A polyphenylene ether foam material and preparation method thereof

Abstract

The present invention relates to a polyphenylene ether foam material and a preparation method thereof, belonging to the technical field of polymer foam material preparation. A redistribution reaction between a phenolic compound and polyphenylene ether can reduce the molecular weight of a commercial polyphenylene ether material, yielding a relatively low-molecular-weight bishydroxy polyphenylene ether, thereby enhancing its processing fluidity. The terminal hydroxyl groups are then reacted with a modifier to produce a polyphenylene ether with a long-chain branching structure. The long-chain branching structure effectively encapsulates gas, forming and stabilizing cellular units, thereby producing a composite material of polyphenylene ether and air, i.e., a foamed polyphenylene ether material. This results in a polyphenylene ether material with a lower dielectric constant.

Description

Technical Field

[0001] The invention relates to a polyphenylene ether foam material and a preparation method thereof, belonging to the technical field of polymer foam material preparation. Background Art

[0002] Polyphenylene ether (poly-2,6-dimethyl-1,4-phenylene oxide), also known as PPO or PPF, is a widely used thermoplastic engineering plastic. It offers numerous advantages, including excellent mechanical properties, dimensional stability, creep resistance, acid and alkali solvent resistance, fatigue resistance, flame retardancy, and outstanding electrical properties. Furthermore, the dielectric constant and dielectric loss tangent of polyphenylene ether are virtually unaffected by temperature, humidity, and frequency, and it exhibits excellent thermal stability, with a glass transition temperature as high as 210°C. Due to its excellent overall performance, it is widely used in electronics, communications, and other fields, particularly in high-frequency and high-speed devices.

[0003] The most prominent features of 5G communication technology are high transmission speeds and low communication latency. The rapid development of 5G communication technology has placed higher demands on material performance. As electrical signal transmission is increasingly moving towards high frequencies and high speeds, the materials used must also have lower dielectric constants and dielectric loss tangents to reduce signal losses during transmission. From a materials perspective, developing polyphenylene ether with even lower dielectric constants and dielectric loss tangents and applying them to 5G communication technology is particularly important.

[0004] In view of the above-mentioned defects, the present invention aims to create a polyphenylene ether foam material and a preparation method thereof, so as to make it more valuable for industrial use. Summary of the Invention

[0005] To address the above-mentioned technical problems, the present invention provides a polyphenylene ether foam material and a method for preparing the same. By introducing air, which has a dielectric constant of only 1.0, into a polyphenylene ether system to prepare the foamed polyphenylene ether material, the dielectric constant of the polyphenylene ether can be further reduced, thereby improving its electrical properties. Furthermore, since commercial polyphenylene ether materials are all thermoplastic and have high molecular weights, which present processing difficulties, the present invention utilizes a redistribution modification method to reduce their molecular weight and increase material fluidity, thereby producing a modified polyphenylene ether material with a branched structure that is conducive to foaming and molding.

[0006] The polyphenylene ether foam material of the present invention comprises the following raw materials in parts by weight:

[0007] 100-120 parts of polyphenylene ether;

[0008] 0.1-0.4 parts of free radical initiator;

[0009] 0.3-0.5 parts of modifier;

[0010] 0.1-0.3 parts of antioxidant;

[0011] 0.1-0.3 parts of nucleating agent;

[0012] The modifier is one or more of ethylene and maleic anhydride copolymer, propylene and maleic anhydride copolymer, styrene and maleic anhydride copolymer, triglycidyl isocyanurate, and styrene-methyl methacrylate-glycidyl methacrylate copolymer.

[0013] Furthermore, the invention further comprises 1 to 5 parts by weight of a redistribution treatment agent;

[0014] The redistribution treatment agent is a phenolic compound, including one or more of phenol, p-bromophenol, 2,6-dimethylphenol, 2,6-dimethyl-4-benzyloxyphenol, bisphenol A, and biphenol.

[0015] Furthermore, the molecular weight of the polyphenylene ether is greater than 50,000.

[0016] Furthermore, the free radical initiator is one or more of dibenzoyl peroxide, di(4-methylbenzoyl) peroxide, tetramethylbenzene, and di-tert-butyl peroxide.

[0017] Furthermore, the antioxidant is one or more of diaryl secondary amine, p-phenylenediamine, ketoamine, aldehyde amine, thiodipropionate, and phosphite.

