A polyphenylene sulfide composition, and a method for preparing and using the same

Abstract

The present application relates to a kind of polyphenyl sulfide composition and its preparation method and application, belong to the composition technical field of polymer compound.The polyphenyl sulfide composition of the present application includes the following weight parts of component: polyphenyl sulfide 85~95, toughening agent 5~15, silane coupling agent 0.5~1.5, diatomite 1~3;The polyphenyl sulfide of crosslinking type polyphenyl sulfide containing oxygen element in molecular chain, the mass content of oxygen element in the polyphenyl sulfide is 0.5%~6%.The polyphenyl sulfide composition has excellent CTI and good mechanical property simultaneously.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer compound compositions, in particular to a polyphenylene sulfide composition and a preparation method and application thereof. Background Art

[0002] Polyphenylene sulfide (PPS) is a high-performance thermoplastic resin, because it has excellent high temperature resistance, corrosion resistance, wear resistance, flame retardancy, high rigidity, low water absorption, and excellent electrical properties, dimensional stability and other properties, and is often used in the fields of electronic appliances, automobiles, machinery, chemical industry. However, although polyphenylene sulfide has excellent heat resistance and flame retardancy, due to its low relative tracking index (CTI), it is impossible to meet the high leakage application requirements of new energy fields such as solar energy and wind power generation, and high-performance power conversion equipment fields. At present, in the prior art (CN103827213A, CN110791095A, CN112795191A, etc.), mainly by adding a large amount of metal oxides or hydroxides as carbonization inhibitors, and adding components such as polyamide and glass fiber to improve the CTI of polyphenylene sulfide, but the improvement degree of CTI is limited and the toughness of polyphenylene sulfide may be caused to deteriorate, i.e., it is difficult to obtain a polyphenylene sulfide material with both high CTI and good toughness. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a polyphenylene sulfide composition and a preparation method and application thereof.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] In a first aspect, the present invention provides a polyphenylene sulfide composition, comprising the following components, by weight: 85 to 95 parts of polyphenylene sulfide, 5 to 15 parts of a toughening agent, 0.5 to 1.5 parts of a silane coupling agent, and 1 to 3 parts of diatomaceous earth; the polyphenylene sulfide is a cross-linked polyphenylene sulfide containing oxygen elements in the molecular chain, and the mass content of the oxygen element in the polyphenylene sulfide is 0.5% to 6%.

[0006] The present invention uses cross-linked polyphenylene sulfide with a specific oxygen content as a matrix resin, combines it with a silane coupling agent and diatomaceous earth, and adds a toughening agent to form a polyphenylene sulfide composition. By regulating the oxygen content in the polyphenylene sulfide, the carbon formed by the polyphenylene sulfide under the action of current or discharge is promoted to form carbon dioxide by reacting part of the carbon with oxygen during the carbonization process. This reduces the formation of a carbon layer on the surface of the material, while reducing the regularity of the formed carbon layer, thereby reducing the conductivity of the conductive path of the carbon layer. The silane coupling agent can effectively improve the compatibility of the toughening agent with the polyphenylene sulfide matrix to enhance the bonding force between the two, thereby disrupting the formation of the carbon skeleton of the polyphenylene sulfide during the carbonization process. The diatomaceous earth can not only use its rich porous structure to absorb oxygen and react with carbon to generate carbon dioxide during the carbonization process of the polyphenylene sulfide to further reduce carbon formation, but also use the silicon, aluminum and other original elements contained in it to hybridize with the carbon layer during the carbonization process of the polyphenylene sulfide to form a carbon-silicon hybrid structure with low conductivity, thereby reducing the formation of the carbon layer while reducing its electrical conductivity, thereby significantly improving the CTI of the polyphenylene sulfide composition. The cross-linked polyphenylene sulfide can also enhance the entanglement between the cross-linked polyphenylene sulfide and the toughening agent molecular chain, so that the polyphenylene sulfide composition also has excellent mechanical properties.

