Preparation method of low-density high-strength glass fiber board cured by epoxy resin

Abstract

The invention discloses a preparation method of a low-density high-strength glass fiber plate cured by epoxy resin, and belongs to the technical field of glass fiber plate preparation. The preparation method of the low-density and high-strength glass fiber board cured by utilizing the epoxy resin comprises the following steps: step 1, adding an organic silicon modifier into the epoxy resin, and stirring for reaction to obtain modified epoxy resin; 2, glass fibers are added into the modified epoxy resin to be soaked, after soaking is completed, the glass fibers are taken out, and modified glass fibers are obtained; and 3, mixing the modified glass fiber with an organic curing agent, stirring, rolling, and drying to obtain the low-density and high-strength glass fiber plate cured by the epoxy resin. The glass fiber plate prepared by the method has excellent mechanical property and weather resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of glass fiber board preparation, and in particular relates to a method for preparing a low-density and high-strength glass fiber board cured by epoxy resin. Background Art

[0002] With the acceleration of the global industrialization process, the requirements for material performance in various industries are increasing. In the fields of aerospace, automobile manufacturing, electronics and electrical, and construction, traditional metal materials have been unable to meet the modern industry's needs for lightweight, high strength, corrosion resistance, and good processing performance due to their high density, easy corrosion, and difficult processing. Therefore, the development of new high-performance composite materials has become a research hotspot in the field of materials science. Among them, low-density and high-strength glass fiber board cured with epoxy resin, as an excellent composite material, has attracted much attention due to its unique performance advantages.

[0003] In the aerospace field, low-density, high-strength fiberglass boards can significantly reduce the overall weight of aircraft and improve fuel efficiency, while maintaining sufficient strength and stability to ensure flight safety. In the automotive manufacturing field, this material can be used to manufacture body structures and interior parts, realize lightweight design of automobiles, and improve fuel economy and driving comfort. In the field of electronics and electrical, fiberglass boards, as the substrate of circuit boards, have excellent insulation properties and high temperature resistance, which can protect circuit boards from external interference and improve the reliability and stability of electronic equipment. In the construction field, fiberglass boards are widely used in decorative materials such as wall panels, base plates and ceilings due to their light weight, high strength, fire resistance and corrosion resistance.

[0004] Patent CN 117384407 B discloses a low-density epoxy resin glass fiber prepreg for marine equipment and a preparation method, a glass fiber composite material and its application. The low-density epoxy resin mixture is coated in a coating machine to form a resin film, and is impregnated with glass fiber in a prepreg machine to obtain a prepreg. The low-density epoxy resin mixture consists of 30-60 parts of epoxy resin, 5-10 parts of toughening agent, 5-10 parts of foaming agent, 2-5 parts of surfactant, 5-10 parts of curing agent, and 2-3 parts of accelerator. The epoxy resin is composed of liquid bisphenol A epoxy resin, solid bisphenol A epoxy resin, and solid phenolic epoxy resin. The viscosity of the epoxy resin mixture is suitable for producing a resin film at 70°C. Through the interaction of foaming agent, surfactant, curing agent, accelerator, etc., the density of the marine equipment sheet produced by the epoxy resin mixture and glass fiber prepreg can be as low as 1.35g / cm 3 The following also makes the laminate have excellent mechanical properties. However, the density, mechanical properties and weather resistance of the glass fiber board prepared by this method are still room for improvement. Summary of the invention

[0005] The object of the present invention is to provide a method for preparing a low-density and high-strength glass fiber board cured by epoxy resin, so as to solve the technical problems of high density, poor mechanical properties and poor weather resistance of the glass fiber board in the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a method for preparing a low-density and high-strength glass fiber board cured by epoxy resin, comprising the following steps:

[0008] Step 1: adding an organosilicon modifier to an epoxy resin, stirring and reacting, and obtaining a modified epoxy resin;

[0009] Step 2: adding the glass fiber into the modified epoxy resin for soaking, and after the soaking is completed, taking it out to obtain the modified glass fiber;

[0010] Step 3: Mix the modified glass fiber and the organic curing agent, stir, roll and dry to obtain a low-density and high-strength glass fiber board cured with epoxy resin.

[0011] Preferably, in the step one, the mass ratio of epoxy resin to silicone modifier is (1-1.5): (0.03-0.05), and the stirring reaction time is 3-5 hours; in the step two, the mass ratio of glass fiber to modified epoxy resin is (1-4): (3-5), and the immersion time is 4-6 hours; in the step three, the mass ratio of modified glass fiber to organic curing agent is (1-2): (0.07-0.09).

