Modified dicyclopentadiene as well as preparation method and application thereof

Abstract

The invention belongs to the field of high polymer materials, and particularly relates to modified dicyclopentadiene as well as a preparation method and application thereof. The modified dicyclopentadiene is hydroxylated or acylated dicyclopentadiene, and is prepared by carrying out allylic reaction on dicyclopentadiene. According to the polymer material prepared from the modified dicyclopentadiene, low odor and low odor are realized through the modified dicyclopentadiene, so that the application range of the dicyclopentadiene and derivatives thereof is widened.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and in particular relates to modified dicyclopentadiene and a preparation method and application thereof. Background Art

[0002] Dicyclopentadiene (DCPD) is a byproduct of the petroleum industry, so it is quite economical and easy to obtain, and is very popular for industrial use. In the past few decades, researchers have conducted in-depth research on the polymerization reaction of DCPD in the presence of different initiators (such as alkylene ruthenium). The two double bonds in the DCPD monomer have different properties. Under the conditions of using suitable catalysts, the initial ring-opening metathesis polymerization (ROMP) is the norbornene part in DPCD, producing a linear polymer, while the highly reactive catalyst can further open the ring of the less reactive cyclopentene part to produce a cross-linked thermosetting polymer PDCPD. PDCPD materials have excellent mechanical and thermal properties such as high modulus, high strength, high temperature resistance and acid and alkali corrosion resistance. Because the processing process adopts reaction injection molding (RIM), the polymer polymerization reaction and plastic molding are combined in one step, and large-scale parts can be quickly prepared. It has a wide range of applications in automotive materials, batteries, petrochemical industry pipelines and other fields.

[0003] Although PDCPD has attracted much attention in industry and academia, it has a significant disadvantage: PDCPD has an unpleasant odor. This characteristic limits its application in many fields, so solving the odor of PDCPD materials is the focus of researchers. Summary of the invention

[0004] In order to solve the above technical problems, the object of the present invention is to provide a modified dicyclopentadiene and a preparation method thereof, which can reduce the odor emission of PDCPD by modifying DCPD, thereby improving its unpleasant odor and maintaining the physical properties of PDCPD.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0006] A modified dicyclopentadiene, the structural formula of which is

[0007]

[0008] The modified dicyclopentadiene of formula (1) or formula (2) is obtained by subjecting dicyclopentadiene to allylic modification reaction.

[0009] The allylic modification reaction is to modify dicyclopentadiene by hydrogenation; or

[0010] The allylic modification reaction is to modify dicyclopentadiene by hydrogenation, oxidation and acylation.

[0011] Furthermore, the modified dicyclopentadiene of formula (1) is prepared by the following method:

[0012] Mix 30-50 parts by weight of dicyclopentadiene, 60-70 parts by weight of 1,4-dioxane and 1-10 parts by weight of deionized water, and then add 30-50 parts by weight of selenium dioxide; heat to 80-120° C. and react for 2-5 hours; after the reaction is completed, cool, remove the solvent, and dry to obtain a crude product; filter, wash, and distill the crude product to obtain modified dicyclopentadiene of formula (1).

[0013] Furthermore, the modified dicyclopentadiene of formula (2) is prepared by the following method:

[0014] 1 part by weight of modified dicyclopentadiene of formula (1), 30-60 parts by weight of dichloromethane and 0.1-10 parts by weight of triethylamine are stirred and mixed at low temperature, and then 0.1-5 parts by weight of acetyl chloride are added to react, and a first product is obtained after the reaction; the first product is washed with deionized water, and the organic layer is separated, dried and purified to obtain modified dicyclopentadiene of formula (2).

[0015] A modified polydicyclopentadiene is prepared by polymerizing modified dicyclopentadiene of formula (1) or formula (2) as a raw material.

[0016] Furthermore, during the above polymerization reaction, tricyclopentadiene, reinforcing material, coupling agent, antioxidant and catalyst are also added.

