Fluorine-free silicon-containing copolymer having high heat resistance and ultra-low dielectric constant, and preparation method therefor

Abstract

The present invention belongs to the technical field of the preparation of materials having high performance and an ultra-low dielectric constant, and discloses a fluorine-free silicon-containing copolymer having high heat resistance and an ultra-low dielectric constant, and a preparation method therefor. The preparation method for a fluorine-free silicon-containing copolymer having high heat resistance and an ultra-low dielectric constant comprises the following steps: mixing a bulky-aryl-substituted symmetrical silicon-containing diene, an α-olefin, a catalyst, a co-catalyst and a hydrocarbon compound solvent to obtain a mixture, and then heating same to perform a polymerization reaction, so as to obtain the fluorine-free silicon-containing copolymer having high heat resistance and an ultra-low dielectric constant. The dielectric constant and dielectric loss of the fluorine-free silicon-containing copolymer having high heat resistance and an ultra-low dielectric constant prepared under optimized conditions can respectively satisfy: ε=1.30-1.50 and tanδ≤3.13×10-4,. Moreover, the copolymer exhibits good heat resistance; the glass transition temperature Tg thereof ranges from 110.0°C to 170.2°C; and the high decomposition temperature Td95 thereof can reach 414.2℃ or higher.

Description

A high heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer and its preparation method Technical Field

[0001] This invention relates to the field of high-performance ultra-low dielectric material preparation technology, and in particular to a high heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer and its preparation method. Background Technology

[0002] With the advent of the era of artificial intelligence, the Internet of Things, and 5G communication, integrated circuits are becoming smaller and more integrated. The parasitic effects of capacitance and resistance (RC) caused by "high speed" and "high frequency" are also intensifying, leading to signal transmission delays, distortion, and even affecting the safety and stability of equipment. To mitigate the impact of parasitic effects, the development of low-dielectric-constant interlayer insulating materials has attracted widespread attention. Inorganic materials, such as silicon oxide and silicon nitride, are commonly used as interlayer dielectrics in microelectronics due to their excellent high-temperature resistance and low dielectric constant. However, their poor processability limits their application in fields such as soft robots and artificial muscles. Polymer-based insulating materials, with their good hydrophobicity, processability, low dielectric constant, and low cost, have attracted widespread attention in the industry. In recent years, dielectric polymers used in the field of electronic information mainly include polyimide (PI), low-density polyethylene (LDPE), poly4-methyl-1-pentene (PMP), polysiloxanes, and fluoropolymers. Polyimide is favored by researchers due to its excellent thermal and chemical stability, but its dielectric constant (ε) is usually between 3.0 and 3.6, which cannot meet the requirements for insulating materials under high frequency and high speed conditions. Low-density polyethylene has good chemical stability, low conductivity, low dielectric constant, and low dielectric loss tangent, but its extremely poor heat resistance limits its application in high-temperature and high-frequency materials. Poly4-methyl-1-pentene is one of the materials with the lowest dielectric constant among synthetic resins (ε≈2.4), but it is expensive, resulting in high synthesis costs. Therefore, designing a low-cost polymer material that combines good high-temperature resistance and ultra-low dielectric constant has become a key focus for researchers in the development of dielectric polymers.

[0003] The main design principles for low dielectric constant materials include reducing the number and strength of dipoles. A common design principle is to introduce low-polarity groups such as fluorine-containing groups. However, the synthetic routes for introducing fluorine-containing groups are relatively complex. Furthermore, the use of fluorine-containing materials may generate corrosive substances such as hydrofluoric acid, posing a potential threat to production equipment and the environment. The treatment and emission of these corrosive substances also increase production costs and environmental burden. Therefore, it is essential to develop a high-heat-resistant, ultra-low dielectric, fluorine-free, low-cost polymer material. Summary of the Invention

[0004] The purpose of this invention is to provide a high heat resistance, ultra-low dielectric fluorine-free silicon-containing copolymer and its preparation method, so as to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] One of the technical solutions of this invention: a high heat-resistant, ultra-low dielectric, fluorine-free silicon-containing copolymer, wherein the structural formula of the high heat-resistant, ultra-low dielectric, fluorine-free silicon-containing copolymer is as follows:

[0007] Where R = H, CH3, or (CH2) n CH3, where n is an integer from 1 to 10, and R3 and R4 are selected from one of the following two cases:

[0008] Option 1: R3 = R4 = phenyl, indole, fluorenyl, naphthyl, or anthracene;

[0009] Option 2: R3 = CH3, R4 = phenyl, indole, fluorenyl, naphthyl, or anthracene.

[0010] To further reduce the dielectric constant and dielectric loss of polymers, while improving the heat resistance and glass transition temperature of materials and significantly reducing synthesis costs, this invention uses inexpensive and readily available α-olefins such as ethylene, propylene, and butene as monomers to replace expensive 4-methyl-1-pentene in constructing the olefin backbone structure. These are then copolymerized with symmetrical dienes containing carbon-silicon covalent bonds and aromatic structures such as benzene rings, indene, and fluorene groups with large steric hindrance. Introducing C-Si bonds into the polymer reduces dipole strength, while introducing sterically hindered aromatic substituents improves the material's high-temperature resistance. By using sterically hindered aryl-substituted symmetrical silicon dienes as the main body, copolymerizing with inexpensive and readily available α-olefins, and controlling the cyclization ratio of the dienes, the copolymerization options for symmetrical silicon dienes are broadened. This novel low-dielectric polymer material not only achieves unprecedented ultra-low dielectric constants (ε=1.30~1.50) and dielectric losses (tanδ≤3.13×10⁻⁶), but also... -4 In addition to improving the performance of the copolymer, the α-olefin copolymer unit further optimizes the mechanical properties of the copolymer and reduces the cost. At the same time, the symmetrical structure and the large aryl steric hindrance effect synergistically improve the glass transition temperature of the copolymer, making up for the poor temperature resistance of polymer-based insulating materials. This new material has broad practical application prospects in the field of high-frequency and high-temperature communication.

[0011] Furthermore, the weight-average molecular weight of the high heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer is (35–150) × 10⁻⁶. 4 g / mol.

[0012] Furthermore, the content of sterically hindered aryl-substituted symmetrical silicon dienes in the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer is 10-100 mol%, but not 100 mol%.

[0013] The second technical solution of the present invention: The preparation method of the above-mentioned high heat resistance, ultra-low dielectric fluorine-free silicon-containing copolymer includes the following steps:

[0014] A mixture is prepared by mixing a sterically hindered aryl-substituted symmetrical silicon diene, an α-olefin, a catalyst, a co-catalyst, a chain transfer agent, and a hydrocarbon solvent to obtain a mixture, which is then heated to carry out a polymerization reaction to obtain the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer.

