A fluorine-containing cycloolefin copolymer and a method for preparing the same

Abstract

The application discloses a fluorine-containing cycloolefin copolymer and a preparation method thereof, and belongs to the technical field of chemical industry. The fluorine-containing cycloolefin copolymer has a structure shown in formula (I), the fluorine-containing cycloolefin monomer in the fluorine-containing cycloolefin copolymer has high reactivity and an insertion rate, and the insertion rate can be adjusted between 3.3% and 40%. Moreover, the fluorine-containing cycloolefin copolymer has high fluorine content, which can reach 15.1wt%-58.3wt%. The fluorine-containing cycloolefin copolymer prepared at low temperature (30 DEG C) has high molecular weight, is easy to be molded, has excellent tear resistance, transparency, low dielectric constant and dielectric loss, and has good antibacterial property, flame retardancy and gas selective permeability.

Description

TECHNICAL FIELD

[0001] The present application relates to the chemical technology field, and particularly relates to a fluorine-containing cycloolefin copolymer and a preparation method thereof. BACKGROUND

[0002] Cycloolefin copolymer (COC) is generally prepared by addition copolymerization of a-olefin and cycloolefin, and has excellent properties such as small density, high transparency, good thermal stability and strong chemical corrosion resistance. Since it was first synthesized in the 1990s, COC has become one of the important engineering plastics and is applied in optical and medical materials. However, under the high insertion rate of cycloolefin, the rigidity of the obtained COC molecule is strong, which makes the brittleness of the copolymer serious, and this shortcoming hinders the application of COC. Currently, Mitsui and Polyplastics in Japan have launched commercialized COC with trade names of APEL and Topas respectively.

[0003] The research results disclosed in the prior art show that COC can be applied not only in the optical field and the medical field, but also in the low dielectric material field, and the development direction has begun to change to high-end applicable materials. Although COC material itself has a low dielectric constant and dielectric loss, it still has a large gap compared with traditional low dielectric materials such as PTFE (polytetrafluoroethylene); and the copolymerization of a-olefin and cycloolefin monomer with fluorine-containing groups usually shows poor activity and insertion rate, which causes the lack of application of this kind of functional material in the low dielectric material field. SUMMARY

[0004] Therefore, the present application aims to provide a fluorine-containing cycloolefin copolymer and a preparation method thereof. The fluorine-containing cycloolefin monomer insertion rate and fluorine content of the fluorine-containing cycloolefin copolymer are high, and the fluorine-containing cycloolefin copolymer has the advantages of low dielectric constant and dielectric loss, high melting point and transparency, and good toughness and tear resistance.

[0005] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0006] The present application provides a fluorine-containing cycloolefin copolymer having the structure shown in formula (I):

[0007]

[0008] wherein m and n are the degree of polymerization, preferably m:n≤30.

[0009] R1 and R2 are independently selected from hydrogen or C1-C 10 saturated aliphatic hydrocarbon group.

[0010] the C1-C10 The saturated aliphatic hydrocarbon group is preferably a C1-C6 saturated aliphatic hydrocarbon group, including but not limited to methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, isohexyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like.

[0011] The dotted line indicates that R3 and R4 exist independently, or R3 and R4 are combined to form a ring through the carbon atoms in each of them.

[0012] R3 and R4 are independently selected from hydrogen, halogen, C1-C 20 Alkyl, C1-C 10 Perfluoroalkyl, C1-C 20 Alkoxy, C1-C 20 One or more of a perfluoroalkoxy group, a cyano group, an ester group, an aldehyde group, a hydroxyl group, a carboxyl group, and a 3-20 membered cycloalkyl group.

[0013] The C1-C 20 The alkyl group is preferably C1-C 10 The alkyl group is preferably a C1-C6 alkyl group. Specific examples include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, isohexyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, heptyl, and octyl.

[0014] The C1-C 10 The perfluoroalkyl group is preferably C4-C 10 The perfluoroalkyl group may specifically be a perfluoromethyl group, a perfluoroethyl group, a perfluoro-n-propyl group, a perfluoro-isopropyl group, a perfluoro-n-butyl group, a perfluoro-n-butyl group, a perfluoro-isobutyl group, a perfluoro-tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluorooctyl group, a perfluorodecyl group, or the like.

[0015] The C1-C 20 The alkoxy group is preferably C1-C 10 More preferably, it is a C1-C6 alkoxy group; further preferably, it is one or more of a methoxy group, an ethoxy group, a n-propoxy group and an isopropoxy group.

[0016] The C1-C 20 The perfluoroalkoxy group is preferably C1-C 10 Perfluoroalkoxy, more preferably C1-C4 perfluoroalkoxy, specifically includes but is not limited to perfluoromethoxy, perfluoroethoxy, and perfluoropropoxy.

