Polydicyclopentadiene / carbon fiber mat composites, methods of making and applications thereof

Abstract

The application relates to the technical field of engineering plastics, and discloses a polydicyclopentadiene / carbon fiber felt composite material and a preparation method and application thereof, wherein the preparation method comprises the following steps: dispersing nano particles and norbornene dicarboxylic acid in a methanol solution to prepare a dispersion solution; immersing carboxyl-modified carbon fiber felt in the dispersion solution to obtain modified carbon fiber felt; immersing dicyclopentadiene, ethylidene norbornene and a Grubbs second-generation catalyst in the modified carbon fiber felt after mixing, and performing hot-pressing and curing to form a composite material. Through construction of an "HCFF-NPA-PDCPD" covalent interface system, a synergistic modification strategy of physical effect (NPs increase surface roughness and provide reaction sites) and chemical bonding (NDA serves as a bridge to connect fibers and a matrix) is realized; the production process of the composite material obtained by the application has the characteristics of green environmental protection, does not produce wastewater, waste gas or dust emission, and has relatively low energy consumption, and meets the requirements of modern industry for sustainable development.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engineering plastics, in particular to a kind of based on norbornene dicarboxylic acid and nanoparticle synergistic modified polydicyclopentadiene / carbon fiber felt composite (PDCPD / HCFF-NPA) and its preparation method and application. BACKGROUND

[0002] Polydicyclopentadiene (PDCPD) as a kind of excellent impact strength, chemical corrosion resistance, low shrinkage and good forming processability thermosetting engineering material, in the field of automobile parts, rail transit, building structure, etc. It shows broad application prospect. Especially in the background of the increasing demand for lightweight materials, PDCPD, with its moderate density (about 1.05 g / cm³) and high strength, becomes an ideal candidate material to replace traditional metal and engineering plastics.

[0003] Carbon fiber felt (CFF) as a kind of high performance fiber reinforced material, has high strength, high modulus, high temperature resistance and low density and other significant advantages, which is combined with polymer matrix can effectively improve the mechanical properties and structural stability of material, is an important reinforcing phase for preparing high performance composite materials. Therefore, the composite system of PDCPD and CFF (PDCPD / CFF) has the performance advantages of both, and has important application potential in high-end equipment manufacturing field.

[0004] However, when PDCPD and CFF are combined, due to the poor interfacial compatibility between them, stress is difficult to be effectively transmitted between the matrix and the fiber, stress concentration is easy to occur at the interface, which further causes fiber debonding, matrix cracking and other failure phenomena, greatly limiting the improvement of the comprehensive performance of the composite material.

[0005] The present application focuses on the above problems, and proposes a kind of PDCPD / CFF composite material based on norbornene dicarboxylic acid / nanoparticle synergistic modification and its preparation method. Nanoparticles can increase the surface roughness of fiber and the crosslinking density of matrix at the same time, and synergistically inhibit the stress concentration at the interface. NDA acts as a bridge between the matrix and the carbon fiber felt, and through chemical reaction, the fiber and the matrix are more closely bonded together. The carboxyl group at one end of NDA bonds with the surface nanoparticles (NP) of the fiber through coordination, and the other end of norbornene ring participates in the polymerization of the matrix, forming a "CFF-NPA-PDCPD" covalent interface, which strengthens the interaction between PDCPD and CFF, and further significantly optimizes the mechanical properties of the composite material. SUMMARY

[0006] The technical problem to be solved by the present application is: in view of the problem of insufficient mechanical properties of composite materials caused by poor compatibility of PDCPD and CFF interface in the prior art, a preparation method for synchronously enhancing the fiber-resin interface bonding force and the matrix performance and improving the mechanical properties of PDCPD composite materials by a norbornene dicarboxylic acid / nanoparticle synergistic modification strategy is provided.

[0007] To achieve the above-mentioned purpose, the present application provides a preparation method of a norbornene dicarboxylic acid and nanoparticle synergistically modified polydicyclopentadiene / carbon fiber felt (PDCPD / HCFF-NPA) composite material, which comprises the following steps:

[0008] S1, dispersing nanoparticles (Nano-Particles, NP) capable of producing coordination with norbornene dicarboxylic acid and norbornene dicarboxylic acid (NDA) in a methanol (MeOH) solution to prepare a dispersion liquid; immersing a carboxylated modified carbon fiber felt in the dispersion liquid to obtain a modified carbon fiber felt (HCFF-NPA) loaded with nanoparticles and norbornene dicarboxylic acid;

[0009] S2, mixing dicyclopentadiene (DCPD), ethylidene norbornene (ENB) and Grubbs second-generation catalyst to form a uniform and stable mixed solution after dispersion treatment;

[0010] S3, immersing the modified carbon fiber felt prepared in step S1 in the mixed solution prepared in step S2, then transferring it to a flat plate vulcanizing instrument, and curing and forming by hot pressing to obtain a norbornene dicarboxylic acid and nanoparticle synergistically modified polydicyclopentadiene / carbon fiber felt composite material.

