Preparation method and application of modified polyphenyl ether foamed plate

Abstract

The application relates to a preparation method and application of a modified polyphenyl ether foamed plate, and belongs to the technical field of new material preparation. The preparation method provided by the application is a production process combining extrusion modification and mold foaming, can realize continuous production of high-multiple-flame-retardant polyphenyl ether plates, and is high in production efficiency. The polyphenyl ether is modified by PA6, the orientation of molecular chains can be overcome, the free volume between molecules is increased, and the plate with a thickness of 8-10 mm can be smoothly extruded and formed. The mold foaming adopts a supercritical fluid process, the cell diameter is small (20-50 microns), the foaming multiple is high (10-20 times), the limiting oxygen index is high (26-32%), and the combustion grade reaches UL94-V0. The polyphenyl ether modified by PA6 is high in heat distortion temperature (HDT is higher than 150 DEG C), can be used in the fields of power batteries, energy storage batteries and new energy vehicles, and the like.

Description

Technical Field

[0001] This invention relates to a method for preparing modified polyphenylene ether foamed boards and their application, belonging to the field of new material preparation technology. Background Technology

[0002] Polyphenylene oxide (PPO) is a high-temperature resistant, self-flame-retardant, non-crystalline resin with excellent dimensional stability, chemical resistance, heat resistance, electrical insulation, high mechanical strength, and good wear-resistant processing properties. It is widely used in many fields such as machinery, automobiles, electronics, and photovoltaics.

[0003] Polyphenylene ether (PPE) typically presents processing challenges due to its rigid chain structure, high viscosity, and poor flowability. It is often blended with other resins such as PA, PC, PS, and PP to prepare alloys. Unmodified PPE has weak foaming ability, typically exhibiting a low foaming ratio of 1-3 times. Existing technologies can use modified PPEs such as HIPS and PS to increase the foaming ratio to 5-10 times, but this leads to performance degradation, typically a decrease in heat distortion temperature and oxygen index, failing to meet the requirements of high-temperature resistance and high flame retardancy in fields such as power batteries and 5G communications. Modified PPE possesses a certain foaming capacity, and foamed products prepared from it offer advantages such as lightweight, material saving, energy efficiency, environmental friendliness, and impact resistance, reducing the waste of Earth's resources. It also exhibits excellent thermal insulation properties, making it suitable for applications such as battery thermal management and thermal insulation in new energy vehicles.

[0004] In view of the above-mentioned shortcomings, the present invention aims to create a method for preparing and applying modified polyphenylene ether foamed boards, so as to make them more valuable for industrial use. Summary of the Invention

[0005] To address the aforementioned technical problems, the purpose of this invention is to provide a method for preparing modified polyphenylene ether foamed boards and their applications.

[0006] A modified polyphenylene ether foam board of the present invention comprises the following raw materials in parts by weight:

[0007] 100 parts polyphenylene ether;

[0008] 20-30 parts Nylon 6;

[0009] 10-15 parts compatibilizer;

[0010] 0.5-1 part antioxidant.

[0011] Furthermore, the polyphenylene ether has a glass transition temperature of 211°C, a density of 1.06 g / ml, and a melt flow rate of 4-15 g / 10 min (315°C / 10 kg), preferably Bluestar LXR045 and LXR050;

[0012] The nylon 6 has a density of 1.13-1.14 g / ml and a melt flow rate of 2.6-2.8 g / 10 min (260°C / 2.16 kg).

[0013] The compatibilizer is a polymer containing maleic anhydride groups, preferably a styrene-maleic anhydride copolymer, i.e., SMA, and polyphenylene ether grafted with maleic anhydride, i.e., PPO-g-MAH.

[0014] The antioxidants are antioxidant 168 and antioxidant 1010, which are compounded in a 2:1 ratio.