[0012] Preferably, the method for preparing the organosilicon modifier comprises the following steps:

[0013] Q1: Add 3-methoxy-4-hydroxybenzaldehyde to a container containing dichloromethane, stir to dissolve, add pyridine, introduce nitrogen after magnetic stirring, add dichloromethane and methacryloyl chloride to a constant pressure dropping funnel, and then add dropwise to the container. After the addition is complete, heat to react. After the reaction is complete, perform rotary evaporation, dissolve the solid, filter, wash, dry, let stand and filter to obtain a filtrate, perform rotary evaporation, dissolve, filter, add to a container containing deionized water, recrystallize at low temperature, filter, and dry to obtain product 1;

[0014] Q2: Add 4-(1,2,2-triphenylvinyl)phenol and triethylamine to a container, then add dichloromethane, add methacryloyl chloride dropwise in an ice-water bath under a nitrogen atmosphere, stir, react at room temperature, wash, rotary evaporate, concentrate, and dry to obtain product 2;

[0015] Q3: Add eugenol, triethylamine and dichloromethane into a container, dissolve dichlorodiphenylsilane in dichloromethane and add the mixture dropwise into the container, heat under reflux and filter, wash, dry, filter, rotary evaporate and dry to obtain product 3;

[0016] Q4: Add product 1, product 2 and product 3 into a container, add azobisisobutyronitrile, introduce nitrogen, then add N,N-dimethylformamide, heat to react, after the reaction is completed, add to anhydrous ethanol, dry, and obtain an organosilicon modifier.

[0017] In the above process, the synthesis reaction formula of the organosilicon modifier is as follows:

[0018]

[0019] The results of mass spectrometry analysis of product 1 are: m / z: 220.07 (100.0%), 221.08 (13.3%), 222.08 (1.6%); the results of mass spectrometry analysis of product 2 are: m / z: 416.18 (100.0%), 417.18 (32.8%), 418.18 (5.5%); the results of mass spectrometry analysis of product 3 are: m / z: 508.21 (100.0%), 509.21 (40.2%), 510.21 (8.5%), 510.20 (3.3%), 511.21 (1.8%).

[0020] Preferably, in Q1, the amount ratio of 3-methoxy-4-hydroxybenzaldehyde, pyridine and methacryloyl chloride is (6.08-7.9) g: (4-5.2) mL: (4.7-6.11) mL, the heating reaction temperature is 40-50°C, the time is 5-7h, the rotary evaporation temperature is 30-32°C, the solid is dissolved with ethyl acetate, washed with saturated sodium chloride and saturated sodium bicarbonate, dried with anhydrous magnesium sulfate, and allowed to stand for 20-30 min, then rotary evaporated at 60-63°C, dissolved with anhydrous ethanol, the low-temperature recrystallization temperature is 3-6°C, and the recrystallization time is 10-12h.

[0021] Preferably, in Q2, the amount ratio of 4-(1,2,2-triphenylvinyl)phenol, triethylamine, dichloromethane and methacryloyl chloride is (1-1.5) g: (0.54-0.81) mL: (40-60) mL: (0.35-0.52) mL, the stirring time is 3-5 min, the reaction time at room temperature is 2-4 h, and the mixture is washed with deionized water and saturated sodium chloride; in Q3, the amount ratio of eugenol, triethylamine and dichlorodiphenylsilane is (6.57-7.88) g:

[0022] (4.05-4.86)g: (5.06-6.07)g, heating reflux temperature is 40-50°C, reflux time is 3-4h, washed with deionized water, and dried with anhydrous magnesium sulfate.

[0023] Preferably, in Q4, product 1, product 2, product 3 、 The dosage ratio of azobisisobutyronitrile and N,N-dimethylformamide is (0.4-0.6) g: (0.1-0.15) g: (0.2-0.25) g: (0.012-0.014) g: (3-5) mL, the heating reaction temperature is 80-85°C, the reaction time is 10-12h, and the drying temperature is 30-40°C, and the time is 10-12h.

[0024] Preferably, the method for preparing the organic curing agent comprises the following steps:

[0025] S1: Add 4,4'-diaminobiphenyl to a container containing glacial acetic acid, add butyl methacrylate, stir, heat in the dark for reaction, then add butyl methacrylate, after the reaction is completed, perform rotary evaporation to obtain a viscous fluid;

[0026] S2: ultrasonically dissolve the viscous fluid with methanol to obtain a viscous fluid solution, take 1,4-cyclohexanediamine and add it to methanol, stir to dissolve, then add it to the viscous fluid solution, under a nitrogen atmosphere, magnetically stir in the dark, after the reaction is completed, rotary evaporate to obtain a crude product, dissolve the crude product in methanol, use ether for precipitation, repeat the operation, filter and obtain an organic curing agent.

[0027] In the above process, the synthetic reaction formula of the organic curing agent is as follows:

[0028]

[0029] The results of mass spectrometry analysis of the organic curing agent were: m / z: 856.61 (100.0%), 857.61 (52.9%), 858.61 (16.5%), 857.60 (3.7%), 859.62 (2.3%), 859.61 (1.0%).

[0030] Preferably, in S1, the molar ratio of 4,4'-diaminobiphenyl, butyl methacrylate added for the first time and butyl methacrylate added for the second time is (1-1.3):(2-2.6):(2-2.5), the stirring time is 4-6 hours, the light-proof heating reaction temperature is 80-85°C, the time is 3-5 hours, and the reaction time after adding butyl methacrylate is 4-6 hours.

[0031] Preferably, in S2, the molar ratio of the viscous fluid to 1,4-cyclohexanediamine is (1-1.2):(4-4.6), the light-proof magnetic stirring temperature is 35-40°C, the stirring time is 20-24h, the rotary evaporation temperature is 50-55°C, and the operation is repeated 4-6 times.

