Compound, polydicyclopentadiene resin and preparation method of polydicyclopentadiene resin

Abstract

The invention discloses a compound, polydicyclopentadiene resin and a preparation method thereof, and the preparation method of the polydicyclopentadiene resin comprises the following steps: mixing dicyclopentadiene, a regulator, a Grubbs catalyst and a compound of formula (I), and reacting at a first temperature to obtain a product. The preparation method comprises the following steps: mixing a compound shown as a formula (I) with DCPD, a Grubbs catalyst and a regulator to form a composition, and controlling a polymerization process to prepare a material which has excellent mechanical strength and can be controllably degraded under the conditions of acid or alkali and the like. The phosphate group contained in the hydrogel can generate inorganic phosphate after being hydrolyzed, the hydrogel has good biocompatibility, pollution which cannot be degraded by traditional cross-linked macromolecules can be relieved, and degradation products still have good environment-friendly properties.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of high polymer materials, and specifically provides a compound, a degradable polydicyclopentadiene and a preparation method thereof. The polydicyclopentadiene resin prepared by the method is suitable for the fields of preparing composite materials and electrical and electronic materials. BACKGROUND

[0002] Dicyclopentadiene (DCPD) is a compound containing a cyclic double bond structure, and as a petroleum chemical by-product, has the advantages of large output and low cost. Under the action of Grubbs catalyst, DCPD can generate polydicyclopentadiene (PDCPD) through ring-opening metathesis polymerization (ROMP) reaction. PDCPD is a high-performance thermosetting polymer, and has the advantages of good mechanical properties, good light transmittance, good dielectric properties, good chemical corrosion resistance and the like, and can be used for preparing composite materials, chemical equipment, electronic equipment and the like.

[0003] PDCPD has a crosslinked network structure, making it difficult to be dissolved or melted, and the excellent chemical corrosion resistance also makes it difficult to be degraded in the natural environment. With the increasingly stringent environmental regulations, the non-degradability of traditional PDCPD has become a problem restricting its sustainable development, and how to realize controllable degradation is a big problem for the development of PDCPD. SUMMARY

[0004] To solve the above problems, the present application provides a composition and a preparation method for preparing a degradable PDCPD material, and the following methods are provided to achieve the above-mentioned purposes: The first application aims to provide a compound having the structure of formula (I): (I) wherein R1 is selected from hydrogen, methyl, ethyl, butyl, isopropyl, chlorophenyl, phenethyl, m-methylphenyl or a benzene ring; m and n are the number of methylene groups, wherein m = 1, 2, 3, 4 or 5, and n = 1, 2, 3, 4 or 5.

[0005] wherein the compound of formula (I) can be selected from any one of compound 1, compound 2, compound 3, compound 4, compound 5 and compound 6, and the structural formulae are as follows: .

[0006] The second application aims to provide a polydicyclopentadiene resin composition, which comprises the following components in parts by weight: 5-100 parts of dicyclopentadiene, 0.1-95 parts of a regulator, 0.05-2 parts of Grubbs catalyst and 2.5-30 parts of the compound of formula (I).

[0007] The compound of formula (I) has the structure: (I) R1 is selected from hydrogen, methyl, ethyl or a benzene ring; m and n are the number of methylene groups, wherein m = 1, 2, 3, 4 or 5, and n = 1, 2, 3, 4 or 5.

[0008] According to an embodiment of the present application, the following components are included by weight parts: dicyclopentadiene 80-100 parts, a modifier 0.1-20 parts, a Grubbs catalyst 0.05-2 parts, and a compound of formula (I) 5-30 parts. Preferably, the compound of formula (I) is 15-20 parts.

[0009] According to an embodiment of the present application, the modifier is selected from one or more than two combinations of norbornene, norbornadiene, ethylidene norbornene, vinyl norbornene, 5-norbornene-2-methanol, 5-norbornene-2-ol, 5-norbornene-2-carboxylic acid, norbornene anhydride, cyclooctene, cyclooctadiene, dibromonorbomene methyl phenyl phosphate, dibromonorbomene phenyl phosphate.

[0010] The structural formula of the modifier is as follows: .