[0015] A method for preparing modified polyphenylene ether foamed boards, the specific preparation steps are as follows:

[0016] 1) After thoroughly drying the polyphenylene ether resin, nylon 6, compatibilizer, and antioxidant, mix them, melt-blend them using a twin-screw extruder, and then extrude them through a die to form the polyphenylene ether preform to be foamed and modified.

[0017] 2) Place the polyphenylene oxide preform to be foamed into a mold cavity at a constant temperature T, fill it with supercritical fluid for infiltration and swelling, and reach an equilibrium state. Then, through rapid depressurization and foaming, a polyphenylene oxide foam board with a foaming ratio of 10-20 times is obtained.

[0018] Furthermore, the melt blending extrusion method described in step 1) includes twin-screw melt blending extrusion;

[0019] The temperature of the melt blend extrusion is 265-285℃;

[0020] The screw speed for the melt blending extrusion is 80~200 rpm;

[0021] The die is a coat hanger type die, and the thickness of the modified polyphenylene ether preform is 8-10mm.

[0022] Further, in step 2), the modified polyphenylene ether preform is placed in a mold cavity at a constant temperature T, where the temperature T is lower than the glass transition temperature Tg of polyphenylene ether, preferably 185℃-195℃.

[0023] Furthermore, in step 2), the supercritical fluid used is supercritical N2 and / or CO2, the supercritical fluid pressure is 7.2-20 MPa, preferably 13-16 MPa, and the swelling equilibrium time is 1-1.5 h.

[0024] Furthermore, in step 2), the pressure in the system is directly reduced to 0 through depressurization foaming, with a depressurization rate of 10-80 MPa / s, preferably 30-50 MPa / s.

[0025] Furthermore, in step 2), the polyphenylene ether foamed board prepared by depressurization foaming has a density of 50-100 g / L and expands 10-20 times relative to the blank board.

[0026] Furthermore, in step 2), the polyphenylene ether foam board prepared by depressurization foaming has a cell diameter of 20-50μm, a limiting oxygen index of 26-29%, and a flame retardant rating of UL94-V0.

[0027] An application of a modified polyphenylene ether foam board for the preparation of materials for 5G communication, power batteries and new energy vehicles.

[0028] By means of the above-described solution, the present invention has at least the following advantages:

[0029] (1) By using the preparation method provided by the present invention, the production process of extrusion modification combined with molding foaming can realize the continuous production of high-ratio flame-retardant polyphenylene ether sheets with high production efficiency.

[0030] (2) Polyphenylene oxide (PPO) has a rigid linear molecular structure with no flexible chain segments, making molecular movement difficult and resulting in small intermolecular free volume. Macroscopically, this manifests as a high glass transition temperature, high resin viscosity, and processing difficulties. During extrusion, the molecules tend to orient themselves, making foaming difficult. Using PA6-modified PPO can overcome the orientation of molecular chains during extrusion, increase the intermolecular free volume, and allow for successful extrusion molding of 8-10 mm thick sheets.

[0031] (3) The molding foaming adopts supercritical fluid process, with small cell diameter (20-50μm), high foaming ratio (10-20 times), high limiting oxygen index (26-32%), and flammability rating reaching UL94-V0 level.

[0032] (4) Polyphenylene ether resin itself has a relatively high heat distortion temperature, but the resin viscosity is high and the flowability is poor, making extrusion processing difficult. PA6 is used to modify polyphenylene ether, which improves the flowability of polyphenylene ether and at the same time reduces the heat distortion temperature of polyphenylene ether. The product has a high heat distortion temperature (HDT above 150℃) and can be used in the fields of power batteries, energy storage batteries and new energy vehicles.

[0033] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below. Detailed Implementation

[0034] The specific embodiments of the present invention will be described in further detail below with reference to the examples. These examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0035] There are no particular restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0036] There are no particular restrictions on the purity of any of the raw materials used in this invention. However, this invention preferably uses analytical grade or the purity requirements conventional in the field of polypropylene material preparation.