[0017] Furthermore, in the process of preparing modified polydicyclopentadiene, the weight ratio of modified dicyclopentadiene, tricyclopentadiene, reinforcing material, coupling agent, antioxidant and catalyst is 70-100:20-30:30-120:5-10:0.5-2:0.1-1.

[0018] Furthermore, the reinforcing material includes but is not limited to carbon black.

[0019] Furthermore, the coupling agent includes but is not limited to a silane coupling agent.

[0020] Furthermore, the antioxidant includes but is not limited to BHT.

[0021] Furthermore, the catalyst includes but is not limited to Grubbs second generation catalyst.

[0022] A vehicle-mounted material comprises modified polydicyclopentadiene obtained by modifying dicyclopentadiene according to formula (1) or formula (2).

[0023] The beneficial effect of adopting the technical solution is that the invention improves the odor of the polydicyclopentadiene product while maintaining the excellent mechanical properties of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The figure is a synthetic route diagram of the hydroxylated dicyclopentadiene of the present invention.

[0025] Figure 2 The figure is a synthetic route diagram of the acylated dicyclopentadiene of the present invention. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the technical solutions in this application, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are only part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0027] Example 1

[0028] The steps for making the modified polydicyclopentadiene material 1 are as follows:

[0029] A1: Mix furnace carbon black (purchased from Greagent) and acetone in a mass ratio of 1:2, add silane coupling agent into the system (the mass ratio of silane coupling agent to carbon black acetone solution is 0.5:100). Stir and react at room temperature at a speed of 200 rpm for 3 hours, then filter and wash with anhydrous ethanol, and vacuum dry at 100°C to obtain the treated carbon black.

[0030] A2: Take dicyclopentadiene and dimerize it at 100°C for 30 minutes, then continue to increase the reaction temperature to 200°C and react for 1 hour to obtain tricyclopentadiene.

[0031] A3: See Figure 1 , dicyclopentadiene, 1,4-dioxane and deionized water are mixed in a weight ratio of 30:65:6, stirred at a speed of 200 rpm at 25°C, and then solid selenium dioxide is added (the weight ratio of selenium dioxide to dicyclopentadiene is 1:1); the temperature is raised to 110°C, and the reaction is refluxed for 3 hours; after the reaction is completed, it is cooled to 25°C, and the solvent is removed by a rotary evaporator at 60°C. After the rotary evaporation, anhydrous magnesium sulfate solid is added, and the mixture is cooled to 25°C; the crude product is filtered and washed with ether three times, and finally a fraction of 70-73°C is collected in a small distillation tower to obtain hydroxylated dicyclopentadiene (hereinafter referred to as DCPD-OH).

[0032] A4: Modified dicyclopentadiene (80 parts by weight), carbon black (30 parts by weight) obtained in step A1, tricyclopentadiene (20 parts by weight) obtained in step A2 and antioxidant BHT (0.5 parts by weight, purchased from Adamas) are mixed, and stirred at 200 rpm at 25°C to mix them evenly to obtain a first mixed solution; Grubbs second-generation catalyst (0.5 parts by weight, purchased from Aladdin) is dissolved in phenyltrimethoxysilane (7 parts by weight), mixed with the first mixed solution and injected into the mold.

[0033] A5: Place the mold in an oven and keep it at 60°C for 15 minutes, then raise the temperature to 140°C and keep it for 1 hour. After cooling, open the mold to obtain the modified dicyclopentadiene material 1.

[0034] Example 2

[0035] The steps for making the modified polydicyclopentadiene material 2 are as follows:

[0036] B1: Same as step A1 in Example 1;

[0037] B2: Same as step A2 of Example 1;

[0038] B3: Same as step A3 of Example 1;

[0039] B4: See Figure 2 , 1 part by weight of DCPD-OH was placed in a round-bottom flask, and vacuum-purged and nitrogen-filled for three consecutive times. Then, 50 parts by weight of dry dichloromethane and 1 part by weight of triethylamine were added to the round-bottom flask, and the system was stirred at 0°C for 30 minutes; then, 2 parts by weight of acetyl chloride were added to the system, and the reaction was stirred at 200 rpm at 25°C for 12 hours. The reaction product was rinsed with deionized water, and the organic layer was separated and dried with anhydrous magnesium sulfate and purified to obtain acylated modified dicyclopentadiene (hereinafter referred to as DCPD-OBz).

