Fiber-reinforced polydicyclopentadiene base material and preparation method thereof

Abstract

According to the fiber-reinforced polydicyclopentadiene base material and the preparation method thereof provided by the invention, solvent pretreatment, alkali washing and silane coupling agent treatment are carried out on chopped fibers or fiber powder of selected aramid fibers, carbon fibers or glass fibers, so that the wettability of the fibers and a dicyclopentadiene feed liquid is improved; and fully infiltrating the fiber reinforced polydicyclopentadiene base material with dehydrated and pour point depressed dicyclopentadiene to finally prepare the fiber reinforced polydicyclopentadiene base material. Through subsequent material liquid preparation and reaction molding detection, compared with a common polydicyclopentadiene base material, the tensile strength and bending strength of fiber-reinforced polydicyclopentadiene prepared from the fiber-reinforced polydicyclopentadiene base material prepared by the method are greatly improved, the impact strength is improved by about 104.67%, and the bending strength is improved by about 65.98%.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer material production, and particularly relates to a fiber-reinforced polydicyclopentadiene base material and a preparation method thereof. Background Art

[0002] Polydicyclopentadiene (PDCPD) is a new type of thermosetting resin material with excellent properties and environmental friendliness, which is obtained by ring-opening metathesis polymerization of dicyclopentadiene (DCPD). Fiber reinforcement of PDCPD materials is beneficial to further improving the mechanical properties of the materials, thereby further expanding the application scenarios of the products. Therefore, how to prepare a composite PDCPD material by low-cost molding of PDCPD materials and fibers is a research direction with commercial prospects and scientific significance. However, due to the dense and smooth surface of the fibers, it is difficult for PDCPD to infiltrate, bond, and form a good interfacial layer with PDCPD, and it is difficult to generate mechanical interlocking with the molded PDCPD. Therefore, the current fiber surface treatment technology has not achieved perfect infiltration and molding between fiber materials and PDCPD raw materials, which greatly hinders the development of fiber-reinforced PDPCD materials. Summary of the Invention

[0003] (1) Technical Problems to be Solved

[0004] The present invention provides a fiber-reinforced polydicyclopentadiene base material and a preparation method thereof, aiming to solve the technical problems of how to improve the wettability between fibers and PDCPD liquid, enhance the molding effect and mechanical interlocking ability of fiber-reinforced polydicyclopentadiene, and thus greatly improve the mechanical properties of PDCPD products.

[0005] (2) Technical Solutions

[0006] To solve the above technical problems, the present invention provides a preparation method of a fiber-reinforced polydicyclopentadiene base material, which comprises the following steps:

[0007] S1. The fibers are pretreated with a solvent by soaking in an excessive amount of organic solvent to remove residual organic impurities on the fiber surface, and then rinsed and dried.

[0008] S2. The fibers obtained in step S1 are placed in an excessive amount of alkaline solution for a water bath treatment, and then rinsed and dried after the water bath.

[0009] S3. An ethanol aqueous solution and a coupling agent are formulated into a mixed solution, the pH value of the mixed solution is adjusted, the fibers obtained in step S2 are added to the mixed solution, the fibers are surface-treated, and then rinsed and dried.

[0010] S4. Melt the dicyclopentadiene raw material into a liquid at 50 °C, add ethylidene norbornene, and stir well until evenly dispersed to obtain a dicyclopentadiene solution;

[0011] S5. Add molecular sieve to the dicyclopentadiene solution obtained in step S4, keep it airtight and stand still, and then filter off the molecular sieve under a nitrogen atmosphere;

[0012] S6. Mix and infiltrate the fiber obtained in step S3 with the dicyclopentadiene solution obtained in step S5, heat and perform ultrasonic treatment to prepare a fiber-reinforced polydicyclopentadiene base material.

[0013] Further, in step S1, the fiber material includes glass fiber, carbon fiber or aramid fiber; among them, the diameter of the glass fiber is 5 - 10 μm; the diameter of the carbon fiber is 5 - 10 μm, and the carbon content is above 90%; the diameter of the aramid fiber is 14 - 16 μm; the form of the fiber is chopped fiber or fiber powder.

[0014] Further, in step S1, the organic solvent is acetone, dichloromethane, tetrahydrofuran or petroleum ether, and the soaking time is 24 - 48 h.