[0017] The 3-20 membered cycloalkyl group is preferably a 3-8 membered cycloalkyl group, more preferably a 3-6 membered cycloalkyl group, and specifically may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and the like.

[0018] When the molecular structure contains the above-mentioned long-chain perfluoroalkyl chain, the flexibility of the polymer will be correspondingly improved, the proportion of the polymerization unit of α-olefin will be reduced, the insertion rate of the fluorinated cycloolefin monomer will be increased, the toughness of the polymer will be improved, and the tear resistance of the fluorinated cycloolefin copolymer will be improved and the brittleness will be improved.

[0019] Or R3 and R4 form a ring. When R3 and R4 form a ring, the structure of the fluorinated cyclic olefin copolymer is as follows:

[0020]

[0021] Ring A is preferably a 4- to 6-membered saturated or unsaturated hydrocarbon ring group.

[0022] Preferably, the 4-6 membered saturated or unsaturated cyclic hydrocarbon group is selected from one or more of cyclobutane, cyclopentane, cyclohexane, cyclobutenyl, cyclohexenyl and cyclopentenyl.

[0023] Preferably, R5 and R6 are independently selected from hydrogen, fluorine, C1-C 10 One or more of the perfluoroalkyl groups.

[0024] The C1-C 10 The perfluoroalkyl group is preferably C4-C 10 The perfluoroalkyl groups include, but are not limited to, perfluoromethyl, perfluoroethyl, perfluoro-n-propyl, perfluoroisopropyl, perfluoro-n-butyl, perfluoroisobutyl, perfluoro-tert-butyl, perfluorooctyl, and perfluorodecyl.

[0025] Preferably, R7 is selected from C1-C 10 perfluoroalkyl, fluorine atom, substituted or unsubstituted C1-C 10 One or more of perfluoroalkoxy, perfluoroaryl, and benzo 3-6 membered perfluorocycloalkyl.

[0026] The C1-C 10 The perfluoroalkyl group is preferably a C1-C6 perfluoroalkyl group, and specifically may be a perfluoromethyl group, a perfluoroethyl group, a perfluoro-n-propyl group, a perfluoro-isopropyl group, a perfluoro-n-butyl group, a perfluoro-n-butyl group, a perfluoro-isobutyl group, a perfluoro-tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, or the like.

[0027] Preferably, the C1-C 10 The perfluoroalkoxy group is selected from C1-C4 perfluoroalkoxy groups, including but not limited to perfluoromethoxy, perfluoroethoxy, and perfluoropropoxy.

[0028] Preferably, the C1-C 10The substituent of the perfluoroalkoxy group is selected from a bromine atom or a chlorine atom. The substituted perfluoroalkoxy group specifically includes, but is not limited to, 2-bromoperfluoroethoxy, 2-chloroperfluoroethoxy, 2-bromoperfluoropropoxy, 2-chloroperfluoropropoxy.

[0029] The perfluoroaryl group is preferably a perfluorophenyl group or a perfluorobenzyl group.

[0030] The benzo 3-6-membered perfluorocycloalkyl group is preferably one or more of a benzo perfluorocyclohexyl group, a benzo perfluorocyclopentyl group, and a benzo perfluorocyclopropyl group.

[0031] Specifically, R7 is preferably one or more of a perfluoromethyl group, a perfluoroethyl group, a perfluoro-n-propyl group, a perfluoro-i-propyl group, a perfluoro-n-butyl group, a perfluoro-n-butyl group, a perfluoro-i-butyl group, a perfluoro-t-butyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoromethoxy group, a perfluoroethoxy group, a perfluoropropoxy group, a 2-bromoperfluoroethoxy group, a 2-chloroperfluoroethoxy group, a 2-bromoperfluoropropoxy group, a 2-chloroperfluoropropoxy group, a perfluorophenyl group, a perfluorobenzyl group, a benzo perfluorocyclohexyl group, a benzo perfluorocyclopentyl group, a benzo perfluorocyclopropyl group, and a fluorine atom.

[0032] q is the number of substituents on the A ring, and is preferably an integer from 0 to 4, and more preferably 1 or 4, i.e., there are 1 or 4 substituents on the A ring.

[0033] In the present application, at least one of R1, R2, R3, R4, R5, R6, and R7 contains a fluorine atom.

[0034] The weight average molecular weight of the fluorine-containing cycloolefin copolymer described above is preferably 14 kg / mol to 193 kg / mol, more preferably 112 kg / mol to 192 kg / mol, and further preferably 112 kg / mol or 192 kg / mol.

[0035] In the present application, the smaller the value of m:n, the higher the insertion rate of the fluorine-containing cycloolefin monomer. The insertion rate of the fluorine-containing cycloolefin monomer in the present application can be adjusted to be between 3.3% and 40%, and the insertion rate of the fluorine-containing cycloolefin monomer is more preferably 3.3% to 17.4%.

