Cycloolefin multi-block copolymer, and preparation method and application thereof
By controlling the molar ratio of catalyst I and catalyst II and the concentration of cyclic olefins, cyclic olefin multiblock copolymers with different insertion rates were prepared, solving the brittleness problem of cyclic olefin copolymer materials and achieving a combination of high elongation at break and high glass transition temperature.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTHERN UNIVERSITY OF SCIENCE AND TECHNOLOGY
- Filing Date
- 2023-03-01
- Publication Date
- 2026-05-19
AI Technical Summary
Existing cyclic olefin copolymer materials suffer from brittleness due to high norbornene insertion rates, resulting in poor mechanical properties and low elongation at break.
By using catalysts I and II with specific structures and controlling their molar ratio and cyclic olefin concentration, cyclic olefin/ethylene segment copolymers with low and high insertion rates were prepared.
The mechanical properties of the material were improved, with the elongation at break increased to 233%, solving the problem of brittleness while maintaining a high glass transition temperature, thus exhibiting excellent mechanical properties.
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Figure CN116284621B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of block copolymer technology, and in particular to a cyclic olefin multiblock copolymer, its preparation method, and its application. Background Technology
[0002] Cyclic olefin copolymers (COCs), as commercially available copolymers of olefins and cyclic olefins, are widely used in optical materials (CDs, lenses), food packaging materials, and medical packaging materials due to their low density, high strength, good dimensional stability, high refractive index, excellent heat resistance, and good water vapor barrier properties. Traditional commercial COC materials are obtained by polymerizing ethylene and norbornene using a single-center catalyst. To broaden the application range of COC materials, a high glass transition temperature (Tg) is generally required. Achieving a high Tg necessitates increasing the insertion rate of norbornene in the copolymer. A high norbornene insertion rate reduces the flexibility of the polymer chain, resulting in poor mechanical properties of COC materials, with an elongation at break of only about 2%, exhibiting significant brittleness.
[0003] Addressing the brittleness of COC materials has been extensively studied. Lee and his collaborators attempted to replace norbornene with a sterically hindered dihydrotricyclopentadiene (HTCPD) monomer in copolymerization with ethylene. The resulting cyclic olefin copolymer exhibited a higher tensile strength (Tg) at the same cyclic olefin insertion ratio. Stress-strain curves showed that this cyclic olefin copolymer had a higher elongation at break (2.8%) compared to norbornene-based COC, but the improvement was not significant (DOI:10.1021 / ma902334d). Li's team used another sterically hindered exo-1,4,4a,9,9a,10-hexahydro-9,10(1',2')benzene-1,4-methanoanthracene (HBMN) monomer in copolymerization with ethylene, and the resulting cyclic olefin copolymer only showed an increase in elongation at break of 7.6% (DOI:10.1021 / ma300730y). Summary of the Invention
[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the first aspect of the present invention proposes a method for preparing a cyclic olefin multiblock copolymer; the prepared cyclic olefin multiblock copolymer simultaneously possesses cyclic olefin / ethylene segments with low insertion rates and cyclic olefin / ethylene segments with high insertion rates, which can effectively solve the brittleness problem of COC materials.
[0005] A second aspect of the present invention also provides a cyclic olefin multiblock copolymer.
[0006] A third aspect of the present invention also provides an application of a cyclic olefin multiblock copolymer.
[0007] A method for preparing a cyclic olefin multiblock copolymer according to a first aspect embodiment of the present invention includes the following steps:
[0008] S1. Mix the solvent, co-catalyst, cyclic olefin, and chain shuttle to obtain a mixture; then add the olefin.
[0009] S2. Add catalyst I and catalyst II to step S1 to carry out polymerization reaction, and then perform post-treatment to obtain cyclic olefin multiblock copolymer;
[0010] The structural formulas of catalyst I and catalyst II are shown below:
[0011]
[0012] Where M represents titanium, zirconium, or hafnium, and X represents halogen or C. 1～10 alkyl, C 1～10 alkoxy or C 1～10 Alkylamines; R1 and R2 are independently selected from C 1～10 Aliphatic groups, substituted or unsubstituted C 6～15 Aromatic groups;
[0013] R3, R4, R5, and R6 are independently selected from H and C. 1～10 alkyl or C 6～15 The aromatic groups are different for R4 and R6.
