Preparation method of heat-resistant high-strength and high-toughness modified vinyl ester resin system

Abstract

The application discloses a preparation method of a heat-resistant high-strength and high-toughness modified vinyl ester resin system, and belongs to the technical field of thermosetting resin materials. The vinyl ester resin system is formed by mixing a tetra-functional compound containing dipropargyl and diallyl as a reactive modifier, a vinyl ester resin, a peroxide curing agent and an accelerator, and the vinyl ester resin system can obtain a cured product through heat curing. The modified vinyl ester resin system prepared by the method has the advantages of high heat resistance, high strength and high toughness, is suitable for manufacturing fiber-reinforced composite materials through various processes such as resin transfer molding (RTM), winding molding and prepreg lay-up molding, and is applied to engineering technical fields such as building, chemical industry and ocean industry.

Description

Technical Field

[0001] The present invention relates to a method for preparing a heat-resistant high-strength and high-toughness modified vinyl ester resin system, belonging to the field of thermosetting resin materials. Background Art

[0002] Vinyl ester resin is a compound containing multiple unsaturated double bonds, formed by the reaction of an unsaturated acid (such as methyl methacrylate and acrylic acid) with an oligomer with active sites (such as epoxy resin) in the presence of a phase transfer catalyst. This compound is mixed with a reactive diluent such as styrene or methacrylate to form a liquid resin. Also known as vinyl resin, it is a recognized corrosion-resistant resin. Vinyl ester resin is a thermosetting resin that combines the chemical resistance, excellent mechanical properties, and heat resistance of epoxy resin with the rapid curing characteristics of unsaturated polyester resin. It exhibits excellent chemical resistance, thermal stability, fatigue resistance, and mechanical properties. Its low viscosity makes it easy to process, and it wets well with reinforcing materials. It can be cured at room temperature or by heating. It is used to make fiber-reinforced composites and is widely used in the chemical, transportation, aerospace, marine, construction, and electronics industries. However, conventional vinyl ester resins currently suffer from inherent drawbacks such as low strength and brittleness, as well as poor high-temperature resistance.

[0003] As the application areas gradually expand, especially in many anti-corrosion projects, materials are often required to be able to operate normally at higher temperatures and have higher mechanical properties. This places higher demands on the strength, toughness and heat resistance of the composite matrix resin.

[0004] In terms of toughening vinyl ester resins, the most common methods are to add rubber as a second phase to the resin system for toughening (patent application 202011580204.9) and polyurethane toughened modified vinyl ester resin (patent application 201911206917.6). However, the introduction of nitrile rubber segments, although it will significantly improve the toughness of the resin, will reduce the strength and heat resistance of the material. When polyurethane grafting is used for toughening, multifunctional isocyanates react with hydroxyl groups in the vinyl ester resin during the reaction process, the viscosity of the system increases rapidly, the reaction is difficult to control, and the risk of gelation is extremely high, which is not conducive to the processing of resin-based composite materials. Therefore, it is necessary to develop a vinyl ester resin toughening method that can simultaneously improve heat resistance and strength and has good processability.

[0005] Propargyl terminated resin (PTR) is a high performance resin with aromatic groups in the main chain and propargyl ether at the end. g) can generally exceed 300°C and has excellent thermal stability in air and nitrogen. Furthermore, PTR has the advantages of easy synthesis, relatively low cost, low moisture absorption, low dielectric constant, and excellent adhesion, making it suitable for the manufacture of advanced resin-based composites. In addition to being used as a single resin system, PTR is more commonly used as a modifier, heat-resistantly modifying other resin systems to form high-performance resin systems. Ge et al. (Reactive and Functional Polymers. 2023, 186: 105570.) synthesized a novel bio-based allyl compound with an aromatic propargyl ether group using honokiol as a raw material, with the structure shown in formula (a). This compound was then copolymerized with 4,4'-bismaleimide diphenylmethane (BDM) to develop a novel high-performance bio-based resin. Compound (a) contains two allyl and two propargyl groups in its molecule, with the goal of forming a complex and dense cross-linked network after copolymerization with BDM, thereby improving the mechanical properties and heat resistance of the bismaleimide resin system. Studies have shown that this blended resin has higher thermal and mechanical properties than other bio-based allyl compound modified BDM. After curing, the resin has a glass transition temperature higher than 440°C, a storage modulus greater than 1.3GPa, a thermal decomposition temperature of approximately 448°C, and a flexural strength range of 106-117MPa.