[0018] Furthermore, the nucleating agent is one or more of butylated hydroxyanisole, butylated hydroxytoluene, tert-butylhydroquinone, and tea polyphenols.

[0019] A method for preparing a polyphenylene ether foam material, the specific preparation steps are:

[0020] (1) adding polyphenylene ether, redistribution treatment agent, free radical initiator, modifier, antioxidant, and nucleating agent into a high-speed mixer according to the formula ratio and mixing;

[0021] (2) After mixing the above materials, the materials are extruded into sheets of a certain thickness through a twin-screw extruder, or are injection-molded into three-dimensional special-shaped parts through a twin-screw injection molding machine;

[0022] (3) The extruded sheet is placed in a supercritical fluid foaming device and foamed under specific process conditions to obtain a polyphenylene ether foam material.

[0023] Furthermore, the thickness of the extruded sheet is 1-5 mm.

[0024] Furthermore, the specific process conditions are a nitrogen pressure of 50-75 MPa, a temperature of 200-230° C., and a pressure relief rate of 15-20 MPa / s.

[0025] An application of polyphenylene ether foaming material is used in 5G communication materials.

[0026] By means of the above solution, the present invention has at least the following advantages:

[0027] The redistribution reaction between phenolic compounds and polyphenylene ether can reduce the molecular weight of commercial polyphenylene ether materials, producing relatively low-molecular-weight bishydroxy polyphenylene ethers (bishydroxy polyphenylene ethers), which enhances their processing fluidity. These terminal hydroxyl groups are then reacted with modifiers to produce polyphenylene ethers with long-chain branches. These long-chain branches effectively encapsulate gas, forming and stabilizing cellular units, allowing the production of polyphenylene ether-air composites, also known as foamed polyphenylene ether materials. This results in polyphenylene ether materials with even lower dielectric constants.

[0028] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate a certain embodiment of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 It is an electron microscope photograph of the foamed polyphenylene ether material of the present invention. DETAILED DESCRIPTION

[0031] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0032] A method for preparing a polyphenylene ether foam material according to a preferred embodiment of the present invention,

[0033] (1) Weighing 100-120 parts of polyphenylene ether, 1-5 parts of redistribution treatment agent, 0.1-0.4 parts of free radical initiator, 0.3-0.5 parts of modifier, 0.1-0.3 parts of antioxidant, and 0.1-0.3 parts of nucleating agent into a high-speed mixer, and stirring and mixing at a speed of 1000-1200 r / min to obtain a premix;

[0034] The molecular structural formula of the polyphenylene ether is:

[0035]

[0036] The molecular weight of the polyphenylene ether is greater than 50,000;

[0037] The redistribution treatment agent is a phenolic compound, including one or more of phenol, p-bromophenol, 2,6-dimethylphenol, 2,6-dimethyl-4-benzyloxyphenol, bisphenol A, and biphenol.

[0038] The free radical initiator is one or more of dibenzoyl peroxide, di(4-methylbenzoyl) peroxide, tetramethylbenzenequinone, and di-tert-butyl peroxide.

[0039] The modifier is one or more of ethylene and maleic anhydride copolymer, propylene and maleic anhydride copolymer, styrene and maleic anhydride copolymer, triglycidyl isocyanurate, and styrene-methyl methacrylate-glycidyl methacrylate copolymer.

[0040] The antioxidant is one or more of diaryl secondary amine, p-phenylenediamine, ketone amine, aldehyde amine, thiodipropionate, and phosphite.

[0041] The nucleating agent is one or more of butylated hydroxyanisole, butylated hydroxytoluene, tert-butylhydroquinone, and tea polyphenols.

[0042] (2) After mixing the above premix, the materials are extruded into a sheet with a thickness of 1 to 5 mm through a twin-screw extruder; the temperature of the twin-screw extruder is controlled at 280 to 330° C., and the screw speed of the twin-screw extruder is controlled at 250 to 400 rpm;

[0043] (3) The extruded sheet is placed in a supercritical fluid foaming device and foamed under the process conditions of a nitrogen pressure of 50 to 75 MPa, a temperature of 200 to 230° C., and a pressure relief rate of 15 to 20 MPa / s to obtain a polyphenylene ether foam material.