[0032] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0033] 1. The present invention firstly uses 3-methoxy-4-hydroxybenzaldehyde 、 Methacryloyl chloride 、 4-(1,2,2-Triphenylvinyl)phenol 、 Eugenol and dichlorodiphenylsilane are used as raw materials to prepare an organosilicon modifier, and then 4,4'-diaminobiphenyl, butyl methacrylate and 1,4-cyclohexanediamine are used as raw materials to prepare an organic curing agent. Applying the organosilicon modifier and the organic curing agent to the preparation process of glass fiber board can effectively reduce the density of glass fiber board and improve the mechanical strength and weather resistance of glass fiber board.

[0034] 2. The present invention adds an organosilicon modifier to an epoxy resin to prepare a modified epoxy resin, and applies the modified epoxy resin to the preparation process of the glass fiber board, which can effectively improve the mechanical properties and weather resistance of the glass fiber board. The silicon element in the organosilicon modifier can form a close bond with the epoxy resin and the glass fiber, thereby improving the overall strength of the glass fiber board, and the complex cross-linked network formed by the organosilicon modifier further enhances its strength. At the same time, the flexible chain segments contained in the organosilicon modifier can absorb and disperse stress, improve the toughness of the glass fiber board, and help it maintain the structural integrity when it is impacted or bent; at the same time, the benzene ring and silicon element contained in the organosilicon modifier can absorb and disperse ultraviolet rays, thereby protecting the glass fiber board from damage by ultraviolet rays and extending its service life.

[0035] 3. The present invention adds the prepared organic curing agent to the preparation process of the glass fiber board, which will make the obtained glass fiber board have excellent mechanical properties and weather resistance. The functional groups contained in the organic curing agent can react with the functional groups in the epoxy resin to form a denser cross-linking network, thereby effectively dispersing the stress and further improving the mechanical properties of the glass fiber board. The aromatic rings contained in the organic curing agent can also be used to absorb and disperse ultraviolet rays, protect the glass fiber board from damage by ultraviolet rays, and extend its service life. The organic curing agent can effectively fill the pores between the epoxy resin and the glass fiber and reduce the porosity, that is, the density of the glass fiber board can be reduced while maintaining the same mechanical properties. DETAILED DESCRIPTION

[0036] The following will be described clearly and completely in conjunction with 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.

[0037] Example 1: This example discloses a method for preparing an organosilicon modifier, comprising the following steps:

[0038] Q1: Add 6.99 g of 3-methoxy-4-hydroxybenzaldehyde to a container containing 60 mL of dichloromethane, stir to dissolve, add 4.6 mL of pyridine, introduce nitrogen after magnetic stirring, add 10 mL of dichloromethane and 5.41 mL of methacryloyl chloride to a constant pressure dropping funnel, and then add dropwise to the container. After the addition is completed, heat to react at 45°C for 5 hours. After the reaction is completed, rotary evaporate at 32°C, dissolve the solid with ethyl acetate, filter, wash with saturated sodium chloride and saturated sodium bicarbonate, dry with anhydrous magnesium sulfate, let stand for 30 minutes, filter to obtain a filtrate, rotary evaporate at 60°C, dissolve with anhydrous ethanol, filter, add to a container containing deionized water, recrystallize at 6°C for 12 hours, filter, and dry to obtain product 1;

[0039] Q2: 1.25 g of 4-(1,2,2-triphenylvinyl)phenol and 0.69 mL of triethylamine were added to a container, followed by 50 mL of dichloromethane. 0.43 mL of methacryloyl chloride was added dropwise in an ice-water bath under a nitrogen atmosphere. After stirring for 3 min, the mixture was reacted at room temperature for 4 h. After the reaction was completed, the mixture was washed with deionized water and saturated sodium chloride, rotary evaporated, concentrated, and dried to obtain product 2.

[0040] Q3: 7.23 g of eugenol, 4.46 g of triethylamine and 80 mL of dichloromethane were added to a container, 5.57 g of dichlorodiphenylsilane was dissolved in 40 mL of dichloromethane and then added dropwise to the container, heated to reflux at 50°C for 4 h, filtered, washed with deionized water, dried with anhydrous magnesium sulfate, filtered, rotary evaporated, and dried to obtain product 3;

[0041] Q4: Add 0.5g of product 1, 0.125g of product 2 and 0.225g of product 3 into a container, add 0.012g of azobisisobutyronitrile, pass nitrogen, then add 4mL of N,N-dimethylformamide, heat to 85℃ for 12h, after the reaction is completed, add to anhydrous ethanol, dry at 40℃ for 12h to obtain an organosilicon modifier.

