Cycloolefin polymer and preparation method thereof

Abstract

The method comprises the following steps: by taking dicyclopentadiene and ethylene as raw materials, firstly preparing a mixture of norbornene and tetracyclododecene, and then directly performing ring-opening metathesis polymerization on the mixture as a monomer under the action of a ruthenium-based carbene complex catalyst without any purification treatment, thereby obtaining the cycloolefin polymer. And carrying out hydrogenation reaction to obtain the final polymer. The glass transition temperature (120 DEG C or above), the melting point (300 DEG C or above), the number-average molecular weight (2000-400000) and the crystallinity (35-65%) of the product can be accurately regulated and controlled by adjusting the raw material proportion and polymerization and hydrogenation process parameters. The complex purification step is omitted, the process is remarkably simplified, the cost is reduced, and the obtained polymer has excellent heat resistance (the heat distortion temperature can reach 480 DEG C or above) and good processing formability and is suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of polymer material synthesis technology, specifically relating to a method for preparing cyclic olefin polymers, and more particularly to a technique for preparing high-performance cyclic olefin polymers through a simplified process. Background Technology

[0002] Cyclic olefin polymers (COPs) occupy a key position in high-end manufacturing fields such as optical lenses, electronic chip packaging, and medical devices due to their low moisture absorption, high transparency, excellent heat resistance, and good dimensional stability. Their unique molecular structure endows the materials with tunable crystallization properties, making them a research focus in the field of polymer materials in recent years. Optimizing their performance is of great significance for expanding the boundaries of applications.

[0003] Currently, traditional processes for preparing cyclic olefin polymers typically require multi-step purification of polymerization raw materials such as norbornene (NB) and tetracyclododecene (TCD) generated from dicyclopentadiene (DCPD) and ethylene. This process aims to remove catalyst residues, unreacted monomers, and byproducts from the reaction system. However, the cumbersome distillation, extraction, or recrystallization steps not only significantly increase production costs and energy consumption but also easily lead to raw material losses, hindering large-scale production efficiency. Furthermore, existing technologies face significant challenges in balancing polymer properties: on the one hand, while some methods can control the melting point and glass transition temperature, it is difficult to ensure that the material maintains a stable crystalline structure after undergoing thermal processing such as melt molding, leading to decreased heat resistance; on the other hand, while some processes can guarantee processing performance, they cannot precisely control the thermodynamic parameters of the polymer, making it difficult to meet the differentiated performance requirements of different applications.

[0004] Therefore, developing a preparation method that requires no raw material purification, allows for precise control of melting point and glass transition temperature, and ensures that the product possesses both excellent heat resistance and processability after melt molding has become a core technological requirement for overcoming the bottlenecks in the industrial application of cyclic olefin polymers. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide a cyclic olefin polymer and its efficient preparation method, which simplifies the process, reduces production costs, and achieves precise control of key polymer properties to meet the needs of industrial production.

[0006] The first aspect of this invention provides a cyclic olefin polymer, which uses dicyclopentadiene (DCPD) and ethylene as raw materials to prepare norbornene (NB) and tetracyclododecene (TCD). After the reaction, no purification step is required, and the polymer can be directly used as raw material for ring-opening metathesis polymerization. The catalyst is a ruthenium-based carbene complex. The melting point and glass transition temperature of the obtained product can be precisely controlled by adjusting the ratio of raw materials.

[0007] A second aspect of the present invention provides a method for preparing the above-mentioned cyclic olefin polymer, using dicyclopentadiene and ethylene as raw materials, including ring-opening metathesis polymerization and hydrogenation reaction steps, the reaction formula of which is shown in formula (I):

[0008]

[0009] (I).

[0010] In the above ring-opening metathesis polymerization reaction, the catalyst is a Grubbs-type catalyst or a ruthenium carbene complex, and the amount used is 0.0025% to 0.2% of the total monomer mass; the solvent is toluene, cyclohexane, tetrahydrofuran, or dichloromethane; the monomer concentration in the solvent is 1% to 50% (w / v); the polymerization temperature is -30℃ to 200℃; the polymerization time is 1 to 24 hours; 1-hexene, styrene, or vinyl ether is added as a molecular weight regulator, and the amount used is 0.1% to 5% of the monomer molar mass; in the above hydrogenation reaction, the catalyst is a ruthenium compound; the hydrogenation reaction temperature is -20℃ to +250℃; the hydrogen pressure is 0.01 to 20 MPa; and the hydrogenation reaction time is 0.1 to 10 hours.

