Modified polyphenyl ether foam material and preparation method thereof

Abstract

The invention discloses a modified polyphenyl ether foam material and a preparation method thereof, and belongs to the technical field of polyphenyl ether foam materials. The foam material is prepared from the following components in percentage by mass: 60 to 90 percent of polyphenyl ether, 5 to 35 percent of nylon, 1 to 10 percent of compatilizer, 0.05 to 5 percent of antioxidant, 0.05 to 0.5 percent of lubricant and 1 to 10 percent of porous filler, and the porous filler is hydrotalcite-like compound or artificial zeolite. The preparation method comprises the following steps: drying and blending the raw materials, and performing extrusion molding to obtain a plate; carrying out vacuum drying on the plate and carrying out constant-temperature and constant-pressure pretreatment; saturation and rapid pressure relief foaming are performed in supercritical carbon dioxide. By introducing the specific porous filler and combining with an optimized pretreatment process, the adsorption capacity and adsorption efficiency of a polyphenyl ether matrix to carbon dioxide are remarkably improved, and the technical problems of low foaming ratio and uneven pores caused by poor adsorption capacity of polyphenyl ether are effectively solved; and the polyphenyl ether foam material with high foaming ratio and uniform and fine pores is successfully prepared.

Description

Technical Field

[0001] This invention relates to the field of polyphenylene ether materials technology, and more specifically, to a modified polyphenylene ether foam material and its preparation method. Background Technology

[0002] Polyphenylene oxide (PPO) is a non-crystalline polymer obtained by oxidative coupling polymerization of 2,6-dimethylphenol. It is one of the five major general-purpose engineering plastics, possessing excellent mechanical strength, heat resistance, outstanding insulation, flame retardancy, and dimensional stability. However, the PPO macromolecule contains a benzene ring structure, resulting in poor chain flexibility and high temperature dependence. Consequently, PPO exhibits poor melt flowability and a tendency to stress cracking, limiting its widespread application in many fields. Industrially, PPO is often modified by blending it with materials such as nylon. This improves the processing performance and solvent resistance of PPO while enhancing the heat resistance and dimensional stability of nylon, thus achieving a complementary advantage.

[0003] Supercritical CO2 is the most commonly used supercritical fluid in industry, mainly due to its non-toxic, non-flammable, and chemically stable properties, as well as its low critical point, making it easier to achieve a supercritical state. Therefore, it is widely used in the field of polymer microporous foaming. Microporous foaming can achieve both material lightweighting and the imbuing of functionalities, such as thermal insulation, sound insulation, dielectric reduction, and shock absorption. However, polyphenylene ether has a rigid main chain structure and high melt viscosity, requiring stringent requirements for foaming equipment and process control, making it difficult to prepare microporous materials with high foaming ratios.

[0004] Chinese invention patent CN119859359A discloses a novel nested structure of polyphenylene ether / polystyrene foam beads and its preparation method. By utilizing the sea-island structure formed by polypropylene in a polyphenylene ether / polystyrene matrix, and through foaming, the foam cell structure is redesigned, resulting in a polypropylene film interior and a polyphenylene ether / polystyrene structure exterior, thus reducing the foaming temperature required for polyphenylene ether foam beads. Chinese invention patent CN119931314A discloses a flame-retardant polyphenylene ether foam material and its preparation method. It improves the processing fluidity of the polyphenylene ether matrix by blending with polyvinyl chloride resin and enhances the fire-retardant properties of the polyphenylene ether foam by adding aminophosphonate flame retardants. Chinese invention patent CN109867942A discloses a method for preparing a flame-retardant micro-foamed polyphenylene ether composite material. Through control of raw material ratios and process conditions, and by heating and foaming, a micro-foamed polyphenylene ether composite material with high expansion ratio and excellent flame-retardant properties is prepared.