[0040] B5: Same as step A4 of Example 1;

[0041] B6: Place the mold in an oven and keep it at 60°C for 15 minutes, then raise the temperature to 140°C and keep it for 1 hour. After cooling, open the mold to obtain the modified dicyclopentadiene material 2.

[0042] Comparative Example 1

[0043] The steps for making polydicyclopentadiene material are as follows:

[0044] C1: same as A1 in Example 1;

[0045] C2: Same as A2 in Example 1.

[0046] C3: Dicyclopentadiene (80 parts by weight), carbon black (30 parts by weight) obtained in step A1, tricyclopentadiene (20 parts by weight) obtained in step A2 and antioxidant BHT (0.5 parts by weight) are mixed, and stirred at 200 rpm at 25°C to make the mixture uniform, to obtain a mixed solution of dicyclopentadiene; Grubbs second-generation catalyst (0.5 parts by weight) is dissolved in phenyltrimethoxysilane (7 parts by weight), mixed with the mixed solution of dicyclopentadiene and injected into the mold.

[0047] C4: Place the mold in an oven and keep it at 60°C for 15 minutes, then raise the temperature to 140°C and keep it for 1 hour. After cooling, open the mold to obtain the polydicyclopentadiene material.

[0048] Test Example 1 Mechanical Properties Test

[0049] Test samples: material specimens of Comparative Example 1, Example 1 and Example 2.

[0050] Test method:

[0051] The tensile test specimens were prepared in accordance with GB / T2567-2008, and the specimens were prepared into a standard dumbbell shape using a dumbbell sample making machine. The specimens were characterized and tested using a CMT4204 microcomputer electronic universal testing machine produced by MTS, USA. Each set of experiments was performed at least 5 times, and the specimen loading rate was 2mm / min.

[0052] The bending test specimens were also prepared according to GB / T2567-2008, and the specimen size was: 80×10×4mm 3 The samples were characterized and tested by CMT4204 microcomputer electronic universal testing machine produced by MTS Corporation of the United States, and each group of experiments was performed at least 5 times.

[0053] The impact strength test specimens are prepared according to GB / T2567-2008, and the specimen size is: 80×10×4mm 3 , and a 2mm (1 / 5 width) notch was punched on one side of the spline using an automatic notching machine. The impact strength with notch was tested using a pendulum impact tester produced by MTS, USA, with each test set being no less than 5 times. The pendulum falls from a fixed position, and the potential energy is converted into kinetic energy, thus breaking the notched end of the spline, and the corresponding impact strength is calculated based on the energy difference.

[0054] Table 1

[0055] name Comparative Example 1 Example 1 Example 2 Tensile modulus 2010.16 2001.49 2039.45 Flexural modulus 1995.71 1919.65 2129.42 Notch shock 4.16 4.13 5.78

[0056] Referring to Table 1, from the mechanical properties comparison of Comparative Example 1, Example 1 and Example 2, the difference between the three is that the raw material used in Comparative Example 1 is DCPD, while the raw material used in Example 1 is hydroxylated DCPD, and the raw material used in Example 2 is acylated DCPD. It can be found that the mechanical properties of the three are not much different. This shows that the use of modified DCPD as a polymerization raw material has little effect on the mechanical properties of the obtained material.

[0057] Test Example 2 Single-body thermal analysis test

[0058] Test method: Thermogravimetric analysis was performed in accordance with GB / T 27761-2011.

