Polydicyclopentadiene / carbon fiber felt composite material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of engineering plastics, and discloses a polydicyclopentadiene / carbon fiber felt composite material and a preparation method and application thereof, and the preparation method comprises the following steps: dispersing nanoparticles and norbornene dicarboxylic acid in a methanol solution to prepare a dispersion liquid; immersing the carboxylated modified carbon fiber felt into the dispersion liquid to obtain a modified carbon fiber felt; and mixing dicyclopentadiene, ethylidene norbornene and a Grubbs second-generation catalyst, immersing the mixture into the modified carbon fiber felt, and carrying out hot-pressing curing molding to obtain the composite material. By constructing an HCFF-NPA-PDCPD covalent interface system, a synergistic modification strategy of a physical effect (NP increases the surface roughness and provides reaction sites) and chemical bonding (NDA serves as a bridge to connect fibers and a matrix) is realized; the production process of the obtained composite material has the characteristic of being green and environment-friendly, waste water, waste gas or dust emission is avoided, the energy consumption is relatively low, and the requirement of the modern industry for sustainable development is met.

Description

Technical Field

[0001] This invention relates to the field of engineering plastics technology, specifically to a polydicyclopentadiene / carbon fiber felt composite material (PDCPD / HCFF-NPA) based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles, its preparation method, and its application. Background Technology

[0002] Polydicyclopentadiene (PDCPD), a thermosetting engineering material with excellent impact strength, chemical resistance, low shrinkage, and good processability, shows broad application prospects in automotive parts, rail transportation, and building structures. Especially against the backdrop of increasing demand for lightweight materials, PDCPD, with its moderate density (approximately 1.05 g / cm³) and high strength, has become an ideal candidate to replace traditional metals and engineering plastics.

[0003] Carbon fiber felt (CFF), as a high-performance fiber-reinforced material, possesses significant advantages such as high strength, high modulus, high temperature resistance, and low density. Combining it with a polymer matrix can effectively improve the mechanical properties and structural stability of the material, making it an important reinforcing phase for the preparation of high-performance composite materials. Based on this, the PDCPD / CFF composite system combines the performance advantages of both and has significant application potential in the field of high-end equipment manufacturing.

[0004] However, when PDCPD is combined with CFF, the poor interfacial compatibility between the two makes it difficult for stress to be effectively transferred between the matrix and the fiber. This easily leads to stress concentration at the interface, which in turn causes failure phenomena such as fiber debonding and matrix cracking, greatly limiting the improvement of the overall performance of the composite material.

[0005] This invention focuses on the above problems and proposes a PDCPD / CFF composite material and its preparation method based on the synergistic modification of norbornene dicarboxylic acid / nanoparticles. The nanoparticles can simultaneously improve the surface roughness of the fiber and the crosslinking density of the matrix, and synergistically suppress interfacial stress concentration. NDA acts as a bridge between the matrix and the carbon fiber felt, and binds the fiber and the matrix together more tightly through a chemical reaction. The carboxyl group at one end of NDA coordinates and bonds to the nanoparticles (NP) on the fiber surface, while the norbornene ring at the other end participates in the matrix polymerization to form a "CFF-NPA-PDCPD" covalent interface, which strengthens the interaction between PDCPD and CFF, thereby significantly optimizing the mechanical properties of the composite material. Summary of the Invention

[0006] The technical problem to be solved by this invention is: to address the problem of insufficient mechanical properties of composite materials caused by poor interfacial compatibility between PDCPD and CFF in the prior art, a preparation method is provided that simultaneously enhances the interfacial bonding force and matrix properties of fiber-resin composite materials and improves the mechanical properties of PDCPD composite materials through a synergistic modification strategy of norbornene dicarboxylic acid / nanoparticles.

[0007] To achieve the above objectives, this invention provides a method for preparing a polydicyclopentadiene / carbon fiber mat (PDCPD / HCFF-NPA) composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles, comprising the following steps: S1. Nanoparticles (NP) that can coordinate with norbornyl dicarboxylic acid (NDA) and norbornyl dicarboxylic acid (NDA) are dispersed in methanol (MeOH) solution to prepare a dispersion; carboxylated modified carbon fiber felt is immersed in the dispersion to obtain modified carbon fiber felt (HCFF-NPA) loaded with nanoparticles and norbornyl dicarboxylic acid. S2. Dicyclopentadiene (DCPD), ethylene norbornene (ENB) and Grubbs second-generation catalyst are mixed and dispersed to form a uniform and stable mixture. S3. The modified carbon fiber felt obtained in step S1 is immersed in the mixture obtained in step S2, and then transferred to a flat vulcanizer and cured by hot pressing to obtain a polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles.