[0044] The final polyphenylene ether foam material has a density of 0.3-0.7g / cm 3 ; The dielectric constant is 1.2~2.1.

[0045] The redistribution reaction mechanism of phenolic compounds and polyphenylene ether is as follows:

[0046]

[0047] Example 1

[0048] (1) See Figure 1, by weight, 100 parts of polyphenylene ether, 1 part of redistribution treatment agent, 0.1 part of free radical initiator, 0.3 part of modifier, 0.1 part of antioxidant, and 0.1 part of nucleating agent were weighed and added into a high-speed mixer, and stirred at a speed of 1000 r / min to obtain a premix;

[0049] The molecular weight of the polyphenylene ether is 60,000; the redistribution treatment agent is the phenolic compound p-bromophenol; the free radical initiator is dibenzoyl peroxide; the modifier is a copolymer of ethylene and maleic anhydride; the antioxidant is a diaryl secondary amine; and the nucleating agent is butylated hydroxyanisole.

[0050] (2) After mixing the above premix, the mixture was extruded into a sheet with a thickness of 1 mm through a twin-screw extruder; the temperature of the twin-screw extruder was controlled at 280° C. and the screw speed of the twin-screw extruder was 250 rpm;

[0051] (3) The extruded sheet is placed in a supercritical fluid foaming device and foamed under the process conditions of a nitrogen pressure of 50 MPa, a temperature of 200°C, and a pressure relief rate of 15 MPa / s to obtain a polyphenylene ether foam material.

[0052] The redistribution reaction mechanism of phenolic compounds and polyphenylene ether is as follows:

[0053]

[0054] Example 2

[0055] (1) Weigh 110 parts of polyphenylene ether, 3 parts of redistribution treatment agent, 0.3 parts of free radical initiator, 0.4 parts of modifier, 0.2 parts of antioxidant, and 0.2 parts of nucleating agent in parts by weight, add them into a high-speed mixer, and stir and mix at a speed of 1100 r / min to obtain a premix;

[0056] The polyphenylene ether has a molecular weight greater than 50,000; the redistribution agent is the phenolic compound 2,6-dimethylphenol; the free radical initiator is di(4-methylbenzoyl)peroxide; the modifier is a copolymer of propylene and maleic anhydride; the antioxidants are p-phenylenediamine and ketoneamine; and the nucleating agent is butylated hydroxytoluene.

[0057] (2) After mixing the above premix, the mixture was extruded into a sheet with a thickness of 3 mm through a twin-screw extruder; the temperature of the twin-screw extruder was controlled at 300° C. and the screw speed of the twin-screw extruder was 300 rpm;

[0058] (3) The extruded sheet is placed in a supercritical fluid foaming device and foamed under the process conditions of a nitrogen pressure of 65 MPa, a temperature of 215°C, and a pressure relief rate of 18 MPa / s to obtain a polyphenylene ether foam material.

[0059] The redistribution reaction mechanism of phenolic compounds and polyphenylene ether is as follows:

[0060]

[0061] Example 3

[0062] (1) Weigh 120 parts of polyphenylene ether, 5 parts of redistribution treatment agent, 0.4 parts of free radical initiator, 0.5 parts of modifier, 0.3 parts of antioxidant, and 0.3 parts of nucleating agent in a high-speed mixer, and stir and mix at a speed of 1200 r / min to obtain a premix;

[0063] The polyphenylene ether has a molecular weight greater than 50,000; the redistribution agent is the phenolic compound 2,6-dimethyl-4-benzyloxyphenol; the free radical initiator is tetramethylbenzenequinone; the modifier is triglycidyl isocyanurate; the antioxidant is thiodipropionate; and the nucleating agent is tert-butylhydroquinone.

[0064] (2) After mixing the above premix, the materials were extruded into a sheet with a thickness of 5 mm through a twin-screw extruder; the temperature of the twin-screw extruder was controlled at 330° C. and the screw speed of the twin-screw extruder was 400 rpm;

[0065] (3) The extruded sheet is placed in a supercritical fluid foaming device and foamed under the process conditions of a nitrogen pressure of 75 MPa, a temperature of 230°C, and a pressure relief rate of 20 MPa / s to obtain a polyphenylene ether foam material.

