206 results about "Nylon 66" patented technology

The invention relates to the technical field of polymer composite materials, in particular to a carbon fiber reinforced nylon 66 / polyphenylene sulfide composite material and a preparation method thereof.The carbon fiber reinforced nylon 66 / polyphenylene sulfide composite material is prepared from, by weight, 40-55 parts of nylon 66, 30-45 parts of polyphenylene sulfide, 15-30 parts of carbon fibers, 5-6 parts of compatilizer, 0.8-1.2 parts of antioxidant and 3-4 parts of flexibilizer, the flexibilizer is ethylene-octylene copolymer grafted maleic anhydride, the grafting rate is 1.2-1.5%, the flexibilizer is ethylene-octylene copolymer grafted maleic anhydride, the grafting rate is 0.8-1.0%, and the antioxidant is a mixture of an antioxidant 1010 and an antioxidant 168 according to a mass ratio of 1: 1. The composite material prepared by the invention is suitable for medium-high temperature scenes, not only solves the problems of insufficient high temperature resistance and poor mechanical properties of traditional materials, but also has good processability and environmental tolerance.

This invention relates to the field of sealing ring technology, and proposes an aging-resistant rubber sealing ring and its preparation method. An aging-resistant rubber sealing ring comprises the following components in parts by weight: 70-80 parts of nitrile rubber, 20-25 parts of chloroprene rubber, 20-30 parts of filler, 3-4 parts of activator, 1-2 parts of co-activator, 2-3 parts of antioxidant, 4-8 parts of plasticizer, 2-3 parts of crosslinking agent, and 1-2 parts of accelerator; the filler includes modified carbon nanotubes and nylon 66 fiber; the preparation method of modified carbon nanotubes includes the following steps: A1, adding carbon nanotubes to mixed acid, soaking, filtering, and drying to obtain pretreated carbon nanotubes; A2, adding the pretreated carbon nanotubes and methyl cyanobenzoate to ethyl acetate, stirring, concentrating, and drying to obtain modified carbon nanotubes. Through the above technical solution, the problem of poor aging resistance of rubber sealing rings in related technologies is solved.

The invention discloses a halogen-free compound flame retardant and application thereof in an antistatic nylon 66 composite material, and belongs to the technical field of polymer composite materials. The halogen-free compound flame retardant is prepared by compounding 68 parts of an organic aluminum hypophosphite flame retardant, 20 parts of a nitrogen-phosphorus intumescent flame retardant, 10 parts of a two-dimensional layered inorganic substance and 2 parts of a coupling agent through a high-speed mixing and drying process. The halogen-free compound flame retardant is blended with nylon 66, reinforced fibers, an antioxidant and the like, and the composite material is prepared through melt extrusion. According to the compound system, the total dosage of the flame retardant is remarkably reduced, the V-0 flame retardant grade is still achieved under the condition that the thickness is 0.8 mm, and the limit oxygen index exceeds 32%. The composite material has excellent flame retardancy and antistatic property while maintaining good mechanical properties, is suitable for a high glass fiber content system, effectively solves the problems of high flame retardant addition amount, difficult processing, high cost and the like in the prior art, and has the advantages of simple process and excellent comprehensive performance.

The invention discloses a preparation method of a nylon 66 salt crystal, which is characterized in that in the method, a nylon 66 salt aqueous solution is subjected to secondary crystallization and a rotary pressure filter process to prepare the nylon 66 salt crystal. According to the technology, the problems of low single-stage yield and large sewage discharge amount are solved by adopting secondary crystallization and evaporation condensate recycling, and the processes of centrifugation, drying, cyclone separation and the like are reduced by replacing a centrifugal machine with a rotary pressure filter, so that the energy consumption per ton of products is reduced.

The invention provides a nylon modified material as well as a preparation method and application thereof, and relates to the technical field of nylon compositing, the nylon modified material comprises the following components: nylon 66, low-viscosity nylon 6, a toughening agent, a compatilizer and a flow crystallization accelerant; wherein the toughening agent comprises a block copolymer containing a polyethylene glycol chain segment and a polydimethylsiloxane chain segment; the compatilizer comprises a compound containing a diglycidyl ether group. According to the nylon modified material provided by the invention, under the condition that the modulus of nylon 66 is slightly reduced, the impact strength is improved, so that the nylon modified material has the characteristics of high flowability, high toughness, self-lubrication and the like, and can meet the requirements of occasions such as automobile parts and industrial production.