[0014] The method for preparing cyclic olefin multiblock copolymers according to embodiments of the present invention has at least the following beneficial effects:
[0015] This invention selects catalysts I and II with specific structures to prepare cyclic olefin multiblock copolymers that simultaneously possess cyclic olefin / olefin chain soft segments with low intercalation rates (low T). g1 ) and hard segments of cyclic olefins / olefin chains with high insertion rates (high T) g2 The resulting material not only solves the brittleness problem of COC plastics, but also produces COC elastomers. Moreover, the preparation method of this invention cannot be achieved by existing catalytic systems.
[0016] According to some embodiments of the present invention, in step S1, the temperature of the mixture is set to 0–150°C. Preferably, the temperature is set to 20–60°C.
[0017] According to some embodiments of the present invention, the molar ratio of catalyst I to catalyst II is 1–10:10–1. The present invention achieves control over the mechanical properties of cyclic olefin block copolymer materials by changing the molar ratio of the two catalysts, thereby altering the ratio of soft segments with low insertion rates to hard segments with high insertion rates in the cyclic olefin / olefin chains.
[0018] According to some embodiments of the present invention, the molar ratio of catalyst I to catalyst II is 1 to 5:1. Therefore, the prepared cyclic olefin block copolymer exhibits good mechanical properties.
[0019] According to some embodiments of the present invention, the structural formulas of catalyst I and catalyst II are as follows:
[0020]
[0021] According to some embodiments of the present invention, the concentration of the cyclic olefin is 0.1–10 mol / L. Therefore, by controlling the polymerization concentration of the cyclic olefin, the mechanical properties of the cyclic olefin multiblock copolymer can be adjusted.
[0022] According to some embodiments of the present invention, the concentration of the cycloolefin is 0.4 to 1 mol / L.
[0023] According to some embodiments of the present invention, the chain shuttle comprises a metal alkyl compound.
[0024] According to some embodiments of the present invention, the metal alkyl compound includes alkyl zinc compound and alkyl aluminum compound.
[0025] According to some embodiments of the present invention, the alkyl zinc compound includes at least one of dimethyl zinc (Me2Zn), diethyl zinc (Et2Zn), and diphenyl zinc (Ph2Zn).
[0026] According to some embodiments of the present invention, the alkylaluminum compound includes trimethylaluminum (Me3Al), triethylaluminum (Et3Al), and triisobutylaluminum (Bu). i 3Al) and tri-tert-butylaluminum (Bu t At least one of (3Al).
[0027] According to some embodiments of the present invention, the cocatalyst includes, but is not limited to, methylaluminoxane, alkylaluminum, and organoboron.
[0028] According to some embodiments of the present invention, the molar ratio of the co-catalyst and the catalyst includes, but is not limited to, 500 to 3000.
[0029] According to some embodiments of the present invention, the amount of olefin used includes, but is not limited to, 0.5 atmospheres to 20 atmospheres.
[0030] According to some embodiments of the present invention, the olefin is selected from at least one of ethylene and propylene.
[0031] According to some embodiments of the present invention, the cycloolefin includes at least one selected from norbornene, cyclopentene, 5-norbornene-2-exo,3-exo-diethanol, exo-5-norbornene carboxylic acid, 5-norbornene-2,3-dicarboxylic acid, 5-ethylidene-2-norbornene, norbornene anhydride, 5-norbornene-di-methylamine, or dicyclopentadiene.
[0032] According to some embodiments of the present invention, the solvent includes, but is not limited to, at least one of hexane, cyclohexane, heptane, toluene, or xylene.
[0033] According to some embodiments of the present invention, the polymerization reaction is carried out at room temperature and pressure.
[0034] According to some embodiments of the present invention, the polymerization reaction takes 5 min to 60 min.
[0035] According to some embodiments of the present invention, the post-treatment includes adding a quencher to the reaction solution to quench the polymerization reaction.
[0036] According to some embodiments of the present invention, the quenching agent includes methanol and ethanol.
[0037] According to some embodiments of the present invention, after quenching, the process further includes purification and drying steps.
[0038] According to a second aspect of the present invention, a cyclic olefin multiblock copolymer is provided, which is prepared by the method for preparing cyclic olefin multiblock copolymers described above.
[0039] A third aspect of the present invention provides the application of the above-described cyclic olefin multiblock copolymers in optical materials, medical materials, and electronic and electrical components.
[0040] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description
[0041] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0042] Figure 1 These are the stretching curves of Examples 1 to 4. Detailed Implementation
[0043] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.
[0044] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.
