High thermal conductivity polyphenylene sulfide composite materials, their preparation methods and applications

Abstract

This application relates to the field of polymer composite materials, specifically to a high thermal conductivity polyphenylene sulfide composite material, its preparation method, and its applications. By designing and synthesizing a block copolymer compatibilizer, polar urea bonds are introduced into the middle of the molecular chain, and trifluoromethyl and phosphoro-phenanthroline structures are introduced into the compatibilizer through the amino groups at both ends. This improves the bonding effect between the compatibilizer and the insulating and thermally conductive filler and the polyphenylene sulfide resin matrix, while simultaneously enhancing the flame retardancy and hydrophobicity of the composite material. Furthermore, the compatibilizer can form an effective thermal conduction pathway, reduce the agglomeration of boron nitride filler, and fill interfacial voids between the filler and the polyphenylene sulfide resin matrix, thereby improving the thermal conductivity, processability, mechanical properties, and reducing the dielectric constant of the composite material. When used in high-frequency circuits, this composite material can reduce signal crosstalk and maintain signal integrity.

Description

Technical Field

[0001] This application relates to the field of polymer composite materials, specifically to a high thermal conductivity polyphenylene sulfide composite material, its preparation method, and its application. Background Technology

[0002] Polyphenylene sulfide (PPS) is widely used as a substrate material for high-frequency circuits in the field of electronic communications due to its excellent thermal stability, dielectric properties, and superior chemical resistance. For applications such as 5G communication, millimeter-wave radar, and high-speed digital circuits, the core requirement for its substrate material is a low dielectric constant (Dk). k ) and low dielectric loss (D f This reduces signal delay and transmission loss. Polyphenylene sulfide (PPS) D k Typically between 3.0 and 3.5, D f Very low, typically in the order of 0.0005-0.002, lower D k It is conducive to high-speed signal transmission and has extremely low D. f This means that signal energy loss during transmission is minimal, which is crucial for maintaining the integrity of high-frequency signals. Furthermore, polyphenylene sulfide (PPS) exhibits excellent thermal stability, particularly dimensional stability at high temperatures, with a heat distortion temperature exceeding 260°C. It can withstand the high-temperature soldering processes in PCB manufacturing and possesses an extremely low coefficient of thermal expansion, resulting in good thermal matching with copper foil and reducing stress-induced circuit detachment or substrate warping during thermal cycling. Finally, PPS has high strength, making it suitable for manufacturing thin substrates, and is resistant to acids, alkalis, and organic solvents, resisting various chemical solvents used in the processing of high-frequency circuit boards.

[0003] The fatal flaw of polyphenylene sulfide is its very low thermal conductivity. The thermal conductivity of pure polyphenylene sulfide without other fillers is less than 0.4 W / (m·K). If it is used directly on high-frequency substrates, its insufficient heat dissipation capacity will become a bottleneck. This is because various high-frequency devices generate a lot of heat when they are working. If the heat cannot be dissipated in time, the device temperature will rise sharply, which will affect the resonant frequency and signal quality of the circuit, leading to unstable device performance and accelerated device aging, and reducing the reliability and lifespan of the entire system.

[0004] To address the poor thermal conductivity of polyphenylene sulfide (PPS), existing technologies involve preparing highly filled insulating and thermally conductive filler / PPS composites. Boron nitride (BN) is the preferred insulating and thermally conductive filler due to its excellent thermal conductivity (approximately 300 W / (m·K)) and its insulator nature, exhibiting extremely low dielectric constant and loss, thus not reducing the dielectric properties of PPS. However, BN and PPS have poor compatibility. Increasing the filler content leads to brittle materials that are difficult to process and apply. Furthermore, the poor compatibility between BN and PPS can cause BN to agglomerate, creating interfacial thermal resistance that actually reduces overall thermal conductivity. This hinders the preparation of PPS composites that combine high thermal conductivity and low dielectric constant. Therefore, achieving uniform dispersion of insulating and thermally conductive fillers such as BN in the PPS matrix is ​​a major challenge in preparing ideal high-frequency circuit board materials. In particular, ensuring the dispersion of highly filled (BN > 60 wt%) PPS composites and preventing agglomeration is crucial. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention proposes the design and synthesis of a novel block copolymer compatibilizer. By adding the compatibilizer, the surface of the insulating and thermally conductive filler boron nitride is modified. Then, a high thermal conductivity polyphenylene sulfide-based composite material is prepared using hot pressing technology. The surface-modified boron nitride is mixed with the PPS matrix, thereby improving the dispersion of boron nitride in the PPS matrix, and thus achieving the preparation of a high thermal conductivity, low dielectric polyphenylene sulfide composite material.