The invention provides a polyamide hot melt adhesive containing dynamic reversible covalent bonds and a preparation method thereof, and belongs to the field of high polymer materials. Caprolactam and nylon 66 salt are used as raw materials, a furan ring and a carbon chain with a specific length are introduced, and the polyamide hot melt adhesive containing the dynamic reversible covalent bond is obtained through polymerization with maleimide and a derivative thereof. The melting point of the polymer can be regulated and controlled by regulating and controlling the carbon chain length of aliphatic diamine introduced into the xF salt, a furan ring in the xF salt is subjected to DA addition reaction with maleimide and a derivative thereof, dynamic reversible sites are provided, crosslinking between molecular chains is formed, a net system is formed, and the bonding strength of the material can be greatly improved. By adjusting the ratio of the xF salt to the maleimide and the derivative thereof, the reversible crosslinking behavior of the polymer can be adjusted, and finally the hot melt adhesive which has a lower melting point and excellent bonding strength and can be repeatedly used and recycled is obtained.

The invention discloses an ultra-high-speed motor bearing anti-deformation crown-shaped retainer and a manufacturing method, and belongs to the technical field of motor bearings. The super-high-speed motor bearing anti-deformation crown-shaped retainer is formed by printing functionally graded materials, the functionally graded materials comprise a hard-phase material and a soft-phase material, the hard-phase material is glass fibers, and the soft-phase material is nylon 66; the equivalent elastic modulus of the functionally graded material is continuously and gradually changed in the axial direction from the bottom of the pocket to the tail end of the lock claw, so that the elastic modulus of the bottom area of the pocket is higher than that of the tail end area of the lock claw, and elliptical deformation of the pocket and centrifugal deformation of the lock claw are cooperatively restrained. And active reconstruction of a rigidity field of the crown-shaped retainer is achieved, specifically, a tough phase is constructed in a locking claw area to absorb collision energy, a strengthening phase is formed in a pocket area to weaken stress concentration, a rigidity gradient is established at a connecting part to restrain the umbrella-shaped effect, and the crown-shaped retainer with the high toughness-gradient-high strength characteristics and the design method of the crown-shaped retainer are provided.

The invention relates to an antibacterial and wear-resistant textile fabric and a preparation method thereof, and belongs to the technical field of textile fabrics, the antibacterial and wear-resistant textile fabric is formed by spinning antibacterial and wear-resistant yarns, and the antibacterial and wear-resistant yarns are formed by winding and twisting wear-resistant fibers on antibacterial fibers; wherein the wear-resistant fiber is prepared from the following raw materials in parts by weight: 10 to 20 parts of silkworm excrement, 5 to 10 parts of rosin, 3 to 8 parts of volcanic rock particles and 50 to 60 parts of bio-based nylon 66 particles; the antibacterial fiber is prepared from the following raw materials in parts by weight: 30-35 parts of natural plant ash, 10-15 parts of Chinese soapberry fruit extract and 60-70 parts of polytetrafluoroethylene particles. The antibacterial and wear-resistant yarn is made into the antibacterial and wear-resistant textile fabric by intertwisting wear-resistant fibers and antibacterial fibers, silkworm excrement and rosin are added into raw materials for preparing the wear-resistant fibers, the wear resistance of the wear-resistant fibers can be improved, and organic matter contained in the silkworm excrement can improve the viscosity of the rosin; the wear-resistant fiber obtained by processing has good wear resistance.

The invention relates to the technical field of textile fabrics, in particular to an antibacterial nylon fabric and a preparation method thereof. The antibacterial nylon fabric is prepared from the following materials in parts by weight: 65 to 75 parts of nylon 66, 8 to 10 parts of modified nano zinc oxide, 2 to 3 parts of silver-loaded zirconium phosphate, 3 to 5 parts of compatilizer, 0.2 to 0.5 part of antioxidant and 0.5 to 1 part of lubricant. Wherein the modified nano-zinc oxide is obtained by firstly coating nano-zinc oxide with polydopamine and then grafting the coated nano-zinc oxide with a silane coupling agent. According to the antibacterial nylon fabric and the preparation method thereof, the durability of the antibacterial performance of the antibacterial nylon fabric is improved, and the effective antibacterial capacity is still kept after the antibacterial nylon fabric is washed for multiple times.

