5695 results about "Polyamide" patented technology

The invention belongs to the technical field of gel materials, and particularly relates to aerogel powder for polyolefin modification and a preparation method and application thereof. The preparation method of the aerogel powder comprises the following steps: (1) preparing aramid nanofiber dispersion liquid; (2) preparing a polypyrrole coated aramid nanofiber dispersion liquid; (3) mixing polyamide acid and the polypyrrole coated aramid nanofiber dispersion liquid, and then carrying out partial imidization and solvent exchange to prepare hydrogel; and (4) carrying out freeze drying, thermal imidization and crushing to obtain the aerogel powder for polyolefin modification. The aerogel powder is a porous solid material formed by forming one-dimensional composite fibers from aramid nanofibers and polypyrrole and combining the one-dimensional composite fibers with polyimide resin. The aerogel powder and polyolefin resin are compounded to obtain the polyolefin resin composite material with high strength and antistatic property, and the polyolefin resin composite material can be widely applied to the fields of pipes, plates, grouting equipment parts, grouting bags and the like.

The invention belongs to the technical field of aerogel materials, and particularly relates to antistatic aerogel for 3D printing as well as a preparation method and application of the antistatic aerogel. The preparation method comprises the following steps: (1) dispersing inorganic nanoparticles modified by a silane coupling agent containing epoxy groups and an aniline monomer in an acidic solvent to obtain a monomer mixed solution; (2) stirring and dissolving polyamide in the monomer mixed solution; (3) initiating a reaction to obtain a polyaniline modified polyamide solution; and (4) freeze-drying to obtain the antistatic aerogel for 3D printing. By controlling synthesis conditions, a core-shell structure of acid-doped polyaniline coated inorganic nanoparticles is formed, and a good conductive path is formed in polyamide with a small addition amount of polyaniline. The antistatic aerogel for 3D printing can be applied to technologies such as photocuring molding and fused deposition of polyurethane resin in a 3D printing technology, and the antistatic property and the mechanical property of a 3D printed product are improved.

The invention belongs to the technical field of aerogel materials, and particularly relates to high-performance antistatic aerogel for 3D printing as well as a preparation method and application thereof. According to the invention, inorganic hollow nanoparticles are selected as a nucleating modifier for in-situ polymerization of aniline monomers in a polyamide solution, so that polyaniline-coated inorganic hollow nanoparticles are uniformly dispersed in polyamide, and the aerogel composite material with polyamide as a continuous phase and polyaniline-coated inorganic hollow nanoparticles as a conductive and reinforced phase is formed. The use of the hollow inorganic nanoparticles avoids the problem that the solid inorganic nanoparticles lose the characteristics of the inorganic nanoparticles due to high specific gravity and high surface energy, and easy agglomeration or adsorption with other substances in the preparation process of the solid inorganic nanoparticles. The inorganic hollow nanoparticles are adopted as a nucleating modifier, so that the problems of agglomeration of solid nanoparticles and dispersion in a polyamide matrix are well solved.

The invention relates to an antistatic MLCC release film base film and a preparation method thereof. The antistatic MLCC release film base film is prepared by melt blending and biaxial stretching of PET master batch, an antistatic composition and a nano filler, wherein the antistatic composition is prepared by compounding modified PET-PEG and thiophene modified aromatic polyamide; the nano filler is prepared by carrying out melt extrusion on KH550 modified talcum powder and MAH-g-PET (maleic anhydride-grafted polyethylene terephthalate). The antistatic composition disclosed by the invention has the beneficial effects that the antistatic composition is formed by interweaving two polymers, and a stable three-dimensional conductive network is constructed in the PET film, so that the antistatic performance is more efficient, lasting and stable. In addition, through chemically bonded modified talcum powder, the smoothness and low roughness are provided, and meanwhile reinforcing and toughening are achieved; and the single-layer extrusion process can realize ultrathin thin film, the production process is simplified, and the production cost is greatly reduced.