[0006]

[0007] The above-mentioned method of modifying resins using compounds containing dipropargyl ether and diallyl groups is simple and effective, but the high cost of honokiol as a raw material hinders further application. The synthesis of compounds containing dipropargyl ether and tetrafunctional diallyl groups needs to be cost-effective, and they have not yet been applied to the modification of vinyl ester resins. Summary of the Invention

[0008] The present invention aims to overcome the technical deficiencies of existing vinyl ester resins, such as their insufficient mechanical properties and poor heat resistance, while simultaneously improving the mechanical and heat resistance of vinyl ester resins. The present invention provides a method for modifying a vinyl ester resin by blending a novel monomer containing a diallyl group as a modifier with the vinyl ester resin. The resulting modified blended resin exhibits ease of preparation, good processability, excellent thermal stability, and superior mechanical properties.

[0009] The present invention solves the above technical problems through the following technical solutions.

[0010] A method for preparing a heat-resistant high-strength and high-toughness modified vinyl ester resin, characterized in that the preparation method comprises the following steps:

[0011] (1) mixing a tetrafunctional compound containing a diallyl group and a diallyl group with a vinyl ester resin in a mass ratio of 1:1 to 1:5;

[0012] (2) simultaneously ultrasonically and mechanically stirring the mixture of step (1) at 25-30° C. to prepare a vinyl ester resin blend;

[0013] (3) adding 0.1% to 5% of the weight of the resin blend of a curing agent and 0.1% to 1% of an accelerator to the vinyl ester resin blend, stirring until homogeneous, and allowing to stand to remove bubbles;

[0014] (4) pouring the product obtained in step (3) into a mold coated with a release agent, and curing at 60 to 250° C. to obtain the modified vinyl ester resin system;

[0015] Wherein: the vinyl ester resin in step (1) is a bisphenol A epoxy vinyl ester resin or a novolac epoxy vinyl ester resin, having an acid value lower than 10 mgKOH / g and a room temperature viscosity lower than 800 mPa s;

[0016] The tetrafunctional compound containing a dipropargyl group and a diallyl group in step (1) is diallyl bisphenol A dipropargyl ether, and its structural formula is shown in Formula I:

[0017] Formula I

[0018]

[0019] The curing agent used in step (3) is one or a mixture of more than one selected from methyl ethyl ketone peroxide, acetylacetone peroxide, cyclohexanone peroxide, benzoyl peroxide, dilauroyl peroxide, tert-butyl perbenzoate, dibenzoyl peroxide and tert-butyl hydroperoxide;

[0020] The accelerator used in step (3) is one or a mixture of more than one selected from the group consisting of cobalt isooctanoate, cobalt naphthenate, dicyclopentadiene cobalt, dicyclopentadiene nickel, nickel acetylacetonate, dimethylaniline and diethylaniline.

[0021] Preferably, the vinyl ester resin in step (1) is a phenolic epoxy vinyl ester resin.

[0022] Preferably, the ultrasound in step (2) is carried out in an ultrasonic water bath, with a stirring speed of 250 rpm and a stirring time of 10 to 15 minutes.

[0023] Preferably, the curing agent in step (3) is methyl ethyl ketone peroxide or tert-butyl perbenzoate, and the amount used is 0.5%-2% of the weight of the vinyl ester resin blend; the accelerator is cobalt isooctanoate or cobalt cyclohexaneate, and the amount used is 0.5% of the weight of the vinyl ester resin blend.