[0007] In addition, the mass percentage of polyphenylene sulfide in the above-mentioned polyphenylene sulfide composition is preferably ≥80%; the melt mass flow rate of the polyphenylene sulfide at 316°C and 5kg is 50 to 2000g / 10min according to ISO 1133:2021 standard. The above-mentioned polyphenylene sulfide (cross-linked polyphenylene sulfide containing oxygen elements in the molecular chain) refers to thermal oxygen cross-linked polyphenylene sulfide, which can be obtained by heat-treating linear polyphenylene sulfide in an air atmosphere at 245 to 255°C, and regulating the mass content of oxygen elements in the polyphenylene sulfide by adjusting the heat treatment time. The specific surface area of ​​the above-mentioned diatomaceous earth is preferably 20 to 600m 2 / g, a large proportion of diatomaceous earth in the polyphenylene sulfide composition will lead to poor mechanical properties.

[0008] Optionally, the mass content of oxygen in polyphenylene sulfide can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or 5.5%. The mass content of oxygen in polyphenylene sulfide can be obtained by performing energy spectrum analysis on the material using a scanning electron microscope coupled to energy spectrum (SEM-EDS).

[0009] Optionally, the weight proportion of polyphenylene sulfide in the polyphenylene sulfide composition may be 86 parts, 88 parts, 90 parts, 92 parts, or 94 parts; the weight proportion of the toughening agent may be 6 parts, 8 parts, 10 parts, 12 parts, or 14 parts; the weight proportion of the silane coupling agent may be 0.6 parts, 0.8 parts, 1 part, 1.2 parts, or 1.4 parts; and the weight proportion of diatomaceous earth may be 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, or 2.8 parts.

[0010] As a preferred embodiment of the polyphenylene sulfide composition of the present invention, the mass content of oxygen in the polyphenylene sulfide is 1% to 4%.

[0011] In a preferred embodiment of the polyphenylene sulfide composition of the present invention, the diatomaceous earth has an average particle size of 20 to 200 μm; alternatively, it can be 25 μm, 50 μm, 75 μm, 100 μm, 125 μm, 150 μm, or 175 μm. Studies have shown that diatomaceous earth within this average particle size range not only effectively improves the CTI of the polyphenylene sulfide composition but also significantly enhances its mechanical properties. The average particle size of the diatomaceous earth can be measured using a microscope.

[0012] As a preferred embodiment of the polyphenylene sulfide composition of the present invention, the silane coupling agent at least includes a silane coupling agent containing an epoxy group.

[0013] The study found that when part or all of the silane coupling agent contains epoxy groups, the epoxy groups in the silane coupling agent can react with the end groups (thiol groups) of polyphenylene sulfide to further destroy the regularity of the carbon skeleton of the polyphenylene sulfide main chain, thereby more effectively reducing the carbon-forming ability of polyphenylene sulfide and thereby improving the CTI of the polyphenylene sulfide composition.

[0014] As a preferred embodiment of the polyphenylene sulfide composition of the present invention, the silane coupling agent containing epoxy groups is coated on the surface of diatomaceous earth.

[0015] The study found that compared with the separate dispersion of silane coupling agent and diatomaceous earth in the polyphenylene sulfide composition, coating the silane coupling agent on the surface of diatomaceous earth is more conducive to improving the dispersion uniformity of diatomaceous earth in the polyphenylene sulfide composition, thereby improving the CTI of the polyphenylene sulfide composition; especially when the silane coupling agent containing epoxy groups is coated on the surface of diatomaceous earth, the large number of epoxy groups in the siloxane coated on the surface of the diatomaceous earth can also react with the end groups of different polyphenylene sulfide molecular chains to form a network structure with diatomaceous earth as the cross-linking center, which can not only more effectively destroy the regularity of the carbon skeleton of the polyphenylene sulfide main chain to reduce the carbon-forming ability of polyphenylene sulfide to improve the CTI of the polyphenylene sulfide composition, but also significantly improve the mechanical properties of the polyphenylene sulfide composition.