The invention discloses a preparation method and application of a water-based polyamide acid sizing agent, and belongs to the technical field of sizing agents. The method comprises the following steps: synthesizing polyamic acid in an organic solvent by adopting dianhydride and diamine in a polymerization manner, after the reaction is finished, cooling a polyamic acid solution to room temperature, transferring into a dropping funnel, dropwise adding into a solvent of which the volume is 10-25 times that of the solution, separating, completely dropwise adding, collecting a precipitate, and drying to obtain solid polyamic acid; and adding a low-grade ester or low-grade ketone solvent into the deionized water, adding the polyamide acid powder into the mixed solvent according to the solid content of 1-20wt.%, stirring at room temperature until the solid disappears, and standing for liquid separation to obtain a lower layer which is the polyamide acid water-based sizing agent. The sizing agent disclosed by the invention shows excellent dispersity and long-term stability. After sizing, polyamide acid on the surface of the carbon fiber is converted into polyimide through a thermal imidization reaction, so that the carbon fiber has high thermal stability and excellent compatibility.

The invention provides a preparation method of an h-BN / PI high-temperature-resistant anticorrosive coating, and relates to the technical field of polymer composites.The preparation method of the h-BN / PI high-temperature-resistant anticorrosive coating comprises the steps that under the protection of inert atmosphere, aromatic diamine containing impurity element five-membered rings and aromatic dianhydride containing ether bonds are taken and subjected to a polymerization reaction in a polar aprotic solvent, and the h-BN / PI high-temperature-resistant anticorrosive coating is obtained. A polyamide acid solution is obtained; performing ultrasonic-assisted liquid phase stripping on the micron-sized hexagonal boron nitride to obtain single-layer hexagonal boron nitride; adding the single-layer hexagonal boron nitride into the polyamide acid solution for multiple times, and uniformly stirring to obtain a hexagonal boron nitride / polyimide composite solution; and coating the hexagonal boron nitride / polyimide composite liquid on a to-be-coated surface, and carrying out gradient heating curing to obtain the h-BN / PI high-temperature-resistant anticorrosive coating. The h-BN / PI high-temperature-resistant anticorrosive coating based on interaction of multiple hydrogen bonds has relatively good high temperature resistance, relatively good resistance mechanical property and excellent corrosion resistance.

The invention provides a 3D printing foaming part and a preparation method and application thereof, and belongs to the technical field of 3D printing. According to the method for 3D printing of the foaming part, polyamide powder serves as a raw material, the 3D printed part is prepared, then the 3D printed part is subjected to supercritical fluid kettle pressure foaming, and the 3D printed foaming part is obtained. By controlling the melting point and the average particle size of the polyamide powder, the printing temperature and the solubility of supercritical fluid in the 3D printing foaming part, the 3D printing foaming part with high rebound resilience, bending resistance and hydrolysis resistance is obtained, and the 3D printing foaming part has wide application prospects in the field of foaming shoe materials.

The invention discloses a high-weather-resistance halogen-free flame-retardant polyamide composite material and a preparation method thereof, and belongs to the technical field of high polymer materials. The composite material comprises the following raw materials in parts by weight: 20-60 parts of polyamide resin A, 0-20 parts of polyamide resin B, 10-50 parts of glass fibers, 0.1-2 parts of an ultraviolet absorbent, 0.1-2 parts of a free radical scavenger, 10-20 parts of a halogen-free flame retardant, 1-15 parts of a flame retardant synergist and 0.5-5 parts of a conventional auxiliary agent. The preparation method comprises the following steps: uniformly mixing the polyamide resin A, the polyamide resin B, the ultraviolet absorbent, the free radical scavenger, the flame-retardant synergist and the conventional auxiliary agent in a high-speed mixer according to the proportion to obtain a mixture, then adding the mixture into a double-screw extruder through main feeding, side feeding of the halogen-free flame retardant through a first side feeding and side feeding of the glass fiber through a second side feeding, and carrying out extrusion molding to obtain the flame-retardant polyamide composite material. And carrying out melt blending and extrusion granulation to obtain the high-weather-resistance halogen-free flame-retardant polyamide composite material. The obtained high-weather-resistance halogen-free flame-retardant glass fiber reinforced polyamide composite material is excellent in mechanical property, flame retardance and weather resistance.