[0024] Preferably, in step (3), the temperature for adding the curing agent and accelerator into the blended resin is 30-50° C., the stirring time is 10-20 min, and the standing time is 10-20 min.

[0025] Preferably, the stirring time in step (3) is 10 min and the standing time is 15 min.

[0026] Preferably, the curing method in step (4) is preferably step curing, which is carried out according to the following steps: keeping warm at 60-80℃ for 2-4h, keeping warm at 100-200℃ for 1-2h, and keeping warm at 200-250℃ for 3-5h. After curing, the obtained product is naturally cooled to 25-30℃.

[0027] The tetrafunctional compound containing a dipropargyl group and a diallyl group shown in Formula I can be prepared via a one-pot reaction. Diallyl bisphenol A dipropargyl ether is prepared by reacting diallyl bisphenol A with 3-halo-1-propyne (propargyl halide) using a phase transfer catalyst. Diallyl bisphenol A and the phase transfer catalyst tetrabutylammonium bromide are added to an alkaline aqueous solution, stirred uniformly, and then propargyl bromide is added. The reaction is carried out at 70-90°C for a predetermined time. The oil phase is separated, washed with water, dried, filtered, and then the solvent is removed by vacuum distillation to obtain diallyl bisphenol A dipropargyl ether.

[0028] The reagents and raw materials used in the present invention are commercially available.

[0029] Beneficial effects

[0030] The positive effects of the present invention are as follows: (1) The diallyl bisphenol A dipropargyl ether used is prepared in a one-pot process, which is simple, low-cost, and suitable for mass production. (2) The method of using diallyl bisphenol A dipropargyl ether to modify a vinyl ester resin proposed in the present invention is the first to be proposed and is innovative. (3) The resulting modified vinyl ester resin has low viscosity, is stable, and has good processing properties. (4) The cured modified vinyl ester resin has both high heat resistance and mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The hydrogen nuclear magnetic resonance spectrum of diallyl bisphenol A dipropargyl ether ( 1 H NMR) spectrum.

[0032] Figure 2 The differential scanning calorimetry (DSC) spectra of the vinyl ester resin blends of Examples 1-4 after adding a curing agent and an accelerator are shown.

[0033] Figure 3 The dynamic thermodynamic analysis (DMA) curves of the modified vinyl ester resin system of Example 1 and the cured resin of Comparative Example 1 are shown.

[0034] Figure 4 The thermogravimetric analysis (TGA) curves of the modified vinyl ester resin system prepared in Example 1 and the cured vinyl ester resin of Comparative Example 1 are shown.

[0035] FIG5(a) and FIG5(b) are scanning electron microscope (SEM) images of the impact cross-section of the modified vinyl ester resin system prepared in Example 1 and the cured vinyl ester resin of Comparative Example 1. Specific implementation methods

[0036] In order to more clearly and completely illustrate the technical solution and advantages of the present invention, the technical solution of the present invention is described in detail below through examples. The described embodiments are only part of the embodiments of the present invention and are only used for illustration, and are not intended to limit the scope of the present invention.

[0037] The diallyl bisphenol A dipropargyl ether in the examples of the present invention is a tetrafunctional compound containing a dipropargyl group and a diallyl group. Its synthesis is different from the method reported in the literature (Reactive and Functional Polymers.2023,186:105570.). It is prepared by reacting allyl bisphenol A (DABPA) with a propargyl halide in an aqueous phase system via phase transfer catalysis. It does not use a large amount of organic solvents and is environmentally friendly. The propargyl halide is propargyl bromide or propargyl chloride, and the phase transfer catalyst is tetrabutylammonium bromide or benzyltriethylammonium chloride.