[0011] As a further preferred technical solution of the present application, the carboxylated modified carbon fiber felt is obtained by surface carboxylated modification of carbon fiber felt with nitric acid; more specifically, the modification temperature is controlled at 80~140 o C, and the modification time is controlled at 2~10 h.

[0012] As a further preferred technical solution of the present application, 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 application include but are not limited to this, and other nanoparticles capable of producing coordination with norbornene dicarboxylic acid (NDA) can also meet the requirements.

[0013] As a further preferred technical solution of the present application, in the dispersion, the addition amount of the nanoparticles (NP) is 40-100 parts by mass, and the addition amount of the norbornene dicarboxylic acid (NDA) is 1-60 parts by mass; more preferably, the addition amount of the nanoparticles (NP) is 100 parts by mass, and the addition amount of the norbornene dicarboxylic acid (NDA) is 10-30 parts by mass.

[0014] As a further preferred technical solution of the present application, in step S2, the addition amount of the ethylidene norbornene (ENB) is 5-30 parts by mass based on 100 parts by mass of the dicyclopentadiene (DCPD); and / or, the addition amount of the Grubbs second-generation catalyst is 0.01-0.1 parts by mass.

[0015] As a further preferred technical solution of the present application, the modified carbon fiber felt prepared in step S1 is immersed in the mixed solution prepared in step S2 under low-temperature conditions, and the low-temperature conditions are 8-11 o C.

[0016] As a further preferred technical solution of the present application, in step S3, the parameters for heat pressing and curing molding are as follows: the temperature control of the flat plate vulcanizing instrument is 70-140 o C; and / or, the pressure control is 1-20 MPa.

[0017] According to another aspect of the present application, the present application further provides a polydicyclopentadiene / carbon fiber felt (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.

[0018] According to still another aspect of the present application, the present application further provides an application of a polydicyclopentadiene / carbon fiber felt composite material based on the synergistic modification of norbornene dicarboxylic acid and nanoparticles as an engineering plastic, such as directly preparing the polydicyclopentadiene / carbon fiber felt composite material into devices such as fan blades, automobile shells, and electrical product shells in a heat pressing and curing molding process.

[0019] Compared with the prior art, the present application can achieve the following beneficial effects:

[0020] 1) The present application selects DCPD as the reaction monomer, and the monomer has low viscosity and high reactivity, so that rapid curing molding of the composite material can be realized;

[0021] 2) The production process of the PDCPD composite material obtained by the present application has the characteristics of green environmental protection, does not produce wastewater, waste gas or dust emission, and has relatively low energy consumption, which meets the requirements of modern industry for sustainable development;

[0022] 3) The present application realizes the synergistic modification strategy of physical effect (NP increases the surface roughness and provides reaction sites) and chemical bonding (NDA as a bridge to connect fibers and matrix) by constructing the "HCFF-NPA-PDCPD" covalent interface system;

[0023] 4) The carboxylation of carbon fiber felt and the nanodispersion impregnation in the present application are both solution treatment, which has strong process compatibility and high scalability;

[0024] 5) The bending strength of the composite material prepared in the present application can be as high as 243.41 MPa (if Nano-CaCO3 is selected as the nanoparticle NP), which is very obviously improved compared with the unmodified system, and meets the application requirements of high bending strength in fan blades, automobile shells and electrical product shells. BRIEF DESCRIPTION OF DRAWINGS

[0025] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0026] Figure 1 For the modification design idea of CFF in the present application, CF in the figure refers to the carbon fiber of carbon fiber felt.

[0027] Figure 2 It is the preparation process of PDCPD / CFF composite material in Example 1.

[0028] Figure 3 It is the surface SEM morphology of each stage of CFF modification: (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.

[0029] Figure 4 It is the three-point bending test diagram of the composite material obtained in Comparative Examples 1-5 and Example 1.

[0030] The purpose realization, functional characteristics and advantages of the present application will be further described in combination with the embodiments and with reference to the drawings. DETAILED DESCRIPTION

[0031] The specific embodiments of the present application will be described in detail below in combination with the drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0032] Unless defined, the technical terms used in the following examples have the same meaning as generally understood by those skilled in the art to which the present application belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods, unless otherwise specified, are all conventional methods.