[0011] According to an embodiment of the present application, the compound of formula (I) is respectively named as compound 1, compound 2, compound 3, compound 4, compound 5, compound 6, and only part of the compounds are listed in the present application, and part of the preferred compounds are adopted, and other compounds with the same structure can also be applied to the present application. The structural formula of each compound is as follows: .

[0012] According to an embodiment of the present application, the Grubbs catalyst is respectively named as Grubbs catalyst 1, Grubbs catalyst 2, Grubbs catalyst 3, Grubbs catalyst 4, Grubbs catalyst 5, Grubbs catalyst 6, Grubbs catalyst 7, and Grubbs catalyst 8, and only part of the Grubbs catalysts are listed in the present application, and other Grubbs catalysts with the same structure can also be applied to the present application. The structural formula of each catalyst is as follows: .

[0013] The third application aims to provide a preparation method of polydicyclopentadiene resin, which comprises mixing dicyclopentadiene, a modifier, a Grubbs catalyst and a compound of formula (I), and then reacting at a first temperature to obtain a product.

[0014] The compound of formula (I) has the structure: (I) wherein: R1 is selected from hydrogen, methyl, ethyl or a benzene ring; m, n is the number of methylene, wherein m = 1, 2, 3, 4 or 5, n = 1, 2, 3, 4 or 5.

[0015] Further, the compound of formula (I) can be selected from compound 1, compound 2, compound 3, compound 4, compound 5, compound 6. The structural formula of each compound is as follows: .

[0016] According to the embodiment of the present application, the first temperature is 20-180℃; the reaction time under the first temperature condition is 0.5-120min.

[0017] The beneficial effects of the present application are: The compound of formula (I) is mixed with DCPD, Grubbs catalyst and regulator to form a composition, and then a material with excellent mechanical strength and controllable degradation under acid or alkaline conditions is prepared by controlling the polymerization process. The phosphate group contained in the material will generate inorganic phosphate after hydrolysis, has good biocompatibility, can reduce the pollution caused by the non-degradable traditional cross-linked polymer, and the degradation product still has good environmental properties. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 DMA curve of the present application examples 2, 3 and 4; Figure 2 DMA curve of the present application examples 14, 15 and 31; Figure 3 DMA curve of the present application comparative examples 1, 5 and 10; Figure 4 DMA curve of the present application recycling examples 1, 3 and 5.

[0019] The present technical solution exemplarily gives the DMA curve of part of the examples, comparative examples and recycling examples. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments.

[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. The terms "first," "second," etc., used in this application do not have a special meaning regarding order of representation or degree of importance.

[0022] Existing technologies for preparing controllable degradable polydicyclopentadiene (PDCPD) include, for example, CN202311266354.6, which discloses the addition of silyl ether monomers, such as silyl ether monomers; and CN202210556129.5, which discloses the use of diene monomers and dimercyclopentadiene monomers to obtain a thermosetting material that can be chemically degraded and recycled through metathesis copolymerization thermosetting.

[0023] This application has discovered through research that compounds of formula (Ⅰ) can form specific chain segments through ROMP reaction. Their chemical bonds are easily hydrolyzed and broken under strongly alkaline conditions such as sodium methoxide and sodium hydroxide (pH greater than 14) or acidic conditions such as hydrochloric acid (pH less than 2), thereby destroying the polymer network, achieving material degradation, and maintaining excellent mechanical strength.

[0024] This application uses Grubbs catalyst as the catalyst for ring-opening metathesis polymerization. Based on the characteristics of ring-opening metathesis polymerization, DCPD can be polymerized into polydicyclopentadiene under the action of Grubbs catalyst.

[0025] The preparation method of polydicyclopentadiene (PDCPD) is as follows: Weigh out dicyclopentadiene, regulator, and compound (I) in proportion, mix them evenly, then add Grubbs catalyst, mix rapidly, and polymerize at 20-180℃ for 0.5-120 min to obtain polydicyclopentadiene.