[0005] In the physical foaming process, the polymer's adsorption capacity for blowing agents such as CO2 affects the final expansion ratio of the material. However, the adsorption of blowing agents by polyphenylene ether (PPE) mainly relies on physical adsorption, and its binding force with CO2 is much weaker than that of chemical adsorption (such as the formation of carbamates from CO2 by amine compounds), resulting in a low CO2 adsorption capacity. Furthermore, for polymers that rely on physical adsorption, the presence of moisture occupies voids and adsorption sites, severely reducing the CO2 adsorption capacity of PPE. Therefore, improving the adsorption capacity and efficiency of PPE for blowing agents during gas saturation is one of the effective means to address its low expansion ratio and poor cell morphology. Currently, there are relatively few studies on the gas adsorption capacity of PPE systems. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the first objective of this invention is to provide a modified polyphenylene ether foam material, which, by mass percentage, comprises the following raw material components: 60-90% polyphenylene ether, 5-35% nylon, 1-10% compatibilizer, 0.05-5% antioxidant, 0.05-0.5% lubricant, and 1-10% porous filler; wherein the porous filler is a hydrotalcite-like material or artificial zeolite.

[0007] Compared with existing technologies, this invention addresses the problem of low gas adsorption capacity and limitations on foaming ratio improvement in polyphenylene ether (PPE) systems. Through innovative raw material formulation design, it introduces 1-10% of specific porous fillers (such as hydrotalcite-like materials or synthetic zeolites) into the blend system, providing a fundamental basis for improving the gas adsorption performance of the material. These porous fillers, with their abundant micro- and nano-pores and large specific surface area, construct additional physical adsorption sites within the polymer matrix, effectively capturing and accommodating more carbon dioxide gas. This directly compensates for the inherent deficiency of pure PPE due to its high molecular chain rigidity and small free volume, resulting in insufficient gas adsorption capacity.

[0008] In one possible implementation, the average particle size of the hydrotalcite-like material is 1-10 μm.

[0009] Given the limited research on gas adsorption in existing polyphenylene ether (PPE) systems, this invention specifically limits the average particle size of the porous filler (such as hydrotalcite-like material) to 1-10 μm. This particle size range aims to balance specific surface area and dispersibility: micron-sized fillers maintain a high specific surface area to provide sufficient gas adsorption sites while achieving good dispersion within the PPE matrix, avoiding a reduction in the effective adsorption interface due to agglomeration. This particle size control optimizes the gas adsorption efficiency of the filler in the polymer from the perspective of its physical morphology, providing a practical materials science approach to solving the common problem of insufficient carbon dioxide adsorption capacity in PPE.

[0010] In one possible implementation, the nylon is nylon 6 and / or nylon 66.

[0011] In one possible implementation, the compatibilizer is a polyphenylene ether-grafted maleic anhydride copolymer; the antioxidant is a 1:1 mixture of antioxidant 168 and antioxidant 1010; and the lubricant is selected from calcium stearate, zinc stearate, and magnesium stearate.

[0012] Compared to existing technologies, this invention addresses the inherent limitations of polyphenylene ether (PPE) matrix gas adsorption capacity by blending nylon 6 / 66 with PPO and using a PPO-g-MAH compatibilizer. This aims to improve the interfacial bonding between the two phases, creating structural conditions for gas diffusion and adsorption in a more uniform matrix with fewer defects. Simultaneously, a specifically formulated antioxidant and lubricant system effectively inhibits the thermal degradation of the PPE matrix and improves melt flowability during processing. This not only protects the surface structure and adsorption activity of the porous filler but also indirectly ensures the full realization of the synergistic adsorption efficiency of the matrix and filler by optimizing the stability of the blending process, providing crucial assistance in improving overall gas adsorption efficiency.

[0013] A second objective of this invention is to provide a method for preparing a modified polyphenylene ether foam material, the method comprising the following steps: S1: Polyphenylene ether, nylon, compatibilizer, antioxidant, lubricant and porous filler are vacuum dried and then mixed evenly to obtain a mixed raw material. The mixed raw material is made into modified polyphenylene ether sheets by melt blending extrusion using a twin-screw extruder. S2: After vacuum drying, the modified polyphenylene ether sheet is placed in a mold cavity with constant temperature and pressure for pretreatment. S3: The pretreated modified polyphenylene ether board is placed in the mold cavity of a constant-temperature foaming equipment, filled with supercritical fluid for saturation, and after reaching equilibrium, foaming is carried out by rapid depressurization to obtain the modified polyphenylene ether foam material.