[0037] All raw materials of this invention are conventional in the field, and each brand name and abbreviation is clear and distinct in its relevant application. Those skilled in the art can purchase them from the market or prepare them by conventional methods based on the brand name, abbreviation and corresponding application. Example 1

[0038] 100 parts of polyphenylene oxide (PPO) (Bluestar LXR050, MI (315℃ / 10 kg) at 5 g / 10 min), 30 parts of nylon 6 (Ube 1013B), 15 parts of compatibilizer SMA (Huawen Chemical SMA-700), and 1 part of antioxidant (BASF antioxidant 168: BASF antioxidant 1010 in a 2:1 ratio) were selected and thoroughly dried before being mixed in a high-speed mixer. The mixture was then compounded and extruded using a co-rotating twin-screw extruder. The feeding section temperature was 265-270℃, the melting section temperature was 270-280℃, and the metering section temperature was 280-285℃. The main feed rate of the extruder was 50 kg / h, the screw speed was 180 rpm, and the die pressure was 6-8 MPa. The molten material was extruded into a continuous sheet with a width of 150 mm, a thickness of 8 mm, and no obvious internal defects.

[0039] Modified PPO sheets were cut into 150×150×8mm samples and placed in a hot press cavity (200×200×15mm) maintained at 185℃. After replacing the air in the cavity, carbon dioxide was introduced to a supercritical state, and the pressure was controlled at 16MPa for 1 hour. The pressure was then released from 16MPa to 0 MPa at a rate of 30MPa / s using a pneumatic ball valve. The cavity was then opened, yielding PPO foamed sheets. Testing showed a density of 50kg / m³, representing a 20-fold expansion compared to the original sheets. SEM analysis of the cross-section revealed an average pore size of 50μm. The foamed sheets passed the UL94 flammability test, achieving a V0 flammability rating and a limiting oxygen index of 26%. Example 2

[0040] 100 parts of polyphenylene oxide (PPO) (Bluestar LXR045, MI (315℃ / 10 kg) at 10 g / 10 min), 20 parts of nylon 6 (Ube 1013B), 10 parts of compatibilizer SMA (Huawen Chemical SMA-725), 20 parts of antioxidant (BASF antioxidant 168: BASF antioxidant 1010 in a 2:1 ratio) were selected and thoroughly dried before being mixed in a high-speed mixer. The mixture was then compounded and extruded through a co-rotating twin-screw extruder. The feeding section temperature was 265-270℃, the melting section temperature was 270-280℃, and the metering section temperature was 280-285℃. The main feed rate of the extruder was 50 kg / h, the screw speed was 180 rpm, and the die pressure was 6-8 MPa. The molten material was extruded into a continuous sheet with a width of 150 mm and a thickness of 10 mm, with no obvious internal defects.

[0041] Modified PPO sheets were cut into 150×150×10mm samples and placed in a hot press cavity (200×200×15mm) maintained at 195℃. After replacing the air in the cavity, carbon dioxide was introduced to a supercritical state, and the pressure was controlled at 13MPa for 1 hour. The pressure was then released from 13MPa to 0 MPa at a rate of 50MPa / s using a pneumatic ball valve. The cavity was then opened, yielding PPO foamed sheets. Testing showed a density of 100kg / m³, representing a 10-fold expansion compared to the original sheets. SEM analysis of the cross-section revealed an average pore size of 20μm. The foamed sheets passed the UL94 flammability test, achieving a V0 flammability rating and a limiting oxygen index of 29%. Example 3

[0042] 100 parts of polyphenylene oxide (PPO) (Bluestar LXR050, MI (315℃ / 10 kg) at 5 g / 10 min), 25 parts of nylon 6 (Ube 1013B), 13 parts of compatibilizer SMA (Huawen Chemical SMA-725), 20 parts of antioxidant (BASF antioxidant 168: BASF antioxidant 1010 in a 2:1 ratio) were selected and thoroughly dried before being mixed in a high-speed mixer. The mixture was then compounded and extruded through a co-rotating twin-screw extruder. The feeding section temperature was 265-270℃, the melting section temperature was 270-280℃, and the metering section temperature was 280-285℃. The main feed rate of the extruder was 50 kg / h, the screw speed was 180 rpm, and the die pressure was 6-8 MPa. The molten material was extruded into a continuous sheet with a width of 150 mm and a thickness of 9 mm, with no obvious internal defects.

