A modified fiber-reinforced resin-based composite material and a preparation method thereof

Abstract

The present invention belongs to the technical field of resin composite materials, and specifically relates to a modified fiber reinforced resin-based composite material and a preparation method thereof, including the following raw materials by weight: 30-50 parts of modified fibers, 60-80 parts of resin matrix, 3-8 parts of initiators, 10-15 parts of sodium silicate, 1-3 parts of flow aids, 2-4 parts of release agents and 1 part of antioxidants. Wherein, the modified fiber is prepared by comprising the following steps: polystyrene sulfonic acid is added to N-methylpyrrolidone solution, glass fiber is added, boron nitride is added, and polystyrene sulfonic acid modified glass fiber loaded with boron nitride, i.e. modified fiber. The present invention realizes multifunctional modification of fiber by combining the mechanical properties of glass fiber, the chemical properties of polystyrene sulfonic acid and the lubricating properties of boron nitride, so that the fiber-reinforced composite material can withstand tensile and compressive loads, so that the composite material has high strength, high thermal stability and excellent toughness.

Description

Technical Field

[0001] The invention belongs to the technical field of textile composite materials, and specifically relates to a modified fiber-reinforced resin-based composite material and a preparation method thereof. Background Art

[0002] Fiber-reinforced resin-based composites are advanced engineering materials, mainly composed of high-molecular organic polymers as the matrix and fibers as reinforcements, such as glass fiber, carbon fiber and basalt fiber. Curing prepares high-performance fiber-reinforced resin-based composites. Fiber-reinforced resin-based composites have excellent mechanical properties, corrosion resistance and thermal stability, and are widely used in aviation, automotive industry, defense and military fields. In order to improve the interfacial bonding and compatibility between the fiber and the resin, the original fiber is surface treated by physical or chemical means to optimize the physical and chemical properties of its surface. Commonly used resin matrices include two main types: thermoplastic resins and thermosetting resins. Thermoplastic resins have the characteristics of being soluble and meltable, while thermosetting resins solidify after heating to form polymer compounds that no longer dissolve or melt. Carbon fiber reinforced epoxy resin composites are a type of fiber-reinforced resin-based composites, which have excellent strength and lightweight characteristics. They are increasingly used in high-end equipment such as aircraft, missiles and satellites, and have made important contributions to promoting technological progress in the aerospace industry. Fiber-reinforced resin-based composites play an indispensable role in the modern engineering field due to their excellent performance and wide applicability.

[0003] In the prior art, traditional fiber-reinforced resin-based composite materials are insufficient in rigidity compared to metal materials, and their elastic modulus is low. At the same time, resin-based composite materials are easily affected by environmental factors and age, resulting in performance degradation, especially under high temperature conditions, and are prone to thermal decomposition and oxidation. Summary of the invention

[0004] The object of the present invention is to provide a modified fiber reinforced resin-based composite material and a preparation method thereof in view of the deficiencies in the prior art.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A modified fiber reinforced resin-based composite material comprises the following raw materials by weight: 30-50 parts of modified fiber, 60-80 parts of resin matrix, 3-8 parts of initiator, 10-15 parts of sodium silicate, 1-3 parts of flow aid, 2-4 parts of release agent and 1 part of antioxidant.

[0007] Preferably, the following raw materials are included by weight: 40-45 parts of modified fiber, 60-70 parts of resin matrix, 3-5 parts of initiator, 13-15 parts of sodium silicate, 3 parts of flow aid, 2 parts of release agent and 1 part of antioxidant.

[0008] Furthermore, the modified fiber is prepared by the following steps:

[0009] Add polystyrene sulfonic acid to N-methylpyrrolidone solution, add glass fiber, stir evenly with a magnetic stirrer, place in a polytetrafluoroethylene lined reactor, add 2,2'-azo (2-methylpropylamidine) sodium dihydrochloride and stannous octoate, stir, control the reaction temperature to 70-80°C, react for 3-5h, add boron nitride, heat to 100-120°C, stir, continue to react for 1-2h, cool to room temperature, filter, wash, and dry to obtain polystyrene sulfonic acid modified glass fiber loaded with boron nitride, i.e., modified fiber.

[0010] The resin matrix is ​​polyester resin, and the initiator includes one or more of benzoyl peroxide, methyl ethyl ketone peroxide, dimethyl aniline and diethyl aniline.

[0011] The flow aid includes one or more of polyethylene glycol, fatty acid amide, polypropylene, polycarbonate and polystyrene.

[0012] The release agent includes one or more of silicone oil, paraffin wax and stearic acid wax.