[0015] Further, in step S2, the alkali solution is a NaOH solution with a mass fraction of 8 - 14%; the water bath temperature is 80 - 100 °C, and the water bath heating time is 2 - 4 h.

[0016] Further, in step S1, the drying temperature is 60 - 80 °C, and the drying time is 8 - 14 h; in steps S2 and S3, the drying temperature is 50 - 70 °C, and the drying time is 4 - 6 h.

[0017] Further, in step S3, the volume ratio in the ethanol aqueous solution is V 乙醇 :V 水 = 3:1; the coupling agent is KH-550, KH-551, KH-560, KH-580 or KH-590; use acetic acid to adjust the pH of the mixed solution to 4 - 5, and the coupling agent concentration is 0.1 - 2%; perform surface treatment on the fiber at room temperature for 1 h.

[0018] Further, in step S4, melt the dicyclopentadiene raw material into a liquid at 50 °C; the mass fraction of ethylidene norbornene is 5 - 13%.

[0019] Further, in step S5, the mass fraction of the added molecular sieve is 5 - 10%; the type of the molecular sieve is 4A molecular sieve, and the standing time is 48 - 72 h.

[0020] Further, in step S6, the mass fraction of the added fiber is 1 - 8%; the heating temperature is 30 - 45 °C, the ultrasonic frequency is 2000 Hz, and the ultrasonic power is 0.5 W / cm 2, the ultrasonic time is 1 to 2.5 h.

[0021] In addition, the present invention also provides a fiber-reinforced dicyclopentadiene base material, which is prepared by the above method.

[0022] (III) Beneficial effects

[0023] The present invention provides a fiber-reinforced dicyclopentadiene base material and a preparation method thereof. By subjecting the short-cut fibers or fiber powders of aramid fibers, carbon fibers or glass fibers selected to solvent pretreatment, alkali washing and silane coupling agent treatment, the wettability of the fibers and the dicyclopentadiene liquid material is improved, and then fully infiltrated with the dehydrated and pour-point-depressed dicyclopentadiene, and finally a fiber-reinforced dicyclopentadiene base material is prepared. After subsequent liquid material preparation and reaction molding detection, compared with the ordinary dicyclopentadiene base material, the tensile strength and flexural strength of the fiber-reinforced dicyclopentadiene prepared from the fiber-reinforced dicyclopentadiene base material prepared according to the present invention are greatly improved, the impact strength is increased by about 104.67%, and the flexural strength is increased by about 65.98%. Description of the drawings

[0024] Figure 1 is a process flow chart of the preparation method of the fiber-reinforced dicyclopentadiene base material of the present invention. Detailed embodiments

[0025] In order to make the purpose, content and advantages of the present invention clearer, the following combines the drawings and embodiments to further describe in detail the specific embodiments of the present invention.

[0026] Example 1

[0027] This example provides a preparation method of a fiber-reinforced dicyclopentadiene base material, and its process is as Figure 1 shown, and mainly includes the following steps:

[0028] S1. Soak with an excessive amount of acetone solvent for 24 h to remove organic impurities such as residual oil stains on the surface of the short-cut aramid fibers. After rinsing with acetone, place them in a blast drying oven and dry at 75 °C for 10 h;

[0029] S2. Place the short-cut aramid fibers obtained in step S1 in an excessive amount of 10% NaOH solution, treat them in a water bath at 80 °C for 8 h, then wash them thoroughly with deionized water at room temperature, and vacuum dry at 60 °C for 4 h;

[0030] S3. Prepare a 0.2% KH-551 solution with an ethanol aqueous solution with a volume ratio of 3:1, adjust the pH of the mixed solution to 5 with acetic acid, add the short-cut aramid fibers obtained in step S2 for surface treatment at room temperature for 1 h, wash them thoroughly with deionized water at room temperature, and vacuum dry at 60 °C for 4 h;

[0031] S4. Melt the DCPD raw material into a liquid at 50 °C, add ethylidene norbornene with a mass fraction of 8%, and stir well to disperse it evenly to obtain a DCPD solution;

[0032] S5. Add 4A molecular sieve with a mass fraction of 5% to the DCPD solution obtained in step S4, keep it airtight and static for 72 h, and then filter off the molecular sieve under a nitrogen atmosphere;