[0045] Catalyst I of the present invention is prepared by the following method:
[0046] 4.5 g of pentafluoroaniline and 5.56 g of 3,5-di-tert-butylsalicylaldehyde were dissolved in 20 mL of methanol and reacted for 24 hours under the catalysis of 10 mg of p-toluenesulfonic acid. After the reaction was completed, the reaction solution was crystallized at low temperature to obtain 8.36 g of ligand.
[0047] 1.92 g of the ligand was dissolved in 20 mL of diethyl ether, cooled to -78 °C, and an equivalent amount of n-butyllithium was added dropwise. The mixture was then brought to room temperature and reacted for 2 hours. Half an equivalent amount of titanium tetrachloride was then added to the reaction solution at low temperature, and the mixture was brought to room temperature and reacted overnight. After the reaction was complete, the solvent was removed, the solid was washed with dichloromethane, the resulting liquid was concentrated, washed with diethyl ether and n-hexane, and the remaining solid was dried to obtain the final catalyst I. 1 H NMR (CDCl3) δ1.32 (s, 18H, tBu), 1.36 (s, 18H, tBu), 7.20 (d, J = 2.4Hz, 2H, aromatic-H), 7.67 (d, J = 2.4Hz, 2H, aromatic-H), 8.21 (s, 2H, CH = N).
[0048] Catalyst II of the present invention is prepared by the following method:
[0049] 4.5 g of pentafluoroaniline and 3.23 g of 3-methylsalicylaldehyde were dissolved in 20 mL of methanol and reacted for 24 hours under the catalysis of 10 mg of p-toluenesulfonic acid. After the reaction was completed, the reaction solution was crystallized at low temperature to obtain 6.06 g of ligand.
[0050] 1.44 g of the ligand was dissolved in 20 mL of diethyl ether, cooled to -78 °C, and an equivalent amount of n-butyllithium was added dropwise. The mixture was then brought to room temperature and reacted for 2 hours. Half an equivalent amount of titanium tetrachloride was then added to the reaction solution at low temperature, and the mixture was brought to room temperature and reacted overnight. After the reaction was complete, the solvent was removed, the solid was washed with dichloromethane, the resulting liquid was concentrated, washed with diethyl ether and n-hexane, and the remaining solid was dried to obtain the final catalyst II. 1H NMR (CDCl3) δ2.08 (s, 6H, Me), 6.99 (t, J = 7.6 Hz, 2H, aromatic-H), 7.26 (dd, J = 7.3, 1.5 Hz, 2H, aromatic-H), 7.48 (dd, J = 7.3, 1.5 Hz, 2H, aromatic-H), 8.24 (s, 2H, CH = N).
[0051] The structural formulas of catalyst I and catalyst II are as follows:
[0052]
[0053] Example 1
[0054] Example 1 provides a cyclic olefin multiblock copolymer, the preparation method of which includes the following steps:
[0055] S1. Mix 500 mL of toluene, 1000 equivalents of methylaluminoxane, 18.8 g of norbornene, and 50 equivalents of diethylzinc, and stabilize the reaction temperature at 20°C; then introduce ethylene at one atmosphere.
[0056] S2. Add the catalyst I and catalyst II prepared above to step S1 for polymerization. After reacting for 20 minutes, stop the ethylene flow and pour the reaction solution into an acidified methanol solution to terminate the reaction. The obtained polymer is repeatedly washed with acidified methanol and then dried in a vacuum oven at 60°C for 24 hours to obtain a cyclic olefin multiblock copolymer.
[0057] The molar ratio of catalyst I to catalyst II is 3:1; the concentration of norbornene is 0.4 mol / L.
[0058] Example 2
[0059] Example 2 provides a cyclic olefin multiblock copolymer, the preparation method of which includes the following steps:
[0060] S1. Mix 500 mL of toluene, 1000 equivalents of methylaluminoxane, 23.5 g of norbornene, and 50 equivalents of diethylzinc, and stabilize the reaction temperature at 20 °C; then introduce ethylene at one atmosphere.
[0061] S2. Add the catalyst I and catalyst II prepared above to step S1 for polymerization. After the predetermined polymerization time of 20 minutes, stop the ethylene flow and pour the reaction solution into an acidified methanol solution to terminate the reaction. The obtained polymer is repeatedly washed with acidified methanol and then dried in a vacuum oven at 60°C for 24 hours to obtain the cyclic olefin multiblock copolymer.