The invention provides a high-performance polyamide flame-retardant composite material based on element synergistic effect and a preparation method thereof, and belongs to the technical field of polyamide flame-retardant materials. The preparation method comprises the following steps: preparing a phosphorus-nitrogen flame retardant, preparing a surface-modified rare earth-silicon-based material, preparing a mixture, extruding and granulating. The step of preparing the mixture comprises the following steps: uniformly mixing brominated polystyrene (BPS), a phosphorus-nitrogen flame retardant, a rare earth-silicon-based material, glass fibers, an antioxidant 1098, a heat stabilizer diisooctyl phenyl phosphite, nylon 66 and nylon 6 to obtain the mixture; according to the invention, the use of antimony oxide in the traditional bromine-antimony flame-retardant system preparation process is abandoned, and the preparation process is simple, good in repeatability, green, environment-friendly and efficient.

The invention relates to the technical field of fibers, and discloses an easily biodegradable polyester-nylon composite fiber and a preparation process thereof.The preparation method comprises the steps that 2-(2-acrylamido ethyl formate) benzoic acid is subjected to graft modification to obtain modified polylactic acid, and the modified polylactic acid, polyethylene glycol terephthalate PET and nylon 66 resin are subjected to blending melt spinning to obtain the polyester-nylon composite fiber. The modified polylactic acid improves the compatibility between the PET and the nylon 66 resin, so that the polyester-nylon composite fiber has higher mechanical properties, and the tensile strength and the elongation at break are obviously improved. The polylactic acid has better biodegradability, and the introduced ester group also has biodegradability, so that the biological decomposition rate of the fiber is improved. The modified polylactic acid contains a large amount of hydrophilic carboxyl and amido bonds, so that the moisture regain of the composite fiber is improved, and the modified polylactic acid can be better applied to hydrophilic moisture absorption fiber textiles.

The invention relates to a large-capacity semi-dull nylon 66 resin continuous polymerization device for civil filaments and a production process, and through a whole-process continuous design (salification-concentration-polymerization-pelletizing) and an intelligent regulation and control system, the production efficiency and the product consistency are remarkably improved. According to the process, high-efficiency production is realized, and meanwhile, the product quality and the functional applicability are greatly improved through innovative structural design; the dispersity of TiO2 master batches in resin is effectively improved through high-shear mixing of a screw system, so that the spinnability is further improved; the continuous process supports the flexible adaptation of the antioxidant and the extinction master batch, reduces the waste of raw materials, lowers the comprehensive production cost, and obviously enhances the market competitiveness.

The invention provides a composite intumescent flame retardant modified polyamide composite material and a preparation method thereof. The flame-retardant nylon 66 and / or nylon 6 composite material is prepared from the following components in parts by weight: 75-85 parts of nylon 66 and / or nylon 6 matrix and 15-25 parts of composite intumescent flame retardant, wherein the composite intumescent flame retardant is prepared from the following components in parts by weight: 30-50 parts of a phytic acid derivative; 20 to 40 parts of melamine pyrophosphate (MPP); 5 to 15 parts of modified nanosheets; and 10-20 parts of a hydrogen bond cross-linking agent. According to the composite intumescent flame retardant modified polyamide composite material disclosed by the invention, the limit oxygen index and the fireproof grade can be remarkably improved under the condition that the addition amount of the composite intumescent flame retardant is low, and the mechanical property of the polyamide material is not influenced.

The invention relates to a reinforced nylon 66 material as well as a preparation method and application thereof. The reinforced nylon 66 material comprises the following components in parts by weight: 20-45 parts of low-viscosity nylon 66; 20 to 45 parts of high-viscosity nylon 66; 15 to 30 parts of ground glass fiber; 3-6 parts of a toughening agent; 0-10 parts of kaolin; 0.8 to 2 parts of a lubricant; 0.2 to 0.4 part of a silane coupling agent; and 0.3 to 0.8 part of an antioxidant. The reinforced nylon 66 material is used for extrusion molding of plates or sheets. Compared with the prior art, the reinforced nylon 66 material prepared by the invention has the advantages that the processing window of extrusion molding is effectively improved by adopting a scheme of compounding high-viscosity nylon 66 and low-viscosity nylon 66, the size stability of a profile is improved and the cost is reduced by adopting ground glass fibers, and further, the surface smoothness of the profile can be better by adding a small amount of kaolin; through particle extrusion, the reinforced nylon 66 material for extrusion molding of sheets or plates is prepared.