[0014] Addressing the current lack of research on pathways to enhance the gas adsorption capacity of polyphenylene ether (PPE) systems in existing technologies, this invention provides a preparation method that constructs a preparation pathway aimed at fundamentally optimizing gas adsorption efficiency through a systematic process of vacuum drying, melt blending, and sheet pretreatment. Specifically, the pretreatment process in step S2 is not simply preheating or prepressurizing; rather, under specific temperature and pressure conditions, it optimizes the accessibility of the filler pores and the free volume distribution within the matrix by promoting interfacial wetting and stress release between the porous filler and the PPE-nylon matrix. This pre-regulates and enhances the overall physical adsorption potential of the material before foaming. This method, through process innovation, directly addresses the microscopic mechanism of synergistic adsorption between the filler and the matrix, providing a systematic solution to the long-standing technical bottlenecks of weak physical adsorption capacity, low expansion ratio, and high moisture sensitivity of porous fillers in PPE, significantly enhancing the material's capacity to accommodate and retain foaming agents.

[0015] In one possible implementation, the parameters for the melt blending extrusion in step S1 are as follows: temperature 250-290℃, screw speed 80-160rpm, and residence time 5-8min.

[0016] Compared with existing technologies, this invention aims to create key process conditions for the efficient bonding of porous fillers and polyphenylene ether-nylon matrices by setting the melt blending extrusion parameters within a specific range. The sufficient residence time under this temperature and rotation speed combination ensures that the nylon is fully melted and the compatibilizer functions effectively, allowing the porous filler to be uniformly dispersed and well coated by the polymer matrix, avoiding filler agglomeration or interfacial defects. This process not only optimizes the dispersion state of the porous filler to maintain its adsorption activity, laying a uniform and stable microstructural foundation for subsequent gas diffusion in the matrix and adsorption on the filler; simultaneously, the uniformly dispersed porous filler also provides heterogeneous nucleation sites for the subsequent foaming process, improving the cell structure of the foam material.

[0017] In one possible implementation, in step S1, the thickness of the modified polyphenylene ether sheet is 5-15 mm.

[0018] To address the current lack of research on the gas adsorption mechanism of polyphenylene ether (PPE) systems, this invention limits the thickness of the modified PPE sheet to 5-15 mm, aiming to establish favorable geometric conditions for gas adsorption and diffusion during the subsequent foaming stage. This thickness range effectively balances the required depth for saturated gas penetration within the sheet with the uniform control of gas desorption and expansion during foaming. Too thin a sheet may lead to rapid gas escape and low material expansion, while too thick a sheet can cause excessively large gas concentration and temperature gradients between the inner and outer layers, resulting in uneven foaming. This limitation optimizes the adsorption-foaming mass transfer path at the physical scale, facilitating efficient and uniform gas adsorption in the matrix and porous filler, and providing structural assurance for improving overall foaming quality.

[0019] In one possible implementation, the pretreatment parameters in step S2 are as follows: pressure 0.1-2 MPa, temperature 50°C, time t=30+10(d-5) min, where d is the thickness of the modified polyphenylene ether sheet in mm.

[0020] The vacuum drying and low-pressure pretreatment parameters set in this invention aim, on the one hand, to increase the CO2 adsorption capacity of polyphenylene ether (PPE) composites by eliminating the voids and adsorption sites occupied by moisture within the composite material; on the other hand, they aim to pre-regulate the free volume and interfacial state within the matrix through mild pressure and temperature conditions, achieving initial CO2 adsorption and plasticization of the material and preventing subsequent moisture infiltration. This combination of parameters, particularly the dynamic time control related to the sheet thickness, helps to partially release the internal stress of the blended sheet before foaming, promoting polymer chain relaxation, thereby optimizing the microstructure around the porous filler and within the matrix itself, creating more accessible and stable physical adsorption sites for subsequent carbon dioxide adsorption. This pretreatment is not simply preheating, but a structural pre-adjustment aimed at enhancing the gas adsorption capacity of the PPE blend system.

[0021] In one possible implementation, the temperature of the foaming equipment cavity in step S3 is from Tg-20℃ to Tg+20℃, where Tg is the glass transition temperature of the modified polyphenylene ether sheet.