[0036] In the present application, 1.5≤m:n≤30 in the structure of formula (I), more preferably 2.3≤m:n≤30, and further preferably 3≤m:n≤30.

[0037] In the present application, the fluorine-containing cycloolefin copolymer has any one of the following structures:

[0038]

[0039] The present application also provides a method for preparing a fluorine-containing cycloolefin copolymer, comprising the following steps:

[0040] The fluorine-containing cycloolefin monomer of the structure shown in formula (II) and α-olefin are subjected to polymerization reaction under the action of metallocene catalyst to obtain the fluorine-containing cycloolefin copolymer of the structure shown in formula (I);

[0041]

[0042] Wherein, m and n are polymerization degree, m:n≤30.

[0043] R1 and R2 are independently selected from hydrogen or C1-C 10 Saturated aliphatic hydrocarbon group.

[0044] R3 and R4 are independently selected from hydrogen, halogen, C1-C 20 Alkyl, C1-C 10 Perfluoroalkyl, C1-C 20 Alkoxy, C1-C 20 Perfluoroalkoxy, cyano, ester group, aldehyde group, hydroxyl, carboxyl, 3-20 membered ring alkyl.

[0045] Or R3 and R4 form a ring, when R3 and R4 form a ring, the fluorine-containing cycloolefin copolymer structure is as follows:

[0046]

[0047] A ring is 4-6 membered saturated or unsaturated ring hydrocarbon group.

[0048] R5 and R6 are independently selected from hydrogen, fluorine atom, C1-C 10 Perfluoroalkyl.

[0049] R7 is selected from C1-C 10 Perfluoroalkyl, fluorine, substituted or unsubstituted C1-C 10 Perfluoroalkoxy, perfluoroaryl, benzene 3-6 membered perfluoro cycloalkyl.

[0050] Q is an integer of 0-4, preferably 1 or 4.

[0051] In the present application, at least one of R1, R2, R3, R4, R5, R6, R7 contains fluorine atom.

[0052] The preferred and more preferred range of R1, R2, R3, R4, R5, R6, R7 is the same as above, which is not repeated here.

[0053] Preferably, the metallocene catalyst is selected from one or more of Cat1 (fluorenyl metallocene zirconium catalyst), Cat2 (dibromo-substituted fluorenyl metallocene zirconium catalyst), Cat3 (allyl-substituted fluorenyl metallocene zirconium catalyst), Cat4 (2,6-diisopropyl phenoxymono metallocene titanium catalyst), Cat5 (di-tert-butyl imido monometallocene titanium catalyst), and Cat6 (trimethylsilyl-substituted cyclopentadienyl monometallocene titanium catalyst); more preferably, the metallocene catalyst is selected from Cat3 (allyl-substituted fluorenyl metallocene zirconium catalyst) or Cat6 (trimethylsilyl-substituted cyclopentadienyl monometallocene titanium catalyst).

[0054] The specific structure of the metallocene catalyst is as follows:

[0055]

[0056] When Cat3 (allyl-substituted fluorenyl metallocene zirconium catalyst) or Cat6 (trimethylsilyl-substituted cyclopentadienyl monometallocene titanium catalyst) is used as the catalyst for the polymerization reaction, the catalyst has better resistance to polar groups, which makes Cat3 or Cat6 have more excellent copolymerization catalytic ability, and the copolymerization reaction of the fluorine-containing cycloolefin monomer and the a-olefin has higher reactivity.

[0057] Preferably, the a-olefin is selected from one or more of ethylene, propylene, 1-butene, isobutylene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 2-ethyl-1-butene; more preferably, one or more of ethylene, propylene, 1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene, and 3-methyl-1-pentene; and further preferably, ethylene.

[0058] Preferably, the molar ratio of the a-olefin to the fluorine-containing cycloolefin monomer of formula (II) is (2.3-20):1; more preferably, (3-18):1; and further preferably, 16:1.

[0059] Preferably, the molar ratio of the catalyst to the fluorine-containing cycloolefin monomer of formula (II) is 1:(200-2400); more preferably, 1:(300-2000). In some specific embodiments of the present application, the molar ratio of the catalyst to the fluorine-containing cycloolefin monomer of formula (II) is 1:384.

[0060] Preferably, the polymerization reaction is carried out in an inert solvent.

[0061] Preferably, the inert solvent is selected from one or more of straight-chain hydrocarbons, cyclic hydrocarbons, aromatic hydrocarbons; more preferably, aromatic hydrocarbons; and further preferably, benzene. In some embodiments of the present application, the inert solvent is selected from toluene.