[0042] This embodiment discloses a method for preparing an organic curing agent, comprising the following steps:

[0043] S1: Add 1.058 g of 4,4'-diaminobiphenyl to a container containing 40 mL of glacial acetic acid, add 1.633 g of butyl methacrylate, stir for 6 h, heat at 85 °C in a dark environment for 5 h, then add 1.598 g of butyl methacrylate, and after the reaction is completed for 6 h, rotary evaporate to obtain a viscous fluid;

[0044] S2: 1.54 g of viscous fluid was ultrasonically dissolved in 10 mL of methanol to obtain a viscous fluid solution, 0.95 g of 1,4-cyclohexanediamine was added to 20 mL of methanol, and after stirring to dissolve, the solution was added to the viscous fluid solution. Under a nitrogen atmosphere, magnetic stirring was carried out at 40 °C in the dark for 24 h. After the reaction was completed, rotary evaporation was performed at 55 °C to obtain a crude product. The crude product was dissolved in methanol and precipitated with ether. The operation was repeated 6 times, and filtered to obtain an organic curing agent.

[0045] This embodiment discloses a method for preparing a low-density and high-strength glass fiber board cured by epoxy resin, comprising the following steps:

[0046] Step 1: Add 0.04 kg of organosilicon modifier to 1.25 kg of epoxy resin, stir and react for 5 hours to obtain modified epoxy resin;

[0047] Step 2: Add 2.5 kg of glass fiber to 4 kg of modified epoxy resin and soak for 6 hours. After soaking, take out to obtain modified glass fiber;

[0048] Step 3: Mix 1.5 kg of modified glass fiber with 0.08 kg of organic curing agent, stir, roll and dry to obtain a low-density and high-strength glass fiber board cured with epoxy resin.

[0049] Example 2: This example discloses a method for preparing an organosilicon modifier, comprising the following steps:

[0050] Q1: Add 6.08 g of 3-methoxy-4-hydroxybenzaldehyde to a container containing 60 mL of dichloromethane, stir to dissolve, add 5.2 mL of pyridine, introduce nitrogen after magnetic stirring, add 10 mL of dichloromethane and 4.7 mL of methacryloyl chloride to a constant pressure dropping funnel, and then add dropwise to the container. After the addition is completed, heat to react at 45°C for 5 hours. After the reaction is completed, rotary evaporate at 32°C, dissolve the solid with ethyl acetate, filter, wash with saturated sodium chloride and saturated sodium bicarbonate, dry with anhydrous magnesium sulfate, let stand for 30 minutes, filter to obtain a filtrate, rotary evaporate at 60°C, dissolve with anhydrous ethanol, filter, add to a container containing deionized water, recrystallize at 6°C for 12 hours, filter, and dry to obtain product 1;

[0051] Q2: 1 g of 4-(1,2,2-triphenylvinyl)phenol and 0.54 mL of triethylamine were added to a container, followed by 40 mL of dichloromethane. 0.35 mL of methacryloyl chloride was added dropwise in an ice-water bath under a nitrogen atmosphere. After stirring for 3 min, the mixture was reacted at room temperature for 4 h. After the reaction was completed, the mixture was washed with deionized water and saturated sodium chloride, rotary evaporated, concentrated, and dried to obtain product 2.

[0052] Q3: 6.57 g of eugenol, 4.05 g of triethylamine and 80 mL of dichloromethane were added to a container, 5.06 g of dichlorodiphenylsilane was dissolved in 40 mL of dichloromethane and then added dropwise to the container, heated to reflux at 50°C for 4 h, filtered, washed with deionized water, dried with anhydrous magnesium sulfate, filtered, rotary evaporated, and dried to obtain product 3;

[0053] Q4: Add 0.4g of product 1, 0.1g of product 2 and 0.2g of product 3 into a container, add 0.013g of azobisisobutyronitrile, pass nitrogen, then add 3mL of N,N-dimethylformamide, heat to 85℃ for 12h, after the reaction is completed, add to anhydrous ethanol, dry at 40℃ for 12h to obtain an organosilicon modifier.

[0054] This embodiment discloses a method for preparing an organic curing agent, comprising the following steps:

[0055] S1: Add 0.92 g of 4,4'-diaminobiphenyl to a container containing 40 mL of glacial acetic acid, add 1.42 g of butyl methacrylate, stir for 6 h, heat at 85 °C in a dark environment for 5 h, then add 1.42 g of butyl methacrylate, and after the reaction is completed for 6 h, rotary evaporate to obtain a viscous fluid;

[0056] S2: 1.39 g of viscous fluid was ultrasonically dissolved in 10 mL of methanol to obtain a viscous fluid solution, 0.91 g of 1,4-cyclohexanediamine was added to 20 mL of methanol, stirred to dissolve, and then added to the viscous fluid solution. Under a nitrogen atmosphere, magnetically stirred at 40 °C in the dark for 24 h. After the reaction was completed, rotary evaporation was performed at 55 °C to obtain a crude product. The crude product was dissolved in methanol and precipitated with ether. The operation was repeated 6 times, and filtered to obtain an organic curing agent.

[0057] This embodiment discloses a method for preparing a low-density and high-strength glass fiber board cured by epoxy resin, comprising the following steps:

[0058] Step 1: Add 0.05 kg of organosilicon modifier to 1.5 kg of epoxy resin, stir and react for 5 hours to obtain modified epoxy resin;

[0059] Step 2: Add 1 kg of glass fiber to 3 kg of modified epoxy resin and soak for 6 hours. After soaking, take out to obtain modified glass fiber;

[0060] Step 3: Mix 1 kg of modified glass fiber with 0.07 kg of organic curing agent, stir, roll and dry to obtain a low-density and high-strength glass fiber board cured with epoxy resin.