[0062] The molar ratio of catalyst I to catalyst II is 3:1; the concentration of norbornene is 0.5 mol / L.
[0063] Example 3
[0064] Example 3 provides a cyclic olefin multiblock copolymer, the preparation method of which includes the following steps:
[0065] S1. Mix 500 mL of toluene, 1000 equivalents of methylaluminoxane, 28.2 g of norbornene, and 50 equivalents of diethylzinc, and stabilize the reaction temperature at 20°C; then introduce ethylene at one atmosphere.
[0066] S2. Add the prepared catalyst I and catalyst II from step S1 to the polymerization reaction. After a predetermined polymerization time of 20 minutes, stop the ethylene flow and pour the reaction solution into an acidified methanol solution to terminate the reaction. The resulting polymer is repeatedly washed with acidified methanol and then dried in a vacuum oven at 60°C for 24 hours to obtain the cyclic olefin multiblock copolymer. The molar ratio of catalyst I to catalyst II is 3:1; the concentration of norbornene is 0.6 mol / L.
[0067] Example 4
[0068] Example 4 provides a cyclic olefin multiblock copolymer, the preparation method of which includes the following steps:
[0069] S1. Mix 500 mL of toluene, 1000 equivalents of methylaluminoxane, 37.6 g of norbornene, and 50 equivalents of diethylzinc, and stabilize the reaction temperature at 20°C; then introduce ethylene at one atmosphere.
[0070] S2. Add the catalyst I and catalyst II prepared above to step S1 for polymerization. After the predetermined polymerization time of 20 minutes, stop the ethylene flow and pour the reaction solution into an acidified methanol solution to terminate the reaction. The obtained polymer is repeatedly washed with acidified methanol and then dried in a vacuum oven at 60°C for 24 hours to obtain the cyclic olefin multiblock copolymer.
[0071] The molar ratio of catalyst I to catalyst II is 3:1; the concentration of norbornene is 0.8 mol / L.
[0072] Example 5
[0073] Example 5 provides a cyclic olefin multiblock copolymer, the preparation method of which includes the following steps:
[0074] S1. Mix 500 mL of toluene, 1000 equivalents of methylaluminoxane, 18.8 g of norbornene, and 50 equivalents of diethylzinc, and stabilize the reaction temperature at 20°C; then introduce ethylene at one atmosphere.
[0075] S2. Add the catalyst I and catalyst II prepared above to step S1 for polymerization. After the predetermined polymerization time of 20 minutes, stop the ethylene flow and pour the reaction solution into an acidified methanol solution to terminate the reaction. The obtained polymer is repeatedly washed with acidified methanol and then dried in a vacuum oven at 60°C for 24 hours to obtain the cyclic olefin multiblock copolymer.
[0076] The molar ratio of catalyst I to catalyst II is 1:1; the concentration of norbornene is 0.4 mol / L.
[0077] Example 6
[0078] Example 6 provides a cyclic olefin multiblock copolymer, the preparation method of which includes the following steps:
[0079] S1. Mix 500 ml of toluene, 1000 equivalents of methylaluminoxane, 18.8 g of norbornene, and 50 equivalents of diethylzinc and heat to a reaction temperature of 20°C; then introduce ethylene at one atmosphere.
[0080] S2. Add the catalyst I and catalyst II prepared above to step S1 for polymerization. After the predetermined polymerization time of 20 minutes, stop the ethylene flow and pour the reaction solution into an acidified methanol solution to terminate the reaction. The obtained polymer is repeatedly washed with acidified methanol and then dried in a vacuum oven at 60°C for 24 hours to obtain the cyclic olefin multiblock copolymer.
[0081] The molar ratio of catalyst I to catalyst II is 2:1; the concentration of norbornene is 0.4 mol / L.
[0082] Example 7
[0083] Example 7 provides a cyclic olefin multiblock copolymer, the preparation method of which includes the following steps:
[0084] S1. Mix 500 mL of toluene, 1000 equivalents of methylaluminoxane, 18.8 g of norbornene, and 50 equivalents of diethylzinc, and stabilize the reaction temperature at 20°C; then introduce ethylene at one atmosphere.
[0085] S2. Add the catalyst I and catalyst II prepared above to step S1 for polymerization. After the predetermined polymerization time of 20 minutes, stop the ethylene flow and pour the reaction solution into an acidified methanol solution to terminate the reaction. The obtained polymer is repeatedly washed with acidified methanol and then dried in a vacuum oven at 60°C for 24 hours to obtain the cyclic olefin multiblock copolymer.