[0008] As a further preferred embodiment of the present invention, the carboxylated modified carbon fiber felt is obtained by surface carboxylation modification of carbon fiber felt with nitric acid; more specifically, the temperature for modification with nitric acid is controlled at 80~140°C. o C, the modification time is controlled between 2 and 10 hours.

[0009] As a further preferred embodiment of the present invention, the nanoparticles are selected from at least one of nano-calcium carbonate (Nano-CaCO3), nano-zinc oxide (Nano-ZnO), and nano-aluminum oxide (Nano-Al2O3). The nanoparticles in the present invention include, but are not limited to, these; other nanoparticles capable of coordinating with norbornene dicarboxylic acid (NDA) may also meet the requirements.

[0010] As a further preferred embodiment of the present invention, the amount of nanoparticles (NP) added in the dispersion is 40-100 parts by mass, and the amount of norbornene dicarboxylic acid (NDA) added is 1-60 parts by mass; more preferably, the amount of nanoparticles (NP) added is 100 parts by mass, and the amount of norbornene dicarboxylic acid (NDA) added is 10-30 parts by mass.

[0011] As a further preferred technical solution of the present invention, in step S2, based on 100 parts by mass of dicyclopentadiene (DCPD): the amount of ethylene norbornene (ENB) added is 5 to 30 parts by mass; and / or, the amount of Grubbs second-generation catalyst added is 0.01 to 0.1 parts by mass.

[0012] As a further preferred embodiment of the present invention, the modified carbon fiber felt obtained in step S1 is immersed in the mixture obtained in step S2 under low-temperature conditions, wherein the low-temperature conditions are 8~11℃. o C.

[0013] As a further preferred embodiment of the present invention, the parameters for hot-press curing molding in step S3 are: the temperature of the flat vulcanizing apparatus is controlled at 70~140°C. o C; and / or, pressure control is 1~20 MPa.

[0014] According to another aspect of the present invention, the present invention also provides a polydicyclopentadiene / carbon fiber mat (PDCPD / HCFF-NPA) composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles, which is prepared by the preparation method of the first aspect described above.

[0015] According to another aspect of the present invention, the present invention also provides an application of polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles as an engineering plastic, such as the polydicyclopentadiene / carbon fiber felt composite material being directly prepared into devices such as wind turbine blades, automobile shells, and electrical product shells during the hot pressing curing process.

[0016] Compared with the prior art, the present invention can achieve the following beneficial effects: 1) This invention selects DCPD as the reactive monomer, which has low viscosity and high reactivity, enabling rapid curing and molding of composite materials; 2) The production process of the PDCPD composite material obtained by this invention is green and environmentally friendly, without generating wastewater, waste gas or dust emissions, and with relatively low energy consumption, which meets the requirements of modern industry for sustainable development. 3) This invention achieves a synergistic modification strategy of physical effects (NP increases surface roughness and provides reaction sites) and chemical bonding (NDA acts as a bridge to connect the fiber and the matrix) by constructing the "HCFF-NPA-PDCPD" covalent interface system; 4) Both the carboxylation of carbon fiber felt and the impregnation of nano-dispersion liquid in this invention are solution-based processes, which have strong process compatibility and high scalability. 5) The composite material prepared by this invention can achieve a bending strength of up to 243.41 MPa (if the nanoparticles NP are selected as Nano-CaCO3), which is significantly improved compared to the unmodified system, meeting the application requirements for high bending strength in wind turbine blades, automobile shells, and electrical product shells. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 This invention represents the design concept for modifying CFF. In the figure, CF refers to the carbon fiber in the carbon fiber felt.

[0019] Figure 2 The process for preparing the PDCPD / CFF composite material in Example 1 is described.