The invention discloses an anti-shrinkage light, soft and elastic sole foaming material and a preparation method thereof, and belongs to the technical field of footwear products. The light, soft and elastic sole foaming material is formed by chemically foaming an EVA (Ethylene Vinyl Acetate) composite raw material, the EVA composite raw material is prepared from 50 to 70 parts of EVA, 20 to 40 parts of olefin thermoplastic elastomer, 10 to 20 parts of styrene elastomer, 1.5 to 3 parts of maleic anhydride grafted ethylene-octylene copolymer compatilizer, 0.4 to 0.8 part of peroxide cross-linking agent, 3 to 4 parts of foaming agent, 1 to 1.5 parts of zinc oxide, 1 to 1.5 parts of polyethylene wax substance and 0.5 to 1.5 parts of poly (butylene succinate). 0.3 to 1 part of polyamide 12 microspheres and 2 to 3 parts of nano montmorillonite. The foaming material can resist shrinkage when being used as a shoe sole part, and has good rebound performance and the like, so that the high-quality requirement of sneakers, the mass production stability and the like are met.

The invention discloses a water-borne epoxy resin coating which comprises a component A and a component B, the component A is prepared from 60 to 80 parts of 50 percent modified water-borne epoxy resin emulsion, 5 to 15 parts of deionized water, 0.5 to 1 part of wetting dispersant, 0.2 to 0.8 part of defoaming agent, 5 to 10 parts of modified zinc phosphate, 3 to 5 parts of ion exchange antirust pigment, 4 to 6 parts of sericite powder, 3 to 5 parts of glass flake, 5 to 10 parts of precipitated barium sulphate, 1 to 5 parts of nano silicon dioxide and 0.5 to 1 part of rheological additive; 1 to 2 parts of modified organic bentonite slurry; 0.1 to 0.3 part of a pH conditioning agent; and 0.2 to 0.8 part of a flash rust inhibitor. The component B is prepared from 40 to 50 parts of waterborne epoxy-amine adduct, 20 to 30 parts of 50 percent modified polyamide curing agent, 5 to 15 parts of 60 percent Mannich base phenolic aldehyde amine curing agent, 0.5 to 1.5 parts of epoxy silane coupling agent, 1 to 2 parts of nonionic surfactant and 15 to 20 parts of deionized water. The emulsion stability of the waterborne epoxy resin coating is improved through a bisphenol A / F mixed epoxy emulsion and a grafted polyethylene glycol hydrophilic chain segment.

The invention belongs to the technical field of aerogel, and particularly relates to high-conductivity aerogel powder as well as a preparation method and application thereof. The preparation method comprises the following steps: firstly preparing a graphene / polypyrrole nanosheet composite material with a three-dimensional structure, and then preparing the polyimide / graphene / polypyrrole ternary hybrid conductive aerogel by taking a polyamide acid solution as a precursor through a solution dipping and freeze drying process. Polyimide is used as a framework of high-conductivity aerogel powder, excellent mechanical strength and structural integrity are provided, the common brittleness problem of a pure graphene carbon material or polypyrrole conductive polymer aerogel is solved, and the three-dimensional graphene / polypyrrole nanosheet composite material has excellent elasticity and toughness and can be used for preparing a composite material with high conductivity. The polyimide aerogel prepared by the method can be dispersed in a polyimide matrix as a nano reinforcement, can effectively transfer stress and prevent crack propagation, and endows the aerogel with higher mechanical properties.

The present invention addresses the problem of providing a method for producing olefins that can sufficiently remove polyamides from waste plastics. [Solution] The method for producing olefins according to the present invention includes a thermal decomposition step of thermally decomposing a waste plastic raw material containing polyolefins and polyamides to obtain a hydrocarbon stream, a separation step of separating a thermal decomposition product of the polyamides from the hydrocarbon stream that has undergone the thermal decomposition step, and a catalytic cracking step of catalytically cracking the hydrocarbon stream that has undergone the separation step in the presence of a catalyst containing zeolite to obtain olefins.