[0061] Example 3: This example discloses a method for preparing an organosilicon modifier, comprising the following steps:

[0062] Q1: Add 7.9 g of 3-methoxy-4-hydroxybenzaldehyde to a container containing 60 mL of dichloromethane, stir to dissolve, add 4 mL of pyridine, introduce nitrogen after magnetic stirring, add 10 mL of dichloromethane and 6.11 mL of methacryloyl chloride to a constant pressure dropping funnel, and then add dropwise to the container. After the addition is completed, heat to react at 45°C for 5 hours. After the reaction is completed, rotary evaporate at 32°C, dissolve the solid with ethyl acetate, filter, wash with saturated sodium chloride and saturated sodium bicarbonate, dry with anhydrous magnesium sulfate, let stand for 30 minutes, filter to obtain a filtrate, rotary evaporate at 60°C, dissolve with anhydrous ethanol, filter, add to a container containing deionized water, recrystallize at 6°C for 12 hours, filter, and dry to obtain product 1;

[0063] Q2: 1.5 g of 4-(1,2,2-triphenylvinyl)phenol and 0.81 mL of triethylamine were added to a container, followed by 60 mL of dichloromethane. 0.52 mL of methacryloyl chloride was added dropwise in an ice-water bath under a nitrogen atmosphere. After stirring for 3 min, the mixture was reacted at room temperature for 4 h. After the reaction was completed, the mixture was washed with deionized water and saturated sodium chloride, rotary evaporated, concentrated, and dried to obtain product 2.

[0064] Q3: 7.88 g of eugenol, 4.86 g of triethylamine and 80 mL of dichloromethane were added to a container, 6.07 g of dichlorodiphenylsilane was dissolved in 40 mL of dichloromethane and then added dropwise to the container, heated to reflux at 50°C for 4 h, filtered, washed with deionized water, dried with anhydrous magnesium sulfate, filtered, rotary evaporated, and dried to obtain product 3;

[0065] Q4: Add 0.6g of product 1, 0.15g of product 2 and 0.25g of product 3 into a container, add 0.014g of azobisisobutyronitrile, pass nitrogen, then add 5mL of N,N-dimethylformamide, heat to 85℃ for 12h, after the reaction is completed, add to anhydrous ethanol, dry at 40℃ for 12h to obtain an organosilicon modifier.

[0066] This embodiment discloses a method for preparing an organic curing agent, comprising the following steps:

[0067] S1: Add 1.196 g of 4,4'-diaminobiphenyl to a container containing 40 mL of glacial acetic acid, add 1.846 g of butyl methacrylate, stir for 6 h, heat at 85 °C in a dark environment for 5 h, then add 1.775 g of butyl methacrylate, and after the reaction is completed for 6 h, rotary evaporate to obtain a viscous fluid;

[0068] S2: Dissolve 1.7 g of viscous fluid with 10 mL of methanol by ultrasonic treatment to obtain a viscous fluid solution; add 1.05 g of 1,4-cyclohexanediamine to 20 mL of methanol, stir to dissolve, and then add to the viscous fluid solution; stir magnetically at 40 °C in the dark for 24 h under a nitrogen atmosphere; after the reaction is completed, perform rotary evaporation at 55 °C to obtain a crude product; dissolve the crude product in methanol, use ether for precipitation, repeat the operation 6 times, and filter to obtain an organic curing agent.

[0069] This embodiment discloses a method for preparing a low-density and high-strength glass fiber board cured by epoxy resin, comprising the following steps:

[0070] Step 1: Add 0.03 kg of organosilicon modifier to 1 kg of epoxy resin, stir and react for 5 hours to obtain modified epoxy resin;

[0071] Step 2: Add 4 kg of glass fiber to 5 kg of modified epoxy resin and soak for 6 hours. After soaking, take out to obtain modified glass fiber;

[0072] Step 3: Mix 2 kg of modified glass fiber with 0.09 kg of organic curing agent, stir, roll and dry to obtain a low-density and high-strength glass fiber board cured with epoxy resin.

[0073] Example 4: This example discloses a method for preparing an organosilicon modifier, comprising the following steps:

[0074] Q1: Add 6.54 g of 3-methoxy-4-hydroxybenzaldehyde to a container containing 60 mL of dichloromethane, stir to dissolve, add 4.8 mL of pyridine, introduce nitrogen after magnetic stirring, add 10 mL of dichloromethane and 5.1 mL of methacryloyl chloride to a constant pressure dropping funnel, and then add dropwise to the container. After the addition is completed, heat to react at 45°C for 5 hours. After the reaction is completed, rotary evaporate at 32°C, dissolve the solid with ethyl acetate, filter, wash with saturated sodium chloride and saturated sodium bicarbonate, dry with anhydrous magnesium sulfate, let stand for 30 minutes, filter to obtain a filtrate, rotary evaporate at 60°C, dissolve with anhydrous ethanol, filter, add to a container containing deionized water, recrystallize at 6°C for 12 hours, filter, and dry to obtain product 1;

[0075] Q2: 1.2 g of 4-(1,2,2-triphenylvinyl)phenol and 0.58 mL of triethylamine were added to a container, followed by 45 mL of dichloromethane. 0.37 mL of methacryloyl chloride was added dropwise in an ice-water bath under a nitrogen atmosphere. After stirring for 3 min, the mixture was reacted at room temperature for 4 h. After the reaction was completed, the mixture was washed with deionized water and saturated sodium chloride, rotary evaporated, concentrated, and dried to obtain product 2.