[0015] The sterically hindered aryl-substituted symmetrical silicones include one of diallyl diphenylsilane (DDPS), diallyl methylphenylsilane (DMPS), diallyl diindylsilane, diallyl methylindylsilane (DMIS), diallyl difluorenylsilane, diallyl methylfluorenylsilane (DMFS), diallyl dinaphthylsilane, diallyl methylnaphthylsilane, diallyl dianthrylsilane, and diallyl methylanthrylsilane;

[0016] The α-olefin includes one of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene;

[0017] Furthermore, the hydrocarbon solvent includes one or more of benzene and its homologues, indene and its homologues, naphthalene and its homologues, alkanes and their homologues, and cycloalkanes and their homologues.

[0018] Furthermore, the catalyst is a single-active-center transition metal catalyst;

[0019] And / or, the cocatalyst comprises one or more of tripentafluorophenyl alkylborane, triperfluorobiphenyl borane, triphenylmethyltetra(pentafluorophenyl)borate ([Ph3C][B(C6F5)4]), and tert-butyltriphenylmethyltetra(pentafluorophenyl)borate.

[0020] And / or, the chain transfer agent includes one or more of methylaluminoxane (MAO), modified methylaluminoxane (MMAO), ethylaluminoxane, isobutylaluminoxane, trimethylaluminum, diethylaluminum chloride, triethylaluminum, triisopropylaluminum, triisobutylaluminum, diethylzinc, diethylmagnesium, dibutylmagnesium, and n-butylethylmagnesium.

[0021] Furthermore, the co-catalyst is preferably triphenylmethyltetra(pentafluorophenyl)borate.

[0022] Furthermore, the chain transfer agent is preferably triisobutylaluminum.

[0023] Furthermore, the concentration of the sterically hindered aryl-substituted symmetrical silicon diene in the mixture is 0.1–0.2 mol / L, preferably 0.2 mol / L;

[0024] And / or, the concentration of the α-olefin in the mixture is 0.02–0.2 mol / L;

[0025] And / or, the concentration of the catalyst in the mixture is (1.5–2) × 10⁻⁶. -4 mol / L, preferably 1.7 × 10⁻⁶ mol / L. -4 mol / L;

[0026] And / or, the molar ratio of the catalyst to the co-catalyst is 1:1 to 2000, preferably 1:2.

[0027] And / or, the molar ratio of the catalyst to the chain transfer agent is 1:10 to 1000, preferably 1:150.

[0028] Furthermore, the polymerization reaction is carried out at a temperature of 20–85°C for a time of 10–720 min.

[0029] Furthermore, after the polymerization reaction is completed, the reaction further includes adding ethanol to terminate the polymerization reaction and obtaining a reaction solution, mixing the reaction solution with an acidified precipitant, and performing a settling, washing, filtration, dissolution, adsorption, settling, filtration, washing, and vacuum drying process.

[0030] Further, the precipitant includes one or more of ethanol, methanol, petroleum ether, diethyl ether, n-hexane, acetone, n-pentane, tetrahydrofuran, and dichloromethane, preferably ethanol;

[0031] And / or, the acidification includes: mixing the acid with a precipitant, i.e., the acidified precipitant is a mixed solution of the precipitant and the acid.

[0032] Furthermore, the acid is hydrochloric acid, and the volume ratio of the precipitant to the hydrochloric acid is 50:1.

[0033] Furthermore, the concentration of the hydrochloric acid is 38 wt%.

[0034] Furthermore, the single-active-center transition metal catalyst is Me2Si(Ind)2ZrCl2 (structural formula: Abbreviated as Cat.4) or with the structure as The compounds in which R1 and R2 are selected from one of the following three cases:

[0035] Option 1: R1 = H, R2 = 2- iPr-Ph (the compound is abbreviated as Cat.1);

[0036] Option 2: R1 = R2 = CH3 (the compound is simply referred to as Cat.2);

[0037] Option 3: R1 = t Bu, R2=CH3 (the compound is simply referred to as Cat.3).

[0038] Furthermore, the single-active-center transition metal catalyst is preferably Cat.1.

[0039] Further, the adsorption includes: adsorption using an adsorbent; the adsorbent includes one of 100-500 mesh silica gel powder, 100-800 mesh neutral alumina, and 100-200 mesh molecular sieve, preferably 200-300 mesh neutral alumina.

[0040] More preferably, the sterically hindered aryl-substituted symmetrical silicon diene is diallylmethylphenylsilane (DMPS), and the structural formula of the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer is shown in Formula I;

[0041] Alternatively, the sterically hindered aryl-substituted symmetrical silicon diene is diallylmethylindenylsilane (DMIS), and the structural formula of the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer is shown in Formula II.

[0042] Alternatively, the sterically hindered aryl-substituted symmetrical silicon diene is diallyl diphenylsilane (DDPS), and the structural formula of the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer is shown in Formula III.

[0043] Alternatively, the sterically hindered aryl-substituted symmetrical silicon diene is diallylmethylfluorenylsilane (DMFS), and the structural formula of the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer is shown in Formula IV.

[0044] Where R = H, CH3, or (CH2) n CH3, where n is an integer from 1 to 10. Preferably, R = H, CH3, CH2CH3, (CH2)2CH3 or (CH2)3CH3.

[0045] The third technical solution of the present invention: the application of the above-mentioned high heat resistance, ultra-low dielectric fluorine-free silicon-containing copolymer in the preparation of high-performance microwave substrates, millimeter-wave substrates or packaging materials.

[0046] This invention mainly utilizes various sterically hindered aromatic-substituted symmetrical silicon dienes to synthesize a series of high-heat-resistant, ultra-low dielectric polymer copolymers with excellent properties. Catalysts with excellent copolymerization ability and high cyclization selectivity for silicon dienes and α-olefins were selected, and the thermal and dielectric properties of copolymers obtained by copolymerizing symmetrical silicon dienes DDPS, DMPS, DMIS, DMFS or their derivatives with ethylene, propylene, 1-butene, 1-pentene, 1-hexene, etc., were investigated.

[0047] The resonant cavity method was used to test the dielectric constant of the polymers, and it was found that the dielectric constant of all polymers was between 1.30 and 1.50, and the dielectric loss was less than or equal to 3.13 × 10⁻⁶. -4 The glass transition temperature (T0) of the copolymer obtained with DDPS (diallyl diphenylsilane) as the main component can be observed by DSC testing. g =133.8~152.4℃), when the monomer is DMFS (diallylmethylfluorenylsilane), the glass transition temperature of the copolymer can reach 170.2℃, which is significantly higher than any previous reports and studies on low dielectric polymers.