[0043] Modified PPO sheets were cut into 150×150×9mm samples and placed in a hot press cavity (200×200×15mm) maintained at 195℃. After replacing the air in the cavity, carbon dioxide was introduced to a supercritical state, and the pressure was controlled at 15MPa for 1.5 hours. The pressure was then released from 15MPa to 0 MPa at a rate of 40MPa / s using a pneumatic ball valve. The cavity was then opened, yielding PPO foamed sheets. Testing showed a density of 80kg / m³, representing a 13.5-fold expansion compared to the original sheets. SEM analysis of the cross-section revealed an average pore size of 30μm. The foamed sheets passed the UL94 flammability test, achieving a V0 flammability rating and a limiting oxygen index of 28%. Comparative Example 1

[0044] Comparative Example 1 is a comparative example of Example 1, with nylon 6 and compatibilizer removed from the original formulation. 100 parts of polyphenylene oxide (PPO) (Bluestar LXR050, MI (315℃ / 10 kg) of 5 g / 10 min) and 1 part of antioxidant (BASF antioxidant 168: BASF antioxidant 1010 in a 2:1 ratio) were selected, and after thorough drying, they were extruded into a continuous sheet with no obvious internal defects using the processing technology of Example 1.

[0045] The board was placed in the mold cavity of a hot press maintained at a constant temperature of 185℃. After displacing the air in the mold cavity, carbon dioxide was introduced until it reached a supercritical state, and the pressure was controlled at 16MPa for 1 hour of pressure infiltration. The pressure in the mold cavity was then released from 16MPa to 0 at a rate of 30MPa / s using a pneumatic ball valve. The mold cavity was then opened, yielding a PPO foamed board. Testing showed that the board density was 350kg / m³, representing a 3-fold expansion compared to the original board, indicating a low foaming ratio.

[0046] Repeat the above foaming process, increasing the foaming temperature to obtain a higher expansion ratio. Raising the foaming temperature to 195℃ yields PPO foamed boards with a density of 225 kg / m³, which expands 4.8 times compared to the original boards, resulting in a low expansion ratio.

[0047] Further increasing the foaming temperature revealed that unmodified PPO had a foaming ratio of 3 to 4.8 times at 185℃ to 205℃, which was low and did not meet the usage requirements of the target market. Comparative Example 2

[0048] The resin ratio of Comparative Example 2 is basically the same as that of Example 1, except that the foaming method is changed and the traditional method of adding foaming agent is used for foaming.

[0049] 100 parts of polyphenylene oxide (PPO) (Bluestar LXR050, MI (315℃ / 10 kg) at 5 g / 10 min), 30 parts of nylon 6 (Ube 1013B), 15 parts of compatibilizer SMA (Huawen Chemical SMA-700), 1 part of antioxidant (BASF antioxidant 168: BASF antioxidant 1010 in a 2:1 ratio), and 10 parts of foaming agent azodicarbonamide were selected. All raw materials were in powder form of the same brand. After being fully dried, they were mixed using a high-speed mixer. The mixture was then pressed into shape using a flat vulcanizing machine at a pressing temperature of 120-150℃, a surface pressure of 6-10 MPa, and a pressing time of 30-45 min. After thorough degassing, pressing, cooling, and demolding, a 150×150×8 mm foamed board with no obvious internal defects was obtained.

[0050] The foamed board was placed in the mold cavity of a hot press at a constant temperature of 185℃. The mold cavity dimensions were 200×200×15mm. After foaming for 1 hour, the mold cavity was opened to obtain PPO foamed board. The board density was tested to be 687kg / m³, which is 1.5 times larger than the original board. The foaming ratio is low and does not meet the requirements of the target market.