[0066] The redistribution reaction mechanism of phenolic compounds and polyphenylene ether is as follows:

[0067]

[0068] Control Example

[0069] Comparative Example 1

[0070] The preparation method of this comparative example is basically the same as that of Example 1, except that no redistribution treatment agent and modifier are added to the raw materials of the foaming material, and the polyphenylene ether material is also prepared;

[0071] The performance tests were performed on Examples 1 to 3 of the present invention and Comparative Example 1, and the test results are shown in Table 1:

[0072] Detection method:

[0073] Density test: Test in accordance with the test conditions specified in GB4472-84;

[0074] Mechanical strength test: Test according to the test conditions specified in ISO527;

[0075] Dielectric performance test: Use RF analyzer for testing;

[0076] Table 1 Performance test results

[0077]

[0078] From the test data in the above table, it can be seen that the mechanical properties and dielectric properties of the polyphenylene ether materials prepared in Examples 1 to 3 of the present invention are excellent, proving that the technical solution of the present application is feasible;

[0079] The performance results of Example 1 of the present invention and Reference Example 1 detection are compared again. Since no redistribution treatment agent and modifier are added in Reference Example 1, a polyphenylene ether material is also obtained. However, the foaming effect is poor and the multiplying power is small. The mechanical properties of the polyphenylene ether material in the final Reference Example 1 are substantially not significantly changed, and are only slightly improved, while the dielectric properties are significantly higher than those of each embodiment. It can be confirmed that the molecular weight of the commercial polyphenylene ether material can be reduced by the redistribution reaction of phenolic compounds and polyphenylene ether, thereby obtaining a relatively low-molecular-weight bishydroxy polyphenylene ether and enhancing its processing fluidity. The polyphenylene ether with a long chain branching structure is then prepared by reacting its terminal hydroxyl group with the modifier. The long chain branching structure can preferably encapsulate gas, form and stabilize a cell unit, and prepare a composite material of polyphenylene ether and air, i.e., a foamed polyphenylene ether material. Thus, a polyphenylene ether material with a lower dielectric constant is obtained.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a polyphenylene ether foam material, characterized in that: The polyphenylene ether foam material comprises the following raw materials in parts by weight: 100-120 parts of polyphenylene ether; 0.1-0.4 parts of free radical initiator; 0.3-0.5 parts of modifier; 0.1-0.3 parts of antioxidant; 0.1-0.3 parts of nucleating agent; 1 to 5 parts of redistribution treatment agent; The modifier is one or more of ethylene and maleic anhydride copolymer, propylene and maleic anhydride copolymer, styrene and maleic anhydride copolymer, triglycidyl isocyanurate, and styrene-methyl methacrylate-glycidyl methacrylate copolymer; The redistribution treatment agent is a phenolic compound, including one or more of phenol, p-bromophenol, 2,6-dimethylphenol, 2,6-dimethyl-4-benzyloxyphenol, bisphenol A, and biphenol; The free radical initiator is one or more of dibenzoyl peroxide, di(4-methylbenzoyl) peroxide, tetramethylbenzenequinone, and di-tert-butyl peroxide; The nucleating agent is one or more of butylated hydroxyanisole, butylated hydroxytoluene, tert-butylhydroquinone, and tea polyphenols; The specific preparation steps are: (1) Add polyphenylene ether, redistribution treatment agent, free radical initiator, modifier, antioxidant and nucleating agent into a high-speed mixer according to the formula ratio and mix; (2) After mixing the above materials, the materials are extruded into sheets of a certain thickness through a twin-screw extruder, or injected into three-dimensional special-shaped parts through a twin-screw injection molding machine; (3) placing the extruded sheet into a supercritical fluid foaming device and foaming it under specific process conditions to obtain a polyphenylene ether foam material; The thickness of the extruded sheet is 1-5 mm; The specific process conditions are a nitrogen pressure of 50-75 MPa, a temperature of 200-230° C., and a pressure relief rate of 15-20 MPa / s.

2. The method for preparing a polyphenylene ether foam material according to claim 1, wherein: The molecular weight of the polyphenylene ether is greater than 50,000.

3. The method for preparing a polyphenylene ether foam material according to claim 1, wherein: The antioxidant is one or more of diaryl secondary amine, p-phenylenediamine, ketone amine, aldehyde amine, thiodipropionate, and phosphite.

4. Use of the polyphenylene ether foam material prepared by the preparation method according to any one of claims 1 to 3, characterized in that: Applied to 5G communication materials.

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