[0022] Compared to existing technologies, this invention sets the foaming saturation temperature within a specific window near the material's glass transition temperature (Tg), aiming to precisely control the balance between polymer chain mobility and gas adsorption. Within this temperature range, the matrix chains possess moderate mobility, which is beneficial for the diffusion and adsorption of carbon dioxide molecules into the porous filler and matrix, while avoiding excessive chain activity, premature gas escape, or cell coalescence caused by excessively high temperatures. This temperature strategy directly addresses the challenge of slow adsorption kinetics in polyphenylene ether systems, providing crucial thermodynamic conditions for increasing the total amount and rate of gas adsorption and ultimately obtaining a uniform, high-ratio foamed structure.

[0023] In one possible implementation, the supercritical fluid in step S3 is supercritical carbon dioxide, with a saturation pressure of 10-20 MPa and a saturation time of t = 30 + 30(d-5) min, where d is the thickness of the modified polyphenylene ether sheet in mm.

[0024] Compared with existing technologies, this invention uses supercritical carbon dioxide as a foaming agent and sets a saturation pressure of 10-20 MPa to leverage its excellent permeability and dissolving ability to promote deep diffusion and adsorption of gas into the porous filler and polymer matrix. Simultaneously, by dynamically adjusting the saturation time based on the sheet thickness, it ensures that the gas reaches a sufficient and uniform adsorption equilibrium across the entire sheet cross-section, overcoming the problem of uneven adsorption between the interior and exterior of the polyphenylene ether matrix caused by high diffusion resistance and slow adsorption. This process design provides key parameter guarantees for fundamentally improving the total gas adsorption and adsorption efficiency of the polyphenylene ether composite system. Attached Figure Description

[0025] Figure 1 This is a photograph of the cross-sectional cell morphology of the polyphenylene ether foam material obtained in Example 3 along the thickness direction; Figure 2 This is a photograph of the cross-sectional cell morphology of the polyphenylene ether foam material obtained in Example 3 in the horizontal direction. Detailed Implementation

[0026] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. It should be noted that the following embodiments are only used to illustrate the implementation methods and typical parameters of the present invention, and are not intended to limit the parameter range described in the present invention. Reasonable variations derived therefrom are still within the protection scope of the claims of the present invention.

[0027] It should be noted that the endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0028] Unless otherwise defined, all terms, symbols, and other scientific terms used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In some instances, terms having a conventional meaning are defined herein for clarification or ease of reference, and such definitions should not be construed as indicating a significant difference from conventional understanding in the art. The technical methods described or referenced herein are generally well understood by those skilled in the art and employed by conventional methods. Unless otherwise stated, the use of commercially available kits, reagents, and instruments shall be performed according to the manufacturer's instructions and parameters.

[0029] Example 1 This embodiment provides a modified polyphenylene ether foam material, which, by mass percentage, consists of: 75% polyphenylene ether, 15% nylon 66, 4% polyphenylene ether grafted maleic anhydride copolymer (PPO-g-MAH), 0.5% antioxidant (antioxidant 168: antioxidant 1010 = 1:1), 0.5% zinc stearate, and 5% hydrotalcite.

[0030] The preparation method is as follows: After vacuum drying all the above raw materials at 90°C for 6 hours, they are mixed evenly in proportion.

[0031] The process involves melt blending and extrusion using a twin-screw extruder with the following parameters: temperature 250-290℃, screw speed 160rpm, material residence time 5min, and extrusion and molding into a 5mm thick sheet.

[0032] The board was vacuum dried at 80℃ for 4 hours, and then placed in the mold cavity for pretreatment at a pressure of 1MPa and a temperature of 50℃. The pretreatment time was calculated according to the formula t=30+10*(5-5)=30min.

[0033] The pretreated board was placed in the foaming mold cavity, and the temperature was set to 200℃, which is within the range of Tg (207℃ measured by DSC) ± 20℃ of the modified polyphenylene ether board. Supercritical carbon dioxide was introduced, with a saturation pressure of 20MPa, and the saturation time was calculated according to the formula t = 30 + 30*(5-5) = 30min. After reaching equilibrium, the pressure was rapidly released for foaming.

