Marine epoxy resin composite material and preparation method thereof

Abstract

The invention relates to a marine epoxy resin composite material. The marine epoxy resin composite material is characterized by comprising the following components in parts by mass: 100 parts of epoxy resin, 20-30 parts of a curing agent, 100-120 parts of a reinforcing material, 2050 parts of hollow microsphere filler and 5-15 parts of a flame retardant, the epoxy resin is one or a mixture of two of bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyphenol type glycidyl ether epoxy resin or aliphatic glycidyl ether epoxy resin. When in use, the marine epoxy resin composite material disclosed by the invention has the advantages of excellent comprehensive performance, corrosion resistance, flame retardance, water resistance, high strength, light weight and the like, still has excellent performance retention rate after being soaked in water for several days, and is more suitable for complex and severe working conditions on a ship.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, in particular to a marine epoxy resin composite material and a preparation method thereof. Background Art

[0002] In the existing technology, epoxy resin (EP) has been widely used in structural fields such as hulls, decks, cabins, rudders, and oars due to its high strength, light weight, corrosion resistance, insulation, and flexible and convenient molding process. According to the International Convention for the Safety of People at Sea (SOLAS Convention), composite materials used in ships must meet certain flame retardant requirements. The limiting oxygen index (LOI) of epoxy resin is about 20%. It is flammable in air and will also produce molten droplets. The potential fire hazard limits its application in fields with high flame retardant requirements. Therefore, it is of great significance to develop environmentally friendly, highly flame retardant, and multifunctional flame retardant EP.

[0003] Halogen flame retardants commonly used in epoxy resins release toxic gases during combustion, causing significant environmental pollution. Halogen-free flame retardants, such as nitrogen-, phosphorus-, and silicon-based flame retardants, and metal hydroxide flame retardants, are generally less compatible with resins and require large addition amounts, significantly reducing the mechanical properties of epoxy resins. Furthermore, water resistance must be considered when using resin-based composites in ship structures. The mechanical properties of resin-based composites deteriorate significantly after being soaked in water, especially after the addition of commonly used flame retardants, which introduce a large number of hydroxyl groups, further increasing the composite's water absorption rate and causing the material to become brittle.

[0004] Therefore, the market is in urgent need of a new marine epoxy composite material with good water resistance and excellent flame retardant properties. Summary of the Invention

[0005] The purpose of the present invention is to provide an improved marine epoxy resin composite material and a preparation method thereof. Through the improvement of the formula and process, the prepared composite material has the characteristics of good water resistance, excellent flame retardancy and excellent mechanical strength.

[0006] In order to achieve the above-mentioned object, the technical solution of the present invention is: a marine epoxy resin composite material, characterized in that: the marine epoxy resin composite material comprises the following components in parts by mass: 100 parts of epoxy resin, 20-30 parts of curing agent, 100-120 parts of reinforcing material, 2050 parts of hollow microsphere filler, and 5-15 parts of flame retardant; the epoxy resin is one or a mixture of two of bisphenol A epoxy resin, bisphenol F epoxy resin, polyphenol glycidyl ether epoxy resin or aliphatic glycidyl ether epoxy resin.

[0007] Preferably, the flame retardant is a nitrogen-phosphorus-silicon synergistic flame retardant, and its preparation method is as follows: the first step is to dissolve 1 mol of cyanuric chloride in 50 ml of tetrahydrofuran, cool to 0°C in an ice bath, slowly add 3 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, react for 12 hours, remove tetrahydrofuran by rotary evaporation, and recrystallize from ethanol to obtain a white solid triazine-tri-DOPO; then dissolve 1 mol of triazine-tri-DOPO and 3 mol of epichlorohydrin in 30 ml of acetonitrile, add 0.2 mol of tetrabutylammonium bromide, heat to 60°C and react for 12 hours, finally wash the reaction solution with water to remove unreacted epichlorohydrin, dry the organic phase with anhydrous sodium sulfate, and obtain a DOPO derivative after rotary evaporation; the second step is to mix 1 mol of octaaminophenylpropyl POSS with 8 mol of octaaminophenylpropyl POSS. The DOPO derivative was dissolved in 60 ml of N,N-dimethylformamide, and 0.1 mol of p-toluenesulfonic acid was added. The mixture was heated to 80°C under nitrogen for 24 hours. After the reaction, the mixture was added dropwise to 500 ml of diethyl ether for precipitation. The solid was collected by centrifugation and then washed three times with a mixture of DMF and diethyl ether. Finally, it was dried under vacuum to obtain a nitrogen-phosphorus-silicon synergistic flame retardant.

