A polydicyclopentadiene / glass mat composite and method of making the same

Abstract

The application provides a polydicyclopentadiene / glass fiber felt composite material and a preparation method thereof. The method comprises the following steps: step (1): laying a glass fiber felt on a glass plate, sequentially laying a release cloth, a flow guide net and a vacuum bag, and performing vacuum pumping and pressure maintaining; step (2): pouring a cyclic olefin liquid into the vacuum bag in step (1), performing stage temperature rising and curing, and releasing a polydicyclopentadiene / glass fiber felt composite material. The cyclic olefin liquid is configured as follows: A1, uniformly mixing 100 parts by mass of DCPD and 5-20 parts by mass of a TCPD system to prepare a mixed solution; wherein the TCPD system comprises 10wt% of TCPD and 90wt% of DCPD; A2, dissolving 0.02-0.06 parts by mass of a Grubbs second-generation catalyst and 0.002-0.006 parts by mass of a retarder in 1-2 parts by mass of a high-boiling-point silane coupling agent, and adding the mixture into the mixed solution in step A1 to prepare a liquid. The method adopts a vacuum-assisted resin infusion molding (VARI) technology, has the characteristics of simple operation and rapid reaction, and the obtained composite material has high mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a polydicyclopentadiene / glass fiber mat composite material and its preparation method. Background Technology

[0002] Polydicyclopentadiene (PDCPD) is a thermosetting polymer resin material derived from dicyclopentadiene (DCPD) via ring-opening metathesis polymerization (ROMP). It possesses excellent properties such as high flexural modulus, high impact strength, and resistance to low temperatures and corrosion. Compared to epoxy resins, it features lower viscosity and faster reaction speed, and the resulting components are lighter, demonstrating broad application prospects. As an emerging polymer material, PDCPD is widely used in vehicle bodies, chemical pipelines, medical equipment, and other fields, and market demand continues to increase.

[0003] To enable PDCPD to meet the higher mechanical performance requirements of applications, the development of PDCPD-based fiber composites has become a current research direction. Currently, the fibers used in composite materials are mainly carbon fiber or glass fiber. However, due to the poor compatibility between the sizing agent on their surface and PDCPD, the bonding between the PDCPD resin and the fiber is insufficient, failing to achieve a synergistic effect.

[0004] CN112961279A describes adding TCPD to DCPD to improve the rigidity of PDCPD. Because tricyclopentadiene TCPD has a larger molecular weight than dicyclopentadiene DCPD, it exhibits greater rigidity. The rigidity of the copolymer of polytricyclopentadiene PTCPD and polydicyclopentadiene PDCPD is greater than that of existing polydicyclopentadiene polymers. While TCPD can improve the rigidity of DCPD, PTCPD itself is non-polar, directly leading to inherently weak bonding between it and fibers or fiber fabrics when applied to fiber composites. For example, CN112980130A discloses a polytricyclopentadiene PTCPD fiber composite material preparation process that requires complex and precise modification of the fiber surface, increasing the complexity and cost of the preparation. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention aims to explore a more efficient and economical method to fundamentally solve the problem of insufficient bonding strength between PDCPD and fibers, while further improving the overall rigidity of the composite material. This invention provides a polydicyclopentadiene / glass fiber mat composite material and its preparation method. This method employs vacuum-assisted resin infusion molding (VARI) technology, which is characterized by simple operation and rapid reaction, resulting in a composite material with high mechanical properties.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] This invention also provides a method for preparing a polydicyclopentadiene / glass fiber mat composite material, comprising:

[0008] Step (1): On the glass plate, lay the release cloth, fiberglass mat, release cloth, flow guide net and vacuum bag in sequence, and draw a vacuum to maintain pressure;

[0009] Step (2): Pour the cycloolefin liquid into the vacuum bag of step (1), heat and cure in stages, and demold to obtain polydicyclopentadiene / glass fiber mat composite material;

[0010] The specific preparation of the cyclic olefin feed solution is as follows:

[0011] A1. Thoroughly mix 100 parts by weight of DCPD and 5-20 parts by weight of TCPD system to prepare a homogeneous mixed solution; wherein the TCPD system contains 10 wt% TCPD and 90 wt% DCPD.

[0012] A2. Dissolve 0.02-0.06 parts by weight of Grubbs second-generation catalyst and 0.002-0.006 parts by weight of retarder in 1-2 parts by weight of high-boiling-point silane coupling agent, and then add them to the mixed solution in step A1 to obtain the feed solution.

[0013] In some embodiments, the vacuum holding time is 1-2 hours. In some embodiments, the retarder is selected from one or any combination of tributyl phosphite, triphenylphosphine, and tributyl phosphate. In a preferred embodiment, the retarder is tributyl phosphite.