[0033] The basic information of part of materials used in the following Example 1 and Comparative Examples 1-5 is as follows:

[0034] Dicyclopentadiene (DCPD) has a molecular weight of 132.202 and a chemical formula of: C 10 H 12 ; ethylidene norbornene (ENB) has a molecular weight of 120.192 and a molecular formula of: C9H 12 ; nano calcium carbonate (Nano-CaCO3, collectively referred to as NP) has a molecular weight of 100.09 and a chemical formula of: CaCO3, with a particle size of 50 nm; norbornene dicarboxylic acid (NDA) has a molecular weight of 182.17 and a chemical formula of: C9H 10 O4; the catalyst is Grubbs second-generation catalyst, with a molecular weight of 848.98 and a molecular formula of: C 46 H 65 Cl2N2PRu.

[0035] Comparative Example 1: Preparation of PDCPD / CFF composite material.

[0036] Step 1: 95 parts by mass of DCPD, 5 parts by mass of ENB, and Grubbs second-generation catalyst were mixed and treated by ultrasonic dispersion to form a uniform and stable mixed solution.

[0037] Step 2: The 0.5 mm thick carbon fiber felt CFF was cut into size, and was immersed in the mixed solution prepared in step 1 in a low-temperature environment of 8-11 o C. Subsequently, it was transferred to a flat vulcanization instrument, and the pressure was set to 15 MPa. It was first prepolymerized at 70 o C for 5 min, and then cured at 130 o C for 2 h to complete the reaction.

[0038] Comparative Example 2: Preparation of PDCPD / CFF-NP composite material, wherein NP is Nano-CaCO3.

[0039] Step 1: The NP was dispersed in a MeOH solution to prepare an NP / MeOH dispersion solution. The 0.5 mm thick CFF was cut into size, and the cut carbon fiber felt CFF was immersed in the dispersion solution and stirred at room temperature for 24 h to obtain a modified carbon fiber felt loaded with NP (CFF-NP).

[0040] Step 2: 95 parts by mass of DCPD, 5 parts by mass of ENB, and Grubbs second-generation catalyst were mixed and treated by ultrasonic dispersion to form a uniform and stable mixed solution.

[0041] Step 3: Under the low temperature environment of 8~11 o C, 10 layers of CFF-NP prepared in step 1 were immersed in the mixed solution prepared in step 2, and then transferred to a flat curing instrument, and the pressure was set to 15 MPa. First, prepolymerization was performed at 70 o C for 5 min, and then cured at 130 o C for 2 h to complete the reaction.

[0042] Comparative Example 3: PDCPD / CFF-NPA composite material was prepared, wherein the NP was Nano-CaCO3.

[0043] Step 1: The NP and NDA were dispersed in the MeOH solution according to the mass ratio of 10:1 to prepare the NPA / MeOH dispersion solution. The 0.5 mm thick carbon fiber felt CFF was cut into size, and the cut CFF was immersed in the dispersion solution, and the reaction was stirred at room temperature for 24 h to obtain a modified carbon fiber felt (CFF-NPA) loaded with NP and NDA.

[0044] Step 2: 95 parts by mass of DCPD, 5 parts by mass of ENB, and Grubbs second-generation catalyst were mixed and ultrasonically dispersed to form a uniform and stable mixed solution.

[0045] Step 3: Under the low temperature environment of 8~11 o C, 10 layers of CFF-NPA prepared in step 1 were immersed in the mixed solution prepared in step 2, and then transferred to a flat curing instrument, and the pressure was set to 15 MPa. First, prepolymerization was performed at 70 o C for 5 min, and then cured at 130 o C for 2 h to complete the reaction.

[0046] Comparative Example 4: PDCPD / HCFF composite material was prepared.

[0047] Step 1: The 0.5 mm thick carbon fiber felt CFF was cut into size, and the CFF was surface carboxylated using nitric acid to obtain a carboxylated modified carbon fiber felt HCFF.

[0048] Step 2: 95 parts by mass of DCPD, 5 parts by mass of ENB, and Grubbs second-generation catalyst were mixed and ultrasonically dispersed to form a uniform and stable mixed solution.

[0049] Step 3: Under the low temperature environment of 8~11 o C, 10 layers of HCFF prepared in step 1 were immersed in the mixed solution prepared in step 2, and then transferred to a flat curing instrument, and the pressure was set to 15 MPa. First, prepolymerization was performed at 70 o C for 5 min, and then cured at 130o C for 2 h to complete the reaction.

[0050] Comparative Example 5: Preparation of PDCPD / HCFF-NP composite material, wherein NP is Nano-CaCO3.

[0051] Step 1: Cut 0.5 mm thick carbon fiber felt CFF into size, and surface carboxylate modification of the CFF is performed using nitric acid to obtain carboxylate modified carbon fiber felt HCFF.

[0052] Step 2: Disperse NP in MeOH solution to prepare NP / MeOH dispersion liquid, and immerse the HCFF prepared in Step 1 in the dispersion liquid, and stir at room temperature for 24 h to obtain modified carbon fiber felt (HCFF-NP) loaded with NP.