[0013] The antioxidants include 2,6-di-tert-butyl-p-cresol, antioxidant 1330 and tris(2,4-di-tert-butylphenyl) phosphite.

[0014] The mass ratio of the polystyrene sulfonic acid, glass fiber, 2,2'-azo(2-methylpropylamidine) sodium dihydrochloride, stannous octoate and boron nitride is (20-22):(10-15):(0.05-0.07):(0.01-0.03):(8-10).

[0015] According to another aspect of the present invention, there is provided a method for preparing a modified fiber-reinforced resin-based composite material, comprising the following steps:

[0016] The modified fiber, resin matrix, initiator, sodium silicate, flow aid, release agent and antioxidant are weighed according to the weight ratio and put into a mixer to mix evenly, the temperature is controlled at 50-60°C, the reaction is carried out for 8-10 hours, and the mixture is cooled to room temperature. After post-processing, cutting and polishing, a modified fiber-reinforced resin-based composite material is obtained.

[0017] Beneficial effects of the present invention:

[0018] 1. In the technical solution of the present invention, glass fiber is used as the main reinforcement, and its surface is covered by polystyrene sulfonic acid. The polystyrene sulfonic acid exists in the form of a film and / or a chemical coating, and is tightly combined with the glass fiber through chemical bonding and electrostatic action. Boron nitride is loaded on the surface of the modified glass fiber through physical adsorption in the form of particles and / or a thin layer. This composite structure combines the mechanical properties of glass fiber, the chemical properties of polystyrene sulfonic acid and the lubricating properties of boron nitride, thereby realizing multifunctional modification of the fiber.

[0019] 2. In the technical solution of the present invention, the modified fiber has improved tensile strength, modulus and toughness by introducing boron nitride. At the same time, it has excellent thermal stability, so that the performance of the modified fiber in a high temperature environment is improved.

[0020] 3. In the technical solution of the present invention, the resistance of the fiber to chemical corrosion is improved by introducing polystyrene sulfonic acid. At the same time, the loading of boron nitride makes the modified fiber have lubricating properties, which helps to reduce friction and wear.

[0021] 4. In the technical solution of the present invention, the bonding strength and compatibility of the interface between the modified fiber and the resin matrix are improved through chemical modification, thereby enhancing the performance of the composite material. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0023] Example 1

[0024] The modified fiber comprises the following steps: adding 20g of polystyrene sulfonic acid into N-methylpyrrolidone solution, adding 10g of glass fiber, stirring evenly with a magnetic stirrer, placing in a polytetrafluoroethylene lined reactor, adding 0.05g of 2,2'-azo (2-methylpropylamidine) sodium dihydrochloride and 0.01g of stannous octoate, stirring, controlling the reaction temperature to 70°C, reacting for 3h, adding 8g of boron nitride, heating to 100°C, stirring, continuing the reaction for 1h, cooling to room temperature, filtering, washing, and drying to obtain polystyrene sulfonic acid modified glass fiber loaded with boron nitride, i.e., modified fiber.

[0025] Example 2

[0026] The modified fiber comprises the following steps: adding 21g of polystyrene sulfonic acid to an N-methylpyrrolidone solution, adding 12.5g of glass fiber, stirring evenly with a magnetic stirrer, placing in a polytetrafluoroethylene-lined reactor, adding 0.06g of 2,2'-azo (2-methylpropylamidine) sodium dihydrochloride and 0.02g of stannous octoate, stirring, controlling the reaction temperature to 70°C, reacting for 3h, adding 9g of boron nitride, heating to 100°C, stirring, continuing the reaction for 1h, cooling to room temperature, filtering, washing, and drying to obtain polystyrene sulfonic acid modified glass fiber loaded with boron nitride, i.e., the modified fiber.

[0027] Example 3

[0028] The modified fiber comprises the following steps: adding 22g of polystyrene sulfonic acid into N-methylpyrrolidone solution, adding 15g of glass fiber, stirring evenly with a magnetic stirrer, placing in a polytetrafluoroethylene lined reactor, adding 0.07g of 2,2'-azo (2-methylpropylamidine) sodium dihydrochloride and 0.03g of stannous octoate, stirring, controlling the reaction temperature to 70°C, reacting for 3h, adding 10g of boron nitride, heating to 100°C, stirring, continuing the reaction for 1h, cooling to room temperature, filtering, washing, and drying to obtain polystyrene sulfonic acid modified glass fiber loaded with boron nitride, i.e., modified fiber.