The invention relates to the technical field of high polymer materials, and particularly discloses modified polyamide, an acid dyeable nylon 66 fiber as well as a preparation method and application of the acid dyeable nylon 66 fiber. The acid dyeable nylon 66 fiber disclosed by the invention has in-situ leveling property, modified monomers, adipic acid and hexamethylenediamine are polymerized to obtain modified polyamide, then the modified polyamide is prepared into pre-oriented yarns, and the pre-oriented yarns are elasticized to obtain the acid dyeable nylon 66 fiber. The ionic group of the modified monomer has an in-situ retarding effect in the nylon 66 fiber and is not combined with a dyeing seat, and an excellent level dyeing effect and a high dye uptake can be obtained without using a leveling agent. The addition amount of the modified monomer is small, the molecular size of the modified monomer is similar to that of adipic acid and hexamethylenediamine monomers, adverse effects on a polymerization process and a nylon 66 molecular structure are small, and the prepared acid dyeable nylon 66 fiber has excellent mechanical properties. The preparation cost of the acid dyeable nylon 66 fiber is low, the process is simple and convenient, and the acid dyeable nylon 66 fiber has a wide application prospect.

The application belongs to the technical field of nylon industrial yarn, and particularly relates to a nylon industrial yarn for airbag and a preparation method thereof. The preparation method of the nylon industrial yarn is as follows: taking nylon 66 salt and benzotriazole-phosphate derivative as raw materials, under the action of sodium hypophosphite, polycondensation is carried out to obtain modified nylon 66 chip, and then the nylon industrial yarn is prepared through melt spinning; the nylon industrial yarn is prepared by one-step direct polymerization, which can effectively avoid the problem of the decline of the comprehensive performance of the finished product nylon 66 caused by the flame-retardant modification, and the preparation process is simple and convenient for production; the prepared nylon industrial yarn has good strength, aging resistance and flame retardance, and has great market application value in the field of automobile airbag.

The anti-tripping composite structure embedded sleeve comprises a body and a stainless steel sleeve, the body is of a tubular structure with one end opened and the other end sealed, external threads, used for being combined with the interior of a sleeper, on the outer circumferential wall of the body are single continuous threads, and the stainless steel sleeve is embedded in the inner wall of the body. And the internal thread on the inner wall of the stainless steel sleeve is combined with the internal thread on the body to form a continuous thread with a consistent thread shape. By optimizing the structure of the pre-embedded sleeve, the torsional shear strength and the tensile strength of the internal thread are further enhanced, the surface hardness of the internal thread of the pre-embedded sleeve is increased, the friction coefficient is reduced, and the service life of the pre-embedded sleeve is prolonged. The potential safety hazard that the pre-embedded sleeve made of the glass fiber reinforced nylon 66 composite material is tripped in construction assembly and operation is solved, and the situation that the surface of the internal thread is scratched due to friction and shearing in the fastening process of the pre-embedded sleeve and a screw spike under the conditions that hard impurities are mixed in the pre-embedded sleeve and water is accumulated and ice is formed is avoided; and the risk of potential failure of the pre-embedded sleeve is further caused.

The invention discloses phosphorus-nitrogen-silicon multi-synergistic halogen-free intrinsic flame-retardant nylon 66 and a preparation method thereof. The phosphorus-nitrogen-silicon multi-synergistic halogen-free intrinsic flame-retardant nylon 66 is prepared from an amino-terminated polysiloxane reactive flame-retardant monomer containing phosphorus, nitrogen and silicon elements and nylon 66 salt through in-situ copolymerization, the flame-retardant monomer is prepared by carrying out hydrosilylation reaction on an amino-terminated polysiloxane precursor with an active Si-H bond and a phosphorus / nitrogen compound containing an unsaturated double bond; through a copolymerization reaction, a flame-retardant unit is introduced into a nylon 66 main chain on a molecular level, so that the problems of poor compatibility and migration of a traditional additive flame retardant are solved. By utilizing the synergistic flame-retardant effect of phosphorus, nitrogen and silicon elements, the obtained copolymerized nylon 66 can achieve excellent flame-retardant property under the condition that the addition amount of a flame-retardant monomer is relatively low, meanwhile, the inherent excellent mechanical properties such as high strength and high toughness of the nylon 66 are maintained to the greatest extent, the technical problem that the flame-retardant property and the mechanical properties are difficult to balance is solved, and the flame-retardant property of the copolymerized nylon 66 is greatly improved. The method has a wide industrial application prospect.