The invention relates to the technical field of material preparation, and discloses a polyamide elastomer and a preparation method and application thereof, and the preparation method of the polyamide elastomer comprises the following steps: mixing raw materials, and carrying out amidation reaction to obtain an amide compound; then adding a catalyst B, and carrying out polyesterification reaction to obtain a polyamide elastomer; the raw materials comprise binary acid, diamine, polyether glycol, a catalyst A and water, the reaction temperature of the amidation reaction is 150-180 DEG C, and the addition amount of the water is 20-40% of the total mass of the binary acid, the diamine and the polyether glycol. The polyamide elastomer which is relatively regular in structure and excellent in comprehensive performance can be prepared, the reaction efficiency can be effectively improved, and the preparation method is suitable for industrial large-scale production.

Provided is a polyamide resin, which is a copolymer of a biodegradable polyamide, such as polyamide 2 to polyamide 4, and another polyamide, the polyamide resin having enhanced biodegradability. The polyamide resin contains a structural unit represented by Formula (1) and another polyamide structural unit, and a difference between a degree of randomness determined based on a proportion of each structural unit as determined by 1H-NMR measurement when structural units are assumed to have an ideal random sequence and a degree of randomness determined based on a proportion of carbonyl carbon of an amide group linking different structural units with respect to a total peak integrated value for carbonyl carbon as determined by 13C-NMR measurement is 0.10 or less, where in Formula (1), x is an integer of 1 or greater and 3 or less.

The invention provides a polyimide multilayer composite membrane material as well as a preparation method and application thereof, and belongs to the technical field of gas separation. According to the method, through collaborative design of a functional support layer, a gradient MOF layer and an ultrathin selection layer structure, the problems of support layer pore seepage, MOF agglomeration, weak interface bonding and the like in an existing composite membrane material are solved. The preparation method comprises the following steps: firstly, carrying out electrostatic spinning on a polyamide acid glue solution, and synchronously introducing dopamine by adopting a chemical imidization method to prepare a functionalized polyimide fiber membrane containing hydroxyl and amino on the surface, so that the mechanical property of a supporting layer and the MOF anchoring capability are remarkably improved; growing MOF layers with different particle sizes on the surface of the fiber membrane by regulating and controlling the concentration gradient of ligand / metal salt and the reaction time, and passivating through a silane coupling agent after each step of growth so as to avoid heterogeneous nucleation and construct a gradient structure; after the MOF gradient layer is subjected to Ar plasma pretreatment to introduce hydroxyl, the ultrathin polyamide selection layer is formed by utilizing interfacial polymerization of fluorine-containing acyl chloride and a macrocyclic amine monomer, and the ultrathin polyamide selection layer is suitable for gas separation work.

The present application relates to the technical field of polyimides and relates to a preparation method for a high-performance polyimide and an application thereof, aiming to solve the problems in the prior art such as numerous side reactions and severe impact on transparency caused by an excessively high imidization reaction temperature during the use of a high-temperature thermal imidization method for the preparation of polyimides. The preparation method comprises: (1) preparing a polyamic acid solution; (2) adding a chemical catalyst and a polyamic acid solution to partially complete an imidization reaction; (3) adding an end group auxiliary agent, performing coating with the solution, heating, and maintaining the heat to complete the imidization reaction; and (4) carrying out high-temperature treatment to obtain a high-performance polyimide. The present application can significantly reduce numerous side reactions present in a traditional imidization reaction, eliminate an adverse effect of high-temperature imidization on the optical performance, greatly improve the mechanical properties, heat resistance, optical performance, etc. of a material, and also achieve both high heat resistance and high transparency.

The invention provides a polyamide composition and application thereof. The polyamide composition comprises the following components in parts by mass: 40-99.5 parts of polyamide, 10-45 parts of a reinforcing material and 5-35 parts of a flame retardant, the flame retardant is prepared from the following components in parts by mass: 30 to 90 parts of diethyl phosphinate, 0.01 to 3 parts of ethyl phosphonate, 5 to 67 parts of dialkyl phosphinate and 0.01 to 5.5 parts of alkyl phosphinate. According to the invention, by introducing the specific flame retardant, an efficient flame retardant effect can be exerted, so that the polyamide composition has excellent flame retardant property and excellent impact resistance.