[0006] In a first aspect, a high thermal conductivity polyphenylene sulfide composite material includes: an insulating and thermally conductive filler, a polyphenylene sulfide resin, an epoxy-containing silane coupling agent, and a block copolymer;

[0007] The general structural formula of the block copolymer is shown below:

[0008] ;

[0009] Wherein, a, b, and c are independent of each other and are all positive integers ≥1; R1 is selected from hydrocarbon groups with 4 to 20 carbon atoms; R2, R3, R4, and R5 are the same or different and are selected from hydrocarbon groups with 1 to 6 carbon atoms or phenyl groups; R6 is selected from aliphatic substituents containing CF bonds; Ar is selected from aromatic rings with 6 to 18 carbon atoms, or aromatic rings linked by carbon-carbon bonds, or fused aromatic rings;

[0010] Preferably, R1 is selected from:

[0011] , or One of them;

[0012] Preferably, R2, R3, R4, and R5 are the same and are selected from methyl groups;

[0013] Preferably, R6 is selected from trifluoromethyl;

[0014] Preferably, Ar is selected from phenyl;

[0015] Preferably, the insulating and thermally conductive filler is selected from boron nitride;

[0016] Preferably, the boron nitride crystal form is hexagonal boron nitride;

[0017] Preferably, the boron nitride has a sub-nanometer or nanometer size, with an average particle size ≤600nm.

[0018] Preferably, the epoxy-containing silane coupling agent is selected from one or more combinations of γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, and oligomers obtained by dehydration condensation of the former four.

[0019] Furthermore, the insulating and thermally conductive filler is surface-treated with sodium hydroxide. The specific method includes: mechanically dispersing the insulating and thermally conductive filler in an aqueous sodium hydroxide solution for 12-48 hours.

[0020] Preferably, a 1-10 mol / L aqueous solution of sodium hydroxide is used;

[0021] Preferably, the temperature for mechanical dispersion is 80-120℃;

[0022] Preferably, the mechanical dispersion method includes mechanical stirring and ultrasonic dispersion.

[0023] Furthermore, the polyphenylene sulfide composite material also includes an antioxidant, which is selected from one or more combinations of hindered phenolic antioxidants and phosphite antioxidants;

[0024] Preferably, the hindered phenolic antioxidant is selected from pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010);

[0025] Preferably, the phosphite antioxidant is selected from tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168);

[0026] More preferably, the antioxidant is selected from compound antioxidant B225, which is composed of antioxidant 168 and antioxidant 1010.

[0027] Furthermore, the components of the high thermal conductivity polyphenylene sulfide composite material, by weight percentage, include: 60-70 wt% boron nitride, 25-35 wt% polyphenylene sulfide, 0.5-2 wt% epoxy-containing silane coupling agent, and 2-8 wt% or more of the block copolymers described above.

[0028] And / or, the high thermal conductivity polyphenylene sulfide composite material further includes 0.5-2 wt% antioxidant.

[0029] Further, the method for preparing the block copolymer includes: the method for preparing the block copolymer includes: reacting an aliphatic diisocyanate with 1,3-bis(aminopropyl)tetramethyldisiloxane, then reacting it with an amino-terminated polydimethylsiloxane, then reacting it with trifluoromethyl-substituted aryl formaldehyde, and finally reacting it with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to obtain the block copolymer.

[0030] Preferably, the aliphatic isocyanate is selected from any one of isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), or 1,6-hexamethylene diisocyanate (HDI).

[0031] Preferably, the average molecular weight of the amino-terminated polydimethylsiloxane is in the range of 400-2000;

[0032] Preferably, the trifluoromethyl-substituted aryl formaldehyde is selected from one or more combinations of monotrifluoromethyl-substituted benzaldehyde, bistrifluoromethyl-substituted benzaldehyde, and bistrifluoromethyl-substituted biphenyl formaldehyde;

[0033] More preferably, the monotrifluoromethyl substituted benzaldehyde is selected from any one or more combinations of o-trifluoromethyl substituted benzaldehyde, m-trifluoromethyl substituted benzaldehyde, and p-trifluoromethyl substituted benzaldehyde;

[0034] More preferably, the bis(trifluoromethyl)-substituted benzaldehyde is selected from any one or a combination of 3,5-bis(trifluoromethyl)benzaldehyde and 2,5-bis(trifluoromethyl)benzaldehyde;

[0035] More preferably, the bis(trifluoromethyl)-substituted biphenylaldehyde is selected from 4-(2,4-bis(trifluoromethyl)phenyl)benzaldehyde.