[0048] In summary, this invention provides a method for preparing a high-heat-resistant, ultra-low-dielectric copolymer based on a series of symmetrical silicon-containing dienes with complex aromatic groups and low-cost α-olefins, thereby preparing a copolymer with high heat resistance (T... g =110.0~170.2℃, T d95 It has a temperature ≥414.2℃ and the lowest dielectric constant and dielectric loss (ε=1.30~1.50, tanδ≤3.13×10) among existing polymer materials. -4 The copolymers of silicone dienes and α-olefins are synthesized using catalysts with excellent copolymerization ability and high cyclization selectivity. The copolymer composition is optimized to achieve efficient synthesis of copolymer materials with ultra-high comprehensive performance (high temperature resistance, high-frequency ultra-low dielectric, low dielectric loss, and excellent mechanical properties). This invention significantly overcomes the limitations of synthesizing non-fluorinated polymer dielectric materials with poor heat resistance. The resulting ultra-low dielectric materials hold promise for applications in high-performance microwave / millimeter-wave substrates and packaging materials.

[0049] The present invention discloses the following technical effects:

[0050] This invention utilizes a single-active-site metal catalyst combined with a co-catalyst to synthesize a series of sterically hindered aryl-substituted symmetrical silicon dienes and α-olefins. Based on the catalyst's copolymerization ability with α-olefins and silicon dienes, various α-olefins were copolymerized with sterically hindered aryl-substituted symmetrical silicon dienes. It was observed that the symmetrical silicon dienes accounted for 10–100 mol% of the copolymer composition, yielding copolymers with high heat resistance and ultra-low dielectric constants. When DDPS (diallyl diphenylsilane) was used… When the aryl group content reaches 90 mol%, the copolymer exhibits a glass transition temperature of up to 152.4 °C and a dielectric constant between 1.36 and 1.50. When the DMPS (diallylmethylphenylsilane) content reaches 90 mol%, the copolymer reaches a glass transition temperature of up to 137.0 °C and a dielectric constant between 1.30 and 1.37. With further increases in aryl steric hindrance and replacement of phenyl groups with indene or fluorenyl groups, the glass transition temperature of the copolymer can be further increased to 170.2 °C, significantly improving the material's heat resistance. Furthermore, the dielectric loss of all polymers is ≤3.13 × 10⁻⁶. -4 Finally, the mechanical properties of the copolymer and the silicon diene homopolymer were compared. The homopolymer exhibited overall brittleness, which is attributed to the high content of ring units in the polymer backbone, restricting molecular chain movement. In contrast, the copolymer, with more α-olefin chain units inserted into its backbone, showed a significant improvement in tensile strength. Notably, the high heat resistance and ultra-low dielectric constant material prepared in this invention has a dielectric constant significantly lower than that of widely used materials in the electronics and information field, such as polytetrafluoroethylene (PTFE, ε≈2.1), polyimide (PI, ε>3.0), polyphenylene ether (PPE, ε≈2.7), and poly4-methyl-1-pentene (PMP, ε≈2.1). This material holds promise for applications in high-performance microwave / millimeter-wave substrates and packaging materials. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 shows the copolymer prepared in Example 5. 1 H NMR and 13 C NMR spectrum;

[0053] Figure 2 shows the copolymer prepared in Example 6. 1 H NMR and 13 C NMR spectrum;

[0054] Figure 3 shows the copolymer prepared in Example 12. 1H NMR and 13 C NMR spectrum;

[0055] Figure 4 is a scatter plot of the dielectric constants of the copolymers prepared in Examples 1, 3, 5, 8, 10, and 12;

[0056] Figure 5 is a scatter plot of dielectric loss of the copolymers prepared in Examples 1, 3, 5, 8, 10, and 12;

[0057] Figure 6 shows the DSC curves of the copolymers prepared in Examples 1, 3, 5, 8, 10, and 12;

[0058] Figure 7 shows the TGA curves of the copolymers prepared in Examples 1, 3, 8, and 10. Detailed Implementation

[0059] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0060] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0061] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0062] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0063] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0064] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0065] As a first aspect of the present invention, the present invention provides a high heat-resistant, ultra-low dielectric, fluorine-free silicon-containing copolymer, wherein the structural formula of the high heat-resistant, ultra-low dielectric, fluorine-free silicon-containing copolymer is as follows:

[0066] Where R = H, CH3, or (CH2) n CH3, where n is an integer from 1 to 10, and R3 and R4 are selected from one of the following two cases:

[0067] Option 1: R3 = R4 = phenyl, indole, fluorenyl, naphthyl, or anthracene;

[0068] Option 2: R3 = CH3, R4 = phenyl, indole, fluorenyl, naphthyl, or anthracene.

[0069] As an embodiment of the present invention, the weight-average molecular weight of the high heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer is (35-150)×10⁻⁶. 4 g / mol.

[0070] In a preferred embodiment of the present invention, the content of sterically hindered aryl-substituted symmetrical silicon diene in the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer is 10-100 mol%, but not 100 mol%.

[0071] As a second aspect of the present invention, the present invention provides a method for preparing a high heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer, comprising the following steps:

[0072] A sterically hindered aryl-substituted symmetrical silicon diene, α-olefin, catalyst, co-catalyst, chain transfer agent, and hydrocarbon solvent are mixed to obtain a mixture, which is then heated to carry out a polymerization reaction to obtain the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer.

[0073] In a preferred embodiment of the present invention, the preparation method includes the following more specific steps:

[0074] (1) Mix sterically hindered aryl-substituted symmetrical silicon diene, α-olefin, catalyst, co-catalyst, chain transfer agent and hydrocarbon solvent to obtain a mixture, and polymerize it at 20-85℃ for 10-720 min. Add ethanol to terminate the polymerization reaction to obtain a reaction solution.

[0075] (2) The reaction solution is mixed with the acidified precipitant, and subjected to one sedimentation, one washing, one filtration, dissolution, adsorption, two sedimentation, two filtration, two washing, and vacuum drying to obtain a high heat-resistant, ultra-low dielectric fluorine-free copolymer.

[0076] As an embodiment of the present invention, the mixing process may first involve mixing the α-olefin with a portion of the solvent, mixing the catalyst and co-catalyst with a portion of the solvent, and then mixing the whole mixture.

[0077] As an embodiment of the present invention, the sterically hindered aryl-substituted symmetrical silicone includes one of diallyl diphenylsilane (DDPS), diallyl methylphenylsilane (DMPS), diallyl diindenylsilane, diallyl methylindenylsilane (DMIS), diallyl difluorenylsilane, diallyl methylfluorenylsilane (DMFS), diallyl dinaphthylsilane, diallyl methylnaphthylsilane, diallyl dianthrylsilane, and diallyl methylanthrylsilane;

[0078] The α-olefins include one of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene.