[0014] In some embodiments, the high-boiling-point silane coupling agent is selected from at least one of diphenyldimethoxysilane, phenyltrimethoxysilane, p-chlorophenyltrimethoxysilane, 3-aminopropyltriethoxysilane, mercaptopropyltrimethoxysilane, benzyltriethoxysilane, triethoxypentylsilane, methylcyclohexyldimethoxysilane, and n-hexyltrimethoxysilane. In a preferred embodiment, the high-boiling-point silane coupling agent is diphenyldimethoxysilane.

[0015] The molecular structure of the Grubbs second-generation catalyst is as follows:

[0016]

[0017] In a preferred embodiment, the staged heating and curing conditions are as follows: first at 60°C for 0.25 to 1.5 hours, and then at 140°C for 0.5 to 1.5 hours.

[0018] In a more preferred embodiment, the staged curing conditions are: 0.25 hours at 60°C and 0.5 hours at 140°C.

[0019] The present invention also provides a polydicyclopentadiene / glass fiber mat composite material prepared using the method described above.

[0020] In a preferred embodiment, the polydicyclopentadiene / glass fiber mat composite material has a tensile strength ≥160MPa and a tensile modulus ≥9000MPa.

[0021] In a preferred embodiment, the elongation at break of the polydicyclopentadiene / glass fiber mat composite material is ≥4%.

[0022] In a preferred embodiment, the polydicyclopentadiene / glass fiber mat composite material has a flexural strength ≥160MPa and a flexural modulus ≥10000MPa.

[0023] Without violating common sense in the field, the above-described embodiments or preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] (1) The preparation method of the polydicyclopentadiene / glass fiber mat composite material of the present invention adopts vacuum assisted resin injection molding (VARI) technology, which has the characteristics of simple operation and fast reaction, and the resulting composite material has high mechanical properties.

[0026] (2) The cyclic olefin liquid used in this invention is reasonably configured, which lowers the freezing point of the liquid and facilitates the injection operation. The cyclic olefin liquid has sufficient contact with the glass fiber mat and strong permeability. The glass fiber mat does not need to be modified, which fundamentally solves the problem of insufficient bonding force between PDCPD and fiber. The tensile strength, tensile modulus and elongation at break of the prepared polydicyclopentadiene / glass fiber mat composite material are significantly improved.

[0027] (3) In the preparation process of the composite material of the present invention, diphenyldimethoxysilane is preferred as the catalyst solvent, which can eliminate the degassing step and simplify the operation process. Detailed Implementation

[0028] Experimental materials:

[0029]

[0030] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are for illustrative purposes only and do not limit the scope of the invention in any way. Furthermore, it should be pointed out that those skilled in the art can make various modifications and improvements to the present invention. These all fall within the protection scope of the present invention.

[0031] Example 1:

[0032] The DCPD raw material was heated to 150-160℃ and held at that temperature for 6 hours. The solution was cooled to room temperature, and light components were removed by vacuum to obtain DCPD with a TCPD content of 10 wt%. The TCPD system described in this invention application is a mixed solution prepared in this embodiment.

[0033] Example 2:

[0034] Apply sealing tape around the glass mold, then lay out the following layers on the surface: adhesive-backed PTFE release cloth, 6 layers of fiberglass mat, release cloth, flow guide net, and vacuum bag. Connect the vacuum pump to evacuate the vacuum bag and ensure its airtightness. Maintain pressure for 1-2 hours.

[0035] Example 3:

[0036] 100 parts by weight of DCPD and 10 parts by weight of TCPD from Example 1 were thoroughly mixed to prepare a homogeneous resin solution. 0.06 parts by weight of Grubbs second-generation catalyst and 0.006 parts by weight of tributyl phosphite were dissolved in 1 part by weight of diphenyldimethoxysilane and then added to the resin solution. The resin solution was injected into a vacuum bag of Example 2, heated to 60°C, held at that temperature for 15 minutes, then heated again to 140°C and held at that temperature for 30 minutes for staged curing. After cooling, the composite material was demolded.

[0037] Example 4:

[0038] 100 parts by weight of DCPD and 10 parts by weight of TCPD from Example 1 were thoroughly mixed to prepare a homogeneous resin solution. 0.03 parts by weight of Grubbs second-generation catalyst and 0.003 parts by weight of tributyl phosphite were dissolved in 1 part by weight of diphenyldimethoxysilane and then added to the resin solution. The resin solution was injected into a vacuum bag of Example 2, heated to 60°C, held at that temperature for 15 minutes, then heated again to 140°C and held at that temperature for 30 minutes for staged curing. After cooling, the composite material was demolded.

