by the invention has a structure represented by a formula I. After a polyimide film is prepared from the polyimide disclosed by the invention, excellent heat resistance, an ultralow thermal expansion coefficient and relatively good mechanical properties and flexibility are shown, and the technical requirements of flexible display industry on development of flexible substrate materials can be met; and the polyimide is applied to production of flexible display devices, and meanwhile, a way of think of designing of a novel monomeric compound is provided for developing high-performance materials.

The invention relates to a preparation method of polyimide profiled fibers. The method comprises the following steps of: (1) preparing a polyamic acid solution; (2) forming by dry spinning; and (3) performing cyclization on the as-spun fibers. The dry spinning process is adopted to prepare polyimide profiled fibers, which has high production efficiency, simple procedures and strong operability, makes solvent volatilization more convenient and can achieve the effect of controlling the degree of profile of polyimide fibers. The prepared polyimide profiled fibers have good mechanical properties and high specific surface areas, maintain good dimensional stability at a high temperature, and can be widely applied to reinforcing fibers of composite materials, protective clothing against high-level radiation and other severe conditions, filtering materials used in high temperature mining conditions and so on.