[0079] As an embodiment of the present invention, the hydrocarbon compound solvent includes one or more of benzene and its homologues, indene and its homologues, naphthalene and its homologues, alkanes and their homologues, and cycloalkanes and their homologues.

[0080] As an embodiment of the present invention, the catalyst is a single-active-center transition metal catalyst; the single-active-center transition metal catalyst is Me2Si(Ind)2ZrCl2 (structural formula: Abbreviated as Cat.4) or with the structure as The compounds in which R1 and R2 are selected from one of the following three cases:

[0081] Option 1: R1 = H, R2 = 2- i Pr-Ph (the compound is abbreviated as Cat.1);

[0082] Option 2: R1 = R2 = CH3 (the compound is simply referred to as Cat.2);

[0083] Option 3: R1 = t Bu, R2=CH3 (the compound is simply referred to as Cat.3).

[0084] As an embodiment of the present invention, the co-catalyst includes one or more of tripentafluorophenyl alkylborane, triperfluorobiphenyl borane, triphenylmethyltetra(pentafluorophenyl)borate ([Ph3C][B(C6F5)4]), and tert-butyltriphenylmethyltetra(pentafluorophenyl)borate.

[0085] As an embodiment of the present invention, the chain transfer agent includes one or more of methylaluminoxane (MAO), modified methylaluminoxane (MMAO), ethylaluminoxane, isobutylaluminoxane, trimethylaluminum, diethylaluminum chloride, triethylaluminum, triisopropylaluminum, triisobutylaluminum, diethylzinc, diethylmagnesium, dibutylmagnesium, and n-butylethylmagnesium.

[0086] In a preferred embodiment of the present invention, the co-catalyst is preferably triphenylmethyltetra(pentafluorophenyl)borate.

[0087] In a preferred embodiment of the present invention, the chain transfer agent is preferably triisobutylaluminum.

[0088] As an embodiment of the present invention, the concentration of the sterically hindered aryl-substituted symmetrical silicon diene in the mixture is 0.1 to 0.2 mol / L, preferably 0.2 mol / L;

[0089] And / or, the concentration of the α-olefin in the mixture is 0.02–0.2 mol / L;

[0090] And / or, the concentration of the catalyst in the mixture is (1.5–2) × 10⁻⁶. -4 mol / L, preferably 1.7 × 10⁻⁶ mol / L. -4 mol / L;

[0091] And / or, the molar ratio of the catalyst to the co-catalyst is 1:1 to 2000, preferably 1:2.

[0092] And / or, the molar ratio of the catalyst to the chain transfer agent is 1:10 to 1000, preferably 1:150.

[0093] As an embodiment of the present invention, the precipitant includes one or more of ethanol, methanol, petroleum ether, diethyl ether, n-hexane, acetone, n-pentane, tetrahydrofuran, and dichloromethane, preferably ethanol;

[0094] And / or, the acidification includes: mixing the acid with a precipitant, i.e., the acidified precipitant is a mixed solution of the precipitant and the acid.

[0095] In an embodiment of the present invention, the acid is hydrochloric acid with a concentration of 38 wt%, and the volume ratio of the precipitant to the hydrochloric acid is 50:1.

[0096] In a preferred embodiment of the present invention, the single active center transition metal catalyst is preferably Cat.1.

[0097] As an embodiment of the present invention, the adsorption includes: adsorption using an adsorbent; the adsorbent includes one of 100-500 mesh silica gel powder, 100-800 mesh neutral alumina, and 100-200 mesh molecular sieve, preferably 200-300 mesh neutral alumina.

[0098] In a preferred embodiment of the present invention, the sterically hindered aryl-substituted symmetrical silicon diene is diallylmethylphenylsilane (DMPS), and the structural formula of the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer is shown in Formula I.

[0099] Alternatively, the sterically hindered aryl-substituted symmetrical silicon diene is diallylmethylindenylsilane (DMIS), and the structural formula of the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer is shown in Formula II.

[0100] Alternatively, the sterically hindered aryl-substituted symmetrical silicon diene is diallyl diphenylsilane (DDPS), and the structural formula of the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer is shown in Formula III.

[0101] Alternatively, the sterically hindered aryl-substituted symmetrical silicon diene is diallylmethylfluorenylsilane (DMFS), and the structural formula of the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer is shown in Formula IV.

[0102] Where R = H, CH3, or (CH2) n CH3, where n is an integer from 1 to 10. Preferably, R = H, CH3, CH2CH3, (CH2)2CH3 or (CH2)3CH3.

[0103] As a preferred embodiment of the present invention, the properties of the high heat resistance, ultra-low dielectric fluorine-free silicon-containing copolymer include: T g =110.0~170.2℃; T d95 ≥414.2℃; the dielectric constant of the copolymer is 1.30~1.50, and the dielectric loss is 2.51×10⁻⁶. -4 ~3.13×10 -4 .

[0104] As a third aspect of the present invention, the present invention provides the application of the above-mentioned high heat resistance, ultra-low dielectric fluorine-free silicon-containing copolymer in the preparation of high-performance microwave substrates, millimeter-wave substrates or packaging materials.

[0105] The structural information of the main raw materials involved in the specific embodiments of the present invention is shown in Table 1.

[0106] Table 1

[0107] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0108] Unless otherwise specified, all raw materials used in the following examples and comparative examples are commercially available products, including anhydrous ethanol, diallyl diphenylsilane (DDPS) with CAS number 10519-88-7, and diallyl methylphenylsilane (DMPS) with CAS number 2633-60-5.

[0109] Catalyst Cat.1 was synthesized according to existing technology (Angewandte Chemie 2006, 45(20), 3278-3283).

[0110] The preparation method of diallylmethylindanylsilane (DMIS) is as follows:

[0111] Using a Schlenk apparatus under a nitrogen atmosphere, 30 g of magnesium powder (1.25 mol) and 400 mL of anhydrous diethyl ether (SPS) were added to a dry 2 L three-necked flask equipped with a mechanical stirrer, a constant-pressure dropping funnel, and a spherical condenser. 40 mL (0.58 mol) of allyl bromide (redistilled) was diluted with 500 mL of anhydrous diethyl ether (SPS) and added to the constant-pressure dropping funnel. The mixture was cooled to 30 °C and then heated. A small amount of the allyl bromide diethyl ether solution was first added dropwise through the constant-pressure dropping funnel to initiate the reaction. After heating, the allyl bromide diethyl ether solution was slowly added dropwise to maintain a gentle boil. After the addition was complete, the liquid gradually turned grayish-black. The reaction was continued for 3 hours (40 °C) to ensure complete reaction.

