A high-strength glass fiber composite material and its preparation method

Abstract

The present invention relates to the technical field of nylon composite materials, and particularly relates to a high-strength glass fiber composite material and a preparation method thereof. The composite material comprises the following components in parts by weight: 80-90 parts of aliphatic nylon, 20-30 parts of polypropylene, 8-16 parts of maleic anhydride grafted polymer, 25-30 parts of flat glass fiber, 2-6 parts of tetrapod-shaped zinc oxide whiskers, 1-5 parts of solid glass microspheres, and 1-10 parts of additives. By selecting flat glass fibers with a specific morphology as fiber reinforcing fillers, the present invention improves the dispersion performance of flat glass fibers through tetrapod-shaped zinc oxide whiskers and solid glass microspheres, enabling the flat glass fibers to be uniformly distributed in the nylon material matrix. This structure enables the enhancement and modification effects of the material to be uniformly distributed in all directions, not only improving the mechanical properties of the composite material, especially the impact performance, but also fundamentally solving the problem of floating fibers.

Description

Technical Field

[0001] The present invention relates to the technical field of nylon composites, and particularly relates to a high-strength glass fiber composite material and a preparation method thereof. Background Art

[0002] Nylon is a polymer with repeating amide groups. In 1938, DuPont officially announced the birth of the world's first synthetic fiber, nylon 66. In China, nylon is also called "polyamide fiber". Nylon has the advantages of good wear resistance, excellent mechanical properties and corrosion resistance, and has important uses in many fields such as military equipment, automobile industry, high-grade imitations, and health care. In the civilian aspect, the more popular ones in the market are nylon-containing blended fabrics, which are durable and wear-resistant and have been widely praised for a long time. There are a variety of nylon products developed so far. Common ones in life are nylon 66 and nylon 6. At the same time, there are also a variety of nylon modified varieties. Modified nylon makes up for the disadvantages of nylon such as poor light and heat resistance, and can meet more actual application requirements.

[0003] Nylon products are widely used. Initially, nylon materials were applied to automobile parts. Due to their advantages such as high toughness, self-lubrication, excellent wear resistance, good stability, wide use temperature range, non-toxicity and excellent processing performance, they are widely used to replace copper and non-ferrous metals to make mechanical, chemical and electrical parts, such as fuel pump gears of diesel engines, water pumps, high-pressure sealing rings, fuel pipes, etc.

[0004] The main purposes of nylon modification are as follows: to improve the performance of nylon at a lower cost. Generally speaking, the price of additives is much lower than that of nylon, thus reducing the cost of the whole composite material; to functionalize the existing nylon to prepare nylon materials with special properties, such as nylon materials with excellent properties such as wear resistance, heat resistance, antistatic, and anti-aging; to improve the mechanical properties of nylon materials so as to replace traditional metal materials. For example, to improve the toughness, strength, hardness, etc. of nylon materials. The prior art usually uses glass fiber to enhance and modify nylon. However, as an inert filler, the compatibility between glass fiber and nylon is poor, and the phenomenon of fiber floating is likely to occur, and the surface of the product is rough, which limits its application in high-precision equipment. Summary of the Invention

[0005] The present invention provides a high-strength glass fiber composite material, which, while improving its strength and toughness, simultaneously solves the problem of fiber floating in nylon composites and expands its application in high-precision equipment such as optical instruments and electronic instruments.

[0006] The specific technical solution is as follows:

[0007] A high-strength glass fiber composite material comprises the following components in parts by weight:

[0008] 80 - 90 parts of aliphatic nylon, 20 - 30 parts of polypropylene, 8 - 16 parts of maleic anhydride grafted polymer, 25 - 30 parts of flat glass fiber, 2 - 6 parts of tetrapod-shaped zinc oxide whiskers, 1 - 6 parts of solid glass microspheres, 1 - 10 parts of additives.