[0033] S6. Mix the chopped aramid fiber obtained in step S3 with the DCPD solution obtained in step S5 at a mass fraction of 5% and fully infiltrate it. After heating to 40 °C, perform ultrasonic treatment. The ultrasonic frequency is 2000 Hz and the power is 0.5 W / cm 2 , and the ultrasonic time is 1.5 h. Finally, a fiber-reinforced polydicyclopentadiene base material is prepared;

[0034] S7. Add the fiber-reinforced polydicyclopentadiene base material obtained in step S6 to styrene-butadiene rubber and dissolve and disperse it fully to prepare a fiber-reinforced polydicyclopentadiene rubber solution. Add triethylaluminum and related additives to material A; add TiCl4 main catalyst system and related additives to material B, and then prepare test specimens by RIM. Five batches of samples are prepared according to this formula and molding experiments are carried out.

[0035] Example 2

[0036] Steps S4, S5, and S7 are the same as those in Example 1;

[0037] S1. Soak the carbon fiber powder in an excessive amount of acetone solvent for 24 h to remove residual organic impurities such as oil stains on the surface of the carbon fiber powder. After rinsing it clean with acetone, place it in a blast drying oven and dry it at 75 °C for 10 h;

[0038] S2. Place the carbon fiber powder obtained in S1 in an excessive amount of NaOH solution with a mass fraction of 10%, treat it in a water bath at 80 °C for 8 h, and then wash it thoroughly with deionized water at room temperature and dry it in a vacuum at 60 °C for 4 h;

[0039] S3. Prepare a KH-551 solution with a mass fraction of 0.2% using an ethanol aqueous solution with a volume ratio of 3:1. Adjust the pH of the mixed solution to 5 with acetic acid, add the carbon fiber powder obtained in step S2 for surface treatment at room temperature for 1 h, wash it thoroughly with deionized water at room temperature, and dry it in a vacuum at 60 °C for 4 h;

[0040] S6. Mix the carbon fiber powder obtained in step S3 with the DCPD solution obtained in step S5 at a mass fraction of 4% and fully infiltrate it. After heating to 40 °C, perform ultrasonic treatment. The ultrasonic frequency is 2000 Hz and the power is 0.5 W / cm 2 , and the ultrasonic time is 1.5 h. Finally, a fiber-reinforced polydicyclopentadiene base material is prepared.

[0041] Example 3

[0042] Steps S4, S5, and S7 are the same as those in Example 1;

[0043] S1. Soak with an excessive amount of acetone solvent for 24 h to remove organic impurities such as residual oil stains on the surface of the chopped glass fibers. After rinsing with acetone, place them in a blast drying oven and dry at 75 °C for 10 h.

[0044] S2. Place the chopped glass fibers obtained in step S1 in an excessive amount of 10% NaOH solution by mass fraction. After treating in a water bath at 80 °C for 8 h, wash them thoroughly with deionized water at room temperature and vacuum dry at 60 °C for 4 h.

[0045] S3. Prepare a 0.2% KH-550 solution by mass fraction using an ethanol aqueous solution with a volume ratio of 3:1. Adjust the pH of the mixed solution to 5 with acetic acid. Add the chopped glass fibers obtained in step S2 for surface treatment at room temperature for 1 h. Wash them thoroughly with deionized water at room temperature and vacuum dry at 60 °C for 4 h.

[0046] S6. Mix the chopped glass fibers obtained in step S3 with the DCPD solution obtained in step S5 at a mass fraction of 5% and soak them fully. After heating to 40 °C, perform ultrasonic treatment. The ultrasonic frequency is 2000 Hz, the power is 0.5 W / cm 2 , and the ultrasonic time is 1.5 h. Finally, prepare a fiber-reinforced poly(dicyclopentadiene) base material.

[0047] Comparative Example

[0048] S1. Melt the DCPD raw material into a liquid at 50 °C, add ethylidene norbornene with a mass fraction of 8%, and stir well to disperse it evenly;

[0049] S2. Add 4A molecular sieve with a mass fraction of 5% to the DCPD solution obtained in step S1, keep it sealed and stand for 72 h, and then filter out the molecular sieve under a nitrogen atmosphere;

[0050] S3. Add the fiber-reinforced poly(dicyclopentadiene) base material obtained in step S2 to styrene-butadiene rubber and dissolve and disperse it fully to prepare a fiber-reinforced poly(dicyclopentadiene) rubber solution. Add triethylaluminum and related additives to the A component; add the main catalyst system of TiCl4 and related additives to the B component, and then prepare test specimens by RIM. Prepare five batches of samples according to this formula and conduct molding experiments.