The invention discloses a high-strength hoop and a processing method thereof in the technical field of mechanical connection fasteners. The high-strength hoop comprises the following raw materials: modified carbon fibers, a modified epoxy resin matrix, chopped glass fibers, an antioxidant and an aluminate coupling agent. Cleaning the modified carbon fibers with acetone to remove oil stains, oxidizing the modified carbon fibers with concentrated nitric acid at 80-85 DEG C to generate polar functional groups containing hydroxyl and carboxyl, washing the modified carbon fibers with water until the modified carbon fibers are neutral, drying the modified carbon fibers, immersing the modified carbon fibers into an absolute ethyl alcohol solution of an aluminate coupling agent for ultrasonic dispersion, and curing the modified carbon fibers at 100-105 DEG C; the modified epoxy resin matrix is prepared by heating and melting epoxy resin, adding nano montmorillonite, stirring and dispersing, adding polyamide, an accelerant and a flexibilizer, and carrying out vacuum defoaming at 100-105 DEG C. The hoop has the advantages of high strength, weather resistance and the like by modifying and enhancing interface bonding and matrix toughness, and is suitable for connection under complex working conditions.

The present invention discloses a high-performance reverse osmosis membrane and a method for preparing the same. The reverse osmosis membrane comprises a polyester non-woven fabric layer, a polysulfone-based membrane, and a polyamide skin layer stacked in sequence. The polysulfone-based membrane has a micron-scale prism structure on the side away from the polyester non-woven fabric layer. The preparation method comprises coating the surface of the polyester non-woven fabric layer with the polysulfone-based membrane, and forming the micron-scale prism structure on the surface of the polysulfone-based membrane by cold pressing with a roller mold during the process of converting the polysulfone-based membrane from a liquid state to a solid state. The present invention improves the flux without affecting the desalination rate of the reverse osmosis membrane or sacrificing the thickness of the skin layer, thereby resolving the trade-off between flux and desalination in the current technology. At the same time, the micron-scale prism structure can be designed into different shapes according to performance requirements, thereby achieving precise control of the flux performance of the reverse osmosis membrane.

The invention relates to the technical field of packaging materials, in particular to a chip inductor packaging material and a preparation method thereof. The packaging material is prepared from epoxy resin serving as a matrix, composite boron nitride modified hollow glass beads, spherical silica powder, a silane coupling agent, a curing agent, an accelerant and a defoaming agent. Wherein the boron nitride modified hollow glass beads are obtained by constructing a boron nitride functional layer through branched polyamidoamine grafting and a melamine-boric acid in-situ method and carrying out high-temperature calcination. By means of the innovative structural design, efficient bonding of a filler interface and ordered construction of a heat conduction path are achieved, the heat conduction performance and the mechanical strength of the composite material are remarkably improved, and the dielectric constant and the dielectric loss are effectively reduced. The packaging material provided by the invention has excellent electrical, thermal and mechanical comprehensive performance, meets the requirements of light weight and high reliability packaging of a new generation of high-performance chip inductor devices, and has important industrialization and application prospects.

The invention discloses a tough full-bio-based polylactic acid / polyamide composite material and a preparation method thereof, and belongs to the technical field of polymer composite material preparation. The tough polylactic acid / polyamide composite material comprises polylactic acid, bio-based polyamide, a core-shell amide modified material, a hydrolysis stabilizer, an antioxidant and a chain extender. The core-shell amide modified material is prepared by filling a functional elastomer copolymer with amino nanoparticles. The core-shell amide modified material formed on the basis of the amino nanoparticle reactive filling functional elastomer copolymer has a micro core-shell structure formed in situ and a large number of amido bonds, so that the number of hydrogen bonds between molecular chains of a blend system is increased, and entanglement and intermolecular acting force between micro molecular chains of the blend material are improved; therefore, the system compatibility is improved, the absorption of the material on external stress and energy is enhanced, more obvious plastic deformation is generated when the material is stressed and deformed, and the material is endowed with better mechanical properties.

The invention discloses an efficient polyester color master batch and a preparation method thereof, and relates to the technical field of polyester color master batches. The high-efficiency polyester color master batch is prepared from the following raw materials in parts by mass: 40-70 parts of a polyamide carrier, 20-50 parts of a coloring agent, 5-15 parts of a dispersing agent, 1-5 parts of a lubricating agent and 0.5-3 parts of an antioxidant. The special antioxidant specially designed for a polyamide carrier is adopted, the compatibility with the carrier is improved based on the principle of similar dissolves, the problem that a traditional antioxidant is uneven in dispersion to form an anti-oxidation blind area is fundamentally solved, meanwhile, volatilization and migration in the processing process are inhibited by means of high thermal stability of the molecular structure of the antioxidant, and the anti-oxidation performance of the carrier is improved. The color master batch endows a polyester product with a longer anti-oxidation protection effect, and the problems of yellowing, chromatic aberration and the like caused by oxidation in the processing and using processes of the product can be effectively reduced.