[0062] The fluorine-containing cyclic olefin monomer of the above formula (II) includes, but is not limited to, the following structures:

[0063]

[0064] The fluorine-containing cyclic olefin monomer of the above formula (II) includes, but is not limited to, the following structures:

[0065] In the present application, the cyclic olefin monomer is preferably prepared by the following route:

[0066]

[0067] The preferred and more preferred ranges of R3 and R4 are the same as above, and are not repeated here.

[0068] Preferably, the molar ratio of the dicyclopentadiene to the substituted ethylene is 1:(1-4); more preferably, 1:(1-2).

[0069] Preferably, the a-olefin is selected from one or more of ethylene, propylene, 1-butene, isobutylene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-butene. After the polymerization reaction is completed, the reaction liquid obtained from the polymerization reaction is treated, which can be specifically:

[0070] The reaction liquid after the polymerization reaction is mixed with an ethanol solution of hydrochloric acid to terminate the growth of the polymerization chain, thereby obtaining a reaction product; the volume fraction of the ethanol solution of hydrochloric acid is preferably 5% to 15%.

[0071] The reaction product is subjected to solid-liquid separation and then dried, thereby obtaining a fluorine-containing cyclic olefin copolymer.

[0072] The method for terminating the growth of the polymerization chain is not particularly limited, and methods well known to those skilled in the art, such as adding an ethanol solution of hydrochloric acid, can be used.

[0073] The method for solid-liquid separation is also not particularly limited, and methods well known to those skilled in the art, such as filtration, can be used.

[0074] The reaction product is preferably subjected to solid-liquid separation by filtration, and the filtered product is washed and dried.

[0075] The solvent for the washing is not particularly limited, and a washing solvent known to those skilled in the art can be used.

[0076] In the present application, the washing reagent is preferably acetone, and the number of washing is preferably 2.

[0077] The drying method is not particularly limited, and a drying method known to those skilled in the art, such as vacuum drying, normal pressure drying, freeze drying, etc., can be used.

[0078] Preferably, the drying is vacuum drying, the drying temperature is 50-80℃, and the drying time is preferably 16-24h.

[0079] After the post-treatment, the fluorine-containing cycloolefin copolymer is obtained, and its structure is identified and its performance is tested, and the specific process is as follows:

[0080] The fluorine-containing cycloolefin copolymer obtained in the present application is detected by nuclear magnetic resonance (NMR), including 1 H-NMR spectrum, 13 CNMR spectrum. The insertion rate of the cycloolefin monomer in the fluorine-containing cycloolefin copolymer is adjustable between 3.3% and 40%, and the fluorine content in the fluorine-containing cycloolefin copolymer is high, being 15.1wt%-58.3wt%.

[0081] The fluorine-containing cycloolefin copolymer obtained in the present application is tested for high-frequency dielectric properties (10GHz), and the results show that the fluorine-containing cycloolefin copolymer has low dielectric constant (2.18-2.33) and dielectric loss (0.0018-0.0027).

[0082] The melting point of the fluorine-containing cycloolefin copolymer obtained in the present application is determined by differential scanning calorimetry (DSC), and the results show that the melting point can reach 122.03℃. Moreover, the elongation at break of the fluorine-containing cycloolefin copolymer is high, reaching 812%. This shows that the fluorine-containing cycloolefin copolymer prepared in the present application has high melting point and good toughness.

[0083] The molecular weight of the cycloolefin copolymer is also determined, and the results show that the weight average molecular weight of the fluorine-containing cycloolefin copolymer is 14kg / mol-193kg / mol, and the molecular weight distribution index is 1.9-3.8, having good molecular weight adjustability.

[0084] The light transmission performance of the cycloolefin copolymer is also determined, and the results show that the fluorine-containing cycloolefin copolymer has high transparency, and the light transmittance in the visible light region is >80%.

[0085] Compared with the prior art, the fluorinated cycloolefin copolymer provided by the present invention has a structure shown in formula (I). Under the action of a metallocene catalyst, the fluorinated cycloolefin monomer in the fluorinated cycloolefin copolymer has high reactivity and insertion rate, and the insertion rate can be adjusted between 3.3% and 40%. In addition, the fluorinated cycloolefin copolymer has a high fluorine content, which can reach 15.1wt% to 58.3wt%. The fluorinated cycloolefin copolymer prepared at low temperature (30°C) has a high molecular weight, is easy to form, has excellent tear resistance and transparency, as well as low dielectric constant and dielectric loss, and has good antibacterial properties, flame retardancy, and gas permselectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the fluorinated cycloolefin monomer 1 prepared in Example 1;

[0087] Figure 2 This is the carbon NMR spectrum of the fluorinated cycloolefin copolymer a prepared in Example 9;

[0088] Figure 3 This is a visible light transmittance curve of the fluorinated cyclic olefin copolymer a prepared in Example 13;

[0089] Figure 4 This is the stress-strain curve of the fluorinated cyclic olefin copolymer b prepared in Example 16. DETAILED DESCRIPTION

[0090] In order to further illustrate the present invention, the fluorinated cyclic olefin copolymer and the preparation method thereof provided by the present invention are described in detail below with reference to the examples.