[0026] The tensile properties, dynamic mechanical properties, dielectric properties, and chemical degradation properties of the samples were tested. Dielectric properties were measured as the dielectric constant and dielectric loss at 1 MHz. The chemical degradation property test method involved placing 0.5 g of the sample in 50 ml of sodium methoxide in tetrahydrofuran solution and allowing it to stand for 0.5 days. The chemical degradation performance of polydicyclopentadiene was evaluated by measuring the percentage of polymer degradation relative to the initial polymer mass. The samples used in this application can be prepared in dumbbell shape, strip shape, or thin plate (100 mm × 100 mm × 2 mm) for testing.

[0027] The controlled degradation capability of this application refers to the ability to copolymerize DCPD with compounds of different contents of formula (Ⅰ) while maintaining the performance of PDCPD.

[0028] The various embodiments are shown in Table 1 below. The units for each component in the table are parts by weight, and the numbers represent the dosage: Table 1 Regarding the selection of implementation schemes, the following comparative examples were established for the selection of various components, parameters, and other factors. These comparative examples do not necessarily represent schemes that do not meet the objectives of this invention. The comparative examples are shown in Table 2 below. The units for each component in the table are parts by weight, and the numbers represent the dosage. Table 2 Comparative Examples 1-4, which do not contain the compound shown in Formula (I), clearly show that the prepared polydicyclopentadiene lacks degradation capability. Comparative Example 5, which added an excess of Compound 4, achieved degradation, but other properties were affected, limiting its application in some fields. Comparative Examples 9, 10, and 12, which provided compounds containing phosphate ester structures but not shown in Formula (I), showed no degradation. Comparative Example 11 provided one part of Compound 3, but the crosslinking product under this scheme only showed slight degradation, indicating a low amount of Compound 3. Comparative Examples 18 and 19 show that increasing the amount of Compound (I) can achieve 100% degradation.

[0029] Generally, with a total of 100 parts dicyclopentadiene and a regulator, adding more than 30 parts of compound (I) can achieve complete degradation. However, as the proportion of compound (I) increases, the overall performance of PDCPD decreases, limiting its application. Comparative Example 6 added a small amount of compound (I), resulting in a relatively low degradation rate, which also limits its application in scenarios requiring high degradation rates.

[0030] While the presence of regulators can provide other properties, they typically reduce the crosslinking density of polydicyclopentadiene, which is closely related to the solubility of the copolymer. Based on the embodiments of this application, it can be inferred that when the content of dicyclopentadiene is relatively high, the crosslinking density of the copolymer is relatively high. If the copolymer can be completely degraded, the amount of compound (I) also needs to be increased accordingly.

[0031] The degradation of PDCP is inherently difficult due to its excellent resistance to chemical corrosion, thus requiring relatively stringent degradation conditions. The products prepared according to the embodiments of this application can be degraded in 50 ml of sodium methoxide in tetrahydrofuran solution, with low degradation requirements. Verification has also shown that it can be degraded in strong acid or strong alkali solutions.

[0032] DMA tests were performed on the examples and comparative examples, and the results are shown in Tables 3 and 4 below: Table 3 Table 4 Polydicyclopentadiene, as a crosslinked thermosetting polymer, has gained attention for its durability and excellent mechanical properties, and has been used in many structural and high-performance applications in civil, energy, and transportation infrastructure. While crosslinking improves performance, it also increases the difficulty of handling. Therefore, thermosetting materials are often disposed of or incinerated at the end of their service life, making recycling troublesome and reuse difficult.

[0033] This invention proposes a method to restore the original thermosetting properties of degraded polydicyclopentadiene powder, giving these networks reprocessability similar to thermoplastics. The solution degraded using the methods disclosed in the above embodiments or existing technologies is recovered as polydicyclopentadiene powder through steps such as concentration, precipitation, and drying. The recovered polydicyclopentadiene powder is then press-molded to form a new monolith. The newly molded polymer sample retains 80%–90% of the original sample's comprehensive mechanical and thermal properties, as shown below: The degraded polydicyclopentadiene powder was uniformly mixed with Grubbs catalyst and incorporated into the catalyst at the same molar concentration as in the corresponding example. The polydicyclopentadiene and catalyst mixture was then added to a mold and sealed under vacuum. The mold was hot-pressed at 10 MPa for 1 hour at the same temperature as in the corresponding example. The tensile properties and dynamic mechanical properties of the reshaped samples were tested. Examples 1-4 and 6 were selected as recovery tests, and are respectively designated as Recovery Examples 1-5.