The invention discloses a nylon fabric capable of preventing a pattern from floating and discoloring and a process for manufacturing a sports cap by using the nylon fabric, and relates to the technical field of clothing textile. The process comprises the following steps: firstly, mixing deionized water with polyethylene glycol 400 to form a transparent solution, then adding waterborne polyurethane emulsion, and stirring to obtain a transparent solution; then adding nano silicon dioxide and modified nano zinc oxide, carrying out ultrasonic dispersion, then adding an ultraviolet light absorber, epoxidized soybean oil and an organic silicon defoaming agent, stirring, and filtering to obtain an anti-discoloration composite coating solution; the preparation method comprises the following steps: pretreating a nylon 66 fabric base material to remove greasy dirt and floating dust, drying, coating the printing surface of the fabric with the obtained coating liquid by adopting a scraper coating machine, sequentially pre-drying, curing, cooling and sealing to obtain the anti-discoloration modified nylon fabric, cutting the anti-discoloration modified nylon fabric according to the sports cap pattern, printing and drying the printing area of the cap body cutting piece, and finally ironing and shaping to obtain the sports cap capable of preventing the pattern from floating and discoloration.

The invention discloses a flame-retardant modified glass fiber reinforced nylon 66 composite material containing phosphaphenanthrene Schiff base imide oligomer and a preparation method of the flame-retardant modified glass fiber reinforced nylon 66 composite material. The raw material formula of the composite material is prepared from the following components in percentage by mass: 25.0 to 40.0 percent of glass fiber, 40.0 to 56.8 percent of nylon 66, 16.1 to 19.7 percent of phosphaphenanthrene-containing Schiff base imide oligomer and 0.1 to 0.3 percent of antioxidant, the phosphaphenanthrene Schiff base-containing imide oligomer contains DOPO, Schiff base and trifluoromethyl, is combined with an imide structure and plays a role in a gas phase and a condensed phase at the same time, so that efficient flame retardance of a glass fiber reinforced nylon 66 composite material is realized; the surface energy of trifluoromethyl is distributed on an interface, agglomeration of the glass fiber is reduced, the processing fluidity is improved, an anhydride group is arranged at the tail end of the imide oligomer and can react with hydroxyl on the surface of the glass fiber and amino at the tail end of nylon 66 at the same time, the interface compatibility is enhanced, and the mechanical property of the material is improved.

The invention belongs to the technical field of nylon 66 polymer performance testing, and particularly relates to a method for simultaneously testing the content of iodide ions and bromide ions in a nylon 66 polymer, which comprises the following steps of: extracting the iodide ions and the bromide ions in the polymer by using weak acid salt (sub-carbonate or bicarbonate) instead of potassium nitrate as an ionic strength regulator; the acid environment in the extracted solution is adjusted with formic acid, silver nitrate is adopted as a titrant, iodide ions and bromide ions in the extract liquor are detected at the same time through potentiometric titration, and the problem that the iodide ions and the bromide ions cannot be detected at the same time is solved.

The invention belongs to the technical field of high polymer materials, and particularly relates to a toughness-enhanced modified nylon material and application of the toughness-enhanced modified nylon material to a detachable seat. The modified nylon material is prepared from the following raw materials: nylon 66, a polyamide thermoplastic elastomer, a maleic anhydride grafted styrene-ethylene-butylene-styrene block copolymer and nano silicon dioxide, the maleic anhydride grafted styrene-ethylene-butylene-styrene block copolymer is used as a molecular bridging agent, and the nano silicon dioxide is used as an auxiliary agent. Maleic anhydride reacts with an amino-terminated group of nylon 66, and a block is compatible with a soft segment of the polyamide thermoplastic elastomer, so that a rigid framework of which the structure is nylon 66-molecular bridging agent-polyamide thermoplastic elastomer is formed; wherein the nano silicon dioxide is combined with a hydrogen bond of a soft segment of the polyamide thermoplastic elastomer, so that a three-dimensional elastic network with a nano silicon dioxide-polyamide thermoplastic elastomer-block structure is formed.