[0036] Preferably, the aliphatic diisocyanate is first reacted with 1,3-bis(aminopropyl)tetramethyldisiloxane in a molar ratio of (1.2-1.5):1;

[0037] Preferably, after the reaction is complete, the solvent is removed by rotary evaporation, and the residual solid is vacuum dried to obtain the block copolymer.

[0038] Preferably, the molar ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to trifluoromethyl-substituted aryl formaldehyde is 1:(1-1.1);

[0039] Furthermore, the block copolymer described above is prepared by a method comprising the following steps:

[0040] S1. An aliphatic diisocyanate is reacted with 1,3-bis(aminopropyl)tetramethyldisiloxane to obtain an isocyanate-terminated prepolymer.

[0041] S2. Add amino-terminated polydimethylsiloxane to the isocyanate-terminated prepolymer to obtain an amino-terminated block polymer.

[0042] S3. Add trifluoromethyl-substituted aryl formaldehyde and an alcohol solvent to the amino-terminated block polymer and continue the reaction to obtain a trifluoromethyl-substituted aryl formaldehyde-terminated block copolymer.

[0043] S4. Add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the trifluoromethyl-substituted aryl formaldehyde-terminated block copolymer and continue the reaction to obtain the final block copolymer.

[0044] S5. The alcohol solvent is removed by vacuum distillation, and the block copolymer is then vacuum dried.

[0045] Preferably, the isocyanate-terminated prepolymer described in step S1 has the following general structural formula:

[0046] ;

[0047] Preferably, the general structural formula of the amino-terminated block polymer described in step S2 is:

[0048] ;

[0049] Preferably, the general structural formula of the trifluoromethyl-substituted aryl formaldehyde-terminated block copolymer described in step S3 is:

[0050] ;

[0051] Preferably, the alcohol solvent in step S3 is selected from one or a combination of ethanol and isopropanol.

[0052] Secondly, a method for preparing a high thermal conductivity polyphenylene sulfide composite material includes: drying and dehydrating the insulating and thermally conductive filler, polyphenylene sulfide and block copolymer, then adding an epoxy-containing silane coupling agent, and obtaining the polyphenylene sulfide composite material by melt blending, extrusion and granulation.

[0053] Preferably, the preparation method includes: drying and dehydrating the insulating and thermally conductive filler, polyphenylene sulfide, antioxidant and block copolymer, then adding an epoxy-containing silane coupling agent, and obtaining the polyphenylene sulfide composite material by melt blending, extrusion and granulation.

[0054] The drying and dehydration method involves vacuum drying at 60-100℃ for 1-24 hours; the extrusion temperature is set to 275±15℃.

[0055] Thirdly, the above-mentioned polyphenylene sulfide composite material is used in the preparation of high-frequency circuit boards or electronic packaging materials.

[0056] Fourthly, a high-frequency circuit board using the aforementioned high thermal conductivity polyphenylene sulfide composite material.

[0057] The beneficial effects of this invention are as follows: By designing and synthesizing a block copolymer compatibilizer, polar urea bonds are introduced into the middle of the molecular chain, and trifluoromethyl and phosphoro-phenanthroline structures are introduced into the compatibilizer through the amino groups at both ends. This improves the bonding effect between the compatibilizer and the insulating and thermally conductive filler and the polyphenylene sulfide resin matrix, while enhancing the flame retardancy and hydrophobicity of the composite material. Furthermore, the compatibilizer can form an effective thermal conduction pathway, reduce the agglomeration of boron nitride filler, and fill interfacial voids between the filler and the polyphenylene sulfide resin matrix, thereby improving the thermal conductivity, processability, mechanical properties, and reducing the dielectric constant of the composite material. When used in high-frequency circuits, this composite material can reduce signal crosstalk and maintain signal integrity. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the embodiments of this application and to more completely understand this application and its beneficial effects, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0059] Figure 1 The cross-sectional surface morphology of the polyphenylene sulfide composite materials prepared in Examples 4-5 and Comparative Examples 4-5 is shown under a scanning electron microscope; wherein (a) Example 4, (b) Example 5, (c) Comparative Example 4, and (d) Comparative Example 5. Detailed Implementation

[0060] The present application will be further described in detail below with reference to the embodiments and examples. It should be understood that these embodiments and examples are for illustrative purposes only and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to enable a more thorough and comprehensive understanding of the disclosure of the present application. It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and the equivalent forms obtained also fall within the protection scope of the present application. Furthermore, numerous specific details are set forth in the following description to provide a fuller understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0061] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0062] the term

[0063] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0064] The terms "and / or," "or / and," and "and / or" as used herein include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes technical solutions connected by "logical AND," and also undoubtedly includes technical solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").