[0039] Example 5:

[0040] 100 parts by weight of DCPD and 10 parts by weight of TCPD from Example 1 were thoroughly mixed to prepare a homogeneous resin solution. 0.02 parts by weight of Grubbs second-generation catalyst and 0.002 parts by weight of tributyl phosphite were dissolved in 1 part by weight of diphenyldimethoxysilane and then added to the resin solution. The resin solution was injected into a vacuum bag of Example 2, heated to 60°C, held at that temperature for 15 minutes, then heated again to 140°C and held at that temperature for 30 minutes for staged curing. After cooling, the composite material was demolded.

[0041] Example 6:

[0042] 100 parts by weight of DCPD and 20 parts by weight of TCPD from Example 1 were thoroughly mixed to prepare a homogeneous resin solution. 0.06 parts by weight of Grubbs second-generation catalyst and 0.006 parts by weight of tributyl phosphite were dissolved in 1 part by weight of diphenyldimethoxysilane and then added to the resin solution. The resin solution was injected into a vacuum bag of Example 2, heated to 60°C, held at that temperature for 15 minutes, then heated again to 140°C and held at that temperature for 30 minutes for staged curing. After cooling, the composite material was demolded.

[0043] Example 7:

[0044] 100 parts by weight of DCPD and 5 parts by weight of TCPD from Example 1 were thoroughly mixed to prepare a homogeneous resin solution. 0.06 parts by weight of Grubbs second-generation catalyst and 0.006 parts by weight of tributyl phosphite were dissolved in 1 part by weight of diphenyldimethoxysilane and then added to the resin solution. The resin solution was injected into a vacuum bag of Example 2, heated to 60°C, held at that temperature for 15 minutes, then heated again to 140°C and held at that temperature for 30 minutes for staged curing. After cooling, the composite material was demolded.

[0045] Comparative Example 1:

[0046] Take 100 parts by weight of DCPD resin solution. Dissolve 0.06 parts by weight of Grubbs second-generation catalyst and 0.006 parts by weight of tributyl phosphite in 1 part by weight of diphenyldimethoxysilane, and then add it to the resin solution. Inject the resin solution into the vacuum bag of Example 2, heat to 60°C, hold at that temperature for 15 min, then heat again to 140°C, hold at that temperature for 30 min for staged curing, then cool down and demold to obtain the composite material.

[0047] Table 1: Composition of resin solutions (parts by weight) in the Examples and Comparative Examples

[0048]

[0049] The composite materials prepared in Examples 3-7 and Comparative Example 1 were cut and their tensile strength, tensile modulus, elongation at break, flexural strength, and flexural modulus were tested. Specific details are shown in Test Examples 1-2.

[0050] Test Example 1: Tensile strength, tensile modulus, and elongation at break

[0051] Test samples: Composite materials prepared in Examples 3-7 and Comparative Example 1;

[0052] The microcomputer-controlled electronic universal testing machine, model CMT4304, manufactured by MTECH Industrial Systems (China) Co., Ltd., was used. The testing speed was 5 mm / min, and the tensile strength, tensile modulus, and elongation at break were tested according to the GB / T 1040.2-2006 standard.

[0053] Tensile strength is calculated according to formula (1):

[0054]

[0055] In the formula σ t denoted as tensile strength (MPa), P as failure load (N), b as specimen width (mm), and h as specimen thickness (mm).

[0056] The tensile modulus is calculated according to formula (2):

[0057]

[0058] In the formula E t Let be the tensile modulus (MPa), L0 be the gauge length (mm), ΔP be the load increment (N) on the initial straight line segment of the load-deformation curve, ΔL be the deformation increment L0 (mm) within the gauge length corresponding to the load increment ΔP, b be the specimen width (mm), and h be the specimen thickness (mm).

[0059] Elongation at break is calculated according to formula (3):

[0060]

[0061] In the formula ε t ΔL represents the elongation at break of the specimen (%). b The elongation (mm) within the gauge length L0 when the specimen breaks is the measurement gauge length (mm).

[0062] Table 2 Summary of Tensile Strength, Tensile Modulus, and Elongation at Break Test Results

[0063] Serial Number Tensile strength (MPa) Tensile modulus (MPa) Elongation at break (%) Example 3 172.6 9367.8 5.6 Example 4 167.8 9212.4 5.2 Example 5 164.5 9083.7 4.9 Example 6 175.9 9534.2 5.8 Example 7 165.7 9163.1 5.1 Comparative Example 1 158.6 8744.8 4.6

[0064] As shown in Table 2, compared to Comparative Example 1, Examples 3-7 used tricyclopentadiene as an additive, which significantly improved tensile strength, tensile modulus, and elongation at break. It also lowered the freezing point of the liquid, facilitating the pouring operation. Using diphenyldimethoxysilane as a catalyst solvent eliminated the degassing step, simplifying the operation process.