The invention relates to a washing and / or cleaning agent, comprising at least one peptide and at least one enzyme which has hydrolytic activity on an ester bond, preferably selected from lipase and esterase, in particular esterase with lipolytic activity, particularly preferably lipase, wherein the peptide is suitable for adhesion to a fat- and / or oil-containing surface or to a surface coated with fat and / or oil or to a surface provided with at least one fat- and / or oil-containing soil, wherein the surface consists of hard surfaces, more preferably surfaces containing or consisting of ceramic (e.g. porcelain, earthenware), metal, steel, stainless steel, plastic, glass, natural and artificial stone, painted and enamelled surfaces, wood, laminate, linoleum and mixtures thereof, particularly preferably tableware (preferably made of ceramic such as porcelain or earthenware and plastic), metal (e.g.cutlery or pots) or glass and mixtures thereof, particularly preferably tableware (preferably made of ceramic such as porcelain or earthenware and plastic), metal (e.g. cutlery or pots) or glass, and / or textiles, more preferably textiles containing or consisting of cotton, polyester, polyamide, polypropylene and mixtures thereof, particularly preferably cotton, polyester and mixtures thereof. Furthermore, the invention relates to methods for cleaning hard surfaces and / or textiles, and to the use of such peptides and agents for improving the cleaning performance on at least one greasy and / or oily soil.

This disclosure relates to the fabrication of high-performance thin film composite (TFC) reverse osmosis (RO) membranes comprising a thin polyamide rejection layer (thickness of 100-200 nanometer), a porous substrate including polysulfone (PSf) layer (thickness of 40-50 micron) cast on polyester nonwoven fabric (thickness of ˜100 micron). Hydrophilic and antibacterial TFC polyamide RO membranes were developed by incorporating green Lignin and nanostructured silver-based metal organic frameworks (MOFs) into the selective layer. The polyamide layer of TFC RO membranes was fabricated on the porous PSf substrate by interfacial polymerization between aqueous monomer solutions containing MPD, and adequate additives in water and organic monomer solutions containing TMC in the mixture of hexane and co-solvents. The optimized produced RO membranes were provided water flux of 95-100 LMH and sodium chloride (NaCl) salt rejection of 98.5-99.0% during filtration of 2000 ppm NaCl solution at 225 psi pressure, and water flux of 55-60 LMH and sodium chloride (NaCl) salt rejection of 98.6-98.9% during filtration of 35000 ppm NaCl solution at 800 psi pressure. This disclosure also relates to developing a roll-to-roll PSf membrane as a substrate for making TFC RO membranes for water desalination

The invention discloses a wide-temperature energy storage aerogel / polymer composite material and a preparation method thereof.The preparation method comprises the steps that oxide aerogel with a three-dimensional skeleton structure is subjected to silanization treatment to obtain hydrophobic oxide aerogel, then the hydrophobic oxide aerogel is dispersed into a solvent to obtain dispersion liquid, and then the dispersion liquid is subjected to ultrasonic treatment to obtain the wide-temperature energy storage aerogel / polymer composite material. The preparation method comprises the following steps: sequentially adding a diamine monomer and an anhydride monomer into a dispersion liquid, reacting under stirring to obtain a polyamide acid precursor solution dispersed with hydrophobic oxide aerogel, carrying out film casting on the polyamide acid precursor solution to obtain a dry film, and carrying out imidization treatment on the dry film to obtain the aerogel / polymer composite material. The obtained aerogel / polymer composite material can still maintain high energy storage performance and stability even at extreme ambient temperature.