[0065] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0066] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0067] In this application, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions containing the listed features.

[0068] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0069] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0070] In this application, % (w / w) and wt% both represent weight percentage, % (v / v) refers to volume percentage, and % (w / v) refers to mass-volume percentage.

[0071] All references to documents mentioned in this application are incorporated herein by reference as if each document were individually incorporated herein by reference. Unless they conflict with the inventive purpose and / or technical solution of this application, all cited documents are incorporated herein by reference in their entirety and for all purposes. When citing documents in this application, the definitions of relevant technical features, terms, nouns, phrases, etc., are also incorporated herein by reference. When citing documents in this application, examples and preferred embodiments of the cited technical features may also be incorporated herein by reference, but only to the extent that they enable the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, this application shall prevail or modifications shall be made adaptably to the description in this application.

[0072] In addition, if the specific experimental conditions are not specified in the examples, they are generally in accordance with conventional conditions in the art or the conditions recommended by the reagent company; the materials and reagents used in the examples can be purchased commercially unless otherwise specified.

[0073] Example 1

[0074] 31.12 g (0.14 mol) of isophorone diisocyanate (IPDI) and 24.85 g (0.1 mol) of 1,3-bis(aminopropyl)tetramethyldisiloxane were added to a round-bottom glass flask equipped with a nitrogen inlet, a condenser, and a magnetic stirrer. The mixture was stirred at 40°C for 2 hours under nitrogen protection. The reaction endpoint was reached when the isocyanate NCO content was below 7.0 wt%, as determined by method Q / SJ 1003-2017. Then, 51.6 g (0.06 mol) of bis(3-aminopropyl)-terminated polydimethylsiloxane (Qitian New Materials) with an average molecular weight of 860 g / mol was added to the flask, and the reaction was continued for 2 hours. The reaction endpoint was reached when the isocyanate NCO content was below 0.1 wt%, as determined by method Q / SJ 1003-2017, yielding an amino-terminated block polymer.

[0075] 9.68 g (0.04 mol) of 3,5-bis(trifluoromethyl)benzaldehyde and 50 mL of ethanol were added to the above flask, and the mixture was heated to 82 °C and reacted for 8 hours. Infrared spectroscopy revealed a 2720 cm⁻¹ chromatogram. -1 Once the nearby absorption peaks completely disappeared, it was assumed that the aldehyde group had fully participated in the reaction. Then, 8.64 g (0.04 mol) of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was added to the flask, and the mixture was cooled to 40°C and reacted for 10 hours. The corresponding infrared spectrum at 1650 cm⁻¹... -1 After the absorption peak near -CH=N- completely disappeared, it was considered that DOPO had reacted completely with -CH=N-, and the reaction was terminated. Subsequently, the solvent was removed by rotary evaporation under reduced pressure at 40°C, and the residual solid was vacuum dried to obtain a light yellow powder, which is the block copolymer of Example 1.

[0076] Example 2

[0077] 36.73 g (0.14 mol) of dicyclohexylmethane diisocyanate (HMDI) and 24.85 g (0.1 mol) of 1,3-bis(aminopropyl)tetramethyldisiloxane were added to a round-bottom glass flask equipped with a nitrogen inlet, a condenser, and a magnetic stirrer. The mixture was stirred at 40°C for 2 hours under nitrogen protection. The reaction endpoint was reached when the isocyanate NCO content was below 6.0 wt%, as determined by method Q / SJ 1003-2017. Then, 51.6 g (0.06 mol) of bis(3-aminopropyl)-terminated polydimethylsiloxane (Qitian New Materials) with an average molecular weight of 860 g / mol was added to the flask, and the reaction was continued for 2 hours. The reaction endpoint was reached when the isocyanate NCO content was below 0.1 wt%, as determined by method Q / SJ 1003-2017, yielding an amino-terminated block polymer.