[0034] Table 5 Table 6 For recycling and reuse, a certain amount of DCPD monomer can be added to improve the performance of the prepared resin. Compared with specific application areas, the cost of resin prepared by recycling is lower, or the performance can be improved by adding new monomers to meet the balance requirements of cost and performance. Research has found that for cured resins with high content of degradable monomers, appropriate addition of monomers will result in a more significant improvement in performance. Cured products with high content of degradable monomers have low crosslinking degree and are more likely to form oligomers or low molecular weight products during degradation. After remolding, the crosslinking degree is not high and the performance is poor. In this case, the performance can be improved by adding new monomers.

[0035] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compound, characterized in that, It has the structure of formula (Ⅰ): （Ⅰ） Wherein: R1 is selected from hydrogen, methyl, ethyl or benzene ring; m and n are the number of methylene groups, where m = 1, 2, 3, 4 or 5, and n = 1, 2, 3, 4 or 5.

2. The compound according to claim 1, characterized in that: The compound of formula (Ⅰ) is selected from any one of compound 1, compound 2, compound 3, compound 4, compound 5 and compound 6, and its structural formula is as follows: 。 3. A polydicyclopentadiene resin, characterized in that, The compound is prepared by weight comprising the following components: 5-100 parts of dicyclopentadiene, 0.1-95 parts of regulator, 0.05-2 parts of Grubbs catalyst, and 2.5-30 parts of compound (I); the structure of compound (I) is as follows: （Ⅰ） Wherein: R1 is selected from hydrogen, methyl, ethyl or benzene ring; m and n are the number of methylene groups, where m = 1, 2, 3, 4 or 5, and n = 1, 2, 3, 4 or 5.

4. The polydicyclopentadiene resin according to claim 3, characterized in that: By weight, it includes the following components: 80-100 parts of dicyclopentadiene, 0.1-20 parts of regulator, 0.05-2 parts of Grubbs catalyst, and 5-30 parts of compound (I).

5. The polydicyclopentadiene resin according to claim 3 or 4, characterized in that: The compound of formula (Ⅰ) is selected from any one of compound 1, compound 2, compound 3, compound 4, compound 5 and compound 6, and its structural formula is as follows: 。 6. The polydicyclopentadiene resin according to claim 3 or 4, characterized in that, The regulator is selected from one or more of norbornene, norbornediene, ethylene norbornene, vinyl norbornene, 5-norbornene-2-methanol, 5-norbornene-2-ol, 5-norbornene-2-carboxylic acid, norbornene anhydride, cyclooctene, cyclooctadiene, dinorbornene methylphenyl phosphate, and dinorbornene phenyl phosphate.

7. The polydicyclopentadiene resin according to claim 3 or 4, characterized in that, The Grubbs catalyst is selected from Grubbs catalyst 1, Grubbs catalyst 2, Grubbs catalyst 3, Grubbs catalyst 4, Grubbs catalyst 5, Grubbs catalyst 6, Grubbs catalyst 7, and Grubbs catalyst 8, and has the following structural formula: 。 8. A method for preparing polydicyclopentadiene resin, characterized in that, Dicyclopentadiene, a regulator, a Grubbs catalyst, and a compound of formula (I) were mixed and reacted at a first temperature to obtain the product. The structure of the compound of formula (I) is as follows: （Ⅰ） Wherein: R1 is selected from hydrogen, methyl, ethyl or benzene ring; m and n are the number of methylene groups, where m = 1, 2, 3, 4 or 5, and n = 1, 2, 3, 4 or 5.

9. The method for preparing the polydicyclopentadiene resin according to claim 8, characterized in that, The compound of formula (Ⅰ) is selected from any one of compound 1, compound 2, compound 3, compound 4, compound 5 and compound 6, and its structural formula is as follows: 。 10. The method for preparing the polydicyclopentadiene resin according to claim 8, characterized in that, The first temperature is 20-180℃; the reaction time under the first temperature condition is 0.5-120 min.

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