[0009] Aliphatic nylon refers to nylon without benzene rings in the molecular chain, and its main categories include nylon 6, nylon 66, etc. Aliphatic nylon has good melt fluidity, is easy to process and form, and has good comprehensive properties, so it is the most widely used and has the largest output in nylon. However, due to its molecular chain being an aliphatic chain, its high-temperature resistance is relatively poor. At the same time, when the number of carbon atoms in the polymerization monomer is small, the proportion of amide bonds in the aliphatic nylon molecular chain is high with the same molecular weight, and the water absorption rate is relatively high. After water absorption, the dimensional stability and mechanical properties of the parts decrease, which limits its application to a certain extent. The prior art generally improves the mechanical properties of nylon by adding high-strength fillers such as glass fiber. Glass fiber generally refers to round glass fiber. In fact, strictly speaking, glass fiber includes round glass fiber and flat glass fiber, and both can improve the mechanical properties of nylon composites. However, during the blending process, due to the large interfacial tension between the two substances, the compatibility of the blending system is poor, resulting in the occurrence of fiber floating phenomenon and rough product appearance. Although the prior art has partially solved the above problems by modifying glass fiber, the modification process has high cost and complex process, and does not have the practicality for large-scale production.

[0010] Therefore, the present invention uses flat glass fibers as reinforcing fillers, and solves the problem of floating fibers of glass fibers by adding zinc oxide whiskers with four-needle shapes and solid glass microspheres with different morphologies. The flat glass fibers are common types in the art, and the ratio of their major axis to minor axis is generally 2-8, and the length is generally 1-30 mm. The zinc oxide whiskers with four-needle shapes, abbreviated as tetrapod-shaped zinc oxide whiskers, have a three-dimensional tetrapod-shaped structure at the microscopic level. This special three-dimensional tetrapod structure can be more closely combined with the nylon base material while isotropically changing the basic properties of the material. Therefore, it has excellent properties that cannot be compared with ordinary fibrous zinc oxide whiskers. At the same time, precisely because the tetrapod-shaped zinc oxide whiskers have a unique tetrapod-shaped three-dimensional structure and the flat glass fibers have a flat structure with a special cross-section, the tetrapod-shaped zinc oxide whiskers and the flat glass fibers are likely to form a "bridging" structure during the processing of the nylon composite material, promoting the dispersion of the flat glass fibers and reducing the degree of floating fibers of the flat glass fibers. At the same time, in order to prevent the tetrapod-shaped zinc oxide whiskers from being interlocked due to their own structural reasons and being difficult to disperse during the mixing process, the present invention adds a certain amount of solid glass microspheres. The particle size of the solid glass microspheres is generally 20-100 μm. As a spherical inorganic particle, the outer surface is smooth and there is no stress concentration phenomenon. Compared with materials of other shapes, the change in the system viscosity is smaller, and its spherical structure can well promote the dispersion of the tetrapod-shaped zinc oxide whiskers. The reason why the present invention selects solid glass microspheres is that the hollow glass microspheres have low mechanical strength, and during the melt processing in the extruder, the rigid tetrapod-shaped zinc oxide whiskers are likely to damage the hollow glass microspheres and cannot exert the dispersion effect of the sphere. Further, the content of the solid glass microspheres is 2-3 parts. Since the density of the solid glass microspheres is relatively large, excessive use may cause sedimentation problems. An appropriate amount of solid glass microspheres takes into account the functions of reinforcement and dispersion.

[0011] The present invention selects glass fibers with specific morphologies as fiber reinforcing fillers, and improves the dispersion performance of the flat glass fibers through the tetrapod-shaped zinc oxide whiskers and the solid glass microspheres, enabling the flat glass fibers to be evenly distributed in the nylon material matrix. This structure enables the enhancement and modification effects of the material to be evenly distributed in all directions, ensuring the isotropy of the material in terms of mechanical properties and fundamentally solving the problem of floating fibers.

[0012] Further, the aliphatic nylon is at least one of nylon 6 and nylon 66.

[0013] In order to further improve the dispersion performance of the filler and the mechanical properties of the composite material, a certain amount of polypropylene is also added in the present invention. The melting point of polypropylene is relatively low, generally around 170 °C, while the melting point of aliphatic nylon is relatively high, usually between 230 - 260 °C. During the melt processing, the pre-melted polypropylene can better disperse the inorganic filler in the system and prevent the appearance of floating fiber phenomenon. At the same time, due to the limited strength and compatibility of polypropylene, when its dosage is too much, it may cause a decrease in mechanical properties. Therefore, a certain amount of maleic anhydride grafted polymer is added in the present invention. Further, when the content of polypropylene is 20 - 26 parts, the performance of the composite material can be better improved.

[0014] Further, the maleic anhydride grafted polymer is at least one of maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, maleic anhydride grafted ethylene-propylene-diene monomer rubber, and maleic anhydride grafted ethylene-octene copolymer. The addition of the maleic anhydride grafted polymer can, by means of the valence bond force between molecules, promote the combination of two high molecular polymers of nylon and polypropylene with large polarity differences and incompatibility, and then obtain a blend in which each phase can be mixed evenly, making the blend material not only have increased compatibility but also improved various properties.