[0011] More preferably, in the above-mentioned ring-opening metathesis polymerization reaction, the amount of catalyst is 0.2% of the total mass of monomer; the solvent is toluene or dichloromethane; the concentration of monomer in the solvent is 2% (w / v); the polymerization temperature is 30°C; and the polymerization time is 2 hours.

[0012] More preferably, in the hydrogenation reaction, the hydrogenation reaction temperature is -10℃ to +220℃; and the hydrogen pressure is 0.05 to 15 MPa.

[0013] More preferably, the hydrogenation reaction temperature is 0℃~200℃.

[0014] Compared with current synthesis methods, the present invention has the following advantages:

[0015] The crystalline cyclic olefin polymers prepared by this method exhibit excellent comprehensive properties.

[0016] Firstly, the melting point is above 300℃, the glass transition temperature is above 120℃, and the number average molecular weight (Mn) is 2000~400000, all of which can be precisely controlled by adjusting the process parameters.

[0017] Secondly, after being melt-molded, the material retains good crystallinity, with a crystallinity of 35% to 65%, and has excellent heat resistance, with a heat distortion temperature of up to 480°C or higher.

[0018] Third, the material has outstanding processing performance and can be adapted to various processing techniques such as injection molding and extrusion, resulting in molded products with stable dimensions and smooth surfaces.

[0019] Fourth, this invention innovatively eliminates the purification step of the monomers and directly uses the crude reaction product for polymerization, thereby significantly simplifying the process, reducing material and energy consumption, and fully meeting the requirements of industrial production while improving production efficiency and economic benefits.

[0020] Instruction manual illustrations

[0021] Figure 1 TG curves for cyclic olefin polymers;

[0022] Figure 2 DSC curves for cyclic olefin polymers;

[0023] Figure 3 GPC diagrams of polymers obtained with different amounts of catalyst. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can better understand the technical solution of the present invention, but the scope of protection of the present invention is not limited to the following embodiments.

[0025] The method for manufacturing the cyclic olefin polymer of the present invention mainly includes two steps: step (I) is a ring-opening metathesis polymerization (ROMP) reaction, and step (II) is a hydrogenation reaction of the main chain double bond.

[0026] Process (I): Ring-opening metasomatic polymerization

[0027] The process involves using a ruthenium-based carbene complex as a polymerization catalyst to directly perform ring-opening polymerization on an unpurified mixture of norbornene and tetracyclododecene, obtained by reacting dicyclopentadiene with ethylene, to obtain a cyclic olefin polymer prepolymer.

[0028] (1) Monomer: As a monomer for cyclic olefin polymers, there are no particular limitations as long as it does not hinder the purpose of this invention. Dicyclopentadienes such as dicyclopentadiene, tricyclo[4.3.12,5.0]dec-3-ene, tricyclo[4.4.12,5.0]undec-3-ene, etc., norbornene such as norbornene, 5-methylnorbornene, 5-ethylidene norbornene, 5-vinylnorbornene, 5-phenylnorbornene, etc., and tetracyclic dodecenes such as 8-methyltetracyclic dodecene, 8-vinyltetracyclic dodecene, 8-phenyltetracyclic dodecene, etc.

[0029] (2) Catalyst: A Grubbs-type catalyst (such as Grubbs II catalyst) or a ruthenium carbene complex (such as Hoveyda-Grubbs catalyst) is used, in an amount of 0.0025% to 0.2% of the total monomer mass. Preferably, 0.2%.

[0030] (3) Solvent: Use non-polar or weakly polar solvents, such as toluene, cyclohexane, tetrahydrofuran (THF) or dichloromethane (DCM), preferably toluene or DCM.

[0031] The monomer concentration in the solvent is 1%–50% (w / v), preferably 2%, to ensure good solubility and reaction controllability. If the monomer concentration is too low, there is a risk of decreased productivity; if it is too high, the viscosity of the reaction solution after polymerization will increase excessively, which may make subsequent hydrogenation reactions difficult.

[0032] (4) Polymerization temperature and time: The ROMP reaction is carried out at -30℃ to 200℃, preferably 30℃, to balance the reaction rate and molecular weight control. The polymerization time is 1 to 24 hours, preferably 2 hours, to ensure monomer conversion ≥95%.

[0033] (5) Molecular weight regulation: Add 1-hexene, styrene or vinyl ether as molecular weight regulators, with an amount of 0.1% to 5% of the molar amount of the monomer.