[0020] Figure 3 The surface SEM morphology of CFF at each stage of modification is shown: (a1), (a2), (a3) ​​original CFF surface; (b1), (b2), (b3) carboxylated modified HCFF surface; (c1), (c2), (c3) HCFF-NP surface; (d1), (d2), (d3) HCFF-NPA surface.

[0021] Figure 4 The images show the three-point bending test results of the composite materials obtained in Comparative Examples 1-5 and Example 1.

[0022] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0023] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0024] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art to which this invention pertains. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; and the experimental methods described are conventional methods.

[0025] The basic information of some of the materials used in Example 1 and Comparative Examples 1-5 is as follows: Dicyclopentadiene (DCPD) has a molecular weight of 132.202 and its chemical formula is: C 10 H 12 Ethylene norbornene (ENB) has a molecular weight of 120.192 and a molecular formula of C9H10⁻¹⁰. 12Nano-calcium carbonate (Nano-CaCO3, collectively referred to as NP) has a molecular weight of 100.09, a chemical formula of CaCO3, and a particle size of 50 nm; norbornene dicarboxylic acid (NDA) has a molecular weight of 182.17 and a chemical formula of C9H2O. 10 O4; the catalyst is a second-generation Grubbs catalyst with a molecular weight of 848.98 and a molecular formula of C. 46 H 65 Cl2N2PRu.

[0026] Comparative Example 1: Preparation of PDCPD / CFF composite material.

[0027] Step 1: Mix 95 parts by weight of DCPD, 5 parts by weight of ENB with Grubbs second-generation catalyst, and then disperse the mixture by ultrasonication to form a uniform and stable mixture.

[0028] Step 2: Cut the 0.5 mm thick carbon fiber felt (CFF) into... Size, between 8 and 11 o At a low temperature of C, 10 layers of pre-cut CFF were immersed in the mixture prepared in step 1, and then transferred to a flat vulcanizing apparatus. The pressure was set to 15 MPa, and the mixture was heated to 70°C. o Prepolymerize at C for 5 min, then at 130 o The reaction is completed by curing at C for 2 hours.

[0029] Comparative Example 2: Preparation of PDCPD / CFF-NP composite material, wherein NP is Nano-CaCO3.

[0030] Step 1: Disperse NP in MeOH solution to prepare NP / MeOH dispersion. Cut 0.5 mm thick CFF into... The size was determined, and the cut carbon fiber felt (CFF) was immersed in the dispersion and stirred at room temperature for 24 h to obtain modified carbon fiber felt (CFF-NP) loaded with NP.

[0031] Step 2: Mix 95 parts by weight of DCPD, 5 parts by weight of ENB with Grubbs second-generation catalyst, and then disperse the mixture by ultrasonication to form a uniform and stable mixture.

[0032] Step 3: In 8~11 o At a low temperature of C, 10 layers of CFF-NP prepared in step 1 were immersed in the mixture prepared in step 2, and then transferred to a flat vulcanizing apparatus with a pressure of 15 MPa, and first subjected to 70... o Prepolymerize at C for 5 min, then at 130 o The reaction is completed by curing at C for 2 hours.

[0033] Comparative Example 3: Preparation of PDCPD / CFF-NPA composite material, wherein NP is Nano-CaCO3.

[0034] Step 1: Disperse NP and NDA in MeOH solution at a mass ratio of 10:1 to prepare an NPA / MeOH dispersion. Cut 0.5 mm thick carbon fiber felt (CFF) into... The size was determined, and the cut CFF was immersed in the dispersion and stirred at room temperature for 24 h to obtain modified carbon fiber felt (CFF-NPA) loaded with NP and NDA.

[0035] Step 2: Mix 95 parts by weight of DCPD, 5 parts by weight of ENB with Grubbs second-generation catalyst, and then disperse the mixture by ultrasonication to form a uniform and stable mixture.

[0036] Step 3: In 8~11 o At a low temperature of C, 10 layers of CFF-NPA obtained in step 1 were immersed in the mixture obtained in step 2, and then transferred to a flat vulcanizing apparatus with a pressure of 15 MPa. The mixture was then subjected to a 70°C test. o Prepolymerize at C for 5 min, then at 130 o The reaction is completed by curing at C for 2 hours.