[0053] Step 3: Mix 95 parts by mass of DCPD, 5 parts by mass of ENB, and Grubbs second-generation catalyst, and perform ultrasonic dispersion treatment to form a uniform and stable mixed liquid.

[0054] Step 4: Immerse 10 layers of HCFF-NP prepared in Step 2 in the mixed liquid prepared in Step 3 in a low-temperature environment of 8~11 o C, and then transfer it to a flat curing instrument, set the pressure to 15 MPa, and first prepolymerize at 70 o C for 5 min, and then cure at 130 o C for 2 h to complete the reaction.

[0055] Example 1: Preparation of PDCPD / HCFF-NPA composite material, wherein NP is Nano-CaCO3.

[0056] Step 1: Cut 0.5 mm thick carbon fiber felt CFF into size, and surface carboxylate modification of the CFF is performed using nitric acid to obtain carboxylate modified carbon fiber felt HCFF.

[0057] Step 2: Disperse NP and NDA in MeOH solution according to a mass ratio of 10:1 to prepare NPA / MeOH dispersion liquid, and immerse the HCFF prepared in Step 1 in the dispersion liquid, and stir at room temperature for 24 h to obtain modified carbon fiber felt (HCFF-NPA) loaded with NP and NDA. The modification design idea of Steps 1 and 2 for CFF is shown in Figure 1 .

[0058] Step 3: Mix 95 parts by mass of DCPD, 5 parts by mass of ENB, and Grubbs second-generation catalyst, and perform ultrasonic dispersion treatment to form a uniform and stable mixed liquid.

[0059] Step 4: 10 layers of HCFF-NPA prepared in step 2 were immersed in the mixed solution prepared in step 3 under the low temperature environment of 8~11 o C, and then transferred to a flat curing instrument, and set to a pressure of 15 MPa. First, pre-polymerization was performed at 70 o C for 5 min, and then curing was performed at 130 o C for 2 h to complete the reaction. The preparation processes of steps 3 and 4 are described in detail in Figure 2 .

[0060] The surface morphology of the CFF before and after modification is compared as shown in Figure 3 . Figure 3 The HCFF-NP in the comparative example 5 (c1, c2, c3) is densely attached with spherical nanoparticles on the surface; Figure 3 The HCFF-NPA in the example 1 (d1, d2, d3) has a significantly improved coverage of nanoparticles on the surface compared with the HCFF-NP, and the uniformity of particle dispersion is significantly improved, which provides a structural basis for subsequent reactions. It is shown that the loading of the NP is improved through the coordination bonding between the carboxyl group of the NDA and the -COOH / Ca²⁺ on the surface of the HCFF, and the particle agglomeration is effectively inhibited.

[0061] The samples obtained in the above comparative examples 1-5 and the example 1 were subjected to bending property tests, and the calculation standard was GB / T9341-2008 (three-point bending); the experimental conditions were that the tensile rate was 20 mm / min, and the span (L) was 64 mm. The results are shown in Figure 4 . After the CFF in the example 1 was modified by nitric acid and loaded with the NP on the surface, the NDA was introduced, and the PDCPD / HCFF-NPA composite material obtained was subjected to the three-point bending test, and the bending strength was 243.41 MPa, which was improved by 67.7% compared with the pure PDCPD / CFF composite material, and was obviously improved. The bending strengths of the PDCPD / CFF-NP, PDCPD / CFF-NPA, PDCPD / HCFF, PDCPD / HCFF-NP composite materials and the PDCPD / CFF composite material were all lower than 150 MPa, which was obviously different from the PDCPD / HCFF-NPA composite material of the present application. It is shown that after the nanoparticles and the norbornene dicarboxylic acid cooperatively modify the carboxylated carbon fiber felt, the compatibility between the PDCPD and the CFF composite can be greatly improved, so that the mechanical properties are improved.

[0062] Example 2

[0063] The PDCPD / HCFF-NPA composite material is prepared by using the same method as that of Example 1, except that the Nano-CaCO3 is replaced by Nano-ZnO of the same mass. The bending load capacity of the material is measured by the same method as above, and is close to that of Example 1, and the bending strength can reach more than 200 MPa.

[0064] Example 3

[0065] The PDCPD / HCFF-NPA composite material is prepared by using the same method as that of Example 1, except that the Nano-CaCO3 is replaced by Nano-ZnO of the same mass. The bending load capacity of the material is measured by the same method as above, and is close to that of Example 1, and the bending strength can reach more than 200 MPa.

[0066] Although the specific embodiments of the present application are described above, those skilled in the art should understand that these are only illustrative, and various changes or modifications can be made to the embodiments without departing from the principles and essence of the present application, and the protection scope of the present application is only defined 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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