[0059] Table 2

[0060]

[0061] As shown in Table 2, the thermal analysis test results of the monomers show that the decomposition temperature of the modified DCPD-OH and DCPD-OBz is higher than that of the DCPD raw material. This may be because the new groups after modification can form hydrogen bonds, and the increase in intermolecular forces also reduces the volatility of the monomers.

[0062] Test Example 3 VOC Detection

[0063] Test samples: material specimens of Comparative Example 1, Example 1 and Example 2.

[0064] Test method: Use the bag method to test the VOC of the material.

[0065] Table 3

[0066]

[0067]

[0068] Referring to Table 3, the VOC data of Comparative Example 1, Example 1 and Example 2 are compared. The difference between the three is that the raw material used in Comparative Example 1 is DCPD, while the raw material used in Example 1 is hydroxylated DCPD, and the raw material used in Example 2 is acylated DCPD. It can be found that after the DCPD raw material is modified, the VOC content decreases by 80%. It shows that using modified DCPD as a polymerization raw material can reduce the VOC of the material. Among them, VOC is mainly the monomer that escapes from the material. Since the monomer in Comparative Example 1 is DCPD, and the monomers in Examples 1 and 2 are modified substances of DCPD, the polarity of the modified DCPD is increased compared to the original substance, the corresponding intermolecular interaction is also increased, and the boiling point of the monomer is increased, so the volatility will be reduced.

Claims

1. A modified dicyclopentadiene having the structural formula 2. The modified dicyclopentadiene according to claim 1, characterized in that The modified dicyclopentadiene is obtained by subjecting dicyclopentadiene to an allylic modification reaction.

3. The modified dicyclopentadiene according to claim 2, characterized in that The allylic modification is hydrogenation modification or hydrogenation, oxidation, acylation modification.

4. The modified dicyclopentadiene according to claim 3, characterized in that The modified dicyclopentadiene of formula (1) is prepared by the following method: Mix 30-50 parts by weight of dicyclopentadiene, 60-70 parts by weight of 1,4-dioxane and 1-10 parts by weight of deionized water, and then add 30-50 parts by weight of selenium dioxide; heat to 80-120° C. and react for 2-5 hours; after the reaction is completed, cool, remove the solvent, and dry to obtain a crude product; filter, wash, and distill the crude product to obtain modified dicyclopentadiene of formula (1).

5. The modified dicyclopentadiene according to claim 4, characterized in that The modified dicyclopentadiene of formula (1) is prepared by the following method: The weight ratio of the dicyclopentadiene, the 1,4-dioxane, the deionized water and the selenium dioxide is 30:65:6:

30.

6. The modified dicyclopentadiene according to claim 3, characterized in that The modified dicyclopentadiene of formula (2) is prepared by the following method: 1 part by weight of the modified dicyclopentadiene of formula (1), 30-60 parts by weight of dichloromethane and 0.1-10 parts by weight of triethylamine are stirred and mixed at low temperature, and then 0.1-5 parts by weight of acetyl chloride are added to react, and a first product is obtained after the reaction; the first product is washed with deionized water, and the organic layer is separated, dried and purified to obtain the modified dicyclopentadiene of formula (2).

7. The modified dicyclopentadiene according to claim 6, characterized in that The weight ratio of the modified dicyclopentadiene of formula (1), the dichloromethane, the triethylamine and the acetyl chloride is 1:50:1:

2.

8. A modified polydicyclopentadiene, characterized in that: The modified dicyclopentadiene of formula (1) or formula (2) described in claim 1 is used as a raw material and polymerized.

9. The modified polydicyclopentadiene according to claim 8, characterized in that During the polymerization process, tricyclopentadiene, a reinforcing material, a coupling agent, an antioxidant and a catalyst are also added; the weight ratio of the modified dicyclopentadiene, the tricyclopentadiene, the reinforcing material, the coupling agent, the antioxidant and the catalyst is 70-100:20-30:30-120:5-10:0.5-2:0.1-1.

10. A vehicle-mounted material, comprising the modified polydicyclopentadiene according to claim 8 or 9.

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