[0037] Comparative Example 4: Preparation of PDCPD / HCFF composite material.

[0038] Step 1: Cut the 0.5 mm thick carbon fiber felt (CFF) into... The size was determined by surface carboxylation modification of CFF with nitric acid, resulting in carboxylated carbon fiber felt HCFF.

[0039] Step 2: Mix 95 parts by weight of DCPD, 5 parts by weight of ENB with Grubbs second-generation catalyst, and then disperse the mixture by ultrasonication to form a uniform and stable mixture.

[0040] Step 3: In 8~11 o At a low temperature of C, 10 layers of HCFF obtained in step 1 were immersed in the mixture obtained in step 2, and then transferred to a flat vulcanizing apparatus. The pressure was set to 15 MPa, and the mixture was first subjected to a 70°C test. o Prepolymerize at C for 5 min, then at 130 o The reaction is completed by curing at C for 2 hours.

[0041] Comparative Example 5: Preparation of PDCPD / HCFF-NP composite material, wherein NP is Nano-CaCO3.

[0042] Step 1: Cut the 0.5 mm thick carbon fiber felt (CFF) into... The size was determined by surface carboxylation modification of CFF with nitric acid, resulting in carboxylated carbon fiber felt HCFF.

[0043] Step 2: Disperse NP in MeOH solution to prepare NP / MeOH dispersion. Immerse HCFF obtained in Step 1 in the dispersion and stir at room temperature for 24 h to obtain modified carbon fiber felt (HCFF-NP) loaded with NP.

[0044] Step 3: Mix 95 parts by weight of DCPD, 5 parts by weight of ENB and Grubbs second-generation catalyst, and then disperse the mixture by ultrasonication to form a uniform and stable mixture.

[0045] Step 4: In 8~11 o At a low temperature of C, 10 layers of HCFF-NP obtained in step 2 were immersed in the mixture obtained in step 3, and then transferred to a flat vulcanizing apparatus with a pressure of 15 MPa, and first subjected to 70 o Prepolymerize at C for 5 min, then at 130 o The reaction is completed by curing at C for 2 hours.

[0046] Example 1: Preparation of PDCPD / HCFF-NPA composite material, wherein NP is Nano-CaCO3.

[0047] Step 1: Cut the 0.5 mm thick carbon fiber felt (CFF) into... The size was determined by surface carboxylation modification of CFF with nitric acid, resulting in carboxylated carbon fiber felt HCFF.

[0048] Step 2: Disperse NP and NDA in MeOH solution at a mass ratio of 10:1 to prepare an NPA / MeOH dispersion. Immerse the HCFF obtained in Step 1 in this dispersion and stir at room temperature for 24 h to obtain modified carbon fiber mat (HCFF-NPA) loaded with NP and NDA. For the modification design ideas of CFF in Steps 1 and 2, please refer to [link to relevant documentation]. Figure 1 As shown.

[0049] Step 3: Mix 95 parts by weight of DCPD, 5 parts by weight of ENB and Grubbs second-generation catalyst, and then disperse the mixture by ultrasonication to form a uniform and stable mixture.

[0050] Step 4: In 8~11 o At a low temperature of C, 10 layers of HCFF-NPA obtained in step 2 were immersed in the mixture obtained in step 3, and then transferred to a flat vulcanizing apparatus with a pressure of 15 MPa. The mixture was then subjected to a 70°C test. o Prepolymerize at C for 5 min, then at 130 oThe reaction was completed by curing at C for 2 hours. Please refer to the preparation process for steps 3 and 4. Figure 2 As shown.

[0051] Comparative test of surface morphology before and after CFF modification, for example Figure 3 As shown. Figure 3 (c1, c2, c3) are HCFF-NPs prepared in Comparative Example 5, with spherical nanoparticles densely attached to their surface; Figure 3 In Example 1, d1, d2, and d3 represent HCFF-NPA prepared in Example 1. Their surface nanoparticle coverage is significantly improved compared to HCFF-NP, and the particle dispersion uniformity is also significantly enhanced, providing a structural basis for subsequent reactions. This indicates that the NP loading is increased through the coordination bonding between the carboxyl groups of NDA and the -COOH / Ca²⁺ groups on the HCFF surface, effectively inhibiting particle aggregation.