[0038] In the present invention, diallyl bisphenol A dipropargyl ether (BAPPP) was synthesized according to the above method. Specifically, 30.84 g (0.1 mol) of DABPA, 6.45 g (0.02 mol) of tetrabutylammonium bromide, 20 g of NaOH (0.5 mol), and 200 mL of deionized water were added sequentially to a 500 mL four-necked flask. The DABPA was completely dissolved at room temperature by vigorous mechanical stirring. 26.17 g (0.22 mol) of 3-bromopropyne was dissolved in toluene and added dropwise to the system over 30 minutes. The reaction was then continued at 80°C overnight. After the reaction was completed, the upper oil phase was separated and washed with alkaline water until neutral. The organic phase was dried over anhydrous sodium sulfate, filtered, and then the solvent was removed by rotary evaporation. The residual volatiles were then dried in a vacuum oven at 100°C for 1 hour to obtain 33.72 g of a dark yellow liquid product with a yield of 87.2%.

[0039] The above product BAPPP hydrogen nuclear magnetic resonance spectrometer ( 1 H NMR was performed using a Bruker AVANCE III 400 superconducting Fourier transform nuclear magnetic resonance spectrometer with an operating frequency of 400 MHz, deuterated DMSO as the solvent, and TMS as the internal standard.

[0040] The phenolic epoxy vinyl ester resin used in the examples and comparative examples of the present invention can be purchased commercially and used directly without further treatment, such as MFE 780 vinyl ester resin produced by Huachang Polymer Co., Ltd. of East China University of Science and Technology.

[0041] The carbon fiber material used in the present invention is T300 carbon fiber plain weave cloth (200g / m 2 ) and used directly without further processing.

[0042] Other reagents used in the examples of the present invention were purchased from commercially available chemically pure reagents and used directly without further treatment.

[0043] The step-wise temperature rise program for thermal curing of the modified vinyl ester resin in the examples of the present invention is determined based on the curing exothermic curve of the modified resin after blending obtained by differential scanning calorimetry (DSC). The specific curing process is related to the mass fraction of the raw materials used in the resin.

[0044] In the following examples and comparative examples:

[0045] The curing behavior of the resin was characterized by DSC. The test instrument was an American TA Q2000 differential scanning calorimeter. The test was carried out in a nitrogen atmosphere with a gas flow rate of 50 mL / min, a heating rate of 10°C / min, and a temperature range of room temperature to 300°C.

[0046] The thermal stability of the cured vinyl ester resin was tested by TGA on a TGA-DSC 1 from Mettler-Toledo with a heating rate of 10°C / min and a nitrogen flow rate of 60 mL / min.

[0047] The glass transition temperatures of the modified vinyl ester resin system and the cured vinyl ester resin of the comparative example were tested using DMA on a Mettler-Toledo DMA-1 at a frequency of 1 Hz and a heating rate of 5°C / min.

[0048] Impact testing of the modified vinyl ester resin system and the comparative example vinyl ester resin cured product was conducted using a 9050 impact tester from CEAST (Italy) in accordance with ISO 180, "Plastics — Determination of impact strength." Impact cross-sections were analyzed using a Hitachi S-3400 field-emission scanning electron microscope (SEM).

[0049] The bending properties of the modified vinyl ester resin system and the comparative example vinyl ester resin cured product were tested with reference to the standard GB / T 2567-2021 "Test method for properties of resin castings" and were tested using a Shenzhen Sansi CMT5504 electronic universal testing machine.

[0050] The room-temperature and elevated-temperature flexural properties and interlaminar shear strength of the modified vinyl ester resin system and the comparative example vinyl ester resin cured products were tested using a CCSS-44100 electronic universal testing machine from the Changchun Institute of Mechanical Science Co., Ltd. The elevated-temperature flexural test was conducted after maintaining the specimens at 200°C for 10 minutes.

[0051] Example 1

[0052] 80 g of vinyl ester resin and 20 g of BAPPP were added to a 250 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, and ultrasonically stirred at room temperature for 15 min to form a uniform blended resin BPV-1.