[0078] 6.96 g (0.04 mol) of 3-trifluoromethylbenzaldehyde and 50 mL of ethanol were added to the above flask, and the mixture was heated to 82 °C and reacted for 8 hours. Infrared spectroscopy revealed a 2720 cm⁻¹ chromatogram. -1 Once the nearby absorption peaks completely disappeared, it was assumed that the aldehyde group had fully participated in the reaction. Then, 8.64 g (0.04 mol) of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was added to the flask, and the mixture was cooled to 40°C and reacted for 10 hours. The corresponding infrared spectrum at 1650 cm⁻¹... -1 Once the absorption peak near -CH=N- completely disappeared, it was considered that DOPO had reacted completely with -CH=N-, and the reaction was terminated. Subsequently, the solvent was removed by rotary evaporation under reduced pressure at 40°C, and the residual solid was vacuum dried to obtain a light yellow powder, which is the block copolymer of Example 2.

[0079] Example 3

[0080] 23.55 g (0.14 mol) of hexamethylene diisocyanate (HDI) and 24.85 g (0.1 mol) of 1,3-bis(aminopropyl)tetramethyldisiloxane were added to a round-bottom glass flask equipped with a nitrogen inlet, a condenser, and a magnetic stirrer. The mixture was stirred at 40°C for 2 hours under nitrogen protection. The reaction endpoint was reached when the isocyanate NCO content was below 7.8 wt%, as determined by method Q / SJ 1003-2017. Then, 51.6 g (0.06 mol) of bis(3-aminopropyl)-terminated polydimethylsiloxane (Qitian New Materials) with an average molecular weight of 860 g / mol was added to the flask, and the reaction was continued for 2 hours. The reaction endpoint was reached when the isocyanate NCO content was below 0.1 wt%, as determined by method Q / SJ 1003-2017, yielding an amino-terminated block polymer.

[0081] 6.96 g (0.04 mol) of p-trifluoromethylbenzaldehyde and 50 mL of ethanol were added to the above flask, and the mixture was heated to 82 °C and reacted for 8 hours. Infrared spectroscopy revealed a 2720 cm⁻¹ chromatogram. -1 Once the nearby absorption peaks completely disappeared, it was assumed that the aldehyde group had fully participated in the reaction. Then, 8.64 g (0.04 mol) of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was added to the flask, and the mixture was cooled to 40°C and reacted for 10 hours. The corresponding infrared spectrum at 1650 cm⁻¹... -1 Once the absorption peak near -CH=N- completely disappeared, it was considered that DOPO had reacted completely with -CH=N-, and the reaction was terminated. Subsequently, the solvent was removed by rotary evaporation under reduced pressure at 40°C, and the residual solid was vacuum dried to obtain a light yellow powder, which is the block copolymer of Example 3.

[0082] Example 4

[0083] The polyphenylene sulfide composite material comprises: 65 wt% sub-nanometer hexagonal boron nitride (average particle size ≤600 nm, Chaowei Nano), 28 wt% polyphenylene sulfide, 1.2 wt% silane coupling agent KH560, 0.8 wt% composite antioxidant B225 (BASF), and 5 wt% block copolymer compatibilizer prepared in Example 1. Specifically, the hexagonal boron nitride, composite antioxidant, polyphenylene sulfide, and block copolymer compatibilizer prepared in Example 1 are dried in a vacuum oven at 80°C for 12 hours. All raw materials are then melt-blended using a twin-screw extruder. The extruder temperature is set within the range of 275 ± 15°C, and the screw speed is 130 rpm. After granulation and drying, the granules are mixed and injection molded into test specimens.

[0084] Example 5

[0085] The polyphenylene sulfide composite material comprises: 65 wt% sub-nanometer hexagonal boron nitride (average particle size ≤600 nm, Chaowei Nano), 28 wt% polyphenylene sulfide, 1.2 wt% silane coupling agent KH560, 0.8 wt% composite antioxidant B225 (BASF), and 5 wt% block copolymer compatibilizer prepared in Example 1. Specifically, the hexagonal boron nitride was ultrasonically dispersed in a 5 mol / L NaOH aqueous solution at 100°C for 20 hours, followed by the same steps as in Example 4.

[0086] Example 6

[0087] The polyphenylene sulfide composite material comprises: 65 wt% sub-nanometer hexagonal boron nitride (average particle size ≤600 nm, Chaowei Nano), 28 wt% polyphenylene sulfide, 1.2 wt% silane coupling agent KH560, 0.8 wt% composite antioxidant B225 (BASF), and 5 wt% block copolymer compatibilizer prepared in Example 2. The specific preparation method is the same as in Example 4.