[0091] Example 1

[0092] Preparation process of fluorinated cycloolefin monomer 1

[0093]

[0094] Perfluorobutylethylene (30.0 g, 122 mmol), dicyclopentadiene (8.0 g, 61 mmol), and a small amount of 2,6-di-tert-butyl-p-cresol (1.1 g, 5.0 mmol) were added to an autoclave. The reaction was stirred at 200°C for approximately 8 hours. The heat was turned off and the mixture was cooled to room temperature. The crude product was purified by vacuum distillation to obtain 1 (25.2 g, 66%) as a colorless oil.

[0095] like Figure 1 As shown, Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the fluorinated cycloolefin monomer 1 prepared in Example 1.

[0096] NMR 1H NMR (500 MHz, 298 K, CDC13, 7.26 ppm): δ = 6.18 (br s, 1.16 H), 5.96 (br s, 0.66 H), 3.16 (br s, 1 H), 2.93 (d, 1 H), 2.79 (m, 0.80 H), 1.98 (m, 1 H), 1.82 (m, 0.38 H), 1.55-1.44 (m, 1 H), 1.39 (m, 1 H), 1.32-1.23 (m, 1 H).

[0097] Example 2

[0098] Process for the preparation of fluorine-containing cycloalkene monomer 2

[0099]

[0100] 1H,1H,2H-perfluoro-1-decene (100.0 g, 220 mmol), dicyclopentadiene (14.5 g, 110 mmol) and a small amount of 2,6-di-tert-butyl-p-cresol (1.1 g, 5.0 mmol) were added to a pressure vessel. The reaction was stirred at 200 °C for about 8 hours. The heating was turned off and the reaction was allowed to cool to room temperature. The crude product was purified by distillation under reduced pressure to give 2 as a colorless oily liquid (84.5 g, 74%).

[0101] NMR 1 H NMR (500 MHz, 298 K, CDC13, 7.26 ppm): δ = 6.18 (br s, 1.16 H), 5.96 (br s, 0.66 H), 3.16 (br s, 1 H), 2.93 (d, 1 H), 2.79 (m, 0.80 H), 1.98 (m, 1 H), 1.82 (m, 0.38 H), 1.55-1.44 (m, 1 H), 1.39 (m, 1 H), 1.32-1.23 (m, 1 H).

[0102] Example 3

[0103] Process for the preparation of fluorine-containing cycloalkene monomer 3

[0104]

[0105] 3,3,4,4-tetrafluorocyclobutene (10.0 g, 79 mmol), dicyclopentadiene (5.2 g, 39.5 mmol) and a small amount of 2,6-di-tert-butyl-p-cresol (1.1 g, 5.0 mmol) were added to a pressure vessel. The reaction was stirred at 200 °C for about 8 hours. The heating was turned off and the reaction was allowed to cool to room temperature. The crude product was purified by distillation under reduced pressure to give 3 as a colorless oily liquid (9.1 g, 60%).

[0106] NMR 1H NMR (500 MHz, 298 K, CDC13, 7.26 ppm): δ = 6.15 (t, 2H), 3.45-3.25 (m, 2H), 2.58 (br s, 2H), 1.74 (d, 1H), 1.38 (d, 1H).

[0107] Example 4

[0108] Preparation of fluorine-containing cycloolefin copolymer a

[0109]

[0110] A 75 mL glass pressure reactor connected to a gas line was first dried under vacuum at 90 °C for 1 h. Then 14 mL of toluene and 1.2 g of the copolymerizable monomer 1 prepared in Example 1 were added to the reactor under inert atmosphere, then 10.0 pmol of Cat 1 catalyst was dissolved in 1 mL of toluene and 3.4 mL of a methylaluminoxane solution in toluene (1.5 M) was added by syringe to the polymerization system. Under rapid stirring (600 rpm), 0.06 mol of ethylene was introduced. After 10 min, the pressure reactor was evacuated, the polymerization was quenched by adding 200 mL of an ethanolic hydrochloric acid solution, the polymer was filtered and dried to constant weight in a vacuum oven to give fluorine-containing cycloolefin copolymer a with a mass of 0.78 g and a weight average molecular weight of 2.7 x 10 4 g / mol.