[0029] Example 4

[0030] A method for preparing a modified fiber-reinforced resin-based composite material comprises the following steps:

[0031] Weigh 40 parts of the modified fiber prepared in Example 1, 60 parts of the resin matrix, 3 parts of the initiator, 13 parts of sodium silicate, 3 parts of the flow aid, 2 parts of the release agent and 1 part of the antioxidant according to the weight ratio, put them into a mixer and mix them evenly, control the temperature at 50°C, react for 8 hours, cool to room temperature, and obtain a modified fiber reinforced resin-based composite material by post-processing, cutting and polishing.

[0032] Example 5

[0033] A method for preparing a modified fiber-reinforced resin-based composite material comprises the following steps:

[0034] 42.5 parts of the modified fiber obtained in Example 2, 65 parts of the resin matrix, 4 parts of the initiator, 14 parts of sodium silicate, 3 parts of the flow aid, 2 parts of the release agent and 1 part of the antioxidant were weighed by weight and put into a mixer to mix evenly. The temperature was controlled at 50°C, the reaction was carried out for 8 hours, and the mixture was cooled to room temperature. After post-processing, cutting and polishing, a modified fiber-reinforced resin-based composite material was obtained.

[0035] Example 6

[0036] A method for preparing a modified fiber-reinforced resin-based composite material comprises the following steps:

[0037] Weigh 45 parts of the modified fiber prepared in Example 3, 70 parts of the resin matrix, 5 parts of the initiator, 15 parts of sodium silicate, 3 parts of the flow aid, 2 parts of the release agent and 1 part of the antioxidant in a mixer according to the weight ratio and mix them evenly. Control the temperature at 50°C, react for 8 hours, cool to room temperature, and obtain a modified fiber-reinforced resin-based composite material by post-processing, cutting and polishing.

[0038] Comparative Example 1

[0039] In this comparative example, only glass fiber was used, and the remaining steps were the same as those in Example 6, namely:

[0040] A method for preparing a modified fiber-reinforced resin-based composite material comprises the following steps:

[0041] 45 parts of glass fiber, 70 parts of resin matrix, 5 parts of initiator, 15 parts of sodium silicate, 3 parts of flow aid, 2 parts of release agent and 1 part of antioxidant were weighed into a mixer according to the weight ratio and mixed evenly. The temperature was controlled at 50°C, reacted for 8 hours, cooled to room temperature, and post-processed by cutting and polishing to obtain a modified fiber-reinforced resin-based composite material.

[0042] With reference to GB / T 1040.1-2018 "Determination of Tensile Properties of Plastics Part 1: General", ASTM D638-22 "Standard Test Method for Tensile Properties of Plastics", GB / T 9341-2008 "Determination of Flexural Properties of Plastics" and GB / T 1843-2008 "Determination of Izod Impact Strength of Plastics", Examples 4-6 and Comparative Example 1 were tested for mechanical properties, and the results are shown in Table 1:

[0043] Table 1. Mechanical properties test results of Examples 4-6 and Comparative Example 1

[0044] project Example 4 Example 5 Example 6 Comparative Example 1 Tensile strength(MPa) 172 176 170 124 Elongation at break (%) 6.2 6.1 6.5 4.6 Bending strength(MPa) 225 229 232 168 Flexural modulus(GPa) 12.6 13.2 12.8 9.5 <![CDATA[Impact strength (kJ / m 2 )]]> 62 59 66 51

[0045] With reference to GB / T 1449-2005 "Fiber Reinforced Plastics Flexural Properties Test Method" and ASTM D790-03 "Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials1", elastic modulus tests were performed on Examples 4-6 and Comparative Example 1. The parameters of the samples were unified as follows: length 100 mm, width 10 mm, thickness 5 mm, span 80 mm and loading rate 1 mm / min. The elastic modulus was calculated, and the results are shown in Table 2:

[0046] Table 2. Elastic modulus test results of Examples 4-6 and Comparative Example 1

[0047] project Example 4 Example 5 Example 6 Comparative Example 1 Maximum load (N) 163 164 169 121 Displacement corresponding to the maximum load point (mm) 0.026 0.029 0.030 0.045 Elastic modulus(GPa) 14.2 13.8 14.5 9.8

[0048] With reference to GB / T 3139-2005 "Test method for thermal conductivity of fiber reinforced plastics", HG / T 2006-2022 "Thermosetting and thermoplastic powder coatings" and GB / T 1634.2-2004 "Determination of load deformation temperature of plastics Part 2: Plastics, hard rubber and long fiber reinforced composite materials", thermal stability tests were conducted on Examples 4-6 and Comparative Example 1, and the results are shown in Table 3:

[0049] Table 3. Thermal stability test results of Examples 4-6 and Comparative Example 1

[0050] project Example 4 Example 5 Example 6 Comparative Example 1 Thermal decomposition temperature (℃) 385 389 388 322 Carbon residue rate (%) 63 61 59 46 Thermal weight loss rate (% / min) 0.68 0.69 0.70 1.05