[0052] The samples obtained from Comparative Examples 1-5 and Example 1 were subjected to bending performance tests, calculated according to GB / T9341-2008 (three-point bending); experimental conditions: tensile rate of 20 mm / min, span (L): 64 mm. The results are as follows. Figure 4 As shown, in Example 1, after CFF was modified with nitric acid and NP was loaded on its surface, NDA was introduced. The resulting PDCPD / HCFF-NPA composite material underwent a three-point bending test, and its bending strength was 243.41 MPa. Compared with the pure PDCPD / CFF composite material, the bending strength was increased by 67.7%, showing a significant improvement. The bending strengths of PDCPD / CFF-NP, PDCPD / CFF-NPA, PDCPD / HCFF, PDCPD / HCFF-NP composite materials and PDCPD / CFF composite material were all below 150 MPa, which was significantly worse than the PDCPD / HCFF-NPA composite material of the present invention. This indicates that the synergistic modification of carboxylated carbon fiber felt by nanoparticles and norbornene dicarboxylic acid can significantly improve the compatibility between PDCPD and CFF composites, thereby improving mechanical properties.

[0053] Example 2 The PDCPD / HCFF-NPA composite material was prepared using essentially the same method as in Example 1, except that the NP was replaced by an equal mass of nano-CaCO3 nano-zinc oxide (Nano-ZnO). The flexural strength of the material, measured using the same method as described above, was close to that of Example 1, reaching over 200 MPa.

[0054] Example 3 The PDCPD / HCFF-NPA composite material was prepared using essentially the same method as in Example 1, except that the NP was replaced by an equal mass of nano-CaCO3 nano-alumina (Nano-Al2O3). The flexural strength of the material, measured using the same method as described above, was close to that of Example 1, reaching over 200 MPa.

[0055] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and various changes or modifications can be made to these embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is defined only by the appended claims.

Claims

1. A method for preparing a polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles, characterized in that, Includes the following steps: S1. Nanoparticles that can coordinate with norbornyl dicarboxylic acid and norbornyl dicarboxylic acid are dispersed in methanol solution to prepare a dispersion; carboxylated modified carbon fiber felt is immersed in the dispersion to obtain modified carbon fiber felt loaded with nanoparticles and norbornyl dicarboxylic acid. S2. Dicyclopentadiene, ethylene norbornene and Grubbs second-generation catalyst are mixed and dispersed to form a uniform and stable mixture. S3. The modified carbon fiber felt obtained in step S1 is immersed in the mixture obtained in step S2, and then transferred to a flat vulcanizer and cured by hot pressing to obtain a polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles.

2. The preparation method of the polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles according to claim 1, characterized in that, The carboxylated modified carbon fiber felt is obtained by surface carboxylation modification of carbon fiber felt with nitric acid.

3. The preparation method of the polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles according to claim 1, characterized in that, The nanoparticles are selected from at least one of nano-calcium carbonate, nano-zinc oxide, and nano-alumina.

4. The preparation method of the polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles according to claim 1, characterized in that, In the dispersion, the amount of nanoparticles added is 40-100 parts by mass, and the amount of norbornene dicarboxylic acid added is 1-60 parts by mass.

5. The preparation method of the polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles according to claim 1, characterized in that, In step S2, based on 100 parts by mass of dicyclopentadiene: the amount of ethylene norbornene added is 5 to 30 parts by mass; and / or, the amount of Grubbs second-generation catalyst added is 0.01 to 0.1 parts by mass.

6. The method for preparing the polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles according to claim 1, characterized in that, The modified carbon fiber felt obtained in step S1 is immersed in the mixture obtained in step S2 under low-temperature conditions, wherein the low-temperature conditions are 8~11℃. o C.

7. The preparation method of the polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles according to claim 1, characterized in that, The parameters for hot pressing and curing in step S3 are: the temperature of the flat vulcanizing machine is controlled at 70~140°C. o C; and / or, pressure control is 1~20 MPa.

8. A polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.

9. The application of the polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles as described in claim 8 as an engineering plastic.

10. The application according to claim 9, characterized in that, Wind turbine blades, automobile housings, or electrical product housings can be prepared from the polydicyclopentadiene / carbon fiber felt composite material.

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