High-strength and high-toughness nylon composite material

Abstract

The invention discloses a high-strength and high-toughness nylon composite material which is prepared by the following method: mixing 10-20 parts by weight of dried nylon particles, 0.05-0.2 part by weight of a lubricant, 0.5-2 parts by weight of a nano filler, 0.01-0.05 part by weight of a plasticizer and 0.5-1 part by weight of tough fibers, adding the mixture into a double-screw extruder, and melting and mixing at 260-280 DEG C to obtain the high-strength and high-toughness nylon composite material. The high-strength and high-toughness nylon composite material is prepared by the following steps: firstly, preparing a high-strength and high-toughness nylon composite material, then extruding the high-strength and high-toughness nylon composite material into a multi-roll calender through a T-shaped die head, preparing a rolled plate with the thickness of 3mm-15mm under the rolling pressure of 10MPa-50MPa, cutting the rolled plate, putting the rolled plate fragments into a double-screw extruder, melting at 260-280 DEG C, extruding, pelletizing and carrying out heat treatment to obtain the high-strength and high-toughness nylon composite material. The scheme belongs to the field of functional plastics, and the high-strength and high-toughness nylon composite material can be obtained by adding a certain amount of specially-made tough fibers and combining a preparation process.

Description

Technical Field

[0001] The invention relates to the field of functional plastics, and in particular to a high-strength and high-toughness nylon composite material. Background Art

[0002] Improving the strength of nylon composites often means sacrificing their toughness. In practical applications, strength and toughness often need to be considered comprehensively. Engineering applications require that the strength of nylon composites be improved while minimizing the loss of toughness.

[0003] CN 106675015A discloses a high-strength and high-toughness long carbon fiber reinforced nylon composite material and a preparation method thereof, wherein the nylon composite material comprises the following raw materials by weight: 40 to 80 parts of nylon 610, 20 to 30 parts of nylon 6, 20 to 60 parts of long carbon fibers, 0.5 to 1 part of lubricant, and 0.1 to 1.5 parts of antioxidant. The advantages of the invention are: 1. The nylon substrate is made of long carbon chain nylon, which has low water absorption and high toughness; 2. The high rigidity of the long carbon fiber makes up for the insufficient rigidity of nylon 610 and nylon 6. 3. The addition of lubricant can greatly reduce the viscosity of the nylon melt, thereby improving the impregnation effect of nylon on carbon fiber. 4. It is not necessary to add toughening agent, thereby avoiding the influence of the addition of toughening agent on the reduction of mechanical properties. CN108864697 A discloses a high-strength and high-toughness nylon composite material, the raw materials of which include by weight: 80-100 parts of nylon, 5-10 parts of polycarbonate, 4-9 parts of silicone rubber, 3-9 parts of polyphenylene sulfide, 0.5-1.5 parts of benzoyl peroxide, 3-9 parts of copper oxide modified carbon nanotubes, 3-7 parts of nano titanium dioxide sol, 5-15 parts of attapulgite, 1-5 parts of aramid pulp, 2-5 parts of zinc monomethacrylate, 2-7 parts of graphene oxide, 2-4 parts of melamine cyanurate, 1-8 parts of hexa(allyloxy)cyclotriphosphazene, 0.3-1.7 parts of whiskers, 5-13 parts of polyether ester, 2-5 parts of polyethylene grafted maleic anhydride, 1-5 parts of halloysite nanotubes, and 0.5-2 parts of calcium stearate. The high-strength and high-toughness nylon composite material proposed in the invention has high strength, good toughness, excellent heat resistance and flame retardancy. The above solutions all start from the perspective of components and can achieve certain effects, but how to make the components disperse more evenly and obtain better performance effects requires further improvement in combination with the process. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a high-strength and high-toughness nylon composite material. By adding specially prepared tough fibers and combining the preparation process, a high-strength and high-toughness nylon composite material can be obtained.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] A high-strength and high-toughness nylon composite material is prepared by the following method:

[0007] By weight, 10 to 20 parts of dry nylon particles, 0.05 to 0.2 parts of lubricants, 0.5 to 2 parts of nanofillers, 0.01 to 0.05 parts of plasticizers, and 0.5 to 1 parts of tough fibers are mixed, added into a twin-screw extruder for melt mixing at 260° C. to 280° C., then extruded into a multi-roll calender through a T-die, and a rolled plate with a thickness of 3 mm to 15 mm is obtained under a rolling pressure of 10 MPa to 50 MPa, the rolled plate is cut, and the rolled plate fragments are put into a twin-screw extruder for melting at 260° C. to 280° C., extruded, pelletized, and heat-treated to obtain a high-strength and high-toughness nylon composite material;