[0088] Example 7

[0089] The polyphenylene sulfide composite material comprises: 65 wt% sub-nanometer hexagonal boron nitride (average particle size ≤600 nm, Chaowei Nano), 28 wt% polyphenylene sulfide, 1.2 wt% silane coupling agent KH560, 0.8 wt% composite antioxidant B225 (BASF), and 5 wt% block copolymer compatibilizer prepared in Example 2. Specifically, the hexagonal boron nitride was ultrasonically dispersed in a 5 mol / L NaOH aqueous solution at 100°C for 20 hours, followed by the same steps as in Example 4.

[0090] Example 8

[0091] The polyphenylene sulfide composite material comprises: 65 wt% sub-nanometer hexagonal boron nitride (average particle size ≤600 nm, Chaowei Nano), 28 wt% polyphenylene sulfide, 1.2 wt% silane coupling agent KH560, 0.8 wt% composite antioxidant B225 (BASF), and 5 wt% block copolymer compatibilizer prepared in Example 3. The specific preparation method is the same as in Example 4.

[0092] Example 9

[0093] The polyphenylene sulfide composite material comprises: 65 wt% sub-nanometer hexagonal boron nitride (average particle size ≤600 nm, Chaowei Nano), 28 wt% polyphenylene sulfide, 1.2 wt% silane coupling agent KH560, 0.8 wt% composite antioxidant B225 (BASF), and 5 wt% block copolymer compatibilizer prepared in Example 3. Specifically, the hexagonal boron nitride was ultrasonically dispersed in a 5 mol / L NaOH aqueous solution at 100°C for 20 hours, followed by the same steps as in Example 4.

[0094] Comparative Example 1

[0095] 17.2 g (0.02 mol) of bis(3-aminopropyl)-terminated polydimethylsiloxane (Qitian New Materials) with an average molecular weight of 860 g / mol, 6.96 g (0.04 mol) of p-trifluoromethylbenzaldehyde, and 50 mL of ethanol were added to a three-necked flask. The mixture was heated to 82 °C and reacted for 8 hours. Infrared spectroscopy revealed a 2720 cm⁻¹... -1Once the nearby absorption peaks completely disappeared, it was assumed that the aldehyde group had fully participated in the reaction. Then, 8.64 g (0.04 mol) of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was added to the flask, and the mixture was cooled to 40°C and reacted for 10 hours. The corresponding infrared spectrum at 1650 cm⁻¹... -1 Once the absorption peak near -CH=N- completely disappeared, it was considered that DOPO had reacted completely with -CH=N-, and the reaction was terminated. Subsequently, the solvent was removed by rotary evaporation at 40℃, and the residual solid was vacuum dried to obtain a light yellow powder, which was the block copolymer compatibilizer of Comparative Example 1.

[0096] Comparative Example 2

[0097] The polyphenylene sulfide composite material comprises: 65 wt% sub-nanometer hexagonal boron nitride (average particle size ≤600 nm, Chaowei Nano), 28 wt% polyphenylene sulfide, 1.2 wt% silane coupling agent KH560, 0.8 wt% composite antioxidant B225 (BASF), and 5 wt% block copolymer compatibilizer prepared in Comparative Example 1. The specific preparation method is the same as in Example 4.

[0098] Comparative Example 3

[0099] The polyphenylene sulfide composite material comprises: 65 wt% sub-nanometer hexagonal boron nitride (average particle size ≤600 nm, Chaowei Nano), 28 wt% polyphenylene sulfide, 1.2 wt% silane coupling agent KH560, 0.8 wt% composite antioxidant B225 (BASF), and 5 wt% block copolymer compatibilizer prepared in Comparative Example 1. Specifically, the hexagonal boron nitride is ultrasonically dispersed in a 5 mol / L NaOH aqueous solution at 100°C for 20 hours, followed by the same steps as in Example 4.

[0100] Comparative Example 4

[0101] The polyphenylene sulfide composite material comprises: 68 wt% sub-nanometer hexagonal boron nitride (average particle size ≤600 nm, Chaowei Nano), 30 wt% polyphenylene sulfide, 1.2 wt% silane coupling agent KH560, and 0.8 wt% composite antioxidant B225 (BASF). The specific preparation method involves directly melt-blending boron nitride, coupling agent, and antioxidant with polyphenylene sulfide; the remaining steps are the same as in Example 4.