[0008] Furthermore, the curing agent is hexamethylenetetramine.

[0009] Furthermore, the reinforcing material is any one of glass fiber, basalt fiber, fiber mesh cloth and fiber felt processed from carbon fiber.

[0010] Furthermore, the hollow microsphere filler includes any one or more of glass microspheres, silica hollow microspheres, titanium dioxide hollow microspheres, and polymer hollow microspheres.

[0011] A method for preparing a marine epoxy resin composite material, characterized in that the preparation method comprises the following steps: S1, mixing the epoxy resin and the curing agent, and stirring until clear and transparent to obtain a resin solution; S2, adding the hollow microsphere filler and the flame retardant to the resin solution and stirring evenly to obtain a modified resin solution; S3, evenly coating the modified resin solution on the fiber cloth made of the reinforcing fiber to obtain a prepreg; S4, cutting the prepreg into specified sizes and laying the prepreg layer by layer on a mold; S5, placing the mold on a press, heating it to a temperature of 90-100°C, curing it for 2-5 hours, taking it out and cooling it, to obtain the epoxy resin composite material.

[0012] Compared with the prior art, the technical solution of the present invention not only improves the overall technical solution, but also includes many improvements in details. Specifically, it has the following beneficial effects: 1. The improved solution of the present invention comprises an epoxy resin composite material for marine use, comprising 100 parts of epoxy resin, 20-30 parts of curing agent, 100-120 parts of reinforcing material, 2050 parts of hollow microsphere filler, and 5-15 parts of flame retardant. The composite material has the characteristics of good water resistance, excellent flame retardancy, and excellent mechanical strength. 2. The marine epoxy resin composite material of the present invention has excellent comprehensive performance, and has the advantages of corrosion resistance, flame retardancy, water resistance, high strength, and light weight. It still has excellent performance retention rate after being immersed in water for several days, and is more suitable for complex and harsh working conditions on board ships; 3. The marine epoxy resin composite material of the present invention has a simple structure, a convenient manufacturing process, a low cost, and is easy to operate and promote. DETAILED DESCRIPTION

[0013] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0014] The present invention provides a marine epoxy resin composite material, which differs from the prior art in that: the marine epoxy resin composite material comprises the following components in parts by mass: 100 parts of epoxy resin, 20-30 parts of curing agent, 100-120 parts of reinforcing material, 2050 parts of hollow microsphere filler, and 5-15 parts of flame retardant; the epoxy resin is one of bisphenol A epoxy resin, bisphenol F epoxy resin, polyphenol glycidyl ether epoxy resin, or aliphatic glycidyl ether epoxy resin, or a mixture of two of the two.

[0015] Specifically, the flame retardant is a nitrogen-phosphorus-silicon synergistic flame retardant, and its preparation method is as follows: the flame retardant is a nitrogen-phosphorus-silicon synergistic flame retardant, and its preparation method is as follows: 5 mol of octaaminophenylpropyl POSS, 90 mmol of paraformaldehyde and 90 mmol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) are placed in a three-necked flask, 80 mL of chloroform is added thereto, the temperature is set to 60°C, and the reaction is stirred under nitrogen for 24 hours; the reaction solution is taken and 5-15% of the solvent is evaporated in a 40°C water bath, and then it is added to an ice methanol solution for precipitation to obtain a yellow solid; the yellow solid is dissolved, centrifuged and washed with chloroform at least three times, and placed in a 60°C oven for vacuum drying for 24 hours to finally obtain a nitrogen-phosphorus-silicon synergistic flame retardant.