[0034] Figure 1 This is a photograph of the cross-sectional cell morphology of the polyphenylene ether foam material obtained in Example 1 along the thickness direction; Figure 2 This is a photograph of the cross-sectional cell morphology of the polyphenylene ether foam material obtained in Example 1 in the horizontal direction.

[0035] Example 2 This embodiment provides a modified polyphenylene ether foam material, which, by mass percentage, consists of: 75% polyphenylene ether, 15% nylon 66, 4% polyphenylene ether grafted maleic anhydride copolymer (PPO-g-MAH), 0.5% antioxidant (antioxidant 168: antioxidant 1010 = 1:1), 0.5% zinc stearate, and 5% hydrotalcite.

[0036] The preparation method is as follows: All the above raw materials were vacuum dried at 100°C for 8 hours and then mixed evenly.

[0037] The process involves melt blending and extrusion using a twin-screw extruder with the following parameters: temperature 250-290℃, screw speed 80rpm, material residence time 8min, and extrusion and molding into a 15mm thick sheet.

[0038] The board was vacuum dried at 85℃ for 6 hours, and then placed in the mold cavity for pretreatment at a pressure of 1MPa and a temperature of 50℃. The pretreatment time was t=30+10*(15-5)=130min.

[0039] The pretreated board is placed in the foaming mold cavity, and the temperature is set to the Tg of the modified polyphenylene ether board (206℃) + 10℃, i.e., 216℃. Supercritical carbon dioxide is introduced, the saturation pressure is 20MPa, and the saturation time is t = 30 + 30*(15-5) = 330min. After reaching equilibrium, the pressure is rapidly released for foaming.

[0040] Example 3 This embodiment provides a modified polyphenylene ether foam material, which, by mass percentage, consists of: 75% polyphenylene ether, 15% nylon 66, 4% polyphenylene ether grafted maleic anhydride copolymer (PPO-g-MAH), 0.5% antioxidant (antioxidant 168: antioxidant 1010 = 1:1), 0.5% zinc stearate, and 5% hydrotalcite.

[0041] The preparation method is as follows: The raw materials are mixed after being vacuum dried.

[0042] The process involves melt blending and extrusion using a twin-screw extruder with the following parameters: temperature 250-290℃, screw speed 120rpm, material residence time 6.5min, and extrusion and molding into a 10mm thick sheet.

[0043] After vacuum drying, the sheet material is placed in a mold cavity and pretreated at a pressure of 1 MPa and a temperature of 50℃ for a time of t = 30 + 10 * (10 - 5) = 80 min.

[0044] The pretreated board was placed in the foaming mold cavity, and the temperature was set to the Tg of the modified polyphenylene ether board (207℃). Supercritical carbon dioxide was introduced, the saturation pressure was 20MPa, and the saturation time was t=30+30*(10-5)=180min. After reaching equilibrium, the pressure was rapidly released for foaming.

[0045] Example 4 This embodiment provides a modified polyphenylene ether foam material, which, by mass percentage, consists of: 75% polyphenylene ether, 15% nylon 66, 4% polyphenylene ether grafted maleic anhydride copolymer (PPO-g-MAH), 0.5% antioxidant (antioxidant 168: antioxidant 1010 = 1:1), 0.5% zinc stearate, and 5% synthetic zeolite.

[0046] The preparation method is as follows: The raw materials are mixed after being vacuum dried.

[0047] The process involves melt blending and extrusion using a twin-screw extruder with the following parameters: temperature 250-290℃, screw speed 120rpm, material residence time 6.5min, and extrusion and molding into a 10mm thick sheet.

[0048] After vacuum drying, the sheet material is placed in a mold cavity and pretreated at a pressure of 1 MPa and a temperature of 50℃ for a time of t = 30 + 10 * (10 - 5) = 80 min.

[0049] The pretreated board was placed in the foaming mold cavity, and the temperature was set to the Tg of the modified polyphenylene ether board (206℃). Supercritical carbon dioxide was introduced, the saturation pressure was 20MPa, and the saturation time was t=30+30*(10-5)=180min. After reaching equilibrium, the pressure was rapidly released for foaming.