[0015] Further, the composite material contains 1 - 8 parts of additives.

[0016] Further, the additives are at least one of coupling agents, lubricants, antioxidants, colorants, flow modifiers, antistatic agents, hydrolysis resistant agents, heat stabilizers, and interface modifiers.

[0017] Further, the coupling agent is at least one of silane coupling agents and titanate coupling agents.

[0018] Further, the lubricant is at least one of silicone powder, erucamide, ethylene bisstearamide, zinc stearate, calcium stearate, and talc powder.

[0019] Further, the antioxidant is at least one of hindered phenol antioxidants and phosphite antioxidants.

[0020] According to another aspect of the present invention, a method for preparing a high-strength glass fiber composite material is provided, including the following steps:

[0021] (1) Weigh each component by weight parts;

[0022] (2) Mix aliphatic nylon, polypropylene, maleic anhydride grafted polymer, tetrapod-shaped zinc oxide whiskers, solid glass microspheres, and additives evenly to obtain a premix;

[0023] (3) Add the premix into an extruder from the main feed port, and add flat glass fibers into the extruder from the side feed port, and then extrude and pelletize to obtain the high-strength glass fiber composite material.

[0024] Further, the extruder is a twin-screw extruder; the screw rotation speed is 300 - 600 r / min, and the extrusion temperature is 260 - 290 °C. Among them, there are no special requirements for the types of flat glass fiber, four-needle-shaped zinc oxide whiskers, and solid glass microspheres used in the present invention, and they are all common types in the art.

[0025] Beneficial effects:

[0026] In the present invention, flat glass fiber is used as a reinforcing filler, and the problem of fiber floating of glass fiber is solved by adding four-needle-shaped zinc oxide whiskers and solid glass microspheres with different morphologies. The special three-dimensional four-needle structure of the four-needle-shaped zinc oxide whiskers can be more closely combined with the nylon base material while isotropically changing the basic properties of the material. The cross-section of the flat glass fiber is a flat structure, and the four-needle-shaped zinc oxide whiskers and the flat glass fiber are easy to form a "bridging" structure during the processing of the nylon composite material, promoting the dispersion of the flat glass fiber and reducing the degree of fiber floating of the flat glass fiber. At the same time, as a spherical inorganic particle, the solid glass microsphere has a smooth and regular outer surface without stress concentration. Compared with materials of other shapes, the change in the system viscosity is small, and its spherical structure can well promote the dispersion of the four-needle-shaped zinc oxide whiskers. Specific embodiments

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] Among them, unless otherwise specified, the types of raw materials used in the above embodiments and comparative examples are the same. Specifically, the diameter of the ordinary round-section glass fiber is 10 μm, and the fiber length is 3 mm; the major axis of the flat glass fiber is 28 μm, the minor axis is 7 μm, and the fiber length is 3 mm; the root diameter of the needle-shaped body of the four-needle-shaped zinc oxide whiskers is between 2 - 8 μm, and the length of the needle-shaped body is between 50 - 80 μm; the particle size of the solid glass microsphere is 40 μm; the particle size of the hollow glass microsphere is 40 μm, and the wall thickness is 1 μm.

[0029] Example 1

[0030] A high-strength glass fiber composite material comprises the following components in parts by weight:

[0031] 80 parts of aliphatic nylon, 20 parts of polypropylene, 8 parts of maleic anhydride grafted polymer, 25 parts of flat glass fiber, 2 parts of four-needle-shaped zinc oxide whisker, 2 parts of solid glass microsphere, 1 part of coupling agent KH550, 1 part of lubricant, 1 part of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted polyethylene; the lubricant is silicone powder; the antioxidant is antioxidant 1010.

[0032] Example 2

[0033] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0034] 90 parts of aliphatic nylon, 26 parts of polypropylene, 16 parts of maleic anhydride grafted polymer, 30 parts of flat glass fiber, 6 parts of four-needle-shaped zinc oxide whisker, 4 parts of solid glass microsphere, 3 parts of coupling agent KH550, 2.2 parts of lubricant, 2.7 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted polypropylene; the lubricant is zinc stearate; the antioxidant is antioxidant 1010.