The invention provides a copolymerization modified flame-retardant high-strength polyamide 66 fiber and a preparation method thereof. The preparation method comprises the following steps: adding pyridine heterocyclic ring-containing amide salt, aromatic structure amide salt, nylon 66 salt and deionized water into a polymerization kettle as a reaction system; regulating and controlling the temperature and the pressure of a reaction system in an inert gas atmosphere, and carrying out staged reaction to obtain copolymerized modified polyamide 66 slices; the copolymerization modified polyamide 66 slices are subjected to melt extrusion and spinning to obtain the copolymerization modified flame-retardant high-strength polyamide 66 fiber, and the polyamide 66 fiber with high strength and lasting flame-retardant characteristics is prepared by introducing a copolymerization modification scheme containing a pyridine structure and an aromatic structure.

The application is a kind of low water absorption and high heat distortion temperature copolymer nylon resin, which comprises the following components in weight percentage: 98% to 99.8% of nylon salt; 0.1% to 1% of end-capping agent; and 0.1% to 1% of hindered phenol monomer. The nylon salt comprises 60% to 80% of nylon 66 salt and 20% to 40% of nylon 6T salt. The end-capping agent is glycidyl ether containing silane and / or siloxane structure. The hindered phenol monomer comprises one or more of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, 4,4'-butylidenebis(6-tert-butyl-3-methylphenol), and tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane. The product of the application can meet the production requirements of differentiated copolymer nylon and has universal applicability. Without adding filling materials such as fiber, kaolin, talc, etc., the water absorption can be significantly reduced, the melting point and heat distortion temperature can be increased, and the inherent properties of nylon 66 resin are not affected.

The application discloses an anti-deformation crown-shaped cage of a super-speed motor bearing and a manufacturing method, and belongs to the technical field of motor bearings. The anti-deformation crown-shaped cage of the super-speed motor bearing is printed by a functionally graded material, the functionally graded material comprises hard-phase material and soft-phase material, the hard-phase material is glass fiber, and the soft-phase material is nylon 66; the equivalent elastic modulus of the functionally graded material continuously and gradually changes along the axial direction from the bottom of the pocket hole to the end of the locking claw, so that the elastic modulus of the bottom area of the pocket hole is higher than that of the end area of the locking claw, and the ovalization deformation of the pocket hole and the centrifugal deformation of the locking claw are cooperatively inhibited; the functionally graded material is introduced to actively reconstruct the stiffness field of the crown-shaped cage; the toughness phase is constructed in the locking claw area to absorb collision energy, the reinforced phase is formed in the pocket hole area to weaken stress concentration, and the stiffness gradient is established at the connecting position to inhibit the umbrella effect; and the application provides the crown-shaped cage with the characteristics of high toughness, gradient and high strength and a design method thereof.

The invention relates to a preparation method of high molecular weight nylon 66 resin, which comprises the following steps: dispersing a catalyst, a stabilizer and an optional lubricant in molten hexamethylenediamine, and then adding the mixture into adipic acid powder or melt stirred in a reaction kettle for mixing; stirring reactants in a reaction kettle for 90 to 600 minutes at the temperature of 145 to 195 DEG C and the pressure of 1 to 10 MPa under the protection of inert gas; the reaction kettle is deflated to a normal pressure state within 30-150 min; vacuumizing the reaction kettle to the pressure of 0.01-0.5 MPa, and then carrying out solid-phase polymerization for 0-300 minutes; and naturally cooling to room temperature, and taking the material to obtain the nylon 66 polymer. According to the invention, decomposition of nylon 66 salt is inhibited by utilizing solid-phase polymerization, adding an auxiliary agent or supplementing pressure, and volatilization of hexamethylenediamine is effectively prevented; the phosphorus compound and the silicon compound are added as stabilizers to improve the thermal stability of the nylon 66 and delay the generation of gel. The nylon 66 product prepared by the invention is high in purity, good in thermal stability and oxidation resistance and good in processability, and is suitable for the fields of civil filaments and engineering plastics.