[0016] As a preferred embodiment of the polyphenylene sulfide composition of the present invention, among the components of the polyphenylene ether composition, the weight proportion of polyphenylene sulfide is 88 to 92 parts, and the weight proportion of the toughening agent is 8 to 12 parts.

[0017] As a preferred embodiment of the polyphenylene sulfide composition of the present invention, the toughening agent includes at least one of a polyolefin elastomer, an ethylene-butyl acrylate-glycidyl methacrylate terpolymer, an ethylene-propylene rubber, a nitrile rubber, a butadiene rubber, an ethylene-vinyl acetate copolymer, a styrene-butadiene-styrene block copolymer, a styrene-ethylene-butylene-styrene block copolymer, a styrene-ethylene-propylene-styrene block copolymer, and maleic anhydride grafts and glycidyl methacrylate grafts thereof.

[0018] As a preferred embodiment of the polyphenylene sulfide composition of the present invention, the silane coupling agent includes at least one of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, methacryloxysilane, propyltrimethoxysilane, and 3-aminopropyltrimethoxysilane.

[0019] In a second aspect, the present invention provides a method for preparing the above-mentioned polyphenylene sulfide composition, comprising the following steps: uniformly mixing the components and then melt-extruding to obtain the polyphenylene sulfide composition; wherein the melt extrusion can be specifically carried out using a twin-screw extruder, the melt extrusion temperature is 260-290°C, and the screw speed of the twin-screw extruder is 100-300rpm.

[0020] In a third aspect, the present invention provides the use of the polyphenylene sulfide composition in the preparation of parts for electronic appliances or electric vehicles.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention uses cross-linked polyphenylene sulfide with a specific oxygen content as a matrix resin, combines it with a silane coupling agent and diatomaceous earth, and adds a toughening agent to form a polyphenylene sulfide composition. By reducing the formation of a carbon layer under the action of current or discharge and reducing the conductivity of the carbon layer, while enhancing the degree of entanglement between polyphenylene sulfide and the toughening agent, the CTI and mechanical properties of the polyphenylene sulfide composition are significantly improved. DETAILED DESCRIPTION

[0023] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0024] Unless otherwise specified, other materials, reagents, etc. used in the Examples and Comparative Examples can be obtained from commercial sources.

[0025] 1. Raw materials and reagents

[0026] 1) Polyphenylene sulfide A: linear PPS, oxygen content of 0%, brand 3450, manufactured by Zhejiang Xinhecheng;

[0027] Polyphenylene sulfide A1 (oxygen content by mass: 0.5%), polyphenylene sulfide A2 (oxygen content by mass: 1%), polyphenylene sulfide A3 (oxygen content by mass: 6%), polyphenylene sulfide A4 (oxygen content by mass: 8%);

[0028] The above-mentioned polyphenylene sulfides A1, A2, A3 and A4 are all thermal oxygen cross-linked PPS, which are obtained by heat-treating polyphenylene sulfide A in an air-blast oven at 250°C for different times; the mass content of oxygen element in the above-mentioned polyphenylene sulfide is obtained by energy spectrum analysis of the material using scanning electron microscopy coupled with energy spectrum (SEM-EDS).

[0029] 2) Toughener 1: Ethylene-butyl acrylate-glycidyl methacrylate terpolymer, brand PTW, manufactured by Dow Chemical, USA;

[0030] Toughener 2: Maleic anhydride grafted styrene-ethylene-butylene-styrene block copolymer, brand FG1901, manufacturer: Kraton, USA.

[0031] 3) Silane coupling agent 1: γ-glycidyloxypropyltrimethoxysilane, brand Z-6040, manufactured by Dow Corning, USA;

[0032] Silane coupling agent 2: γ-aminopropyltriethoxysilane, brand Z-6011, manufactured by Dow Corning, USA;

[0033] Titanate coupling agent: isopropyl tris (dioctyl phosphate) titanate, brand KR-12, manufacturer is Kenrich, USA.