[0053] 1g of tert-butyl perbenzoate and 0.5g of cobalt isooctanoate were added to 100g of BPV-1 blended resin, and the mixture was stirred thoroughly at room temperature until uniform. The resin was subjected to DSC analysis. The results were as follows: Figure 2 The resin was then poured into a mold coated with a release agent and preheated at 100°C for 10 minutes. The mold was then cured in a high-temperature oven at 60°C / 1 hour, 80°C / 1 hour, 120°C / 1 hour, 200°C / 1 hour, and 250°C / 0.5 hour. After curing, the mixture was naturally cooled to room temperature to obtain the cured product of the blended resin BPV-1, namely, modified vinyl ester resin system 1.

[0054] The test results of mechanical properties and thermal stability of the modified vinyl ester resin cured product obtained in Example 1 are shown in Table 1.

[0055] Example 2

[0056] 75 g of vinyl ester resin and 25 g of BAPPP were added to a 250 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, and ultrasonically stirred at room temperature for 15 min to form a uniform blended resin BPV-2.

[0057] 1g of tert-butyl perbenzoate and 0.5g of cobalt isooctanoate were added to 100g of BPV-2 blended resin, and the mixture was stirred thoroughly at room temperature until uniform. The resin was subjected to DSC analysis. The results were as follows: Figure 2 The resin was then poured into a mold coated with a release agent and preheated at 100°C for 10 minutes. The mold was then cured in a high-temperature oven at 60°C / 1 hour, 80°C / 1 hour, 120°C / 1 hour, 200°C / 1 hour, and 250°C / 0.5 hour. After curing, the mixture was naturally cooled to room temperature to obtain the cured product of the blended resin BPV-2, namely, modified vinyl ester resin system 2.

[0058] The test results of mechanical properties and thermal stability of the modified vinyl ester resin cured product obtained in Example 2 are shown in Table 1.

[0059] Example 3

[0060] 70 g of vinyl ester resin and 30 g of BAPPP were added to a 250 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, and ultrasonically stirred at room temperature for 15 min to form a uniform blended resin BPV-3.

[0061] 1g of tert-butyl perbenzoate and 0.5g of cobalt isooctanoate were added to 100g of BPV-3 blended resin, and the mixture was stirred thoroughly at room temperature until uniform. The resin was subjected to DSC analysis. The results were as follows: Figure 2 The resin was then poured into a mold coated with a release agent and preheated at 100°C for 10 minutes. The mold was then placed in a high-temperature oven and cured at 60°C / 1 hour, 80°C / 1 hour, 120°C / 1 hour, 200°C / 1 hour, and 250°C / 0.5 hour. After curing, the mixture was naturally cooled to room temperature to obtain the cured product of the blended resin BPV-3, namely, modified vinyl ester resin system 3.

[0062] The test results of mechanical properties and thermal stability of the modified vinyl ester resin cured product obtained in Example 3 are shown in Table 1.

[0063] Example 4

[0064] 75 g of vinyl ester resin and 25 g of BAPPP were added to a 250 mL three-necked flask equipped with a mechanical stirrer and a reflux condenser, and stirred at room temperature for 15 min to form a uniform blended resin BPV-2.

[0065] Add 1.5g of methyl ethyl ketone peroxide and 0.5g of cobalt naphthenate to 100g of BPV-2 blended resin, stir thoroughly at room temperature until uniform, and perform DSC analysis on the resin. The results are as follows: Figure 2 The resin was then poured into a mold coated with a release agent and preheated at 100°C for 10 minutes. The mold was then placed in a high-temperature oven and cured at 60°C / 1 hour, 80°C / 1 hour, 120°C / 1 hour, 200°C / 1 hour, and 250°C / 0.5 hour. After curing, the mixture was naturally cooled to room temperature to obtain the cured product of the blended resin BPV-4, the modified vinyl ester resin system 4.

[0066] The test results of mechanical properties and thermal stability of the modified vinyl ester resin cured product obtained in Example 4 are shown in Table 1.