[0034] Process (II) Hydrogenation reaction

[0035] Step (II) is a step of hydrogenating the carbon-carbon double bonds in the main chain of the cyclic olefin polymer obtained in step (I) with hydrogen and a hydrogenation catalyst to obtain the cyclic olefin polymer of the present invention.

[0036] (1) Hydrogenation catalyst: Ruthenium compounds are preferred as the hydrogenation catalyst used.

[0037] (2) Reaction temperature, pressure, and time: The temperature of the hydrogenation reaction varies depending on the hydrogenation catalyst used, but is generally -20°C to +250°C, preferably -10°C to +220°C, and more preferably 0°C to 200°C. If the hydrogenation temperature is too low, the reaction rate may become too slow; if it is too high, side reactions may occur. The hydrogen pressure is generally 0.01 to 20 MPa, preferably 0.05 to 15 MPa, and more preferably 0.1 to 10 MPa. If the hydrogen pressure is too low, the hydrogenation rate may become too slow; if it is too high, it may impose equipment limitations in areas requiring high-pressure reaction equipment. The reaction time varies depending on the scale of the reaction, but is generally 0.1 to 10 hours.

[0038] After the hydrogenation reaction, the cyclic olefin polymer can be recovered using conventional methods. During polymer recovery, catalyst residues can be removed by methods such as filtration.

[0039] Example 1

[0040] 100g of dicyclopentadiene was dissolved in toluene and added to a reactor equipped with a stirrer. Ethylene was introduced, and the reaction temperature was controlled at 200℃ for 6 hours. After complete reaction, crude products of norbornene and tetracyclododecene were obtained, which were directly introduced into the next polymerization step without any purification. The crude products were transferred to another polymerization reactor, toluene was added as solvent, and Grubbs second-generation catalyst was used as catalyst at a concentration of 0.5% of the total mass of norbornene and tetracyclododecene. The reaction was carried out at 30℃ for 2 hours to complete the ring-opening metathesis polymerization. Hydrogen gas was introduced into the polymerization product, and hydrogenation was carried out at a pressure of 1.5MPa and a temperature of 100℃ for 3 hours. After the reaction, the catalyst residue was removed by filtration, and the product was precipitated, washed, and dried to obtain a crystalline cyclic olefin polymer. The polymer was found to have a glass transition temperature of 130℃ and a number average molecular weight of 45,000 g / mol.

[0041] Example 2

[0042] Following the method of Example 1, monomer mixtures with different compositions were obtained by varying the initial feed ratio of dicyclopentadiene to ethylene. In these mixtures, norbornene (NB) comprised approximately 30%, tetracyclododecene (TCD) approximately 60%, and dicyclopentadiene (DCPD) approximately 10%. This crude product was directly used for polymerization, with the Grubbs II catalyst again, at an amount of 0.5% of the total monomer mass, and the reaction was carried out at 30°C for 2 hours. After polymerization, hydrogenation was performed under the same conditions as in Example 1 (1.5 MPa, 100°C, 3 hours). A cyclic olefin polymer was obtained with a glass transition temperature of 164°C.

[0043] Example 3

[0044] Following the method of Example 1, by changing the initial feed ratio of dicyclopentadiene to ethylene, a crude monomer mixture with a similar composition to that of Example 2 was obtained (approximately 30% NB, 60% TCD, and 10% DCPD). The crude product was directly used for polymerization using a Grubbs second-generation catalyst at a catalyst-to-monomer mass ratio of 1:40000, reacting at 30°C for 2 hours. Subsequently, a hydrogenation reaction was carried out under the conditions of a hydrogen pressure of 5 MPa, a temperature of 120°C, and a reaction time of 4 hours. A cyclic olefin polymer was obtained with a glass transition temperature of 140°C and a number-average molecular weight of 280,000 g / mol.

[0045] Comparative Example 1

[0046] The crude product obtained from the reaction of dicyclopentadiene and ethylene was finely purified using conventional methods (including vacuum distillation and silica gel column chromatography) to obtain a high-purity mixture of NB and TCD monomers (with DCPD content less than 0.5%). This purified monomer was then polymerized using the same catalyst, solvent, polymerization temperature, and time as in Example 1. Following polymerization, the same hydrogenation reaction was performed (1.5 MPa, 100°C, 3 hours). This yielded a cyclic olefin polymer with a glass transition temperature of 132°C.

[0047] Comparing Examples 1-3 with Comparative Example 1 reveals that the glass transition temperature of the cyclic olefin polymer obtained using the direct polymerization process of this invention, which requires no purification, not only does not decrease but is even significantly higher than that of the product polymerized after traditional purification (164℃ vs 132℃) in Example 2, and the molecular weight is controllable. This fully demonstrates that the process of this invention, while simplifying the process and reducing costs, can fully achieve and potentially optimize the key performance of the final product, possessing significant advantages for industrial applications.