[0076] Q3: 6.9 g of eugenol, 4.25 g of triethylamine and 80 mL of dichloromethane were added to a container, 5.25 g of dichlorodiphenylsilane was dissolved in 40 mL of dichloromethane and then added dropwise to the container, heated to reflux at 50°C for 4 h, filtered, washed with deionized water, dried with anhydrous magnesium sulfate, filtered, rotary evaporated, and dried to obtain product 3;

[0077] Q4: Add 0.45g of product 1, 0.12g of product 2 and 0.21g of product 3 into a container, add 0.012g of azobisisobutyronitrile, pass nitrogen, then add 3.5mL of N,N-dimethylformamide, heat to 85℃ for 12h, after the reaction is completed, add to anhydrous ethanol, dry at 40℃ for 12h to obtain an organosilicon modifier.

[0078] This embodiment discloses a method for preparing an organic curing agent, comprising the following steps:

[0079] S1: Add 0.98 g of 4,4'-diaminobiphenyl to a container containing 40 mL of glacial acetic acid, add 1.57 g of butyl methacrylate, stir for 6 h, heat at 85 °C in a dark environment for 5 h, then add 1.48 g of butyl methacrylate, and after the reaction is completed for 6 h, rotary evaporate to obtain a viscous fluid;

[0080] S2: 1.48 g of viscous fluid was ultrasonically dissolved in 10 mL of methanol to obtain a viscous fluid solution, 0.92 g of 1,4-cyclohexanediamine was added to 20 mL of methanol, stirred to dissolve, and then added to the viscous fluid solution. Under a nitrogen atmosphere, magnetically stirred at 40 °C in the dark for 24 h. After the reaction was completed, rotary evaporated at 55 °C to obtain a crude product. The crude product was dissolved in methanol and precipitated with ether. The operation was repeated 6 times, and filtered to obtain an organic curing agent.

[0081] This embodiment discloses a method for preparing a low-density and high-strength glass fiber board cured by epoxy resin, comprising the following steps:

[0082] Step 1: Add 0.04 kg of organosilicon modifier to 1.1 kg of epoxy resin, stir and react for 5 hours to obtain modified epoxy resin;

[0083] Step 2: Add 2 kg of glass fiber to 3.5 kg of modified epoxy resin and soak for 6 hours. After soaking, take out to obtain modified glass fiber;

[0084] Step 3: Mix 1.2 kg of modified glass fiber with 0.075 kg of organic curing agent, stir, roll and dry to obtain a low-density and high-strength glass fiber board cured with epoxy resin.

[0085] Example 5: This example discloses a method for preparing an organosilicon modifier, comprising the following steps:

[0086] Q1: Add 7.45g of 3-methoxy-4-hydroxybenzaldehyde to a container containing 60mL of dichloromethane, stir to dissolve, add 5mL of pyridine, introduce nitrogen after magnetic stirring, add 10mL of dichloromethane and 5.83mL of methacryloyl chloride to a constant pressure dropping funnel, and then add dropwise to the container. After the addition is completed, heat to react at 45°C for 5h. After the reaction is completed, rotary evaporate at 32°C, dissolve the solid with ethyl acetate, filter, wash with saturated sodium chloride and saturated sodium bicarbonate, dry with anhydrous magnesium sulfate, let stand for 30min, filter to obtain a filtrate, rotary evaporate at 60°C, dissolve with anhydrous ethanol, filter, add to a container containing deionized water, recrystallize at 6°C for 12h, filter, and dry to obtain product 1;

[0087] Q2: 1.4 g 4-(1,2,2-triphenylvinyl)phenol and 0.73 mL triethylamine were added to a container, followed by 55 mL dichloromethane. 0.49 mL methacryloyl chloride was added dropwise in an ice-water bath under a nitrogen atmosphere. After stirring for 3 min, the mixture was reacted at room temperature for 4 h. After the reaction was completed, the mixture was washed with deionized water and saturated sodium chloride, rotary evaporated, concentrated, and dried to obtain product 2.

[0088] Q3: 7.55 g of eugenol, 4.62 g of triethylamine and 80 mL of dichloromethane were added to a container, 5.75 g of dichlorodiphenylsilane was dissolved in 40 mL of dichloromethane and then added dropwise to the container, heated to reflux at 50°C for 4 h, filtered, washed with deionized water, dried with anhydrous magnesium sulfate, filtered, rotary evaporated, and dried to obtain product 3;

[0089] Q4: Add 0.55g of product 1, 0.13g of product 2 and 0.24g of product 3 into a container, add 0.012g of azobisisobutyronitrile, pass nitrogen, then add 4.5mL of N,N-dimethylformamide, heat to 85℃ for 12h, after the reaction is completed, add to anhydrous ethanol, dry at 40℃ for 12h to obtain an organosilicon modifier.