[0051] The detection results of various parameters and various physical properties of the test specimens prepared in Examples 1 to 3 and the comparative example are shown in Table 1 (the values in the table are the average values of five data).

[0052] Table 1 Comparison of the test results of various parameters of the test splines prepared in Examples 1 to 3 and the comparative example

[0053]

[0054] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a fiber-reinforced polydicyclopentadiene base material, characterized in that, The preparation method comprises the following steps: S1. Solvent pretreatment of the fiber by soaking it in an excess of organic solvent to remove residual organic impurities on the fiber surface, followed by rinsing and drying; S2. The fiber obtained in step S1 is placed in an excess of an alkaline solution and treated in a water bath, and then rinsed and dried in a water bath; S3. The ethanol aqueous solution and the coupling agent are prepared into a mixed solution, the pH value of the mixed solution is adjusted, the fiber obtained in step S2 is added to the mixed solution, the fiber is surface treated, and then rinsed and dried; S4. The dicyclopentadiene raw material was melted into a liquid at 50 ° C, ethylidene norbornene was added, and stirred until uniformly dispersed to obtain a dicyclopentadiene solution; S5. The dicyclopentadiene solution obtained in step S4 is added with molecular sieves, and kept sealed and allowed to stand, and then the molecular sieves are filtered out under a nitrogen atmosphere; S6. The fiber obtained in step S3 is mixed and infiltrated with the dicyclopentadiene solution obtained in step S5, heated and ultrasonically treated to obtain a fiber-reinforced polydicyclopentadiene base material.

2. The preparation method of the fiber-reinforced polydicyclopentadiene base material according to claim 1, characterized in that In step S1, the fiber material includes glass fiber, carbon fiber or aramid fiber; wherein the diameter of the glass fiber is 5 to 10 μm; the diameter of the carbon fiber is 5 to 10 μm, and the carbon content is above 90%; the diameter of the aramid fiber is 14 to 16 μm; and the fiber is in the form of chopped fibers or fiber powder.

3. The preparation method of the fiber-reinforced polydicyclopentadiene base material according to claim 1, characterized in that, In step S1, the organic solvent is acetone, dichloromethane, tetrahydrofuran or petroleum ether, and the soaking time is 24 to 48 hours.

4. The preparation method of the fiber-reinforced polydicyclopentadiene base material according to claim 1, characterized in that, In step S2, the alkaline solution is a NaOH solution with a mass fraction of 8-14%; the water bath temperature is 80-100°C, and the water bath heating time is 2-4 hours.

5. The preparation method of the fiber-reinforced polydicyclopentadiene base material according to claim 1, characterized in that, In step S1, the drying temperature is 60-80°C and the drying time is 8-14 hours; in steps S2 and S3, the drying temperature is 50-70°C and the drying time is 4-6 hours.

6. The preparation method of the fiber-reinforced polydicyclopentadiene base material according to claim 1, wherein, In step S3, the volume ratio in the aqueous ethanol solution is V 乙醇 :V 水 = 3:1; the coupling agent is KH-550, KH-551, KH-560, KH-580 or KH-590; the pH of the mixed solution is adjusted to 4-5 with acetic acid, and the concentration of the coupling agent is 0.1-2%; the fiber is surface-treated at room temperature for 1 h.

7. The preparation method of the fiber-reinforced polydicyclopentadiene base material according to claim 1, wherein, In step S4, the dicyclopentadiene raw material is melted into a liquid at 50° C.; the mass fraction of ethylidene norbornene is 5 to 13%.

8. The preparation method of the fiber-reinforced polydicyclopentadiene base material according to claim 1, characterized in that, In step S5, the mass fraction of the added molecular sieve is 5 to 10%; the type of the molecular sieve is 4A molecular sieve, and the standing time is 48 to 72 hours.

9. The method for preparing a fiber-reinforced polydicyclopentadiene base material according to claim 1, characterized in that, In step S6, the mass fraction of the added fiber is 1-8%; the heating temperature is 30-45°C, the ultrasonic frequency is 2000 Hz, and the ultrasonic power is 0.5 W / cm 2 , and the ultrasonic time is 1-2.5 h.

10. A fiber-reinforced polydicyclopentadiene base material, characterized in that, The fiber-reinforced polydicyclopentadiene base material is prepared by the method according to any one of claims 1 to 9.

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