[0112] Then, 47 mL (0.25 mol) of methylindenyldichlorosilane (CAS No.: 17478-29-4) was slowly added dropwise to the above reaction system through a constant-pressure dropping funnel (exothermic reaction). After the addition was complete, the mixture was heated to reflux at 40 °C for 3 hours to ensure complete reaction. After the reaction was complete, a saturated ammonium chloride aqueous solution was slowly added dropwise to the reaction system to destroy the unreacted Grignard reagent (exothermic reaction). The insoluble matter was removed by filtration, and the filter cake was washed three times with diethyl ether. The filtrate was extracted three times with diethyl ether, the ether layers were combined, dried over anhydrous magnesium sulfate, and the ether was removed by rotary evaporation. The resulting liquid was further distilled under reduced pressure to obtain 50 mL of diallylmethylindenylsilane. Yield: 85%.

[0113] The preparation method of diallyl methylfluorenylsilane (DMFS) is the same as that of diallyl methylindenesilane (DMIS), except that methylindene dichlorosilane is replaced with methylfluorenyl dichlorosilane (CAS No.: 164462-10-6).

[0114] Diallyldiindylsilane, diallyldifluorenylsilane, diallyldinaphthylsilane, diallylmethylnaphthylsilane, diallyldianthrylsilane, and diallylmethylanthrylsilane can be prepared via synthetic routes similar to those used for DMIS and DMFS.

[0115] In the synthesis of the catalyst, unless otherwise specified, all operations involved are performed by those skilled in the art under an inert gas atmosphere such as nitrogen or argon, in an MBraun glove box or using standard Schlenk techniques. Furthermore, all solvents used in this invention are post-treated to be anhydrous and oxygen-free. Additionally, in the preparation of the high-heat-resistant, ultra-low dielectric fluorine-free copolymer, all polymerization reactions must be carried out under anhydrous and oxygen-free conditions. All glassware used for weighing and transferring catalysts, co-catalysts, chain transfer agents, solutions, etc., in the preparation steps, such as ampoules, syringes, and polymerization bottles, are treated to be anhydrous and oxygen-free. All operations sensitive to moisture and oxygen are performed by those skilled in the art under an inert gas atmosphere, in an MBraun glove box or using standard Schlenk techniques.

[0116] Example 1

[0117] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallyldiphenylsilane / ethylene copolymer, structural formula shown in Formula III, wherein R = H) comprises the following steps:

[0118] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent solution was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 9 equivalents (10.8 mmol) of DDPS were added (to bring the final concentration of DDPS in the mixture to 0.18 mol / L), and 1 equivalent (containing 1.2 mmol of ethylene) of an ethylene / toluene solution was added (to bring the final concentration of ethylene in the mixture to 0.02 mol / L); after stabilization, [the following was added]... A mixed solution of Cat.1 / [Ph3C][B(C6F5)4] / toluene (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was prepared. The amount of toluene in the ethylene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to make the total volume of the final mixture 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization and the reaction solution was obtained. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl diphenylsilane / ethylene copolymer.

[0119] Example 2

[0120] Same as Example 1, except that the amount of DDPS used is 8 equivalents (9.6 mmol), that is, the concentration in the final mixture is 0.16 mol / L; the amount of ethylene used is 2 equivalents (2.4 mmol), that is, the concentration in the final mixture is 0.04 mol / L.

[0121] Example 3

[0122] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallyldiphenylsilane / propylene copolymer, structural formula as shown in Formula III, wherein R = CH3) comprises the following steps:

[0123] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent solution was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 9 equivalents (10.8 mmol) of DDPS were added (to bring the final concentration of DDPS in the mixture to 0.18 mol / L), and 1 equivalent (containing 1.2 mmol of propylene) of a propylene / toluene solution was added (to bring the final concentration of propylene in the mixture to 0.02 mol / L); after stabilization, [the following was added]... A mixed solution of Cat.1 / [Ph3C][B(C6F5)4] / toluene (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was prepared. The amount of toluene in the propylene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to make the total volume of the final mixture 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization and the reaction solution was obtained. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid in a volume ratio of 50:1) to settle. After settling for 6 hours, the solution was washed and filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The solution was then poured into the ethanol / hydrochloric acid solution to settle for 6 hours, followed by washing, filtering, and vacuum drying at 70 °C to obtain diallyl diphenylsilane / propylene copolymer.

[0124] Example 4

[0125] Same as Example 3, except that the amount of DDPS used is 8 equivalents (9.6 mmol), that is, the concentration in the final mixture is 0.16 mol / L; the amount of propylene used is 2 equivalents (2.4 mmol), that is, the concentration in the final mixture is 0.04 mol / L.

[0126] Example 5

[0127] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallyldiphenylsilane / 1-butene copolymer, structural formula as shown in Formula III, wherein R = CH2CH3) comprises the following steps:

[0128] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent solution was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 9 equivalents (10.8 mmol) of DDPS were added (to bring the final concentration of DDPS in the mixture to 0.18 mol / L), followed by 1 equivalent (containing 1.2 mmol) of... A 1-butene / toluene mixed solution was prepared (to achieve a 1-butene concentration of 0.02 mol / L in the final mixture). After stabilization, a Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was added. The amount of toluene in the 1-butene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to ensure that the total volume of the final mixture was 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization, yielding the reaction solution. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl diphenylsilane / 1-butene copolymer.

[0129] Example 6

[0130] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallyldiphenylsilane / 1-pentene copolymer, structural formula as shown in Formula III, wherein R = (CH2)2CH3) comprises the following steps:

[0131] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent solution was added to a polymerization flask (to achieve a final triisobutylaluminum concentration of 0.025 mol / L in the mixture); then 9 equivalents (10.8 mmol) of DDPS were added (to achieve a final concentration of 0.18 mol / L in the mixture), followed by 1 equivalent (containing 1.2 mmol... A 1-pentene / toluene mixed solution was prepared (to make the concentration of 1-butene in the final mixture 0.02 mol / L); after stabilization, a Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was added, and the amount of toluene in the 1-pentene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled so that the total volume of the final mixture was 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min; after the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization and the reaction solution was obtained. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl diphenylsilane / 1-pentene copolymer.

[0132] Example 7

[0133] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallyldiphenylsilane / 1-hexene copolymer, structural formula as shown in Formula III, wherein R = (CH2)3CH3) comprises the following steps:

[0134] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent mixture was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 9 equivalents (10.8 mmol) of DDPS were added (to bring the final concentration of DDPS in the mixture to 0.18 mol / L), followed by 1 equivalent (containing 1.2 mmol) of... A 1-hexene / toluene mixed solution was prepared (to achieve a 1-hexene concentration of 0.02 mol / L in the final mixture). After stabilization, a Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was added. The amount of toluene in the 1-hexene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to ensure that the total volume of the final mixture was 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization, yielding the reaction solution. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl diphenylsilane / 1-hexene copolymer.