[0035] Example 3

[0036] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0037] 86 parts of aliphatic nylon, 30 parts of polypropylene, 10 parts of maleic anhydride grafted polymer, 28 parts of flat glass fiber, 4 parts of four-needle-shaped zinc oxide whisker, 3 parts of solid glass microsphere, 2.2 parts of coupling agent KH550, 1.8 parts of lubricant, 1.7 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted ethylene-octene copolymer; the lubricant is talcum powder; the antioxidant is antioxidant 1010.

[0038] Example 4

[0039] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0040] 80 parts of aliphatic nylon, 26 parts of polypropylene, 8 parts of maleic anhydride grafted polymer, 30 parts of flat glass fiber, 2 parts of four-needle-shaped zinc oxide whisker, 4 parts of solid glass microsphere, 1 part of coupling agent KH550, 3 parts of lubricant, 1 part of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted ethylene-propylene-diene monomer; the lubricant is calcium stearate; the antioxidant is antioxidant 1010.

[0041] Example 5

[0042] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0043] 86 parts of aliphatic nylon, 23 parts of polypropylene, 10 parts of maleic anhydride grafted polymer, 28 parts of flat glass fiber, 4 parts of four-needle-shaped zinc oxide whisker, 1 part of solid glass microsphere, 2.2 parts of coupling agent KH550, 1.8 parts of lubricant, 1.7 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted ethylene-octene copolymer; the lubricant is talcum powder; the antioxidant is antioxidant 1010.

[0044] Example 6

[0045] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0046] 83 parts of aliphatic nylon, 22 parts of polypropylene, 9.5 parts of maleic anhydride grafted polymer, 26.5 parts of flat glass fiber, 3.5 parts of four-needle-shaped zinc oxide whisker, 2.5 parts of solid glass microsphere, 1.6 parts of coupling agent KH550, 1.8 parts of lubricant, 1.7 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted polyethylene; the lubricant is silicone powder; the antioxidant is antioxidant 1010.

[0047] Example 7

[0048] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0049] 86 parts of aliphatic nylon, 23 parts of polypropylene, 10 parts of maleic anhydride grafted polymer, 28 parts of flat glass fiber, 4 parts of four-needle-shaped zinc oxide whisker, 6 parts of solid glass microsphere, 2.2 parts of coupling agent KH550, 1.8 parts of lubricant, 1.7 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted ethylene-octene copolymer; the lubricant is talcum powder; the antioxidant is antioxidant 1010.

[0050] Example 8

[0051] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0052] 88 parts of aliphatic nylon, 25 parts of polypropylene, 14.5 parts of maleic anhydride grafted polymer, 28 parts of flat glass fiber, 5.5 parts of four-needle-shaped zinc oxide whisker, 3.5 parts of solid glass microsphere, 2.5 parts of coupling agent KH550, 2 parts of lubricant, 2.5 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted polypropylene; the lubricant is zinc stearate; the antioxidant is antioxidant 1010.

[0053] Example 9

[0054] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0055] 84 parts of aliphatic nylon, 22.5 parts of polypropylene, 14.5 parts of maleic anhydride grafted polymer, 25.5 parts of flat glass fiber, 4.5 parts of four-needle-shaped zinc oxide whiskers, 2.5 parts of solid glass microspheres, 1 part of coupling agent KH550, 2 parts of lubricant, 3 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted ethylene-propylene-diene monomer rubber; the lubricant is calcium stearate; the antioxidant is antioxidant 1010.

[0056] Example 10

[0057] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0058] 86.5 parts of aliphatic nylon, 25.5 parts of polypropylene, 11 parts of maleic anhydride grafted polymer, 26 parts of flat glass fiber, 3.5 parts of four-needle-shaped zinc oxide whiskers, 3 parts of solid glass microspheres, 2.2 parts of coupling agent KH550, 1.4 parts of lubricant, 1.8 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted ethylene-octene copolymer; the lubricant is talcum powder; the antioxidant is antioxidant 1010.

[0059] Example 11

[0060] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0061] 86 parts of aliphatic nylon, 23 parts of polypropylene, 10 parts of maleic anhydride grafted polymer, 28 parts of flat glass fiber, 4 parts of four-needle-shaped zinc oxide whiskers, 3 parts of solid glass microspheres, 2.2 parts of coupling agent KH550, 1.8 parts of lubricant, 1.7 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted ethylene-octene copolymer; the lubricant is talcum powder; the antioxidant is antioxidant 1010.