[0111] Examples 5-9

[0112] Effect of different metallocene catalysts on the catalysis of the copolymerization of ethylene with fluorine-containing cycloolefin monomers

[0113] A 75 mL glass pressure reactor connected to a gas line was first dried under vacuum at 90 °C for 1 h. Then 14 mL of toluene and 1.2 g of the copolymerizable monomer 1 prepared in Example 1 were added to the reactor under inert atmosphere, then 10.0 pmol of Cat 1 catalyst was dissolved in 1 mL of toluene and 3.4 mL of a methylaluminoxane solution in toluene (1.5 M) was added by syringe to the polymerization system. Under rapid stirring (600 rpm), 0.06 mol of ethylene was introduced. After 10 min, the pressure reactor was evacuated, the polymerization was quenched by adding 200 mL of an ethanolic hydrochloric acid solution, the polymer was filtered and dried to constant weight in a vacuum oven to give fluorine-containing cycloolefin copolymer a with a mass of 0.78 g and a weight average molecular weight of 2.7 x 10

[0114] Table 1 Effect of different metallocene catalysts on the catalysis of the copolymerization of ethylene with fluorine-containing cycloolefin monomers

[0115]

[0116] Note: all data are based on results of at least two parallel experiments (unless otherwise stated). Activity: in 10 6 gmol -1 h -1 as units; M n , M w , M w / M n : number average molecular weight, weight average molecular weight, polydispersity index, respectively; determined by GPC in 1,2,4-trichlorobenzene at 150°C, relative to polystyrene standards. T m is the melting temperature, determined by DSC; the insertion rate is determined by carbon NMR; the fluorine content is the mass fraction of fluorine in the polymer.

[0117] Table 1 shows that by screening metallocene catalysts, the catalytic activity of Cat3 is the best among Cat1-Cat3; the catalytic activity of Cat6 is the best among the single metallocene catalysts Cat3-Cat6. The ethylene and cyclic olefin monomer 1 in Example 9 react to obtain copolymer a, and the carbon NMR spectrum of copolymer a is shown in 13 Figure 1. Figure 2

[0118] Examples 10-13

[0119] Effect of reaction temperature on metallocene catalyst catalyzed copolymerization of ethylene and fluorine-containing cyclic olefin monomer

[0120] First, a 75 mL glass pressure reactor connected with a gas pipeline is vacuum dried at a certain temperature for 1 h. Then 14 mL of toluene and 1.2 g of copolymer monomer 1 prepared in Example 1 are added to the reactor under an inert atmosphere, then 10.0 μmol of a specific catalyst is dissolved in 1 mL of toluene, and 3.4 mL of a methylaluminoxane toluene solution (1.5 M) is added, which is injected into the polymerization system by a syringe. Under rapid stirring (600 rpm), 0.06 mol of ethylene is introduced. After 10 min, the pressure reactor is emptied, 200 mL of hydrochloric acid ethanol solution is added to quench the polymerization reaction, the polymer is filtered, and dried to constant weight in a vacuum oven to obtain a fluorine-containing cyclic olefin copolymer a. The specific reaction conditions and results are shown in Table 2.

[0121] Table 2 Effect of reaction temperature on metallocene catalyst catalyzed copolymerization of ethylene and fluorine-containing cyclic olefin monomer

[0122]

[0123] Note: all data are based on results of at least two parallel experiments (unless otherwise stated). Activity: in 10 6 gmol -1 h -1 as units; M​n , M w , M w / M n : number average molecular weight, weight average molecular weight, polydispersity index, respectively; measured by GPC in 1,2,4-trichlorobenzene at 150°C, relative to polystyrene standards. T m is the melting temperature, measured by DSC; the insertion rate is measured by carbon nuclear magnetic resonance spectroscopy; the fluorine content is the mass fraction of fluorine in the polymer.

[0124] Table 2 shows that under the catalysis of Cat3 and Cat6, the polymer cycloolefin monomer insertion rate gradually increases with the increase of temperature, and the melting point also increases, and the polymer molecular weight gradually decreases, at the same time, the polymerization activity of Cat6 is gradually decreasing, but the activity of Cat3 is gradually increasing, which is due to the unique effect of the ligand produced by Cat3. The visible light transmittance curve of the fluorine-containing cycloolefin copolymer a obtained by reacting ethylene and cycloolefin monomer 1 in Example 13 is shown in Figure 3 , which shows that the fluorine-containing cycloolefin copolymer a has high transparency, and the light transmittance in the visible light region is greater than 80%. Figure 3

[0125] Examples 14-17

[0126] Effect of different monomers on the copolymerization of ethylene and fluorine-containing cycloolefin monomers catalyzed by metallocene catalyst

[0127] First, a 75 mL glass pressure reactor connected with a gas pipeline is vacuum dried at a certain temperature for 1 h. Then 14 mL of toluene and 2.0 g of fluorine-containing cycloolefin monomer 2 are added to the reactor under an inert atmosphere, then 10.0 μmol of a specific catalyst is dissolved in 1 mL of toluene, and 3.4 mL of a methylaluminoxane toluene solution (1.5 M) is added, which is injected into the polymerization system by a syringe. Under rapid stirring (600 revolutions), 0.06 mol of ethylene is introduced. After 10 min, the pressure reactor is emptied, 200 mL of hydrochloric acid ethanol is added to quench the polymerization reaction, the polymer is filtered, and dried to constant weight in a vacuum oven to obtain a fluorine-containing cycloolefin copolymer b.