[0135] Example 8

[0136] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallylmethylphenylsilane / ethylene copolymer, structural formula as shown in Formula I, where R = H) comprises the following steps:

[0137] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent solution was added to a polymerization flask (to bring the final concentration of triisobutylaluminum to 0.025 mol / L); then 9 equivalents (10.8 mmol) of DMPS were added (to bring the final concentration to 0.18 mol / L), and 1 equivalent (containing 1.2 mmol of ethylene) of an ethylene / toluene solution was added (to bring the final concentration of ethylene to 0.02 mol / L). After stabilization, [the following was added]... A mixed solution of Cat.1 / [Ph3C][B(C6F5)4] / toluene (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was prepared. The amount of toluene in the ethylene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to make the total volume of the final mixture 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization and the reaction solution was obtained. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl methylphenylsilane / ethylene copolymer.

[0138] Example 9

[0139] Same as Example 8, except that the amount of DMPS used is 8 equivalents (9.6 mmol), that is, the concentration in the final mixture is 0.16 mol / L; the amount of ethylene used is 2 equivalents (2.4 mmol), that is, the concentration in the final mixture is 0.04 mol / L.

[0140] Example 10

[0141] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallylmethylphenylsilane / propylene copolymer, structural formula as shown in Formula I, wherein R = CH3) comprises the following steps:

[0142] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent mixture was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 9 equivalents (10.8 mmol) of DMPS were added (to bring the final concentration of DMPS in the mixture to 0.18 mol / L), and 1 equivalent (containing 1.2 mmol of propylene) of a propylene / toluene mixture was added (to bring the final concentration of propylene in the mixture to 0.02 mol / L); after stabilization, [the following was added]... A mixed solution of Cat.1 / [Ph3C][B(C6F5)4] / toluene (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was prepared. The amount of toluene in the propylene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to make the total volume of the final mixture 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization and the reaction solution was obtained. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl methylphenylsilane / propylene copolymer.

[0143] Example 11

[0144] Same as Example 10, except that the amount of DMPS used is 8 equivalents (9.6 mmol), that is, the concentration in the final mixture is 0.16 mol / L; the amount of propylene used is 2 equivalents (2.4 mmol), that is, the concentration in the final mixture is 0.04 mol / L.

[0145] Example 12

[0146] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallylmethylphenylsilane / 1-butene copolymer, structural formula as shown in Formula I, wherein R = CH2CH3) comprises the following steps:

[0147] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent solution was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 9 equivalents (10.8 mmol) of DMPS were added (to bring the final concentration of DMPS in the mixture to 0.18 mol / L), followed by 1 equivalent (containing 1.2 mmol) of... A 1-butene / toluene mixed solution was prepared (to achieve a 1-butene concentration of 0.02 mol / L in the final mixture). After stabilization, a Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was added. The amount of toluene in the 1-butene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to ensure that the total volume of the final mixture was 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization, yielding the reaction solution. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl methylphenylsilane / 1-butene copolymer.

[0148] Example 13

[0149] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallylmethylphenylsilane / 1-pentene copolymer, structural formula as shown in Formula I, wherein R = (CH2)2CH3) comprises the following steps:

[0150] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent solution was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 9 equivalents (10.8 mmol) of DMPS were added (to bring the final concentration of DMPS in the mixture to 0.18 mol / L), followed by 1 equivalent (containing 1.2 mmol) of... A 1-pentene / toluene mixed solution was prepared (to achieve a 1-pentene concentration of 0.02 mol / L in the final mixture). After stabilization, a Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was added. The amount of toluene in the 1-pentene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to ensure that the total volume of the final mixture was 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization, yielding the reaction solution. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again. After washing and filtering, it was dried under vacuum at 70 °C to obtain diallyl methylphenylsilane / 1-pentene copolymer.

[0151] Example 14

[0152] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallylmethylphenylsilane / 1-hexene copolymer, structural formula as shown in Formula I, wherein R = (CH2)3CH3) comprises the following steps:

[0153] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent mixture was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 9 equivalents (10.8 mmol) of DMPS were added (to bring the final concentration of DMPS in the mixture to 0.18 mol / L), followed by 1 equivalent (containing 1.2 mmol) of... A 1-hexene / toluene mixed solution was prepared (to achieve a 1-hexene concentration of 0.02 mol / L in the final mixture). After stabilization, a Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was added. The amount of toluene in the 1-hexene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to ensure that the total volume of the final mixture was 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization, yielding the reaction solution. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl methylphenylsilane / 1-hexene copolymer.

[0154] Example 15

[0155] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallylmethylindenylsilane / ethylene copolymer, structural formula as shown in Formula II, wherein R = H) comprises the following steps:

[0156] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent solution was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 9 equivalents (10.8 mmol) of DMIS were added (to bring the final concentration of DMIS in the mixture to 0.18 mol / L), and 1 equivalent (containing 1.2 mmol of ethylene) of an ethylene / toluene solution was added (to bring the final concentration of ethylene in the mixture to 0.02 mol / L); after stabilization, [the following was added]... A mixed solution of Cat.1 / [Ph3C][B(C6F5)4] / toluene (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was prepared. The amount of toluene in the ethylene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to make the total volume of the final mixture 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization and the reaction solution was obtained. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl methyl indenyl silane / ethylene copolymer.

[0157] Example 16

[0158] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallylmethylindenylsilane / propylene copolymer, structural formula as shown in Formula II, wherein R = CH3) comprises the following steps:

[0159] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent solution was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 9 equivalents (10.8 mmol) of DMIS were added (to bring the final concentration of DMIS in the mixture to 0.18 mol / L), and 1 equivalent (containing 1.2 mmol of propylene) of a propylene / toluene solution was added (to bring the final concentration of propylene in the mixture to 0.02 mol / L); after stabilization, [the following was added]... A mixed solution of Cat.1 / [Ph3C][B(C6F5)4] / toluene (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was prepared. The amount of toluene in the propylene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to make the total volume of the final mixture 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization and the reaction solution was obtained. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered, dissolved in toluene, and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl methyl indenyl silane / propylene copolymer.