[0016] Another preparation method of nitrogen-phosphorus-silicon synergistic flame retardant is as follows: In the first step, 1 mol of cyanuric chloride was dissolved in 50 ml of tetrahydrofuran (THF), cooled to 0°C in an ice bath, and 3 mol of DOPO was slowly added dropwise. After reacting for 12 hours, the THF was removed by rotary evaporation and recrystallized from ethanol to obtain a white solid triazine-tris-DOPO (Tri-DOPO-Triazine intermediate). 1 mol of Tri-DOPO-Triazine and 3 mol of epichlorohydrin were dissolved in 30 ml of acetonitrile, 0.2 mol of tetrabutylammonium bromide (TBAB) was added, and the mixture was heated to 60°C and reacted for 12 hours. Finally, the reaction solution was washed with water to remove unreacted epichlorohydrin. The organic phase was dried over anhydrous sodium sulfate and rotary evaporated to obtain DOPO-Triazine-Epoxy (DOPO derivative). In the second step, 1 mol of octaaminophenylpropyl POSS (OctaNAPA-POSS) and 8 mol of DOPO-Triazine-Epoxy were dissolved in 60 ml of N,N-dimethylformamide (DMF). 0.1 mol of p-toluenesulfonic acid (PTSA) was added and the mixture was heated to 80°C for 24 hours under nitrogen. After the reaction, the mixture was added dropwise to 500 ml of diethyl ether for precipitation. The solid was collected by centrifugation and then washed three times with a mixture of DMF and diethyl ether (DMF:diethyl ether in a 1:5 ratio by weight). Finally, the mixture was vacuum-dried to obtain a nitrogen-phosphorus-silicon synergistic flame retardant (DOPO-Triazine@POSS). This flame retardant, obtained in this manner, has better performance in applications. Combining the flame-retardant properties of nitrogen, phosphorus, and silicon, it forms a stable protective layer during combustion, effectively inhibiting the spread of flames while reducing the generation of smoke and toxic gases. It exhibits high thermal stability and durability.

[0017] Example 1 The epoxy resin composite material in this embodiment has the following formula: 100 parts of bisphenol A epoxy resin, 30 parts of hexamethylenetetramine as a curing agent, 20 parts of glass microspheres, 5 parts of a flame retardant (OctaDOPO-POSS), and 100 parts of glass fiber cloth.

[0018] The preparation process of the composite material is as follows: S1, mixing the epoxy resin and curing agent, and stirring until clear and transparent to obtain a resin solution; S2, adding the inorganic filler and flame retardant to the resin solution and stirring evenly to obtain a modified resin solution; S3, uniformly coating the modified resin solution on the fiber cloth made of the reinforcing fibers to obtain a prepreg; S4, cutting the prepreg into specified sizes and laying the prepreg layer by layer on the mold; S5, placing the mold on a press, setting the temperature to 100 °C, curing for 2 h, taking it out and cooling it, and then obtaining an epoxy resin composite material.

[0019] In this embodiment, The flame retardant is a nitrogen-phosphorus-silicon synergistic flame retardant, and its preparation method is as follows: In the first step, 1 mol of cyanuric chloride was dissolved in 50 ml of tetrahydrofuran (THF), cooled to 0°C in an ice bath, and 3 mol of DOPO was slowly added dropwise. After reacting for 12 hours, the THF was removed by rotary evaporation and recrystallized from ethanol to obtain a white solid triazine-tris-DOPO (Tri-DOPO-Triazine intermediate). 1 mol of Tri-DOPO-Triazine and 3 mol of epichlorohydrin were dissolved in 30 ml of acetonitrile, 0.2 mol of tetrabutylammonium bromide (TBAB) was added, and the mixture was heated to 60°C and reacted for 12 hours. Finally, the reaction solution was washed with water to remove unreacted epichlorohydrin. The organic phase was dried over anhydrous sodium sulfate and rotary evaporated to obtain DOPO-Triazine-Epoxy (DOPO derivative).

[0020] In the second step, 1 mol of octaaminophenylpropyl POSS (OctaNAPA-POSS) and 8 mol of DOPO-Triazine-Epoxy were dissolved in 60 ml of N,N-dimethylformamide (DMF), and 0.1 mol of p-toluenesulfonic acid (PTSA) was added. The mixture was heated to 80°C under nitrogen protection and reacted for 24 hours. After the reaction, the mixture was dropped into 500 ml of diethyl ether for precipitation. The solid was collected by centrifugation and then washed three times with a detergent mixture of DMF and diethyl ether (the mass percentage of DMF and diethyl ether was 1:5). Finally, it was vacuum dried to obtain a nitrogen-phosphorus-silicon synergistic flame retardant (DOPO-Triazine@POSS).