[0051] As can be seen from Table 1, tensile strength: The average tensile strength of Example 4-6 is 172.7MPa, which is significantly higher than 124MPa of Comparative Example 1, indicating that the modified fiber can enhance the tensile properties of the composite material. The average elongation at break of Example 4-6 is 6.3%, which is higher than 4.6% of Comparative Example 1, indicating that the modified fiber has a certain effect on improving the toughness of the composite material. The average flexural strength of Example 4-6 is 228.7MPa, and the average flexural modulus is 12.8GPa, which are higher than 168MPa and 9.5GPa of Comparative Example 1, indicating that the modified fiber significantly enhances the flexural properties of the composite material. The average impact strength of Example 4-6 is 62.3kJ / m 2 , higher than 51kJ / m in Comparative Example 1 2 , indicating that the modified fiber improves the impact resistance of the composite material.

[0052] It can be seen from Table 2 that the elastic modulus values ​​of Examples 4-6 are 14.2 GPa, 13.8 GPa and 14.5 GPa, respectively. In comparison, the elastic modulus value of Comparative Example 1 is 9.8 GPa, indicating that through the reinforcement effect of the modified fiber, the composite materials of Examples 4-6 have a higher elastic modulus, that is, better bending resistance.

[0053] As shown in Table 3, the average thermal decomposition temperature of Examples 4-6 is 387.3°C, which is higher than 322°C of Comparative Example 1, indicating that the modified fiber improves the thermal stability of the composite material. The average carbon residue rate of Examples 4-6 is 61%, which is higher than 46% of Comparative Example 1, indicating that the modified fiber helps the carbonization process of the composite material at high temperature, further proving the improvement effect of the modified fiber on thermal stability. The average thermal weight loss rate of Examples 4-6 is 0.69% / min, which is lower than 1.05% / min of Comparative Example 1, indicating that the modified fiber reduces the mass loss rate of the composite material at high temperature.

[0054] In summary, Examples 4-6 significantly improved the mechanical properties, elastic modulus and thermal stability of the composite materials by introducing modified fibers.

[0055] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0056] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the present invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A modified fiber reinforced resin-based composite material, It is characterized in that The following raw materials are included by weight: 30-50 parts of modified fiber, 60-80 parts of resin matrix, 3-8 parts of initiator, 10-15 parts of sodium silicate, 1-3 parts of flow aid, 2-4 parts of release agent and 1 part of antioxidant; The following raw materials are included by weight: 40-45 parts of modified fiber, 60-70 parts of resin matrix, 3-5 parts of initiator, 13-15 parts of sodium silicate, 3 parts of flow aid, 2 parts of release agent and 1 part of antioxidant; Modified Fiber The method comprises the following steps: Add polystyrene sulfonic acid to N-methylpyrrolidone solution, add glass fiber, stir evenly with a magnetic stirrer, place in a polytetrafluoroethylene lined reactor, add 2,2'-azo (2-methylpropyl amidine) sodium dihydrochloride and stannous octoate, stir, control the reaction temperature to 70-80°C, react for 3-5h, add boron nitride, heat to 100-120°C, stir, continue to react for 1-2h, cool to room temperature, filter, wash, and dry to obtain polystyrene sulfonic acid modified glass fiber loaded with boron nitride, i.e., modified fiber; The resin matrix is ​​a polyester resin, and the initiator includes one or more of benzoyl peroxide, methyl ethyl ketone peroxide, dimethylaniline and diethylaniline; The flow aid includes one or more of polyethylene glycol, fatty acid amide, polypropylene, polycarbonate and polystyrene; The release agent includes one or more of silicone oil, paraffin wax and stearic acid wax; Antioxidants include 2,6-di-tert-butyl-p-cresol, antioxidant 1330 and tris(2,4-di-tert-butylphenyl) phosphite; The mass ratio of polystyrene sulfonic acid, glass fiber, 2,2'-azo(2-methylpropylamidine) sodium dihydrochloride, stannous octoate and boron nitride is (20-22):(10-15):(0.05-0.07):(0.01-0.03):(8-10).

2. A method for preparing a modified fiber-reinforced resin-based composite material according to claim 1, It is characterized in that The following steps are involved: The modified fiber, resin matrix, initiator, sodium silicate, flow aid, release agent and antioxidant are weighed according to the weight ratio and put into a mixer to mix evenly, the temperature is controlled at 50-60°C, the reaction is carried out for 8-10 hours, and the mixture is cooled to room temperature. After post-processing, cutting and polishing, a modified fiber-reinforced resin-based composite material is obtained.