[0067] Comparative Example 1

[0068] To compare the performance advantages of the modified vinyl ester resins obtained in Examples 1-4 above, a comparative example was designed, which was a commercially available vinyl ester resin without the addition of BPAPP for modification.

[0069] To 100 g of the vinyl ester resin was added 1 g of t-butyl peroxybenzoate and 0.5 g of cobalt isooctoate, and the mixture was stirred at room temperature until uniform. Then, the mixture was poured into a mold coated with a release agent and preheated at 100°C for 20 min, and the mixture was allowed to pre-cure at room temperature for 24 h, and then cured in a high-temperature oven according to the process of 60°C / 1 h + 80°C / 1 h + 140°C / 1 h. After the curing was completed, the mixture was naturally cooled to room temperature to obtain a cured vinyl ester resin.

[0070] The test results of the mechanical properties and thermal stability of the cured vinyl ester resin obtained in Comparative Example 1 are shown in Table 1.

[0071] Table 1 Performance results of the cured modified vinyl ester resins of Examples 1-4 and the cured vinyl ester resin of Comparative Example 1.

[0072]

[0073] As can be seen from Table 1, the modified vinyl ester resins of Examples 1-4 have better bending properties and higher thermal stability than the unmodified vinyl ester resin, and have excellent comprehensive performance, and in particular, the impact strength of the modified resins is higher than that of the unmodified resin of Comparative Example 1, which indicates that BPAPP has the effect of toughening the vinyl ester resin. As shown in Figure 5, the impact fracture surface of the vinyl ester resin is relatively smooth, and the impact fracture surface of the modified resin is very rough, and complex fracture lines appear, which is a typical characteristic of a ductile fracture surface. The above shows that the modified vinyl ester resin has advantages in mechanical properties and thermal stability.

[0074] Further, the T300 carbon fiber composite material prepared from the modified resin further shows the advantage of heat resistance.

[0075] Example 5

[0076] A T300 carbon fiber composite material was prepared using the BPV-3 resin of Example 3 above.

[0077] After adding 1g of tert-butyl peroxybenzoate and 0.5g of cobalt isooctanoate to 100g of BPV-3 resin, the mixture was thoroughly stirred and ultrasonically applied for 15 minutes to form a uniform, transparent adhesive. An appropriate amount of the adhesive was evenly applied to each layer of T300 carbon cloth (200mm×150mm) over 30 minutes. Twelve layers of carbon cloth were stacked one on top of the other and placed in a metal mold. A T300 carbon fiber-reinforced modified vinyl ester resin composite (T300CF / BAPPP / VER) was produced at 3MPa using a heating program of 60°C / 1h + 80°C / 1h + 120°C / 1h + 200°C / 1h + 250°C / 30min. After hot pressing, the composite panels were cut into the required test dimensions according to standard standards.

[0078] The mechanical property test results of the T300 carbon fiber reinforced modified vinyl ester resin composite material obtained in Example 5 are shown in Table 2.

[0079] Comparative Example 2

[0080] Comparative Example 2 is a T300 carbon fiber composite material prepared from a commercially available vinyl ester resin without the addition of BAPPP.

[0081] To 100g of vinyl ester resin, add 1g of tert-butyl perbenzoate and 0.5g of cobalt isooctanoate and stir thoroughly at room temperature until uniform. An appropriate amount of adhesive is evenly applied to each layer of T300 carbon cloth (200mm x 150mm) over 30 minutes. Twelve layers of carbon cloth are stacked one on top of the other and placed in a metal mold. At 3MPa, a heating program of 60°C / 1h, 80°C / 1h, and 120°C / 1h is used to produce a T300 carbon fiber reinforced vinyl ester resin composite (T300CF / VER). After hot pressing, the composite panels are cut into the required test dimensions according to standards.

[0082] The mechanical property test results of the T300 carbon fiber reinforced vinyl ester resin composite material obtained in Comparative Example 2 are shown in Table 2.

[0083] Table 2 Performance results of the modified vinyl ester resin composite material of Example 5 and the vinyl ester resin composite material of Comparative Example 2.