[0008] The tough fiber is prepared by the following steps:

[0009] Step (1) preparing bamboo fiber powder: taking 3-5 years old bamboo, cleaning the surface with sandpaper, and then peeling off the bamboo green layer; crushing the bamboo green layer, and screening the bamboo green powder; mixing 10-20 parts of bamboo green powder and 15-25 parts of sodium hydroxide solution with a mass concentration of 10%-15% by weight, introducing them into a ball mill, and then adding 0.5%-1% of the mass of the bamboo green powder and 1%-2% of sodium sulfide, ball milling for 1h-3h, sieving, and dehydrating to obtain a cake; steaming the cake at 160°C-170°C for 1h-2h, adding it to 2%-3% hydrogen peroxide with a mass concentration of 2-3 times the mass of the cake, bleaching it at 60°C-80°C for 1h-2h, washing and filtering, and baking it at 130°C-150°C under nitrogen for 10min-20min to obtain bamboo fiber powder; the average particle size of the bamboo fiber powder is 10μm-50μm;

[0010] Step (2): by weight, add 10 to 20 parts of bamboo fiber powder, 2 to 5 parts of acrylate monomer, and 0.2 to 0.5 parts of initiator to 20 to 50 parts of ethanol aqueous solution with a mass concentration of 20% to 50%, react for 3 hours to 5 hours under nitrogen atmosphere, 60°C to 80°C, 800 r / min to 1000 r / min stirring conditions, then filter, dry, and disperse to obtain tough fiber.

[0011] Bamboo green refers to the outer skin of bamboo, which is approximately 2mm to 5mm thick.

[0012] Preferably, the lubricant is one of dendritic nylon lubricant, ethylene bis stearamide lubricant, and stearate lubricant; the nanofiller is one or more of nano zinc oxide, nano magnesium oxide, nano calcium carbonate, nano silicon dioxide, and nano titanium dioxide.

[0013] Preferably, the plasticizer is a mixture of benzene sulfonate and POE in a mass ratio of 2 to 3:1.

[0014] Preferably, the process conditions of the heat treatment are: keeping the temperature at 80°C to 120°C for 30min to 60min in a nitrogen atmosphere.

[0015] Preferably, in step (1), the average particle size of the bamboo green powder after screening is 200 μm to 500 μm.

[0016] Preferably, in step (1), the penetrant is fatty alcohol polyoxyethylene ether.

[0017] Preferably, in step (1), the moisture content of the bamboo fiber powder is less than 0.5%.

[0018] Preferably, in step (2), the acrylic acid ester monomer is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, butyl acrylate and methyl acrylate.

[0019] Preferably, in step (2), the initiator is potassium persulfate.

[0020] Compared with the existing technology, the advantages of this solution are:

[0021] 1. Process: After the nylon particles are mixed with the additives of each component, they are first extruded and rolled to make the components closely mixed, squeeze the nylon molecules into the shrunken tough fibers, and depolymerize some of the agglomerated fillers. In the second melting process, each component, especially the filler and functional fiber, is fully combined with the nylon molecules and can be better dispersed, so that the performance uniformity is guaranteed. The pelletized particles are further heat treated to eliminate the thermal stress between different components.

[0022] 2. Raw materials: tough fibers were prepared using bamboo green as raw materials to enhance the strength and toughness of nylon composite materials. The tough fibers were selected from bamboo green as raw materials. First, the bamboo green fiber used as raw materials has high fiber content, high fiber strength, and large aspect ratio. The toughness of bamboo fiber powder modified with acrylic ester is enhanced; second, the bamboo fiber powder undergoes alkali treatment, ball milling treatment, bleaching treatment, and high temperature treatment during the preparation process. It does not maintain a long straight morphology, but shrinks like a ball of yarn, and has a certain plastic deformation ability. During the rolling process, after the nylon molecules are fully in contact with the bamboo fiber powder, the nylon molecules enter the shrunken part, which improves the toughness of the composite material. DETAILED DESCRIPTION

[0023] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Example 1

[0025] To achieve the above object, the technical solution of the present invention is:

[0026] A high-strength and high-toughness nylon composite material is prepared by the following method:

[0027] By weight, 15 parts of dry nylon 66 particles, 0.1 parts of dendritic nylon lubricant CYD-C603A, 0.5 parts of nano zinc oxide, 0.5 parts of nano magnesium oxide and 0.5 parts of nano calcium carbonate, 0.03 parts of a mixture of alkyl sulfonate phenyl ester and POE in a mass ratio of 2:1, and 0.6 parts of tough fiber were mixed, added into a twin-screw extruder for melt mixing at 270° C., and then extruded into a multi-roll calender through a T-die head, and a rolled plate with a thickness of 10 mm was obtained under a rolling pressure of 40 MPa, and the rolled plate was cut. , the rolled plate fragments are put into a twin-screw extruder for melting at 270°C, extruded, pelletized, and kept at 100°C for 60 minutes under a nitrogen atmosphere to obtain a high-strength and high-toughness nylon composite material; the tough fiber mainly functions to enhance the strength and toughness of nylon 66; after being rolled by a multi-roll calender, the various phase components can fully contact, and the agglomeration of some nanofillers can be broken, so that the tough fiber and the nylon molecules are fully combined, and when the rolled plate fragments are put into the twin-screw extruder again for melt extrusion, the various component phases can be better dispersed;

[0028] The tough fiber is prepared by the following steps:

[0029] Step (1) preparing bamboo fiber powder: taking 3-year-old bamboo, cleaning the surface with sandpaper, removing waxy substances and impurities on the bamboo surface, and then peeling off the bamboo green layer; the bamboo green layer is crushed and screened to obtain bamboo green powder with an average particle size of 315 μm, the bamboo green layer has high toughness, and is easier to crush after drying; in order to further crush the bamboo green powder and also to better delignify and desiliconize, by weight, 15 parts of bamboo green powder and 20 parts of sodium hydroxide solution with a mass concentration of 13% are mixed and introduced into a ball mill, and then 0.7% of fatty alcohol polyoxyethylene ether by mass of the bamboo green powder and 1.5% of sodium sulfide are added, ball milling for 2.5 hours, sieving, and dehydrating to obtain a cake, wherein the fatty alcohol polyoxyethylene ether is a penetrant, which mainly promotes alkali and sodium sulfide to better enter the bamboo green. In the powder, the active sulfur produced by the hydrolysis of sodium sulfide can react with the phenolic hydroxyl group, methoxyl group and other functional groups in the lignin to form a soluble sodium salt (such as alkaline lignin), thereby destroying the three-dimensional network structure of the lignin and promoting its dissolution; the cake was steamed at 170°C for 1.5 hours, added into 3% hydrogen peroxide with a mass concentration of 3 times the mass of the cake, bleached at 70°C for 2 hours, washed and filtered, and baked at 140°C for 10 minutes under nitrogen conditions to obtain a bamboo fiber powder with a moisture content of 0.35%. The steaming process is to make the silicon and lignin separate more fully, and the baking process is to reduce the surface active hydroxyl groups of the bamboo fiber powder, reduce its water absorption capacity, and make the fiber curl up; the average particle size of the bamboo fiber powder is 28μm;

[0030] Step (2): by weight, 15 parts of bamboo fiber powder, 4 parts of butyl acrylate, and 0.3 parts of potassium persulfate are added to 30 parts of 30% ethanol aqueous solution, and reacted for 4 hours under nitrogen atmosphere, 70°C, and 900 r / min stirring conditions, and then filtered, dried at 60°C, and dispersed to obtain tough fibers; polyacrylate is grafted onto the cellulose skeleton of the bamboo fiber powder to form a "hard-soft" structure, which can significantly improve the elongation at break.

[0031] Example 2

[0032] A high-strength and high-toughness nylon composite material is prepared by the following method:

[0033] The method comprises the following steps: mixing 10 parts of dry nylon 66 particles, 0.05 parts of calcium stearate, 0.3 parts of nano calcium carbonate, 0.5 parts of nano silicon dioxide and 0.2 parts of nano titanium dioxide, 0.02 parts of a mixture of alkyl sulfonate phenyl ester and POE in a mass ratio of 3:1, and 0.5 parts of tough fiber, adding the mixture into a twin-screw extruder for melt mixing at 270° C., then extruding the mixture into a multi-roll calender through a T-die, obtaining a rolled plate with a thickness of 8 mm under a rolling pressure of 30 MPa, cutting the rolled plate, and putting the rolled plate fragments into a twin-screw extruder for melting at 270° C., extruding, pelletizing, and keeping the mixture at 110° C. for 40 minutes under a nitrogen atmosphere to obtain a high-strength and high-toughness nylon composite material;

[0034] The tough fiber is prepared by the following steps:

[0035] Step (1) preparing bamboo fiber powder: taking 4-year-old bamboo, cleaning the surface with sandpaper, and then peeling off the bamboo green layer; the bamboo green layer is crushed and sieved to obtain bamboo green powder with an average particle size of 285 μm; by weight, 10 parts of bamboo green powder and 20 parts of sodium hydroxide solution with a mass concentration of 10% are mixed and introduced into a ball mill, and then 0.8% of fatty alcohol polyoxyethylene ether by mass of bamboo green powder and 1.8% of sodium sulfide are added, ball milling for 2 hours, sieving, and dehydrating to obtain a cake; the cake is steamed at 165° C. for 1.5 hours, added into 3% hydrogen peroxide with a mass concentration of twice the mass of the cake, bleached at 60° C. for 1 hour, washed and filtered, and baked at 130° C. for 10 minutes under nitrogen conditions to obtain bamboo fiber powder with a moisture content of 0.31%; the average particle size of the bamboo fiber powder is 35 μm;

[0036] Step (2): by weight, add 15 parts of bamboo fiber powder, 2 parts of hydroxyethyl acrylate, and 0.2 parts of potassium persulfate to 30 parts of 40% ethanol aqueous solution, react for 4 hours under nitrogen atmosphere, 75°C, and 1000r / min stirring conditions, then filter, dry at 60°C, and disperse to obtain tough fiber.

[0037] Example 3

[0038] A high-strength and high-toughness nylon composite material is prepared by the following method:

[0039] The invention discloses a method for preparing a high-strength and high-toughness nylon composite material comprising mixing 20 parts of dry nylon 66 particles, 0.13 parts of ethylene bis stearamide lubricant, 0.3 parts of nano calcium carbonate, 0.5 parts of nano silicon dioxide and 0.5 parts of nano titanium dioxide, 0.03 parts of a mixture of alkyl sulfonate phenyl ester and POE in a mass ratio of 3:1, and 0.8 parts of tough fiber, and adding the mixture into a twin-screw extruder for melt mixing at 270°C, and then extruding the mixture into a multi-roll calender through a T-die, and obtaining a rolled plate with a thickness of 5 mm under a rolling pressure of 50 MPa, cutting the rolled plate, and putting the rolled plate fragments into a twin-screw extruder for melting at 270°C, extruding, pelletizing, and keeping the temperature at 90°C for 60 minutes under a nitrogen atmosphere to obtain a high-strength and high-toughness nylon composite material;

[0040] The tough fiber is prepared by the following steps:

[0041] Step (1) preparing bamboo fiber powder: taking 4-year-old bamboo, cleaning the surface with sandpaper, and then peeling off the bamboo green layer; the bamboo green layer is crushed and sieved to obtain bamboo green powder with an average particle size of 234 μm; by weight, 10 parts of bamboo green powder and 20 parts of sodium hydroxide solution with a mass concentration of 14% are mixed and introduced into a ball mill, and then 0.9% of fatty alcohol polyoxyethylene ether by mass of bamboo green powder and 1.3% of sodium sulfide are added, ball milling for 2 hours, sieving, and dehydrating to obtain a cake; the cake is steamed at 160° C. for 2 hours, added into 2% hydrogen peroxide with a mass concentration of 3 times the mass of the cake, bleached at 60° C. for 1 hour, washed and filtered, and baked at 130° C. for 10 minutes under nitrogen conditions to obtain bamboo fiber powder with a moisture content of 0.29%; the average particle size of the bamboo fiber powder is 35 μm;

[0042] Step (2): by weight, add 15 parts of bamboo fiber powder, 2 parts of hydroxyethyl methacrylate, and 0.2 parts of potassium persulfate to 30 parts of 40% ethanol aqueous solution, react for 4 hours under nitrogen atmosphere, 75°C, and 1000r / min stirring conditions, then filter, dry at 60°C, and disperse to obtain tough fiber.

[0043] Comparative Example 1

[0044] The difference from Example 1 is that no tough fiber is added, specifically:

[0045] A high-strength and high-toughness nylon composite material is prepared by the following method:

[0046] The invention discloses a method for preparing a high-strength and high-toughness nylon composite material. The method comprises the following steps: mixing 15 parts of dry nylon 66 particles, 0.1 part of dendritic nylon lubricant CYD-C603A, 0.5 part of nano zinc oxide, 0.5 part of nano magnesium oxide and 0.5 part of nano calcium carbonate, and 0.03 part of a mixture of alkyl sulfonate phenyl ester and POE in a mass ratio of 2:1, adding the mixture into a twin-screw extruder for melt kneading at 270°C, then extruding the mixture into a multi-roll calender through a T-die, and obtaining a rolled plate with a thickness of 10 mm under a rolling pressure of 40 MPa. The rolled plate is cut, and the rolled plate fragments are put into a twin-screw extruder for melting at 270°C, extruding, pelletizing, and heat-preserving at 100°C for 60 minutes under a nitrogen atmosphere to obtain the high-strength and high-toughness nylon composite material.