This invention relates to the field of polymer materials technology, and discloses a low-temperature resistant and high-impact protective face shield material and its preparation method. The protective face shield material of this invention comprises the following raw materials in parts by weight: 55-70 parts of nylon 66, 5-15 parts of nylon 6, 5-12 parts of a low-temperature toughening agent, 4-10 parts of a high-temperature resistant additive, 0.5-1 part of oleamide, 0.2-0.5 parts of silane coupling agent 550, 0.2-0.5 parts of an antioxidant, and 0.5-1.5 parts of an ultraviolet absorber. The low-temperature toughening agent of this invention can improve the impact resistance of nylon materials in low-temperature environments, maintaining excellent impact strength even at low temperatures. The high-temperature resistant additive gives the nylon material excellent high-temperature thermal stability, avoiding problems such as softening deformation, yellowing cracking, and mechanical property degradation at high temperatures.

The invention provides modified nylon obtained by modifying nylon by using a flexibilizer and reinforced fibers together and a preparation method thereof, the weld line strength of the nylon modified material is greater than or equal to 72 MPa, and the tensile strength is greater than or equal to 155 MPa. The nylon modified material comprises the following components in parts by weight: 60-80 parts of nylon 66 resin; 0.5 to 5.5 parts by weight of a heat stabilizer; 20-40 parts by weight of reinforcing fibers; 4.5 to 9.5 parts by weight of a toughening agent; 0.1 to 0.5 part by weight of an antioxidant; and 0.1-0.5 part by weight of a lubricant. By adjusting the proportion of the flexibilizer and the reinforcing fibers in the modified raw materials, the strength and performance of the prepared part are better guaranteed, the weld line strength and tensile strength are improved while toughening and reinforcing are achieved, and therefore the mechanical property of the nylon 66 is comprehensively improved. The nylon modified material provided by the invention can replace part of metal materials, light-weight design is realized, energy consumption and operation cost are further reduced, a prepared finished product is higher in actual use strength and more impact-resistant, and the blank of related technical fields is filled.

The application belongs to the technical field of nylon 66 composite materials, and discloses a heat-conducting composite filler, a preparation method thereof and application of the heat-conducting composite filler in nylon 66. The heat-conducting composite filler is composed of boron nitride (BN@PDA) modified by dopamine and magnesium oxide (MgO-KH560) modified by a silane coupling agent, and the mass ratio is 1-3:1. Through two-step surface modification and solution chemical bonding, the close combination between components is realized, and the problems of uneven dispersion of traditional single heat-conducting filler, poor compatibility with the nylon 66 matrix and weak heat-conducting synergistic effect are effectively solved. When the heat-conducting composite filler is applied to nylon 66 composite materials at an addition amount of 10-30wt%, the thermal conductivity of the nylon 66 can be improved to more than 0.8 W / (m·K), the tensile strength is improved by 17%, and the heat-conducting composite filler has excellent processing performance, and is suitable for the fields of electronic equipment heat dissipation components, LED packaging materials, automobile heat management components and other fields with strict requirements on the thermal conductivity of materials.

The invention relates to a preparation method of nylon 66 resin, which comprises the following steps: step 1, reacting hexamethylenediamine with adipic acid in water to generate a nylon 66 salt solution; 2, adding a certain amount of phenylenediamine into the nylon 66 salt solution, and stirring until the phenylenediamine is completely dissolved to form a modified nylon 66 salt solution; and step 3, putting the modified nylon 66 salt solution into a high-pressure reaction kettle, and sequentially carrying out a heating and pressurizing prepolymerization stage, a heating and depressurizing stage, a normal-pressure polymerization stage and a vacuum polymerization stage on the modified nylon 66 salt solution in an inert atmosphere to obtain the nylon 66 resin. According to the invention, phenylenediamine is selected as a modifier to prepare the nylon 66, so that the inherent contradiction between the strength and the flowability of the traditional nylon 66 is fundamentally solved, and the mechanical property of the nylon 66 is remarkably improved on the premise of not remarkably improving the melt viscosity.