[0062] Comparative Example 1

[0063] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0064] 86 parts of aliphatic nylon, 23 parts of polypropylene, 10 parts of maleic anhydride grafted polymer, 28 parts of ordinary round-section glass fiber, 4 parts of four-needle-shaped zinc oxide whiskers, 3 parts of solid glass microspheres, 2.2 parts of coupling agent KH550, 1.8 parts of lubricant, 1.7 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted ethylene-octene copolymer; the lubricant is talc powder; the antioxidant is antioxidant 1010.

[0065] Comparative Example 2

[0066] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0067] 86 parts of aliphatic nylon, 23 parts of polypropylene, 10 parts of maleic anhydride grafted polymer, 28 parts of flat glass fiber, 7 parts of four-needle-shaped zinc oxide whiskers, 0 parts of solid glass microspheres, 2.2 parts of coupling agent KH550, 1.8 parts of lubricant, 1.7 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted ethylene-octene copolymer; the lubricant is talc powder; the antioxidant is antioxidant 1010.

[0068] Comparative Example 3

[0069] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0070] 86 parts of aliphatic nylon, 23 parts of polypropylene, 10 parts of maleic anhydride grafted polymer, 28 parts of flat glass fiber, 0 parts of four-needle-shaped zinc oxide whiskers, 7 parts of solid glass microspheres, 2.2 parts of coupling agent KH550, 1.8 parts of lubricant, 1.7 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted ethylene-octene copolymer; the lubricant is talc powder; the antioxidant is antioxidant 1010.

[0071] Comparative Example 4

[0072] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0073] 86 parts of aliphatic nylon, 23 parts of polypropylene, 10 parts of maleic anhydride grafted polymer, 28 parts of flat glass fiber, 4 parts of four-needle-shaped zinc oxide whiskers, 3 parts of hollow glass microspheres, 2.2 parts of coupling agent KH550, 1.8 parts of lubricant, 1.7 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted ethylene-octene copolymer; the lubricant is talc powder; the antioxidant is antioxidant 1010.

[0074] Comparative Example 5

[0075] A high-strength glass fiber composite material, comprising the following components in parts by weight:

[0076] 86 parts of aliphatic nylon, 23 parts of polypropylene, 10 parts of maleic anhydride grafted polymer, 28 parts of flat glass fiber, 9 parts of tetrapod-shaped zinc oxide whiskers, 3 parts of solid glass microspheres, 2.2 parts of coupling agent KH550, 1.8 parts of lubricant, 1.7 parts of antioxidant; the aliphatic nylon is nylon 66; the maleic anhydride grafted polymer is maleic anhydride grafted ethylene-octene copolymer; the lubricant is talcum powder; the antioxidant is antioxidant 1010.

[0077] The specific preparation processes of the above Examples 1-11 and Comparative Examples 1-5 are the same, specifically as follows:

[0078] (1) Weigh each component according to the parts by weight;

[0079] (2) Mix the aliphatic nylon, polypropylene, maleic anhydride grafted polymer, tetrapod-shaped zinc oxide whiskers, solid glass microspheres (or hollow glass microspheres), and additives evenly to obtain a premix;

[0080] (3) Add the premix into the extruder from the main feed port, and add the flat glass fiber (or ordinary round cross-section glass fiber) into the extruder from the side feed port, and extrude and pelletize to obtain the high-strength glass fiber composite material;

[0081] The extruder is a twin-screw extruder; the screw speed is 400 r / min, and the extrusion temperature is 270 °C.

[0082] Product performance testing: Prepare standard specimens from the high-strength glass fiber composite materials obtained in Examples 1-11 and Comparative Examples 1-5, and respectively test their mechanical properties such as tensile strength (refer to standard ISO527), flexural strength (refer to standard ISO178), and notched impact strength (refer to standard ISO179). And observe the floating fiber situation on the surface of the specimens, and divide the surface into five grades from 1 to 5. From 1 to 5, as the grade increases, it means that the floating fiber condition is more serious. The results are shown in Table 1 - Table 2.