[0090] This embodiment discloses a method for preparing an organic curing agent, comprising the following steps:

[0091] S1: Add 1.083 g of 4,4'-diaminobiphenyl to a container containing 40 mL of glacial acetic acid, add 1.73 g of butyl methacrylate, stir for 6 h, heat at 85 °C in a dark environment for 5 h, then add 1.63 g of butyl methacrylate, and after the reaction is completed for 6 h, rotary evaporate to obtain a viscous fluid;

[0092] S2: Dissolve 1.63 g of viscous fluid with 10 mL of methanol by ultrasonic treatment to obtain a viscous fluid solution; add 1.01 g of 1,4-cyclohexanediamine to 20 mL of methanol, stir to dissolve, and then add to the viscous fluid solution; stir magnetically at 40 °C in the dark for 24 h under a nitrogen atmosphere; after the reaction is completed, perform rotary evaporation at 55 °C to obtain a crude product; dissolve the crude product in methanol, use ether for precipitation, repeat the operation 6 times, and filter to obtain an organic curing agent.

[0093] This embodiment discloses a method for preparing a low-density and high-strength glass fiber board cured by epoxy resin, comprising the following steps:

[0094] Step 1: Add 0.03 kg of organosilicon modifier to 1.4 kg of epoxy resin, stir and react for 5 hours to obtain modified epoxy resin;

[0095] Step 2: Add 3 kg of glass fiber to 4.5 kg of modified epoxy resin and soak for 6 hours. After soaking, take out to obtain modified glass fiber;

[0096] Step 3: 1.7 kg of modified glass fiber is mixed with 0.085 kg of organic curing agent, stirred, rolled, and dried to obtain a low-density and high-strength glass fiber board cured with epoxy resin.

[0097] Comparative Example 1: Compared with Example 1, in the preparation process of the organosilicon modifier in Comparative Example 1, no dichlorodiphenylsilane is added, and other conditions remain unchanged.

[0098] Comparative Example 2: Compared with Example 1, in Comparative Example 2, during the preparation of the organic curing agent, butyl methacrylate was not added, and other conditions remained unchanged.

[0099] Comparative Example 3: Compared with Example 1, in the preparation process of the glass fiber board in Comparative Example 3, the silane coupling agent KH-550 is used instead of the organosilicon modifier, and other conditions remain unchanged.

[0100] Comparative Example 4: Compared with Example 1, in the preparation process of the glass fiber board in Comparative Example 4, ethylenediamine is used instead of the organic curing agent, and other conditions remain unchanged.

[0101] Experimental example: The tensile properties of the samples were tested according to GB / T 1040.1-2018, and the weather resistance of the samples was tested according to GB / T16422.1-2019. The tensile properties of the samples before and after the experiment were measured, and the tensile strength change rate = [(before the experiment-after the experiment) / before the experiment] × 100%. According to density = mass / volume, the density of the samples was tested. The test results are shown in Table 1:

[0102] Table 1

[0103]

[0104]

[0105] From the test results in Table 1, it can be seen that the glass fiber boards prepared in Examples 1-5 of the present invention have low density and excellent weather resistance and mechanical properties. From the comparison between Comparative Example 1 and Examples 1-5, it can be seen that the addition of dichlorodiphenylsilane can improve the weather resistance and mechanical properties of the glass fiber board; from the comparison between Comparative Example 2 and Examples 1-5, it can be seen that the addition of butyl methacrylate can improve the weather resistance and mechanical properties of the glass fiber board and can also reduce its density; from the comparison between Comparative Example 3 and Examples 1-5, it can be seen that the use of an organic silicon modifier can improve the weather resistance and mechanical properties of the glass fiber board; from the comparison between Comparative Example 4 and Examples 1-5, it can be seen that the use of an organic curing agent can improve the weather resistance and mechanical properties of the glass fiber board and can also reduce its density.

[0106] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0107] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a low-density and high-strength glass fiber board cured by epoxy resin, characterized in that: The following steps are involved: Step 1: adding an organosilicon modifier to an epoxy resin, stirring and reacting, and obtaining a modified epoxy resin; Step 2: adding the glass fiber into the modified epoxy resin for soaking, and after the soaking is completed, taking it out to obtain the modified glass fiber; Step 3: Mix the modified glass fiber and the organic curing agent, stir, roll and dry to obtain a low-density and high-strength glass fiber board cured with epoxy resin.

2. The method for preparing a low-density and high-strength glass fiber board cured by epoxy resin according to claim 1, characterized in that: In the step 1, the mass ratio of epoxy resin to silicone modifier is (1-1.5): (0.03-0.05), and the stirring reaction time is 3-5 hours; in the step 2, the mass ratio of glass fiber to modified epoxy resin is (1-4): (3-5), and the immersion time is 4-6 hours; in the step 3, the mass ratio of modified glass fiber to organic curing agent is (1-2): (0.07-0.09).