[0128]

[0129] Example 18

[0130] Preparation of fluorine-containing cycloolefin copolymer c

[0131]

[0132] ​A 75 mL glass pressure reactor connected to a gas line was first vacuum dried at 90 °C for 1 h. Then 14 mL of toluene and 0.74 g of comonomer 3 were added to the reactor under inert atmosphere, followed by dissolution of 10.0 pmol of Cat 3 catalyst in 1 mL of toluene and addition of 3.4 mL of a methylaluminoxane solution in toluene (1.5 M) by syringe injection into the polymerization system. Under rapid stirring (600 rpm), 0.06 mol of ethylene was passed through. After 10 min, the pressure reactor was evacuated, the polymerization was quenched by addition of 200 mL of an ethanolic hydrochloric acid solution, the polymer was filtered and dried to constant weight in a vacuum oven to give a fluorine-containing cycloolefin copolymer c with a mass of 0.76 g and a weight average molecular weight of 4.9 x 10 4 g / mol.

[0133] Comparative Example 1

[0134] Preparation of ethylene copolymers with norbornene (NBE)

[0135]

[0136] A 150 mL glass pressure reactor connected to a gas line was first vacuum dried at 90 °C for 1 h. Then 49 mL of toluene and 4.0 g of purified, commercially available norbornene were added to the reactor under inert atmosphere, followed by dissolution of 10.0 pmol of Cat 3 catalyst in 1 mL of toluene and addition of 5.0 mL of a methylaluminoxane solution in toluene (1.5 M) by syringe injection into the polymerization system. Under rapid stirring (600 rpm), 0.36 mol of ethylene was passed through. After 10 min, the pressure reactor was evacuated, the polymerization was quenched by addition of 200 mL of an ethanolic hydrochloric acid solution, the polymer was filtered and dried to constant weight in a vacuum oven to give a copolymer d with a mass of 6.50 g and a weight average molecular weight of 17.0 x 10 4 g / mol.

[0137] The specific reaction conditions and results of Examples 14-18 and Comparative Example 1 described above are shown in Table 3.

[0138] The fluorine-containing cycloolefin copolymers a prepared in Examples 6, 9, 11, 13, the fluorine-containing cycloolefin copolymers b prepared in Examples 14-17 and the cycloolefin copolymer c prepared in Example 18 and the cycloolefin copolymer d prepared in Comparative Example 1 were tested for their properties, and the specific property characterization results are shown in Table 4.

[0139] Table 3 Influence of different monomers on the copolymerization of ethylene with fluorine-containing cycloolefin monomers catalyzed by metallocene catalysts

[0140]

[0141] Note: All data are based on at least two parallel runs (unless otherwise indicated). Activity: in 10 6 gmol -1 h -1 as units; M n , M w , M w / M n : number average molecular weight, weight average molecular weight, polydispersity index, respectively; determined by GPC in 1,2,4-trichlorobenzene at 150°C, relative to polystyrene standards; T m is the melting temperature, determined by DSC. The insertion rate is determined by carbon NMR; the fluorine content is the mass fraction of fluorine in the polymer.

[0142] The fluorine-containing cyclic olefin copolymer a prepared in the above Examples 6, 9, 11, 13, the fluorine-containing cyclic olefin copolymer b prepared in Examples 14-17, and the fluorine-containing cyclic olefin copolymer c prepared in Example 18 only have a melting temperature T m (°C), and the cyclic olefin copolymer d prepared in Comparative Example 1 only has a glass transition temperature Tg(°C).

[0143] The fluorine-containing cyclic olefin copolymer prepared by the catalyst Cat3 or Cat6 has a high molecular weight (more than 100,000) at low temperature (30°C), is easy to be formed, and can be used in actual production.

[0144] Table 3 shows that, at the same reaction temperature, Cat3 has higher catalytic activity for the fluorine-containing cyclic olefin monomer 2, and Cat6 has higher catalytic activity for the fluorine-containing cyclic olefin monomer 1. The insertion rate of the fluorine-containing cyclic olefin monomer 2 greatly affects the fluorine content of the fluorine-containing cyclic olefin copolymer, and the fluorine content is higher when the insertion rate is higher. The stress-strain curve of the fluorine-containing cyclic olefin copolymer b prepared by copolymerization of ethylene and the cyclic olefin monomer 2 in Example 16 is shown in Figure 4 , and it can be seen that the tensile strength of the copolymer is 18 MPa, and the elongation at break can reach 812%, which has excellent toughness. Figure 4

[0145] Table 4 Properties of fluorine-containing cyclic olefin copolymers

[0146]