[0083] Table 1

[0084]

[0085] Table 2

[0086]

[0087] As can be seen from the data in Table 1 and Table 2, the present invention uses flat glass fiber as the reinforcing filler. By adding zinc oxide whiskers with four - needle shapes and solid glass microspheres with different morphologies, not only the mechanical properties of the composite material, especially the impact property, are improved, but also the problem of floating fibers of glass fiber is solved. Compared with Example 11, in Comparative Example 1, ordinary round - section glass fiber is used as the reinforcing filler. Although the mechanical properties change little, the floating fiber condition on its surface is serious. In Comparative Examples 2 - 3, zinc oxide whiskers with four - needle shapes and solid glass microspheres are respectively missing, and both the mechanical properties and the surface condition deteriorate. This is because the zinc oxide whiskers with four - needle shapes have a unique four - needle - shaped three - dimensional structure, and the cross - section of the flat glass fiber is a flat structure. The zinc oxide whiskers with four - needle shapes and the flat glass fiber with a special cross - section are prone to form a "bridging" structure during the processing of the nylon composite material, promoting the dispersion of the flat glass fiber and reducing the degree of floating fibers of the flat glass fiber. At the same time, in order to prevent the zinc oxide whiskers with four - needle shapes from interlocking with each other and being difficult to disperse during the mixing process, the present invention adds a certain amount of solid glass microspheres, and its spherical structure can well promote the dispersion of the zinc oxide whiskers with four - needle shapes. Comparative Example 4 shows that the hollow glass microspheres have low strength, and during the melt - processing in the extruder, the rigid zinc oxide whiskers with four - needle shapes are prone to damage the hollow glass microspheres, and the dispersion effect of the spheres cannot be exerted. Comparative Example 5 shows that as a modified filler with a special morphology, the dosage of the zinc oxide whiskers with four - needle shapes cannot be too much, otherwise its own special morphology is prone to cause it to fix each other during the processing and occur the "self - locking" agglomeration phenomenon, which is not conducive to the improvement of product performance.

[0088] In summary, the present invention selects glass fibers with specific morphologies as the fiber - reinforcing filler, and improves the dispersion performance of the flat glass fiber through zinc oxide whiskers with four - needle shapes and solid glass microspheres, enabling the flat glass fiber to be evenly distributed in the nylon material matrix. This structure makes the strengthening and modification effects of the material evenly distributed in all directions, not only improving the mechanical properties of the composite material, especially the impact property, but also fundamentally solving the problem of floating fibers.

Claims

1. A high-strength glass fiber composite material, characterized in that, It comprises components in the following parts by weight: 80 - 90 parts of aliphatic nylon, 20 - 30 parts of polypropylene, 8 - 16 parts of maleic anhydride grafted polymer, 25 - 30 parts of flat glass fiber, 2 - 6 parts of tetrapod-shaped zinc oxide whiskers, 1 - 6 parts of solid glass microspheres, 1 - 10 parts of additives; the additives are at least one of coupling agent, lubricant, antioxidant, colorant, flow modifier, antistatic agent, hydrolysis resistant agent, heat stabilizer.

2. The high-strength glass fiber composite material according to claim 1, wherein The aliphatic nylon is at least one of nylon 6 and nylon 66.

3. A high-strength glass fiber composite material according to claim 1, characterized in that, The maleic anhydride grafted polymer is at least one of maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, maleic anhydride grafted ethylene-propylene-diene monomer rubber, maleic anhydride grafted ethylene-octene copolymer.

4. A high-strength glass fiber composite material according to claim 1, characterized in that, The composite material contains 1 - 8 parts of additives.

5. A high-strength glass fiber composite material as claimed in claim 1, wherein The coupling agent is at least one of silane coupling agent and titanate coupling agent.

6. A high-strength glass fiber composite material according to claim 1, characterized in that, The lubricant is at least one of silicone powder, erucamide, ethylene bisstearamide, zinc stearate, calcium stearate, talc powder.

7. A high-strength glass fiber composite material as described in claim 1, wherein, The antioxidant is at least one of hindered phenol antioxidants and phosphite antioxidants.

8. The preparation method of a high-strength glass fiber composite material as described in claim 1, characterized in that, It includes the following steps: (1) Weigh each component according to the parts by weight. (2) Mix the aliphatic nylon, polypropylene, maleic anhydride grafted polymer, tetrapod-shaped zinc oxide whiskers, solid glass microspheres and additives evenly to obtain a premix. (3) Add the premix into an extruder from the main feeding port, and add the flat glass fiber into the extruder from the side feeding port, then extrude and pelletize to obtain the high-strength glass fiber composite material.

9. The preparation method of a high-strength glass fiber composite material according to claim 8, wherein, The extruder is a twin-screw extruder; the screw speed is 300 - 600 r / min, and the extrusion temperature is 260 - 290 °C.

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