[0160] Example 17

[0161] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallylmethylfluorenylsilane / ethylene copolymer, structural formula as shown in Formula IV, where R = H) comprises the following steps:

[0162] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent mixture was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 9 equivalents (10.8 mmol) of DMFS were added (to bring the final concentration of DMFS in the mixture to 0.18 mol / L), and 1 equivalent (containing 1.2 mmol of ethylene) of an ethylene / toluene mixture was added (to bring the final concentration of ethylene in the mixture to 0.02 mol / L); after stabilization, [further steps were taken]. A mixed solution of Cat.1 / [Ph3C][B(C6F5)4] / toluene (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was added. The amount of toluene in the ethylene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to make the total volume of the mixed system 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization and the reaction solution was obtained. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl methylfluorenylsilane / ethylene copolymer.

[0163] Example 18

[0164] A method for preparing a high-heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer (diallylmethylfluorenylsilane / propylene copolymer, structural formula as shown in Formula IV, wherein R = CH3) comprises the following steps:

[0165] Using the Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent mixture was added to a polymerization flask (to bring the final concentration of triisobutylaluminum to 0.025 mol / L). Then, 9 equivalents (10.8 mmol) of DMFS were added (to bring the final concentration to 0.18 mol / L), followed by 1 equivalent (containing 1.2 mmol of propylene) of a propylene / toluene mixture (to bring the final concentration of propylene to 0.02 mol / L). After stabilization, [the following was added]... A mixed solution of Cat.1 / [Ph3C][B(C6F5)4] / toluene (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was prepared. The amount of toluene in the propylene / toluene mixed solution and the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixed solution was controlled to make the total volume of the final mixture 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min. After the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization and the reaction solution was obtained. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl methylfluorenylsilane / propylene copolymer.

[0166] Comparative Example 1

[0167] Using a Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent mixture was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 12 mmol of DDPS was added (to bring the final concentration of the mixture to 0.2 mol / L); after stabilization, a Cat.1 / [Ph3C][B(C6F5)4] / toluene mixture (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was added, controlling the amount of toluene in the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixture to bring the total volume of the final mixture to 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min; after the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization, yielding the reaction solution. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again, followed by washing, filtration, and vacuum drying at 70 °C to obtain diallyl diphenylsilane homopolymer.

[0168] Comparative Example 2

[0169] Using a Schlenk apparatus under a nitrogen atmosphere, 1.5 mL of a 1.0 mol / L triisobutylaluminum / toluene chain transfer agent mixture was added to a polymerization flask (to bring the final concentration of triisobutylaluminum in the mixture to 0.025 mol / L); then 12 mmol of DMPS was added (to bring the final concentration of the mixture to 0.2 mol / L); after stabilization, a Cat.1 / [Ph3C][B(C6F5)4] / toluene mixture (containing 10 μmol of catalyst Cat.1 and 20 μmol of co-catalyst [Ph3C][B(C6F5)4]) was added, controlling the amount of toluene in the Cat.1 / [Ph3C][B(C6F5)4] / toluene mixture to bring the total volume of the final mixture to 60 mL. The polymerization reaction was carried out at 25 °C and 500 rpm for 240 min; after the polymerization reaction was completed, 0.5 mL of ethanol was added to terminate the polymerization, yielding the reaction solution. The reaction solution was slowly poured into a beaker containing 300 mL of a mixed ethanol / hydrochloric acid solution (made by mixing ethanol and 38 wt% hydrochloric acid at a volume ratio of 50:1) to settle. After washing for 6 hours, the mixture was filtered. Then, it was dissolved in toluene and adsorbed with 200-300 mesh neutral alumina to remove impurities. The mixture was then poured into the ethanol / hydrochloric acid solution to settle again. After washing and filtering, it was dried under vacuum at 70 °C to obtain diallyl methylphenyl silane homopolymer.

[0170] Test case

[0171] The copolymers obtained in Examples 1-18 and the homopolymers obtained in Comparative Examples 1-2 were subjected to relevant property tests. The chemical structure of the polymers was characterized by nuclear magnetic resonance spectroscopy (NMR), the thermal properties of the polymers were characterized by differential scanning calorimetry (DSC), and the molecular weight (weight-average molecular weight M) of the polymers was characterized by high-temperature gel permeation chromatography (GPC). w The polymer's molecular weight distribution (PDI) is as follows: (g / mol). 1 H and 13 C10 NMR was measured by a Bruker-400 NMR spectrometer at 25 °C, with TMS as an internal standard and deuterated o-dichlorobenzene or deuterated 1,1,2,2-tetrachloroethane as the solvent. The glass transition temperature (Tg) of the polymer was also determined. g Thermogravimetric analysis (TGA) was performed using a differential scanning calorimeter (Q2000 DSC) under nitrogen atmosphere conditions, with a heating / cooling rate of 20 °C / min. The thermal decomposition temperature (T0) of the polymer was determined. d95 The testing instrument was a Swiss-made Mettler-TGA2, employing a constant-rate heating method under a nitrogen atmosphere. The heating range was set between 100-600℃, with a heating rate maintained at 10℃ / min. The decomposition temperature T of the polymer was determined by measuring the temperature at which the polymer lost 95% of its weight. d95Gel permeation chromatography was performed using a PL GPC-220 gel permeation chromatograph. The instrument was an RI-Laser, with PL EasiCal PS-1 as the standard. The packed column was a Plgel 10μm MIXED-BLS, and 1,2,4-trichlorobenzene (TCB) was used as the solvent (with 0.05wt% 2,6-di-tert-butyl-4-methylphenol (BHT) added as an antioxidant). The test temperature was 150℃, and the flow rate was 1.0 mL / min. The dielectric properties of the polymer at 12 GHz were tested using a resonant cavity-vector network analyzer (Agilent, USA). Tensile testing of the polymer samples was performed using a universal testing machine (Instron 3360) at 25℃ (tensile specimen length 10 mm, width 3.4 mm, thickness 0.24 mm; tensile rate 10 mm / min according to ISO 527-1 standard).

[0172] Figure 1 shows the copolymer prepared in Example 5. 1 H NMR and 13 C10 NMR spectrum.

[0173] Figure 2 shows the copolymer prepared in Example 6. 1 H NMR and 13 C10 NMR spectrum.

[0174] Figure 3 shows the copolymer prepared in Example 12. 1 H NMR and 13 C10 NMR spectrum.

[0175] The reaction conditions of Examples 1-18 and Comparative Examples 1-2, as well as the performance data of the obtained copolymers (DSC, GPC, TGA, resonant cavity-vector network analyzer test data), are shown in Table 2.

[0176] Table 2 Note: a Reaction conditions; b High-temperature GPC testing revealed; c DSC test results; d TGA test results; e 13 Calculated by C NMR; f The ratio of polymer yield to input monomers; g The results were obtained using a resonant cavity-vector network analyzer. h The results were obtained from a tensile testing machine.