[0086] The molar ratio of catalyst I to catalyst II is 4:1; the concentration of norbornene is 0.4 mol / L.
[0087] Example 8
[0088]
[0089] Example 8 provides a cyclic olefin multiblock copolymer, the preparation method of which includes the following steps:
[0090] S1. Mix 500 mL of toluene, 1000 equivalents of methylaluminoxane, 37.6 g of norbornene, and 50 equivalents of diethylzinc, and stabilize the reaction temperature at 20°C; then introduce ethylene at one atmosphere.
[0091] S2. Add the catalysts I-2 and II-2 prepared above to step S1 for polymerization. After the predetermined polymerization time of 20 minutes, stop the ethylene flow and pour the reaction solution into an acidified methanol solution to terminate the reaction. The obtained polymer is repeatedly washed with acidified methanol and then dried in a vacuum oven at 60°C for 24 hours to obtain the cyclic olefin multiblock copolymer.
[0092] The molar ratio of catalyst I-2 to catalyst II-2 is 1:4; the concentration of norbornene is 0.8 mol / L.
[0093] Performance testing
[0094] The cyclic olefin multiblock copolymers prepared in Examples 1-8 were subjected to DSC testing. The test procedure was as follows: heating from -50°C to 160°C at a heating rate of 10°C / min, holding at 160°C for 5 min; then cooling to -50°C at a cooling rate of -10°C / min; and finally heating back to 160°C at a heating rate of 10°C / min. The results are shown in Table 1.
[0095] The cyclic olefin multiblock copolymers prepared in Examples 1-8 were subjected to tensile characterization at a test temperature of 20°C and a tensile rate of 50 mm / min. ε represents the elongation at break, σ represents the fracture stress, and SR represents the cyclic tensile test, characterizing the elastic recovery rate of the elastomer.
[0096] Table 1
[0097]
[0098] a The molar ratio of catalyst I-2 to catalyst II-2.
[0099] As shown in Table 1, from Example 1 to Example 4, by increasing the concentration of the polymerized norbornene monomer (from 0.4 mol / L...), the polymerization process... -1 Up to 0.8 mol L -1The glass transition temperature of the obtained cyclic olefin multiblock copolymer increased from -4°C to 22°C. The tensile data showed that the elongation at break decreased but the fracture stress increased. As can be seen from Examples 5, 6, 1 and 7, the properties of the materials obtained by changing the feed ratio of the two catalysts changed significantly. The material of Example 5 showed the highest fracture stress, while the material of Example 7 showed the best elastic recovery performance (86%).
[0100] like Figure 1 When the polymerization concentration of norbornene is between 0.4 and 0.8%, the properties of the resulting cyclic olefin multiblock copolymer can be well controlled, realizing the transformation from plastic (Example 4) to elastomer (Examples 1-3). The cyclic olefin plastic of Example 4 exhibits superior mechanical properties not found in previous cyclic olefin copolymers, with an elongation at break reaching 233%. This property is not possessed by traditional COC materials with the same heat resistance (Tg greater than 120°C) (elongation at break around 2%).
[0101] The present invention has been described in detail above with reference to the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.
Claims
1. A method for preparing a cyclic olefin multiblock copolymer, characterized in that, Includes the following steps: S1. Mix the solvent, co-catalyst, cyclic olefin, and chain shuttle to obtain a mixture; then introduce an olefin at one atmosphere of pressure. S2. Add catalyst I and catalyst II to step S1 to carry out polymerization reaction, and then perform post-treatment to obtain cyclic olefin multiblock copolymer; The concentration of the cyclic olefin is 0.4~1 mol / L; the molar ratio of catalyst I to catalyst II is 1~5:1; The olefin is selected from ethylene; the cyclic olefin includes norbornene; the chain shuttle includes a metal alkyl compound; the cocatalyst includes at least one of methylaluminoxane, alkylaluminum, or organoboron. The structural formulas of catalyst I and catalyst II are shown below: ； When catalyst I is selected from catalyst I-1, catalyst II is selected from catalyst II-1; When catalyst I is selected from catalyst I-2, catalyst II is selected from catalyst II-2.
2. A cyclic olefin multiblock copolymer, characterized in that, Prepared by the method of claim 1.
3. The application of the cyclic olefin multiblock copolymer according to claim 2 in optical materials, medical materials, and electronic and electrical components.