[0048] At the same time, attached Figure 1 The thermogravimetric analysis (TG) curves of the cyclic olefin polymers of this invention show that they maintain a high quality retention rate even at high temperatures (such as near 480°C), confirming their excellent heat resistance with a heat distortion temperature exceeding 480°C. Compared with Comparative Example 1, the unpurified product exhibits comparable thermal stability, indicating that this process effectively resists impurity interference.

[0049] Appendix Figure 2 Differential scanning calorimetry (DSC) curves show that the glass transition temperatures (Tg) of Examples 1-3 are 130℃, 164℃, and 140℃, respectively. These are all above 120℃, and the Tg can be precisely controlled by adjusting the raw material ratio. The DSC melting peak confirms the crystallinity of the product, with a crystallinity ranging from 35% to 65%, and the melting point can be adjusted to above 300℃. Although Comparative Example 1 was purified, its Tg (132℃) was still lower than that of Example 2, highlighting that this method simplifies the process while optimizing performance.

[0050] Appendix Figure 3 The gel permeation chromatography (GPC) chromatograms show that the molecular weights of Examples 1 and 3 are 45,000 and 280,000 g / mol, respectively, both falling within the range of 2,000–400,000, indicating that molecular weight can be effectively controlled by adjusting the catalyst dosage. Compared with Comparative Example 1, this method can still obtain polymers with good molecular weight distribution under purification-free conditions, demonstrating the robustness and efficiency of the process.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A cyclic olefin polymer, characterized in that, Norbornene and tetracyclododecene were prepared from dicyclopentadiene and ethylene. After the reaction, they can be directly used as raw materials for ring-opening metathesis polymerization. The catalyst is a ruthenium-based carbene complex. The melting point and glass transition temperature of the obtained products can be precisely controlled by adjusting the ratio of raw materials.

2. The cyclic olefin polymer according to claim 1, characterized in that, The cyclic olefin polymer contains repeating units derived from tetracyclododecene.

3. The cyclic olefin polymer according to claim 1, characterized in that, The cyclic olefin polymer contains repeating units derived from dicyclopentadiene.

4. The cyclic olefin polymer according to claim 1, characterized in that, The cyclic olefin polymer contains repeating units derived from norbornene.

5. The cyclic olefin polymer according to claim 1, characterized in that, The number-average molecular weight Mn of the cyclic olefin polymer is 2000 to 400000.

6. The cyclic olefin polymer according to claim 1, characterized in that, The glass transition temperature of the cyclic olefin polymer is above 120°C.

7. A method for preparing the cyclic olefin polymer according to any one of claims 1 to 6, using dicyclopentadiene and ethylene as raw materials, which can be directly used as raw materials for ring-opening metathesis polymerization and hydrogenation reaction without purification after the reaction, as shown in formula (I): （Ⅰ） Its features are, In the ring-opening metathesis polymerization reaction, the catalyst is a Grubbs-type catalyst or a ruthenium carbene complex, and the amount used is 0.0025% to 0.2% of the total monomer mass; the solvent is toluene, cyclohexane, tetrahydrofuran, or dichloromethane; the concentration of monomer in the solvent is 1% to 50% (w / v); the polymerization temperature is -30℃ to 200℃; the polymerization time is 1 to 24 hours; 1-hexene, styrene, or vinyl ether is added as a molecular weight regulator, and the amount used is 0.1% to 5% of the monomer molar mass; In the hydrogenation reaction, the catalyst is a ruthenium compound; the hydrogenation reaction temperature is -20℃ to +250℃; the hydrogen pressure is 0.01 to 20 MPa; and the hydrogenation reaction time is 0.1 to 10 hours.

8. The method for preparing the cyclic olefin polymer according to claim 7, characterized in that, In the ring-opening metathesis polymerization reaction, the amount of catalyst used is 0.2% of the total mass of monomer; the solvent is toluene or DCM; the concentration of monomer in the solvent is 2% (w / v); the polymerization temperature is 30℃ and the polymerization time is 2 hours; In the hydrogenation reaction, the hydrogenation temperature is -10℃ to +220℃; the hydrogen pressure is 0.05 to 15 MPa.

9. The method for preparing the cyclic olefin polymer according to claim 7, characterized in that, The hydrogenation reaction temperature is 0℃~200℃.

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