[0147] ​Note: All data are based on at least two parallel experiments (unless otherwise stated). The NB insertion rate is determined by carbon nuclear magnetic resonance spectroscopy, and the fluorine content is the mass fraction of fluorine in the polymer, which is determined by carbon nuclear magnetic resonance spectroscopy. The mechanical and dielectric properties of the polymer are tested on films prepared by a high-temperature film press. The mechanical properties are tested in accordance with international standard ISO 1184-1983 "Determination of tensile properties of plastic films". The dielectric properties are tested in accordance with SJ / T 1147-1993 "Test method for dielectric loss tangent and dielectric constant of organic film for capacitors". The antibacterial properties are tested mainly against Staphylococcus aureus and Escherichia coli in accordance with GB / T 31402-2015. The flame retardant test is performed in accordance with GB-2406 "Test method for oxygen index of plastics". The gas separation test is performed using an MBR gas membrane separation tester.

[0148] The NB insertion rate represents the molar fraction of cyclic olefin monomers (fluorine-containing cyclic olefin monomers or norbornene monomers) in the polymer chain, Dk(10 GHz) represents the dielectric constant, Df(10 GHz) represents the dielectric loss, Anti-SPA / E.coli represents the antibacterial property, and a p CO2 / N2 represents the selectivity for CO2 and N2.

[0149] Since the fluorine-containing cyclic olefin copolymers with high molecular weights are easy to mold and practical, the fluorine-containing cyclic olefin copolymers prepared in Examples 14 and 16 are selected for testing of dielectric, antibacterial, and other properties.

[0150] Tables 3 and 4 show that although the catalytic activity of Comparative Example 1 is high, the NB insertion rate of the copolymer of Comparative Example 1 is as high as 46.9%, which reduces the flexibility of the main chain and results in an elongation at break of only 5%. In contrast, the elongation at break of the fluorine-containing cyclic olefin copolymers b prepared in Examples 14 and 16 can reach 764% and 812%, respectively. This is because the copolymers in Examples 14 and 16 are inserted with cyclic olefin monomers containing flexible long-chain perfluorinated substituents, with an insertion rate of 4.2 mol% or 7.3 mol%, respectively, which greatly improves the elongation at break. In addition, the high fluorine content also reduces the dielectric constant and dielectric loss of the fluorine-containing cyclic olefin copolymers, and improves the antibacterial property, flame retardancy, and gas selectivity of the copolymers.

[0151] The above examples are only used to help understand the method of the present application and its core idea. It should be noted that for those skilled in the art, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A method for preparing a fluorinated cyclic olefin copolymer, characterized in that: The following steps are involved: The fluorinated cycloolefin monomer of the structure represented by formula (II) and α-olefin are polymerized in the presence of a metallocene catalyst to obtain a fluorinated cycloolefin copolymer of the structure represented by formula (I); Formula (I) Formula (II); Wherein, m and n are the degree of polymerization, m:n≤30; R1 and R2 are independently selected from hydrogen or C1-C 10 Saturated aliphatic hydrocarbon group; R3 and R4 are independently selected from hydrogen, halogen, C1-C 20 Alkyl, C1-C 10 Perfluoroalkyl, C1-C 20 Alkoxy, C1-C 20 One of a perfluoroalkoxy group and a 3-20-membered cycloalkyl group; Or R3 and R4 form a ring. When R3 and R4 form a ring, the structure of the fluorinated cyclic olefin copolymer is as follows: Formula (I-a); Ring A is a 4- to 6-membered saturated or unsaturated hydrocarbon ring; R5 and R6 are independently selected from hydrogen, fluorine, C1-C 10 One of the perfluoroalkyl groups; R7 is selected from C1~C 10 Perfluoroalkyl, fluorine, substituted or unsubstituted C1~C 10 One of perfluoroalkoxy, perfluoroaryl, and benzo 3- to 6-membered perfluorocycloalkyl; q is selected from 1 or 4; At least one of R3, R4, R5, R6, and R7 contains a fluorine atom; The insertion rate of fluorinated cyclic olefin monomers is 3.3%-17.4%; The metallocene catalyst is selected from the catalysts of the following structures: 。 2. The preparation method according to claim 1, characterized in that The α-olefin is selected from one or more of ethylene, propylene, 1-butene, isobutylene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 2-ethyl-1-butene.

3. The preparation method according to claim 1, characterized in that The molar ratio of the α-olefin to the fluorinated cycloolefin monomer of the structure represented by formula (II) is (2.3-20):

1.

4. The preparation method according to claim 1, characterized in that The molar ratio of the metallocene catalyst to the fluorine-containing cycloolefin monomer having the structure represented by formula (II) is 1:(200-2400).

5. The preparation method according to claim 1, characterized in that The polymerization reaction is carried out in an inert solvent.

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