The invention discloses a bending-resistant and low-dielectric transparent polyimide film for a flexible electronic device as well as a preparation method and application of the bending-resistant and low-dielectric transparent polyimide film. The surfaces of glass beads are subjected to grafting modification treatment by adopting alkali liquor and a coupling agent; performing ultrasonic dispersion to uniformly disperse the grafted and modified glass beads in a solvent; the preparation method comprises the following steps: dissolving a fluorine-containing diamine monomer in a solvent containing graft modified glass beads under a nitrogen protection atmosphere, after the fluorine-containing diamine monomer is completely dissolved, slowly adding a fluorine-containing dianhydride monomer in batches under a continuous stirring condition, and preparing a transparent polyamide acid solution containing glass beads through a condensation polymerization reaction; and uniformly coating the polyamide acid solution containing the glass beads on a glass substrate through a blade coating machine, and then carrying out gradient heating to obtain the glass bead compounded transparent polyimide film. Fluorine atoms are introduced into molecular structures of dianhydride and diamine, and grafting modified glass beads are doped to serve as filler, so that the transparent polyimide film with bending resistance and low dielectric constant characteristics is successfully prepared.

The invention relates to the technical field of membrane separation, in particular to a preparation method of a pH-step-by-step thermocuring regulation sodium-magnesium separation nanofiltration membrane. The method comprises the following steps: (1) pre-treating a base membrane; (2) preparation and treatment of an aqueous phase solution: S1, preparing the aqueous phase solution according to mass fraction: sequentially adding 1.2%-1.6% of piperazine, 0.10%-0.14% of triaminopyrimidine and 0.14%-0.18% of polyethylene glycol into deionized water, and stirring until the piperazine, the triaminopyrimidine and the polyethylene glycol are completely dissolved to form the aqueous phase solution; s2, adjusting the pH value of the water-phase solution to 10-11 by using hydrochloric acid; s3, pouring the water-phase solution of which the pH is adjusted on the surface of the pretreated base membrane, standing, and blow-drying to form a uniform water-phase layer; (3) interfacial polymerization reaction: S1, preparing an oil phase solution: adding 0.10-0.14% of trimesoyl chloride into n-hexane, and performing ultrasonic treatment until the trimesoyl chloride is completely dissolved; s2, pouring the oil-phase solution on the surface of the base membrane subjected to water-phase treatment, and after reaction, pouring out redundant solution to form a polyamide separation layer, so as to obtain a membrane sheet; (4) performing a step-by-step thermocuring process; and (5) cleaning and storing.

The invention relates to the technical field of membrane separation and seawater desalination, in particular to a high-boron-removal-rate reverse osmosis membrane and a preparation method and application thereof. The polyamide reverse osmosis membrane with at least 70% nodular areas on the surface is prepared by introducing the ethylenediamine tetraacetic acid metal salt into the water phase solution as a complexing additive, and the boron removal rate of the membrane can be improved on the basis of ensuring the retention rate and flux of the membrane.

The invention discloses intrinsic copolymerized low-temperature toughened polyamide resin which comprises a polyamide component and a flexible chain segment component, and the molar ratio of the polyamide component to the flexible chain segment component is 98.5: 1.5-85: 15; the invention also discloses a preparation method of the intrinsic copolymerized low-temperature toughened polyamide resin, which comprises the following steps: mixing a polyamide component and a flexible chain segment component, and carrying out polymerization reaction in a sectional or continuous manner, and comprises a pre-polymerization process and a post-polymerization process; the intrinsic copolymerized low-temperature toughened polyamide resin obtained by the preparation method disclosed by the invention keeps excellent mechanical strength and modulus while improving low-temperature resistance of the intrinsic copolymerized low-temperature toughened polyamide resin.

In one aspect, the disclosure relates to a flame retardant composition comprising a brominated polystyrene reacted with a first portion of a second polymer, and optionally at least a second portion of the second polymer that is not premixed with the brominated polystyrene alone. In some aspects, the first portion and the second portion of the second polymer can be selected from the group consisting of polyamides, polyolefins, polyesters, styrenic polymers or copolymers, or any combination thereof. In any of these aspects, the flame retardant compositions of the present disclosure are sufficiently mixed and have excellent properties, and can optionally include crosslinking to increase mechanical strength. Also disclosed herein are methods for preparing the compositions and articles of manufacture comprising the compositions.