[0051] The above provides a detailed description of the preparation method and application of a modified polyphenylene ether foam board provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention, including the best mode, and also to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the textual description of the claims, or if they include equivalent structural elements that are not substantially different from the textual description of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A method for preparing modified polyphenylene ether foamed board, characterized in that: The following ingredients are included by weight: 100 parts polyphenylene ether; 20-30 parts Nylon 6; 10-15 parts compatibilizer; 0.5-1 part antioxidant; The specific preparation steps are as follows: 1) After thoroughly drying the polyphenylene ether resin, nylon 6, compatibilizer, and antioxidant, mix them, melt-blend them using a twin-screw extruder, and then extrude them through a die to form the polyphenylene ether preform to be foamed and modified. 2) Place the polyphenylene oxide preform to be foamed into a mold cavity at a constant temperature T, fill it with supercritical fluid for infiltration and swelling, and reach an equilibrium state. Then, through rapid depressurization and foaming, a polyphenylene oxide foam board with a foaming ratio of 10-20 times is obtained.

2. The method for preparing a modified polyphenylene ether foam board according to claim 1, characterized in that: The polyphenylene ether has a glass transition temperature of 211℃, a density of 1.06g / ml, a melt flow rate of 4-15g / 10min, and is tested under the following conditions: 315℃ / 10kg. The polyphenylene ether is Bluestar LXR045 or LXR050. The nylon 6 has a density of 1.13-1.14 g / ml, a melt flow rate of 2.6-2.8 g / 10 min, and is tested under the following conditions: 260°C / 2.16 kg. The compatibilizer is a polymer containing maleic anhydride groups, specifically a styrene-maleic anhydride copolymer (SMA) and polyphenylene ether grafted with maleic anhydride (PPO-g-MAH). The antioxidants are antioxidant 168 and antioxidant 1010, which are compounded in a 2:1 ratio.

3. The method for preparing a modified polyphenylene ether foam board according to claim 1, characterized in that: The melt blending extrusion method described in step 1) includes twin-screw melt blending extrusion; The temperature of the melt blend extrusion is 265-285℃; The screw speed for the melt blending extrusion is 80~200 rpm; The die is a coat hanger type die, and the thickness of the modified polyphenylene ether preform is 8-10mm.

4. The method for preparing a modified polyphenylene ether foamed board according to claim 1, characterized in that: Step 2) Place the modified polyphenylene ether masterbatch in a mold cavity at a constant temperature T. The temperature T is lower than the glass transition temperature Tg of polyphenylene ether, specifically 185℃-195℃.

5. The method for preparing a modified polyphenylene ether foamed board according to claim 1, characterized in that: Step 2) The supercritical fluid used is supercritical N2 and / or CO2, the supercritical fluid pressure is 7.2-20 MPa, and the swelling equilibrium time is 1-1.5 h.

6. The method for preparing a modified polyphenylene ether foam board according to claim 1, characterized in that: Step 2) By depressurizing and foaming, the pressure in the system is directly depressurized to 0, with a depressurization rate of 10-80 MPa / s.

7. The method for preparing a modified polyphenylene ether foam board according to claim 1, characterized in that: Step 2) The density of the polyphenylene ether foamed board prepared by depressurization foaming is 50-100 g / L, and it expands 10-20 times relative to the blank board.

8. The method for preparing a modified polyphenylene ether foam board according to claim 1, characterized in that: Step 2) The polyphenylene ether foam board prepared by depressurization foaming has a cell diameter of 20-50μm, a limiting oxygen index of 26-29%, and a flame retardant rating of UL94-V0.

9. The application of the modified polyphenylene ether foamed board prepared by the method as described in claim 1, characterized in that: Used to prepare materials for 5G communication, power batteries and new energy vehicles.