[0102] Comparative Example 5

[0103] The polyphenylene sulfide composite material comprises: 68 wt% sub-nanometer hexagonal boron nitride (average particle size ≤600 nm, Chaowei Nano), 30 wt% polyphenylene sulfide, 1.2 wt% silane coupling agent KH560, and 0.8 wt% composite antioxidant B225 (BASF). The specific preparation method involves ultrasonically dispersing hexagonal boron nitride in a 5 mol / L NaOH aqueous solution at 100°C for 20 hours, followed by the same steps as in Comparative Example 4.

[0104] Test section

[0105] Mechanical properties: The tensile strength and elongation at break of the composite material specimens prepared in the above examples and comparative examples were tested using a universal testing machine in accordance with the test standard ISO 527-2:2025. The loading rate of the testing machine during the tensile process was 10 mm / min.

[0106] Water contact angle: The contact angle of water on the surface of the composite material specimen was tested using a contact angle measuring instrument and the built-in analysis and fitting software.

[0107] Electrical properties: Referring to the method for testing dielectric constant of stripline in the X-band of IPC-TM-650 test standard 2.5.5.5, the dielectric constant of the composite material specimens prepared in the above examples and comparative examples was tested using a vector network analyzer at frequencies of 100MHz and 10GHz.

[0108] Thermal conductivity: The thermal conductivity value was obtained directly by the TPS2200 Hot Disk instrument, referring to the test standard of ISO 22007-2:2022.

[0109] Processing performance: The mixture of boron nitride, polyphenylene sulfide and block copolymer compatibilizer was tested using a Haake torque rheometer (275°C, 50 rpm). The torque-time curve was recorded for 600 seconds, and the corresponding equilibrium torque value was obtained from the stable region at the end of the torque-time curve.

[0110] Surface morphology analysis: The surface morphology of the fracture surfaces of the specimens in Examples 4-5 and Comparative Examples 4-5 was analyzed using a VEGA3 scanning electron microscope to observe the compatibility between the filler and the resin matrix.

[0111] The test data above is recorded in Table 1.

[0112] Analysis of the data in Table 1 shows that the polyphenylene sulfide composites prepared using the block copolymer compatibilizers in Examples 1-3 exhibit higher mechanical properties, thermal conductivity, processability, and a lower dielectric constant. The compatibilizer contains imino-NH- groups at both ends of the molecule and urea-NH- (C=O)-NH- groups in the middle of the molecular chain. Through intermolecular forces, it binds the polyphenylene sulfide resin matrix and boron nitride filler, effectively reducing the melt viscosity during the melting and mixing process. This prevents the agglomeration of boron nitride filler and reduces friction between fillers or between the filler and the resin matrix. Specifically, the addition of the compatibilizer results in lower equilibrium torque and dielectric constant. Furthermore, the introduction of the compatibilizer allows for the formation of an effective heat transfer pathway when the polyphenylene sulfide matrix is ​​highly filled with insulating and thermally conductive fillers such as boron nitride. The compatibilizer forms a protective layer on the surface of boron nitride. Compared to Comparative Examples 4-5 without compatibilizer, the composites in Examples 4-9 show lower interfacial thermal resistance between boron nitride and the polyphenylene sulfide resin matrix, resulting in higher thermal conductivity. Finally, compatibilizers can effectively reduce the agglomeration of boron nitride fillers and reduce interfacial void defects between the fillers and the polyphenylene sulfide resin matrix, preventing the boron nitride fillers from becoming stress concentration points, thereby improving the overall tensile strength and elongation at break of the composite material.

[0113] Table 1

[0114]

[0115] Comparative Example 1 differs from Examples 1-3 in that it does not introduce aliphatic diisocyanate as a chain extender. Instead, it directly reacts amino silicone oil with trifluoromethylbenzaldehyde and DOPO. The main chain of the compatibilizer only contains polydimethylsiloxane structures and lacks urea bonds. Therefore, it has a weaker interfacial bonding effect on the polyphenylene sulfide matrix or boron nitride filler, resulting in lower mechanical properties, thermal conductivity, and processing performance of Comparative Examples 2-3 compared to Examples 4-9.

[0116] Pretreatment of boron nitride filler with NaOH can introduce polar hydroxyl groups onto its surface, thereby improving its bonding effect with compatibilizers and polyphenylene sulfide resins, and further improving its mechanical properties, thermal conductivity, and processing performance. However, the introduction of hydroxyl groups onto the boron nitride surface leads to stronger interfacial polarization and increases the hygroscopicity of the composite material, which in turn increases the dielectric constant, making it difficult to reduce signal crosstalk and maintain signal integrity.