[0034] 4) Diatomaceous earth 1, diatomaceous earth 2, and diatomaceous earth 3 were obtained by crushing and screening large-particle diatomaceous earth (brand name Celite R566, manufacturer: Ingérôme, France). The average particle size of diatomaceous earth 1 was 25 μm, the average particle size of diatomaceous earth 2 was 85 μm, and the average particle size of diatomaceous earth 3 was 200 μm.

[0035] Activated carbon, brand GH-20, manufactured by Jiangsu Enkai Activated Carbon Co., Ltd.

[0036] Carbonization inhibitor 1 is magnesium hydroxide, and carbonization inhibitor 2 is triphenyl phosphate, both of which are commercially available.

[0037] 2. Examples 1 to 13 and Comparative Examples 1 to 7

[0038] Table 1 Weight parts of each component of the polyphenylene ether composition in Examples 1 to 12

[0039]

[0040] The preparation method of the polyphenylene sulfide composition in Examples 1 to 4 and Examples 7 to 12 comprises the following steps: first, according to a formula, mixing a silane coupling agent 1 with diatomaceous earth to form diatomaceous earth coated with the silane coupling agent 1; then, uniformly mixing the diatomaceous earth with polyphenylene sulfide and a toughening agent; and then adding the mixture to a twin-screw extruder for melt extrusion to obtain the polyphenylene sulfide composition; wherein the speed of the twin-screw extruder is 400 rpm, the feeding rate is 450 kg / h, and the extrusion temperature is 280°C.

[0041] The preparation method of the polyphenylene sulfide composition in Example 5 comprises the following steps: first, according to the formula, mixing silane coupling agent 1 with diatomaceous earth to form diatomaceous earth coated with silane coupling agent 1; then, uniformly mixing the diatomaceous earth with polyphenylene sulfide, a toughening agent, and silane coupling agent 2; and then adding the mixture to a twin-screw extruder for melt extrusion to obtain the polyphenylene sulfide composition; wherein the speed of the twin-screw extruder is 400 rpm, the feeding rate is 450 kg / h, and the extrusion temperature is 280°C.

[0042] The preparation method of the polyphenylene sulfide composition in Example 6 comprises the following steps: directly mixing polyphenylene sulfide, a toughening agent, a silane coupling agent 2, and diatomaceous earth according to a formula, and then adding the mixture to a twin-screw extruder for melt extrusion to obtain the polyphenylene sulfide composition; wherein the speed of the twin-screw extruder is 400 rpm, the feeding rate is 450 kg / h, and the extrusion temperature is 280°C.

[0043] Example 13

[0044] An embodiment of the polyphenylene sulfide composition of the present invention is provided. The polyphenylene sulfide composition of this embodiment is substantially the same as that of Example 1, except that the preparation method of the polyphenylene sulfide composition comprises the following steps:

[0045] According to the formula, polyphenylene sulfide A1, toughening agent 1, silane coupling agent 1 and diatomaceous earth 1 were directly mixed and evenly added to a twin-screw extruder for melt extrusion to obtain a polyphenylene sulfide composition; wherein the rotation speed of the above-mentioned twin-screw extruder is 400 rpm, the feeding rate is 450 kg / h, and the extrusion temperature is 280°C.

[0046] Table 2 Weight parts of each component of the polyphenylene sulfide composition in Comparative Examples 1 to 7

[0047]

[0048] The preparation method of the polyphenylene sulfide composition in Comparative Examples 1 to 7 comprises the following steps: directly mixing the components according to the formula and then adding them to a twin-screw extruder for melt extrusion to obtain the polyphenylene sulfide composition; wherein the speed of the twin-screw extruder is 400 rpm, the feeding rate is 450 kg / h, and the extrusion temperature is 280°C.

[0049] 3. Performance testing

[0050] 1) Tensile strength: tested in accordance with standard ISO 527-1-2021 at a tensile rate of 50 mm / min.

[0051] 2) Izod notched impact strength: tested in accordance with ISO 180:2019, type A notch.

[0052] 3) CTI test: According to IEC 60112:2020, the highest voltage at which the test material can pass 50 drops of electrolyte without failure.