[0084]

[0085] Table 2 shows that the modified vinyl ester resin composite material of Example 5 has better mechanical properties than the unmodified vinyl ester resin composite material, and has higher mechanical properties at a high temperature of 200° C. This demonstrates the superiority of the heat-resistant high-strength and high-toughness vinyl ester resin described herein.

[0086] The above merely describes preferred embodiments of the present application, and does not limit the present application in any form. Any skilled person in the art can make some changes or modifications to the above-mentioned technical content as equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application, without departing from the technical solution of the present application, still belongs to the scope of the present application.

Claims

1. A method for preparing a heat-resistant high-strength and high-toughness modified vinyl ester resin system, characterized in that: The preparation method comprises the following steps: (1) mixing a tetrafunctional compound containing a dipropargyl group and a diallyl group with a vinyl ester resin in a mass ratio of 1:1 to 1:5; (2) simultaneously ultrasonically and mechanically stirring the mixture of step (1) at 25-30° C. to prepare a vinyl ester resin blend; (3) adding 0.1%-5% of the weight of the resin blend of a curing agent and 0.1%-1% of an accelerator to the vinyl ester resin blend, stirring until homogeneous, and standing to remove bubbles; (4) pouring the product obtained in step (3) into a mold coated with a release agent, and curing at 60-250° C. to obtain the modified vinyl ester resin system; Wherein: the vinyl ester resin in step (1) is a bisphenol A epoxy vinyl ester resin or a novolac epoxy vinyl ester resin, having an acid value lower than 10 mgKOH / g and a room temperature viscosity lower than 800 mPas; The tetrafunctional compound containing a dipropargyl group and a diallyl group in step (1) is diallyl bisphenol A dipropargyl ether, and its structural formula is shown in Formula I: Formula I ； The curing agent used in step (3) is one or a mixture of two or more selected from methyl ethyl ketone peroxide, acetylacetone peroxide, cyclohexanone peroxide, benzoyl peroxide, dilauroyl peroxide, tert-butyl perbenzoate, dibenzoyl peroxide and tert-butyl hydroperoxide; The accelerator used in step (3) is one or a mixture of two or more selected from the group consisting of cobalt isooctanoate, cobalt naphthenate, dicyclopentadiene cobalt, dicyclopentadiene nickel, nickel acetylacetonate, dimethylaniline and diethylaniline.

2. The method for preparing the modified vinyl ester resin system according to claim 1, wherein The vinyl ester resin in step (1) is a phenolic epoxy vinyl ester resin.

3. The method for preparing the modified vinyl ester resin system according to claim 1, wherein The ultrasound in step (2) is carried out in an ultrasonic water bath with a stirring speed of 250 rpm for 10 to 15 minutes.

4. The method for preparing the modified vinyl ester resin system according to claim 1, wherein The curing agent in step (3) is methyl ethyl ketone peroxide or tert-butyl perbenzoate, and the amount used is 0.5%-2% of the weight of the vinyl ester resin blend; the accelerator is cobalt isooctanoate or cobalt cyclohexaneate, and the amount used is 0.5% of the weight of the vinyl ester resin blend.

5. The method for preparing the modified vinyl ester resin system according to claim 1, wherein: In step (3), the curing agent and accelerator are added to the blended resin at a temperature of 30-50°C, the stirring time is 10-20 minutes, and the standing time is 10-20 minutes.

6. The method for preparing the modified vinyl ester resin system according to claim 5, wherein: The stirring time in step (3) is 10 min and the standing time is 15 min.

7. The method for preparing the modified vinyl ester resin system according to claim 1, wherein: The curing method in step (4) is step curing, which is carried out according to the following steps: keeping warm at 60-80 °C for 2-4 h, keeping warm at 100-200 °C for 1-2 h, and keeping warm at 200-250 °C for 3-5 h. After curing, the obtained product is naturally cooled to 25-30 °C.

Images