[0177] Figure 4 is a scatter plot of the dielectric constants of the copolymers prepared in Examples 1, 3, 5, 8, 10, and 12 (drawn based on the data in Table 2);

[0178] Figure 5 is a scatter plot of dielectric loss of the copolymers prepared in Examples 1, 3, 5, 8, 10, and 12 (drawn based on the data in Table 2);

[0179] Figure 6 shows the DSC curves of the copolymers prepared in Examples 1, 3, 5, 8, 10, and 12 (the DSC curves corresponding to the data in Table 2);

[0180] Figure 7 shows the TGA curves of the copolymers prepared in Examples 1, 3, 8, and 10 (the TGA curves corresponding to the data in Table 2, where the right figure is a partial enlarged view of the left figure).

[0181] In addition to the data listed in Table 2, DSC testing also showed that the polymers obtained in Examples 1-18 and Comparative Examples 1-2 all exhibited amorphous behavior.

[0182] Table 2 shows that the copolymerization of DDPS (diallyl diphenylsilane) with simple olefins catalyzed by Cat.1 achieved a glass transition temperature as high as 152.4℃ and a dielectric constant between 1.36 and 1.50. Furthermore, replacing the phenyl groups with indene and fluorenyl groups to increase steric hindrance further increased the glass transition temperature to 170.2℃, significantly improving the material's heat resistance. This indicates that this material is highly effective in compensating for the thermal performance defects of dielectric polymers. Regarding the mechanical properties, a comparison was made between the symmetrical silicon-containing diene homopolymer and copolymers prepared by copolymerizing it with ethylene, propylene, butene, 1-pentene, and 1-hexene, respectively. The results show that the homopolymer exhibits significant brittleness, while the copolymers have significantly higher tensile strength than the homopolymer, indicating that the insertion of α-olefins into the polymer backbone has a good modifying effect on mechanical properties. The dielectric constants of the copolymers prepared by Cat.1 catalysis are all between 1.30 and 1.50, and the dielectric loss is around 10. -4 The magnitude is far lower than any previous reports and studies on low-dielectric polymers.

[0183] The invention discloses a method for preparing high-heat-resistant, ultra-low-dielectric fluorine-free silicon-containing copolymer materials based on sterically hindered aryl-substituted symmetrical silicon-containing dienes (DDPS, DMPS, DMIS, DMFS, etc.) and simple olefins (α-olefins). This method is of great research significance for improving the thermal stability and reducing the dielectric constant of dielectric polymer materials, and is expected to be applied in high-performance microwave / millimeter-wave substrates and packaging materials.

[0184] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A high-heat-resistant, ultra-low-dielectric fluorine-free silicon-containing copolymer, characterized in that, The structural formula of the high heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer is: Where R = H, CH3, or (CH2) n CH3, where n is an integer from 1 to 10, and R3 and R4 are selected from one of the following two cases: Option 1: R3 = R4 = phenyl, indole, fluorenyl, naphthyl, or anthracene; Option 2: R3 = CH3, R4 = phenyl, indole, fluorenyl, naphthyl, or anthracene.

2. A method for preparing the high heat-resistant, ultra-low dielectric fluorine-free silicon-containing copolymer as described in claim 1, characterized in that, Includes the following steps: A mixture is prepared by mixing a sterically hindered aryl-substituted symmetrical silicon diene, an α-olefin, a catalyst, a co-catalyst, a chain transfer agent, and a hydrocarbon solvent to obtain a mixture, which is then heated to carry out a polymerization reaction to obtain the high heat resistance, ultra-low dielectric fluorine-free silicon copolymer. The sterically hindered aryl-substituted symmetrical silicones include one of diallyl diphenylsilane, diallyl methylphenylsilane, diallyl diindenylsilane, diallyl methylindenylsilane, diallyl difluorenylsilane, diallyl methylfluorenylsilane, diallyl dinaphthylsilane, diallyl methylnaphthylsilane, diallyl dianthrylsilane, and diallyl methylanthrylsilane. The α-olefins include one of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene.

3. The preparation method according to claim 2, characterized in that, The hydrocarbon solvents include one or more of benzene and its homologues, indene and its homologues, naphthalene and its homologues, alkanes and their homologues, and cycloalkanes and their homologues.

4. The preparation method according to claim 2, characterized in that, The catalyst is a single-active-center transition metal catalyst; And / or, the cocatalyst comprises one or more of tripentafluorophenyl alkylborane, triperfluorobiphenylborane, triphenylmethyltetra(pentafluorophenyl)borate and tert-butyltriphenylmethyltetra(pentafluorophenyl)borate; And / or, the chain transfer agent includes one or more of methylaluminoxane, modified methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, trimethylaluminum, diethylaluminum chloride, triethylaluminum, triisopropylaluminum, triisobutylaluminum, diethylzinc, diethylmagnesium, dibutylmagnesium, and n-butylethylmagnesium.

5. The preparation method according to claim 2, characterized in that, The concentration of the sterically hindered aryl-substituted symmetrical silicon diene in the mixture is 0.1–0.2 mol / L; And / or, the concentration of the α-olefin in the mixture is 0.02–0.2 mol / L; And / or, the concentration of the catalyst in the mixture is (1.5–2) × 10⁻⁶. -4 mol / L; And / or, the molar ratio of the catalyst to the co-catalyst is 1:1 to 2000; And / or, the molar ratio of the catalyst to the chain transfer agent is 1:10 to 1000.

6. The preparation method according to claim 2, characterized in that, The polymerization reaction is carried out at a temperature of 20–85°C for a time of 10–720 min.

7. The preparation method according to claim 2, characterized in that, After the polymerization reaction is completed, the reaction further includes adding ethanol to terminate the polymerization reaction and obtaining a reaction solution. The reaction solution is then mixed with an acidified precipitant and subjected to a series of steps including sedimentation, washing, filtration, dissolution, adsorption, sedimentation, filtration, washing, and vacuum drying.

8. The preparation method according to claim 7, characterized in that, The precipitant includes one or more of ethanol, methanol, petroleum ether, diethyl ether, n-hexane, acetone, n-pentane, tetrahydrofuran, and dichloromethane; And / or, the acidification includes: mixing the acid with a precipitant.

9. The preparation method according to claim 4, characterized in that, The single-active-center transition metal catalyst is Me₂Si(Ind)₂ZrCl₂ or has the following structural formula: The compounds in which R1 and R2 are selected from one of the following three cases: Option 1: R1 = H, R2 = 2- i Pr-Ph; Option 2: R1 = R2 = CH3; Option 3: R1 = t Bu, R2 = CH3.

10. The application of the high heat resistance, ultra-low dielectric fluorine-free silicon-containing copolymer as described in claim 1 in the preparation of high-performance microwave substrates, millimeter-wave substrates or packaging materials.

Images