[0047] Comparative Example 2

[0048] The difference from Example 1 is that no rolling process is performed, specifically:

[0049] A high-strength and high-toughness nylon composite material is prepared by the following method:

[0050] By weight, 15 parts of dry nylon 66 particles, 0.1 parts of dendritic nylon lubricant CYD-C603A, 0.5 parts of nano zinc oxide, 0.5 parts of nano magnesium oxide and 0.5 parts of nano calcium carbonate, 0.03 parts of a mixture of alkyl sulfonate phenyl ester and POE in a mass ratio of 2:1, and 0.6 parts of tough fiber are mixed, added into a twin-screw extruder, melt-kneaded at 270° C., extruded, pelletized, and kept warm at 100° C. for 60 minutes under a nitrogen atmosphere to obtain a high-strength and high-toughness nylon composite material;

[0051] The tough fiber is prepared by the following steps:

[0052] Step (1) preparing bamboo fiber powder: taking 3-year-old bamboo, cleaning the surface with sandpaper, and then peeling off the bamboo green layer; crushing the bamboo green layer, and screening the bamboo green layer to obtain bamboo green powder with an average particle size of 315 μm; mixing 15 parts of bamboo green powder and 20 parts of sodium hydroxide solution with a mass concentration of 13% by weight, introducing them into a ball mill, and then adding 0.7% fatty alcohol polyoxyethylene ether by weight of the bamboo green powder and 1.5% sodium sulfide, ball milling for 2.5 hours, sieving, and dehydrating to obtain a cake; steaming the cake at 170° C. for 1.5 hours, adding it to 3% hydrogen peroxide with a mass concentration of 3 times the mass of the cake, bleaching it at 70° C. for 2 hours, washing and filtering, and baking it at 140° C. for 10 minutes under nitrogen conditions to obtain bamboo fiber powder with a moisture content of 0.35%; the average particle size of the bamboo fiber powder is 28 μm;

[0053] Step (2): by weight, add 15 parts of bamboo fiber powder, 4 parts of butyl acrylate, and 0.3 parts of potassium persulfate to 30 parts of 30% ethanol aqueous solution, react for 4 hours under nitrogen atmosphere, 70°C, and 900r / min stirring conditions, then filter, dry at 60°C, and disperse to obtain tough fiber.

[0054] Comparative Example 3

[0055] The difference from Example 1 is that the toughness fiber is added in excess, specifically:

[0056] A high-strength and high-toughness nylon composite material is prepared by the following method:

[0057] 15 parts of dry nylon 66 particles, 0.1 parts of dendritic nylon lubricant CYD-C603A, 0.5 parts of nano zinc oxide, 0.5 parts of nano magnesium oxide and 0.5 parts of nano calcium carbonate, 0.03 parts of a mixture of alkyl sulfonate phenyl ester and POE in a mass ratio of 2:1, and 1.5 parts of tough fiber are mixed, added into a twin-screw extruder for melt mixing at 270°C, then extruded into a multi-roll calender through a T-die, and a rolled plate with a thickness of 10 mm is obtained under a rolling pressure of 40 MPa, the rolled plate is cut, and the rolled plate fragments are put into a twin-screw extruder for melting at 270°C, extruded, pelletized, and kept warm at 100°C for 60 minutes under a nitrogen atmosphere to obtain a high-strength and high-toughness nylon composite material;

[0058] The tough fiber is prepared by the following steps:

[0059] Step (1) preparing bamboo fiber powder: taking 3-year-old bamboo, cleaning the surface with sandpaper, and then peeling off the bamboo green layer; crushing the bamboo green layer, and screening the bamboo green layer to obtain bamboo green powder with an average particle size of 315 μm; mixing 15 parts of bamboo green powder and 20 parts of sodium hydroxide solution with a mass concentration of 13% by weight, introducing them into a ball mill, and then adding 0.7% fatty alcohol polyoxyethylene ether by weight of the bamboo green powder and 1.5% sodium sulfide, ball milling for 2.5 hours, sieving, and dehydrating to obtain a cake; steaming the cake at 170° C. for 1.5 hours, adding it to 3% hydrogen peroxide with a mass concentration of 3 times the mass of the cake, bleaching it at 70° C. for 2 hours, washing and filtering, and baking it at 140° C. for 10 minutes under nitrogen conditions to obtain bamboo fiber powder with a moisture content of 0.35%; the average particle size of the bamboo fiber powder is 28 μm;

[0060] Step (2): by weight, add 15 parts of bamboo fiber powder, 4 parts of butyl acrylate, and 0.3 parts of potassium persulfate to 30 parts of 30% ethanol aqueous solution, react for 4 hours under nitrogen atmosphere, 70°C, and 900r / min stirring conditions, then filter, dry at 60°C, and disperse to obtain tough fiber.