[0021] Example 2 In this embodiment, the epoxy resin composite material has the following formula: 100 parts of bisphenol A epoxy resin, 30 parts of hexamethylenetetramine as a curing agent, 20 parts of hollow silica microspheres, 10 parts of a flame retardant (OctaDOPO-POSS), and 100 parts of glass fiber cloth.

[0022] The preparation process of the composite material is as follows: S1, mixing the epoxy resin and curing agent, and stirring until clear and transparent to obtain a resin solution; S2, adding the inorganic filler and flame retardant to the resin solution and stirring evenly to obtain a modified resin solution; S3, uniformly coating the modified resin solution on the fiber cloth made of the reinforcing fibers to obtain a prepreg; S4, cutting the prepreg into specified sizes and laying the prepreg layer by layer on the mold; S5, placing the mold on a press, setting the temperature to 100 °C, curing for 2 h, taking it out and cooling it, and then obtaining an epoxy resin composite material.

[0023] Example 3 In this embodiment, the epoxy resin composite material has the following formula: 100 parts of bisphenol A epoxy resin, 30 parts of hexamethylenetetramine as a curing agent, 20 parts of titanium dioxide hollow microspheres, 5 parts of a flame retardant (OctaDOPO-POSS), and 120 parts of glass fiber cloth.

[0024] The preparation process of the composite material is as follows: S1, mixing the epoxy resin and curing agent, and stirring until clear and transparent to obtain a resin solution; S2, adding the inorganic filler and flame retardant to the resin solution and stirring evenly to obtain a modified resin solution; S3, uniformly coating the modified resin solution on the fiber cloth made of the reinforcing fibers to obtain a prepreg; S4, cutting the prepreg into specified sizes and laying the prepreg layer by layer on the mold; S5, placing the mold on a press, setting the temperature to 100 °C, curing for 2 h, taking it out and cooling it, and then obtaining an epoxy resin composite material.

[0025] Comparative Example 1 The epoxy resin composite material formula is: 100 parts of bisphenol A epoxy resin, 30 parts of curing agent (hexamethylenetetramine), 20 parts of glass microspheres, and 100 parts of glass fiber cloth. The preparation process of the composite material is also consistent with that of Example 1.

[0026] Comparative Example 2 The epoxy resin composite material formula is: 100 parts bisphenol A epoxy resin, 30 parts curing agent (hexamethylenetetramine), 20 parts glass microspheres as filler, 100 parts glass fiber cloth, and 15 parts flame retardant (DOPO). The composite material preparation process remains the same as in Example 1.

[0027] Comparative Example 3 The epoxy resin composite material formula is: 100 parts bisphenol A epoxy resin, 30 parts curing agent (hexamethylenetetramine), 20 parts glass microspheres, 100 parts glass fiber cloth, and 15 parts flame retardant (triphenyl phosphate). The composite material preparation process remains the same as in Example 1.

[0028] The main properties of the composite material profiles in Example 13 and Comparative Examples 1-3 were tested according to the corresponding international standards or national standards. The test data are shown in Table 1 below. Table 1 Performance test results of composite materials The test standards in Table 1 are as follows: (1) Flame retardant performance test: Refer to UL-94 standard, use horizontal vertical burning tester for testing, sample size is 100mm*10mm*3.2mm; according to ISO 4589-2 standard, use oxygen index meter to measure the limiting oxygen index (LOI).

[0029] (2) Water absorption test: Cut the sample into 100mm*10mm*3.2mm size and immerse it in deionized water at room temperature. The mass of the sample before immersion is recorded as M1, and the mass of the sample after immersion for 30 days is recorded as M2 (wipe off the surface moisture). The water absorption calculation formula is: (3) Compression strength test: The test is carried out at room temperature according to GB / T 1448-2005 “Test method for compression properties of fiber reinforced plastics”; (4) Water resistance test: Cut the sample size to 100mm*10mm*3.2mm, soak it in deionized water for 30 days, wipe the surface moisture of the sample dry, and test the compressive strength at room temperature according to GB / T 14482005 "Test method for compression properties of fiber reinforced plastics". The compressive strength before soaking in water is recorded as P1, and the compressive strength after soaking in water is recorded as P2. Compression strength retention rate: Compared to Comparative Example 1, Examples 1-3 added a flame retardant. The nitrogen-phosphorus-silicon synergistic flame retardant prepared in the present invention exhibits excellent flame retardancy. The resulting epoxy resin composites achieved a UL-94 flame retardancy rating of V0 and an oxygen index exceeding 32%. The addition of the flame retardant did not affect the mechanical properties or water resistance of the material.