3. The method for preparing a low-density and high-strength glass fiber board cured by epoxy resin according to claim 1, characterized in that: The preparation method of the organosilicon modifier comprises the following steps: Q1: Add 3-methoxy-4-hydroxybenzaldehyde to a container containing dichloromethane, stir to dissolve, add pyridine, introduce nitrogen after magnetic stirring, add dichloromethane and methacryloyl chloride to a constant pressure dropping funnel, and then add dropwise to the container. After the addition is complete, heat to react. After the reaction is complete, perform rotary evaporation, dissolve the solid, filter, wash, dry, let stand and filter to obtain a filtrate, perform rotary evaporation, dissolve, filter, add to a container containing deionized water, recrystallize at low temperature, filter, and dry to obtain product 1; Q2: Add 4-(1,2,2-triphenylvinyl)phenol and triethylamine to a container, then add dichloromethane, add methacryloyl chloride dropwise in an ice-water bath under a nitrogen atmosphere, stir, react at room temperature, wash, rotary evaporate, concentrate, and dry to obtain product 2; Q3: Add eugenol, triethylamine and dichloromethane into a container, dissolve dichlorodiphenylsilane in dichloromethane and add the mixture dropwise into the container, heat under reflux and filter, wash, dry, filter, rotary evaporate and dry to obtain product 3; Q4: Add product 1, product 2 and product 3 into a container, add azobisisobutyronitrile, introduce nitrogen, then add N,N-dimethylformamide, heat to react, after the reaction is completed, add to anhydrous ethanol, dry, and obtain an organosilicon modifier.

4. The method for preparing a low-density and high-strength glass fiber board cured by epoxy resin according to claim 3, characterized in that: In the Q1, the amount ratio of 3-methoxy-4-hydroxybenzaldehyde, pyridine and methacryloyl chloride is (6.08-7.9) g: (4-5.2) mL: (4.7-6.11) mL, the heating reaction temperature is 40-50°C, the time is 5-7h, the rotary evaporation temperature is 30-32°C, the solid is dissolved with ethyl acetate, washed with saturated sodium chloride and saturated sodium bicarbonate, dried with anhydrous magnesium sulfate, and allowed to stand for 20-30 min, then rotary evaporated at 60-63°C, dissolved with anhydrous ethanol, the low-temperature recrystallization temperature is 3-6°C, and the recrystallization time is 10-12h.

5. The method for preparing a low-density and high-strength glass fiber board cured by epoxy resin according to claim 3, characterized in that: In Q2, the amount ratio of 4-(1,2,2-triphenylvinyl)phenol, triethylamine, dichloromethane and methacryloyl chloride is (1-1.5) g: (0.54-0.81) mL: (40-60) mL: (0.35-0.52) mL, the stirring time is 3-5 min, the reaction time at room temperature is 2-4 h, and the mixture is washed with deionized water and saturated sodium chloride. In Q3, the amount ratio of eugenol, triethylamine and dichlorodiphenylsilane is (6.57-7.88) g: (4.05-4.86)g: (5.06-6.07)g, heating reflux temperature is 40-50°C, reflux time is 3-4h, washed with deionized water, and dried with anhydrous magnesium sulfate.

6. The method for preparing a low-density and high-strength glass fiber board cured by epoxy resin according to claim 3, characterized in that: In Q4, product 1, product 2, product 3 、 The dosage ratio of azobisisobutyronitrile and N,N-dimethylformamide is (0.4-0.6) g: (0.1-0.15) g: (0.2-0.25) g: (0.012-0.014) g: (3-5) mL, the heating reaction temperature is 80-85°C, the reaction time is 10-12h, the drying temperature is 30-40°C, and the time is 10-12h.

7. The method for preparing a low-density and high-strength glass fiber board cured by epoxy resin according to claim 1, characterized in that: The preparation method of the organic curing agent comprises the following steps: S1: Add 4,4'-diaminobiphenyl to a container containing glacial acetic acid, add butyl methacrylate, stir, heat in the dark for reaction, then add butyl methacrylate, after the reaction is completed, perform rotary evaporation to obtain a viscous fluid; S2: Ultrasonic dissolve the viscous fluid with methanol to obtain a viscous fluid solution, take 1,4-cyclohexanediamine and add it to methanol, stir to dissolve, then add it to the viscous fluid solution, under a nitrogen atmosphere, magnetically stir in the dark, after the reaction is completed, rotary evaporate to obtain a crude product, dissolve the crude product in methanol, use ether for precipitation, repeat the operation, filter and obtain an organic curing agent.

8. The method for preparing a low-density and high-strength glass fiber board cured by epoxy resin according to claim 7, characterized in that: In S1, the molar ratio of 4,4'-diaminobiphenyl, butyl methacrylate added for the first time and butyl methacrylate added for the second time is (1-1.3):(2-2.6):(2-2.5), the stirring time is 4-6 hours, the light-proof heating reaction temperature is 80-85°C, the time is 3-5 hours, and the reaction time after adding butyl methacrylate is 4-6 hours.

9. The method for preparing a low-density and high-strength glass fiber board cured by epoxy resin according to claim 7, characterized in that: In S2, the molar ratio of the viscous fluid to 1,4-cyclohexanediamine is (1-1.2): (4-4.6), the light-proof magnetic stirring temperature is 35-40°C, the stirring time is 20-24h, the rotary evaporation temperature is 50-55°C, and the operation is repeated 4-6 times.

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