[0061] Comparative Example 4

[0062] The difference from Example 1 is that bamboo fiber powder is added instead of modified tough fiber:

[0063] A high-strength and high-toughness nylon composite material is prepared by the following method:

[0064] The invention discloses a method for preparing a nylon composite material having high strength and high toughness. The method comprises the following steps: mixing 15 parts of dry nylon 66 particles, 0.1 part of dendritic nylon lubricant CYD-C603A, 0.5 part of nano zinc oxide, 0.5 part of nano magnesium oxide and 0.5 part of nano calcium carbonate, 0.03 part of a mixture of alkyl sulfonate phenyl ester and POE in a mass ratio of 2:1, and 0.6 part of bamboo fiber powder, adding the mixture into a twin-screw extruder for melt mixing at 270°C, then extruding the mixture into a multi-roll calender through a T-die, and obtaining a rolled plate with a thickness of 10 mm under a rolling pressure of 40 MPa, cutting the rolled plate, and putting the rolled plate fragments into a twin-screw extruder for melting at 270°C, extruding, pelletizing, and keeping the temperature at 100°C for 60 minutes under a nitrogen atmosphere to obtain a high-strength and high-toughness nylon composite material;

[0065] The tough fiber is prepared by the following steps:

[0066] Preparation of bamboo fiber powder: Take 3-year-old bamboo, clean the surface with sandpaper, and then peel off the bamboo green layer; after the bamboo green layer is crushed and screened, obtain bamboo green powder with an average particle size of 315 μm; by weight, 15 parts of bamboo green powder and 20 parts of sodium hydroxide solution with a mass concentration of 13% are mixed and introduced into a ball mill, and then 0.7% of fatty alcohol polyoxyethylene ether by mass of bamboo green powder and 1.5% of sodium sulfide are added, ball milled for 2.5 hours, sieved, and dehydrated to obtain a cake; after steaming the cake at 170°C for 1.5 hours, add it into 3% hydrogen peroxide with a mass concentration of 3 times the mass of the cake, bleach at 70°C for 2 hours, wash and filter, and bake under nitrogen at 140°C for 10 minutes to obtain bamboo fiber powder with a moisture content of 0.35%; the average particle size of the bamboo fiber powder is 28 μm.

[0067] Comparative Example 5

[0068] The difference from Example 1 is that the average particle size of the bamboo fiber powder is too large, specifically:

[0069] A high-strength and high-toughness nylon composite material is prepared by the following method:

[0070] 15 parts of dry nylon 66 particles, 0.1 parts of dendritic nylon lubricant CYD-C603A, 0.5 parts of nano zinc oxide, 0.5 parts of nano magnesium oxide and 0.5 parts of nano calcium carbonate, 0.03 parts of a mixture of alkyl sulfonate phenyl ester and POE in a mass ratio of 2:1, and 0.6 parts of tough fiber are mixed, added into a twin-screw extruder for melt mixing at 270°C, then extruded into a multi-roll calender through a T-die, and a rolled plate with a thickness of 10 mm is obtained under a rolling pressure of 40 MPa, the rolled plate is cut, and the rolled plate fragments are put into a twin-screw extruder for melting at 270°C, extruded, pelletized, and kept warm at 100°C for 60 minutes under a nitrogen atmosphere to obtain a high-strength and high-toughness nylon composite material;

[0071] The tough fiber is prepared by the following steps:

[0072] Step (1) preparing bamboo fiber powder: taking 3-year-old bamboo, cleaning the surface with sandpaper, and then peeling off the bamboo green layer; crushing the bamboo green layer, and screening the bamboo green layer to obtain bamboo green powder with an average particle size of 315 μm; mixing 15 parts of bamboo green powder and 20 parts of sodium hydroxide solution with a mass concentration of 13% by weight, introducing them into a ball mill, and then adding 0.7% fatty alcohol polyoxyethylene ether by mass of the bamboo green powder and 1.5% sodium sulfide, ball milling for 0.5h, sieving, and dehydrating to obtain a cake; steaming the cake at 170°C for 1.5h, adding it into 3% hydrogen peroxide with a mass concentration of 3 times the mass of the cake, bleaching it at 70°C for 2h, washing and filtering, and baking it at 140°C under nitrogen for 10min to obtain bamboo fiber powder with a moisture content of 0.35%; the average particle size of the bamboo fiber powder is 70 μm;

[0073] Step (2): by weight, add 15 parts of bamboo fiber powder, 4 parts of butyl acrylate, and 0.3 parts of potassium persulfate to 30 parts of 30% ethanol aqueous solution, react for 4 hours under nitrogen atmosphere, 70°C, and 900r / min stirring conditions, then filter, dry at 60°C, and disperse to obtain tough fiber.