[0050] Example 5 This embodiment provides a modified polyphenylene ether foam material, which, by mass percentage, consists of: 75% polyphenylene ether, 10% nylon 66, 4% polyphenylene ether-grafted maleic anhydride copolymer (PPO-g-MAH), 0.5% antioxidant (antioxidant 168: antioxidant 1010 = 1:1), 0.5% zinc stearate, and 10% hydrotalcite-like material. The preparation method is as follows: The raw materials are mixed after being vacuum dried.

[0051] The process involves melt blending and extrusion using a twin-screw extruder with the following parameters: temperature 250-290℃, screw speed 120rpm, material residence time 6.5min, and extrusion and molding into a 10mm thick sheet.

[0052] After vacuum drying, the sheet material is placed in a mold cavity and pretreated at a pressure of 1 MPa and a temperature of 50℃ for a time of t = 30 + 10 * (10 - 5) = 80 min.

[0053] The pretreated board was placed in the foaming mold cavity, and the temperature was set to the Tg of the modified polyphenylene ether board (209℃). Supercritical carbon dioxide was introduced, the saturation pressure was 20MPa, and the saturation time was t=30+30*(10-5)=180min. After reaching equilibrium, the pressure was rapidly released for foaming.

[0054] Comparative Example 1 This comparative example provides a modified polyphenylene ether foam material, differing from Example 3 only in that the raw materials in this comparative example do not contain hydrotalcite-like substances. Specifically, by mass percentage, the raw material composition is: 80% polyphenylene ether, 15% nylon 66, 4% polyphenylene ether grafted maleic anhydride copolymer (PPO-g-MAH), 0.5% antioxidant (antioxidant 168: antioxidant 1010 = 1:1), and 0.5% zinc stearate. Other aspects are the same as in Example 3 and will not be repeated here.

[0055] Comparative Example 2 This comparative example provides a modified polyphenylene ether foam material, which differs from Example 3 only in that the mass percentage of hydrotalcite-like material in the raw materials of this comparative example is 15%. Specifically, by mass percentage, the raw material composition is: 69% polyphenylene ether, 15% nylon 66, 4% polyphenylene ether grafted maleic anhydride copolymer (PPO-g-MAH), 0.5% antioxidant (antioxidant 168: antioxidant 1010 = 1:1), 0.5% zinc stearate, and 15% hydrotalcite-like material.

[0056] Comparative Example 3 This comparative example provides a modified polyphenylene ether foam material. The only difference between this comparative example and Example 3 is that the saturation pressure of this comparative example is 10 MPa. Everything else is the same as Example 3, and will not be repeated here.

[0057] Comparative Example 4 This comparative example provides a modified polyphenylene ether foam material, which differs from Example 3 only in that no pretreatment was performed during the preparation process. The preparation method is as follows: The raw materials are mixed after being vacuum dried.

[0058] The process involves melt blending and extrusion using a twin-screw extruder with the following parameters: temperature 250-290℃, screw speed 120rpm, material residence time 6.5min, and extrusion and molding into a 10mm thick sheet.

[0059] The board is placed in the foaming mold cavity, and the temperature is set to the Tg of the modified polyphenylene ether board (207℃). Supercritical carbon dioxide is introduced, the saturation pressure is 20MPa, and the saturation time is t=30+30*(10-5)=180min. After reaching equilibrium, the pressure is rapidly released for foaming.

[0060] Everything else is the same as in Example 3, and will not be repeated here.

[0061] The gas adsorption capacity of Examples 1-5 and Comparative Examples 1-4 was tested. The test method for gas adsorption capacity is as follows: First, accurately weigh the sample and record it as m0 (g). After depressurizing the reactor, record the time, and then quickly remove the foamed sample and place it on a balance for accurate weighing, recording it as m. t (g) Record the weight of the foamed sample at different times. Record the mass change of the foamed sample over time. Calculate the gas adsorption capacity (S) according to the formula: The expansion ratio is calculated by dividing the density of the sample before foaming by the density after foaming.

[0062] The test results are shown in the table below: As shown in Table 1, the modified polyphenylene ether composite material prepared in this invention has a density of less than 80 kg / m³. 3 The foamed material, samples of different thicknesses, all showed good expandability.