[0030] Compared with Comparative Examples 2-3, Examples 1-2 change the type and amount of the flame retardant. It can be seen that the flame retardant proposed in the present invention has a smaller amount than the flame retardant in the comparative example, has a better flame retardant effect, and the added flame retardant does not affect the mechanical properties of the material, and has excellent water resistance.

[0031] The epoxy resin composite profile and preparation process described in this application have the following advantages: the epoxy resin composite material uses hollow microspheres and glass fiber cloth as reinforcing materials, epoxy resin as the matrix material, and nitrogen-phosphorus-silicon synergistic flame retardant as the functional filler. The material has excellent flame retardant effect and high mechanical strength, and still has excellent performance retention rate after being soaked in water for several days. It can be used in fields with high requirements for flame retardancy, mechanical strength and water resistance, thereby expanding its application range.

[0032] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be considered that the specific implementation of the present invention is limited to the above description. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A marine epoxy resin composite material, characterized by: The marine epoxy resin composite material comprises the following components by weight: 100 parts of epoxy resin, 20-30 parts of curing agent, 100-120 parts of reinforcing material, 2050 parts of hollow microsphere filler, and 5-15 parts of flame retardant; The epoxy resin is one of bisphenol A epoxy resin, bisphenol F epoxy resin, polyphenol glycidyl ether epoxy resin or aliphatic glycidyl ether epoxy resin or a mixture of two of them.

2. The marine epoxy resin composite material according to claim 1, characterized in that: The flame retardant is a nitrogen-phosphorus-silicon synergistic flame retardant, and its preparation method is as follows: First, 1 mol of cyanuric chloride is dissolved in 50 ml of tetrahydrofuran, cooled to 0°C in an ice bath, and 3 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is slowly added dropwise. After reacting for 12 hours, the tetrahydrofuran is removed by rotary evaporation and the mixture is recrystallized from ethanol to obtain a white solid triazine-tris-DOPO. Then, 1 mol of triazine-tris-DOPO and 3 mol of epichlorohydrin are dissolved in 30 ml of acetonitrile, 0.2 mol of tetrabutylammonium bromide is added, and the mixture is heated to 60°C and reacted for 12 hours. Finally, the reaction solution is washed with water to remove unreacted epichlorohydrin, and the organic phase is dried over anhydrous sodium sulfate and rotary evaporated to obtain a DOPO derivative. In the second step, 1 mol of octaaminophenylpropyl POSS and 8 mol of a DOPO derivative were dissolved in 60 ml of N,N-dimethylformamide. 0.1 mol of p-toluenesulfonic acid was added, and the mixture was heated to 80°C under nitrogen for 24 hours. After the reaction, the mixture was added dropwise to 500 ml of diethyl ether for precipitation. The solid was collected by centrifugation and washed three times with a mixture of DMF and diethyl ether. Finally, it was dried under vacuum to obtain a nitrogen-phosphorus-silicon synergistic flame retardant.

3. The marine epoxy resin composite material according to claim 1, characterized in that: The curing agent is hexamethylenetetramine.

4. The marine epoxy resin composite material according to claim 1, characterized in that: The reinforcing material is any one of glass fiber, basalt fiber, fiber mesh cloth and fiber felt processed from carbon fiber.

5. The marine epoxy resin composite material according to claim 1, characterized in that: The hollow microsphere filler includes any one or more of glass microspheres, silicon dioxide hollow microspheres, titanium dioxide hollow microspheres, and polymer hollow microspheres.

6. The method for preparing a marine epoxy resin composite material according to claim 1, wherein: The preparation method comprises the following steps: S1, mixing the epoxy resin and curing agent, and stirring until clear and transparent to obtain a resin solution; S2, adding the hollow microsphere filler and flame retardant to the resin solution and stirring evenly to obtain a modified resin solution; S3, uniformly coating the modified resin solution on the fiber cloth made of the reinforcing fibers to obtain a prepreg; S4, cutting the prepreg into specified sizes and laying the prepreg layer by layer on the mold; S5, placing the mold on a press, heating it to a temperature of 90-100 °C, curing it for 2-5 h, taking it out and cooling it, and then obtaining the epoxy resin composite material.

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