[0053] Table 3 Properties of the polyphenylene sulfide compositions in various examples and comparative examples

[0054]

[0055] According to the data in Table 3, the CTI of the polyphenylene sulfide compositions in Examples 1 to 13 reached 200 to 210 V, and the Izod notched impact strength was greater than or equal to 16 kJ / m 2 , and the tensile strength reaches 45-55 MPa, indicating that the polyphenylene sulfide composition of the present invention has both excellent CTI and good mechanical properties. Meanwhile, according to Comparative Examples 1 and 2, it can be seen that either too low or too high a mass content of oxygen in polyphenylene sulfide cannot balance the CTI and toughness of the polyphenylene sulfide composition, resulting in poor CTI or toughness and difficulty meeting application requirements. According to Example 13 and Comparative Example 3, it can be found that compared with silane coupling agents containing epoxy groups, titanate coupling agents cannot react with the terminal groups (thiol groups) of polyphenylene sulfide, nor can they hybridize with the carbon layer during the carbonization process of polyphenylene sulfide to form a carbon-silicon hybrid structure with low conductivity, resulting in poor CTI of the polyphenylene sulfide composition and also reducing the toughness of the polyphenylene sulfide composition to a certain extent. In addition, according to Comparative Examples 4 and 5, although the use of a carbonization inhibitor can also maintain good toughness of the polyphenylene sulfide composition, it is difficult to effectively improve the CTI of the polyphenylene sulfide composition. According to Comparative Examples 6 and 7, it can be found that replacing diatomaceous earth with activated carbon has similar performance to that without adding porous materials, and it is difficult to effectively improve the CTI of the polyphenylene sulfide composition.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polyphenylene sulfide composition, characterized in that Calculated by weight, it includes the following components: 85-95 parts of polyphenylene sulfide, 5-15 parts of a toughening agent, 0.5-1.5 parts of a silane coupling agent, and 1-3 parts of diatomaceous earth; the polyphenylene sulfide is a cross-linked polyphenylene sulfide containing oxygen elements in the molecular chain, and the mass content of the oxygen elements in the polyphenylene sulfide is 0.5%-6%.

2. The polyphenylene sulfide composition according to claim 1, wherein The mass content of oxygen element in the polyphenylene sulfide is 1% to 4%.

3. The polyphenylene sulfide composition according to claim 1, wherein The average particle size of the diatomaceous earth is 20-200 μm.

4. The polyphenylene sulfide composition according to claim 1, wherein The silane coupling agent at least includes a silane coupling agent containing an epoxy group.

5. The polyphenylene sulfide composition according to claim 4, wherein The silane coupling agent containing epoxy groups is coated on the surface of diatomaceous earth.

6. The polyphenylene sulfide composition according to claim 1, wherein Among the components of the polyphenylene sulfide composition, the weight proportion of polyphenylene sulfide is 88 to 92 parts, and the weight proportion of the toughening agent is 8 to 12 parts.

7. The polyphenylene sulfide composition according to any one of claims 1 to 6, characterized in that The toughening agent includes at least one of ethylene-butyl acrylate-glycidyl methacrylate terpolymer, ethylene-propylene rubber, nitrile rubber, butadiene rubber, ethylene-vinyl acetate copolymer, styrene-butadiene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, styrene-ethylene-propylene-styrene block copolymer and their maleic anhydride grafts and glycidyl methacrylate grafts.

8. The polyphenylene sulfide composition according to any one of claims 1 to 6, wherein The toughening agent includes a polyolefin elastomer.

9. The polyphenylene sulfide composition according to claim 1, wherein The silane coupling agent includes at least one of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, methacryloxypropyltrimethoxysilane, and 3-aminopropyltrimethoxysilane.

10. The method for preparing the polyphenylene sulfide composition according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: uniformly mixing the components and then melting and extruding the components to obtain a polyphenylene sulfide composition.

11. Use of the polyphenylene sulfide composition according to any one of claims 1 to 9 in the preparation of parts for electronic appliances or electric vehicles.

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