[0063] Meanwhile, comparing Examples 1-5 with Comparative Example 1, it can be found that by adding porous fillers for modification, the CO2 adsorption capacity of the composite material during the gas saturation process can be improved, thus realizing the preparation of polyphenylene ether foam with high expansion ratio.

[0064] Comparing Examples 3 and 5 with Comparative Example 2, it can be observed that as the amount of porous filler added increases, the CO2 adsorption capacity gradually increases, but the expansion ratio shows a negative correlation trend. On the one hand, when a large amount of porous filler is added, there is an aggregation phenomenon, which limits the improvement of gas adsorption capacity. On the other hand, the introduction of high content of porous filler will significantly increase the modulus of the polymer, resulting in excessively high matrix melt strength and hindering cell growth.

[0065] Comparative Example 3, with its lower saturation pressure, still yielded products with a density less than 80 kg / m³. 3 The foaming material indicates that the modified polyphenylene ether composite material of the present invention has good expandability.

[0066] Comparative Example 4, without pretreatment, showed a lower CO2 adsorption capacity compared to Example 3. This is because the porous packing material exhibits strong electrostatic interactions, causing water molecules to be preferentially adsorbed during processing, thus affecting its selectivity and leading to a decrease in CO2 adsorption performance. Therefore, appropriate pretreatment is necessary.

[0067] While the disclosure is as stated above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this invention.

Claims

1. A modified polyphenylene ether foam material, characterized in that, The modified polyphenylene ether foam material comprises, by weight percentage, the following raw material components: 60-90% polyphenylene ether, 5-35% nylon, 1-10% compatibilizer, 0.05-5% antioxidant, 0.05-0.5% lubricant and 1-10% porous filler; the porous filler is hydrotalcite-like or artificial zeolite.

2. The modified polyphenylene ether foam material as described in claim 1, characterized in that, The average particle size of the hydrotalcite-like material is 1-10 μm.

3. The modified polyphenylene ether foam material as described in claim 1, characterized in that, The nylon is nylon 6 and / or nylon 66.

4. The modified polyphenylene ether foam material as described in claim 1, characterized in that, The compatibilizer is a polyphenylene ether-grafted maleic anhydride copolymer; the antioxidant is a mixture of antioxidant 168 and antioxidant 1010 in a 1:1 ratio; the lubricant is selected from calcium stearate, zinc stearate and magnesium stearate.

5. A method for preparing a modified polyphenylene ether foam material, characterized in that, The preparation method includes the following steps: S1: Polyphenylene ether, nylon, compatibilizer, antioxidant, lubricant and porous filler are vacuum dried and then mixed evenly to obtain a mixed raw material. The mixed raw material is made into modified polyphenylene ether sheets by melt blending extrusion using a twin-screw extruder. S2: After vacuum drying, the modified polyphenylene ether sheet is placed in a mold cavity with constant temperature and pressure for pretreatment. S3: The pretreated modified polyphenylene ether board is placed in the mold cavity of a constant-temperature foaming equipment, filled with supercritical fluid for saturation, and after reaching equilibrium, foaming is carried out by rapid depressurization to obtain the modified polyphenylene ether foam material.

6. The preparation method according to claim 5, characterized in that, The parameters for melt blending extrusion in step S1 are as follows: temperature 250-290℃, screw speed 80-160rpm, residence time 5-8min.

7. The preparation method according to claim 5, characterized in that, In step S1, the thickness of the modified polyphenylene ether sheet is 5-15 mm.

8. The preparation method according to claim 5, characterized in that, The pretreatment parameters in step S2 are as follows: pressure is 0.1-2 MPa, temperature is 50℃, and time is t=30+10(d-5)min, where d is the thickness of the modified polyphenylene ether sheet in mm.

9. The preparation method according to claim 5, characterized in that: The temperature of the foaming equipment cavity in step S3 is from Tg-20℃ to Tg+20℃, where Tg is the glass transition temperature of the modified polyphenylene ether board.

10. The preparation method according to claim 5, characterized in that, The supercritical fluid mentioned in step S3 is supercritical carbon dioxide, with a saturation pressure of 10-20 MPa and a saturation time of t = 30 + 30(d-5) min, where d is the thickness of the modified polyphenylene ether sheet in mm.

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