[0065] Test Example 2: Bending Strength and Bending Modulus

[0066] Test samples: Composite materials prepared in Examples 3-7 and Comparative Example 1;

[0067] The flexural strength and flexural modulus were tested using a microcomputer-controlled electronic universal testing machine (model CMT4304) from METS Industrial Systems (China) Co., Ltd., at a test speed of 2 mm / min, in accordance with the GB / T 9341-2008 standard.

[0068] Bending strength is calculated according to formula (4):

[0069]

[0070] In the formula σ t ρ is the bending strength (MPa), p is the maximum load (N), L is the span (mm), b is the specimen width (mm), and h is the specimen thickness (mm).

[0071] The flexural modulus is calculated according to formula (5):

[0072]

[0073] In the formula E t ΔP is the bending modulus (MPa), L is the span (mm), ΔP is the load increment (N) corresponding to the initial straight line segment on the load-deflection curve, b is the specimen width (mm), h is the specimen thickness (mm), and ΔS is the mid-span deflection (mm) corresponding to the load increment ΔP.

[0074] Table 3 Summary of flexural strength and flexural modulus test results

[0075] Serial Number Bending strength (MPa) Flexural modulus (MPa) Example 3 174.5 11581.5 Example 4 171.8 10976.3 Example 5 167.7 10283.6 Example 6 178.2 12667.4 Example 7 168.4 10538.9 Comparative Example 1 160.6 9856.3

[0076] As shown in Table 3, compared to Comparative Example 1, Examples 3-7 used tricyclopentadiene as an additive, resulting in a significant improvement in flexural strength and flexural modulus. Simultaneously, it lowered the freezing point of the liquid, facilitating the pouring operation. Using diphenyldimethoxysilane as a catalyst solvent eliminates the degassing step, simplifying the operation process. Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for preparing a polydicyclopentadiene / glass fiber mat composite material, characterized in that, include: Step (1): On the glass plate, lay the release cloth, fiberglass mat, release cloth, flow guide net and vacuum bag in sequence, and draw a vacuum to maintain pressure; Step (2): Pour the cycloolefin liquid into the vacuum bag of step (1), heat and cure in stages, and demold to obtain polydicyclopentadiene / glass fiber mat composite material; The specific preparation of the cyclic olefin feed solution is as follows: A1. Thoroughly mix 100 parts by weight of DCPD and 5-20 parts by weight of TCPD system to prepare a homogeneous mixed solution; wherein the TCPD system contains 10 wt% TCPD and 90 wt% DCPD. A2. Dissolve 0.02-0.06 parts by weight of Grubbs second-generation catalyst and 0.002-0.006 parts by weight of retarder in 1-2 parts by weight of high-boiling-point silane coupling agent, and add them to the mixed solution in step A1 to obtain the feed solution.

2. The method according to claim 1, characterized in that, The polymerization retarder is selected from one or any combination of tributyl phosphite, triphenylphosphine, and tributyl phosphate.

3. The method according to claim 2, characterized in that, The retarder is tributyl phosphite.

4. The method according to claim 1, characterized in that, The high-boiling-point silane coupling agent is selected from at least one of diphenyldimethoxysilane, phenyltrimethoxysilane, p-chlorophenyltrimethoxysilane, 3-aminopropyltriethoxysilane, mercaptopropyltrimethoxysilane, benzyltriethoxysilane, triethoxypentylsilane, methylcyclohexyldimethoxysilane, and n-hexyltrimethoxysilane.

5. The method according to claim 4, characterized in that, The high-boiling-point silane coupling agent is diphenyldimethoxysilane.

6. The method according to claim 1, characterized in that, The stage heating and curing conditions are: 0.25 to 1.5 hours at 60°C and 0.5 to 1.5 hours at 140°C.

7. The method according to claim 1, characterized in that, The vacuuming and pressure holding time is 1-2 hours.

8. A polydicyclopentadiene / glass fiber mat composite material, prepared using the method described in any one of claims 1 to 7.

9. The composite material according to claim 8, characterized in that, The tensile strength of the composite material is ≥160MPa, and the tensile modulus is ≥9000MPa; The elongation at break of the composite material is ≥4%; The composite material has a flexural strength ≥160MPa and a flexural modulus ≥10000MPa.

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