[0117] SEM surface morphology analysis confirmed that adding block copolymer compatibilizers and introducing hydroxyl groups on the surface of boron nitride can improve the dispersibility of boron nitride with the polyphenylene sulfide resin matrix, and avoid the agglomeration of boron nitride particles that would lead to a decline in the performance of the composite material.

[0118] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Furthermore, it should be understood that after reading the above teachings of this application, those skilled in the art can make various alterations or modifications to this application, and the equivalent forms obtained also fall within the scope of protection of this application. It should also be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A block copolymer characterized in that, The aliphatic diisocyanate is first reacted with 1,3-bis(amino propyl) tetramethyl disiloxane, then reacted with amino-terminated polydimethylsiloxane, then reacted with trifluoromethyl-substituted aryl aldehyde, and finally reacted with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to obtain the block copolymer. The block copolymer is prepared by a method comprising the following steps: S1, reacting aliphatic diisocyanate with 1,3-bis(amino propyl) tetramethyl disiloxane, the molar ratio of the two being (1.2-1.5):1, to obtain an isocyanate group-terminated prepolymer; S2, adding amino-terminated polydimethylsiloxane to the isocyanate group-terminated prepolymer to obtain an amino-terminated block polymer; S3, adding trifluoromethyl-substituted aryl aldehyde and an alcohol solvent to the amino-terminated block polymer to continue the reaction, to obtain a trifluoromethyl-substituted arylimine-terminated block copolymer; S4, adding 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the trifluoromethyl-substituted arylimine-terminated block copolymer to continue the reaction, to obtain the final block copolymer; S5, removing the alcohol solvent by vacuum distillation, and vacuum drying the block copolymer; The molar ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the trifluoromethyl-substituted arylimine-terminated block copolymer is 1:(1-1.1); The average molecular weight of the amino-terminated polydimethylsiloxane ranges from 400 to 2000. The aliphatic diisocyanate is selected from any one of isophorone diisocyanate, dicyclohexylmethane diisocyanate, or 1,6-hexane diisocyanate.

2. The block copolymer of claim 1, wherein The trifluoromethyl-substituted aryl aldehyde is selected from one or a combination of mono-trifluoromethyl-substituted benzaldehyde, bis-trifluoromethyl-substituted benzaldehyde, and bis-trifluoromethyl-substituted benzaldehyde.

3. The block copolymer of claim 1, wherein After the reaction is complete, the solvent is removed by rotary evaporation, and the residual solid is vacuum dried to obtain the block copolymer.

4. The block copolymer of claim 1, wherein The composite material comprises: an insulating and heat-conducting filler, a polyphenylene sulfide resin, an epoxy-containing silane coupling agent, and the block copolymer of any one of claims 1-4.

5. A polyphenylene sulfide composite material, characterized by, The insulating and heat-conducting filler is selected from boron nitride.

6. A polyphenylene sulfide composite according to claim 5, wherein The polyphenylene sulfide composite material further comprises an antioxidant selected from one or a combination of a hindered phenol antioxidant and a phosphite antioxidant.

7. A polyphenylene sulfide composite according to Claim 5 wherein, The insulating and heat-conducting filler is surface treated with sodium hydroxide, and the specific method comprises: mechanically dispersing the insulating and heat-conducting filler in a sodium hydroxide aqueous solution for 12-48 hours.

8. The polyphenylene sulfide composite of Claim 5 wherein, The polyphenylene sulfide composite material comprises, by weight percentage: 60-70wt% insulating and heat-conducting filler, 25-35wt% polyphenylene sulfide, 0.5-2wt% epoxy-containing silane coupling agent, and 2-8wt% block copolymer.

9. The polyphenylene sulfide composite of Claim 5 wherein, The polyphenylene sulfide composite material further comprises 0.5-2wt% antioxidant.

10. A polyphenylene sulfide composite according to claim 9, wherein After the insulating and heat-conducting filler, polyphenylene sulfide, and block copolymer are dried to remove water, the epoxy-containing silane coupling agent is added, and the polyphenylene sulfide composite material is obtained by melt blending, extrusion, and granulation.

11. A process for the production of a polyphenylene sulfide composite material as claimed in any one of claims 5 to 10, characterized in that, ​ The drying method is vacuum drying at 60-100℃ for 1-24 hours; the extrusion temperature is set at 275±15℃.

12. Use of the polyphenylene sulfide composite material according to any one of claims 5-10 for preparing a high-frequency circuit substrate or an electronic packaging material.

13. A high-frequency circuit substrate, characterized by comprising: The polyphenylene sulfide composite material according to any one of claims 5-10 is prepared.

Images