[0074] Comparative Example 6

[0075] The difference from Example 1 is that the high-strength and high-toughness nylon composite material is not subjected to heat treatment, specifically:

[0076] A high-strength and high-toughness nylon composite material is prepared by the following method:

[0077] By weight, 15 parts of dry nylon 66 particles, 0.1 parts of dendritic nylon lubricant CYD-C603A, 0.5 parts of nano zinc oxide, 0.5 parts of nano magnesium oxide and 0.5 parts of nano calcium carbonate, 0.03 parts of a mixture of alkyl sulfonate phenyl ester and POE in a mass ratio of 2:1, and 1.5 parts of tough fiber are mixed, added into a twin-screw extruder for melt mixing at 270° C., then extruded into a multi-roll calender through a T-die, and a rolled plate with a thickness of 10 mm is obtained under a rolling pressure of 40 MPa, the rolled plate is cut, and the rolled plate fragments are put into a twin-screw extruder for melting at 270° C., extruded, and pelletized to obtain a high-strength and high-toughness nylon composite material;

[0078] The tough fiber is prepared by the following steps:

[0079] Step (1) preparing bamboo fiber powder: taking 3-year-old bamboo, cleaning the surface with sandpaper, and then peeling off the bamboo green layer; crushing the bamboo green layer, and screening the bamboo green layer to obtain bamboo green powder with an average particle size of 315 μm; mixing 15 parts of bamboo green powder and 20 parts of sodium hydroxide solution with a mass concentration of 13% by weight, introducing them into a ball mill, and then adding 0.7% fatty alcohol polyoxyethylene ether by weight of the bamboo green powder and 1.5% sodium sulfide, ball milling for 2.5 hours, sieving, and dehydrating to obtain a cake; steaming the cake at 170° C. for 1.5 hours, adding it to 3% hydrogen peroxide with a mass concentration of 3 times the mass of the cake, bleaching it at 70° C. for 2 hours, washing and filtering, and baking it at 140° C. for 10 minutes under nitrogen conditions to obtain bamboo fiber powder with a moisture content of 0.35%; the average particle size of the bamboo fiber powder is 28 μm;

[0080] Step (2): by weight, add 15 parts of bamboo fiber powder, 4 parts of butyl acrylate, and 0.3 parts of potassium persulfate to 30 parts of 30% ethanol aqueous solution, react for 4 hours under nitrogen atmosphere, 70°C, and 900r / min stirring conditions, then filter, dry at 60°C, and disperse to obtain tough fiber.

[0081] Performance tests were performed on Examples 1-3 and Comparative Examples 1-6.

[0082] Tensile performance test: according to ISO 527-2 standard, tensile speed is 50mm / min;

[0083] Bending performance test: According to ISO 178 standard, the bending speed is 2mm / min;

[0084] Notched impact strength test: according to ISO 180 standard;

[0085] The performance test results are shown in Table 1.

[0086] Table 1

[0087]

[0088] Generally speaking, the improvement of strength means the loss of some toughness, especially elongation at break. From the analysis of the results of Examples 1-3 and Comparative Examples 1-6, the present solution can obtain samples with good comprehensive performance. The performance differences of Examples 1-3 are the differences in formulation and process details, and the overall performance level is not much different.

[0089] Comparative Example 1 is a nylon 66 material without adding toughness fiber, which has good elongation at break, but poor mechanical indicators such as tensile strength and bending strength.

[0090] The difference between Comparative Example 2 and Example 1 is that the rolling process is not performed. The rolling process can make the components more closely bonded, and then the components are more evenly distributed in the subsequent extrusion process, the performance uniformity is better, and the stress concentration is reduced. Comparative Example 2 is only added according to the conventional process, the tough fiber and the nylon molecules are fully contacted, and the filler component is not fully dispersed, which leads to stress concentration and poorer performance than Example 1.

[0091] The difference between Comparative Example 3 and Example 1 is that the toughness fiber is added in excess. Although Comparative Example 3 can obtain better mechanical properties such as tensile strength and flexural strength, it sacrifices toughness and the elongation at break is too small. This may be due to the large amount of toughness fiber added, the small distribution distance in nylon, the overlap of the influence areas of adjacent toughness fibers, resulting in stress concentration, and then causing instantaneous breakage, resulting in a small elongation at break. The difference between Comparative Example 5 and Example 1 is that the average particle size of the bamboo fiber powder is too large, which affects the uniformity of the overall performance and may also cause the overlap of the influence areas of adjacent toughness fibers, resulting in stress concentration, and then causing instantaneous breakage.

[0092] The difference between Comparative Example 4 and Example 1 is that bamboo fiber powder is added instead of modified tough fiber. Since it is not modified, its compatibility with the nylon substrate is poor, so the strength increase is not large compared with Comparative Example 1; the modification of this solution mainly improves the toughness of the bamboo fiber powder, and the bamboo fiber powder of Comparative Example 4 is not modified, which is equivalent to only enhancing the rigidity, so the elongation at break is small.

[0093] The difference between Comparative Example 6 and Example 1 is that the high-strength and high-toughness nylon composite material is not heat-treated, so that the stress between the components is not offset. At the same time, since heat treatment can also affect the crystal distribution of the polymer, the uniform distribution of the crystal phase is equivalent to the uniform distribution of the rigid segment, which can improve the mechanical properties. Comparative Example 6 is not heat-treated, so the mechanical properties are worse than those of Example 1.

Claims

1. A high-strength and high-toughness nylon composite material, characterized in that: Prepared by the following method: By weight, 10 to 20 parts of dry nylon particles, 0.05 to 0.2 parts of lubricants, 0.5 to 2 parts of nanofillers, 0.01 to 0.05 parts of plasticizers, and 0.5 to 1 parts of tough fibers are mixed, added into a twin-screw extruder for melt mixing at 260° C. to 280° C., then extruded into a multi-roll calender through a T-die, and a rolled plate with a thickness of 3 mm to 15 mm is obtained under a rolling pressure of 10 MPa to 50 MPa, the rolled plate is cut, and the rolled plate fragments are put into a twin-screw extruder for melting at 260° C. to 280° C., extruded, pelletized, and heat-treated to obtain a high-strength and high-toughness nylon composite material; The tough fiber is prepared by the following steps: Step (1) preparing bamboo fiber powder: taking 3-5 years old bamboo, cleaning the surface with sandpaper, and then peeling off the bamboo green layer; crushing the bamboo green layer, and screening the bamboo green powder; mixing 10-20 parts of bamboo green powder and 15-25 parts of sodium hydroxide solution with a mass concentration of 10%-15% by weight, introducing them into a ball mill, and then adding 0.5%-1% of the mass of the bamboo green powder and 1%-2% of sodium sulfide, ball milling for 1h-3h, sieving, and dehydrating to obtain a cake; steaming the cake at 160°C-170°C for 1h-2h, adding it to 2%-3% hydrogen peroxide with a mass concentration of 2-3 times the mass of the cake, bleaching it at 60°C-80°C for 1h-2h, washing and filtering, and baking it at 130°C-150°C under nitrogen for 10min-20min to obtain bamboo fiber powder; the average particle size of the bamboo fiber powder is 10μm-50μm; Step (2): by weight, add 10 to 20 parts of bamboo fiber powder, 2 to 5 parts of acrylate monomer, and 0.2 to 0.5 parts of initiator to 20 to 50 parts of ethanol aqueous solution with a mass concentration of 20% to 50%, react for 3 hours to 5 hours under nitrogen atmosphere, 60°C to 80°C, 800 r / min to 1000 r / min stirring conditions, then filter, dry, and disperse to obtain tough fiber.

2. The high-strength and high-toughness nylon composite material according to claim 1, characterized in that: The lubricant is one of dendritic nylon lubricant, ethylene bis stearamide lubricant and stearate lubricant; the nano filler is one or more of nano zinc oxide, nano magnesium oxide, nano calcium carbonate, nano silicon dioxide and nano titanium dioxide.

3. The high-strength and high-toughness nylon composite material according to claim 1, characterized in that: The plasticizer is a mixture of benzene sulfonate and POE in a mass ratio of 2 to 3:

1.

4. The high-strength and high-toughness nylon composite material according to claim 1, characterized in that: The process conditions of the heat treatment are: in a nitrogen atmosphere, keeping the temperature at 80° C. to 120° C. for 30 min to 60 min.

5. The high-strength and high-toughness nylon composite material according to claim 1, characterized in that: In step (1), the average particle size of the bamboo green powder after screening is 200 μm to 500 μm.

6. The high-strength and high-toughness nylon composite material according to claim 1, characterized in that: In step (1), the penetrant is fatty alcohol polyoxyethylene ether.

7. The high-strength and high-toughness nylon composite material according to claim 1, characterized in that: In step (1), the moisture content of the bamboo fiber powder is less than 0.5%.

8. The high-strength and high-toughness nylon composite material according to claim 1, characterized in that: In step (2), the acrylic acid ester monomer is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, butyl acrylate, and methyl acrylate.

9. The high-strength and high-toughness nylon composite material according to claim 1, characterized in that: In step (2), the initiator is potassium persulfate.

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