Lightweight ppo / pa foam and method for producing same

Abstract

This application discloses a lightweight PPO / PA foam material and its preparation method, relating to the field of polymer foam material technology. The method involves constructing a foaming composition using polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, and epoxy-based reactive additives. After mixing and molding, the foam material is obtained through supercritical carbon dioxide saturation foaming and shaping. Further introduction of flame-retardant fillers composed of bisphenol A bis(diphenyl phosphate), melamine cyanurate amide, and zinc borate, as well as SiO2 aerogel or PTFE low-dielectric fillers, can yield flame-retardant, low-dielectric, and flame-retardant low-dielectric foam materials. The beneficial effects of this application are: it can maintain flame-retardant and low-dielectric properties while maintaining low-density mechanical properties, improve foaming stability and cell structure uniformity, enhance the overall structural continuity and comprehensive level of the molded body, and achieve synergy or combination of flame-retardant and low-dielectric functions.

Description

Technical Field

[0001] This invention relates to the field of polymer foam materials technology, and in particular to a lightweight PPO / PA foam material and its preparation method. Background Technology

[0002] With the increasing demand for lightweight and functionally integrated materials in the fields of new energy vehicles, advanced buildings, aerospace, and electronics and electrical engineering, engineering plastic foam materials that combine heat resistance, dimensional stability, and insulation have attracted more and more attention. Polyphenylene ether resins have high heat resistance, mechanical properties, and electrical insulation properties, and have been widely used in electronic, electrical, and automotive components; however, their molecular chains are relatively rigid and their processing window is relatively limited. Under conventional foaming conditions, they are often prone to problems such as insufficient molding stability, uneven cell structure, and weak material toughness. Therefore, the development of high-performance engineering plastic foam materials and their preparation technologies that combine low density, good structural integrity, and multifunctional characteristics has become an important research direction in this field.

[0003] In existing technologies, one type of approach mainly focuses on the foaming formulation and molding process of engineering plastic systems, such as patent CN101565539A "Foaming Formulation of Polyphenylene Ether," indicating that this type of material has a foundation for foaming applications. Another type of approach employs a pre-foamed granule re-molding method, such as patent CN112384558A "Pre-foamed Polyamide Granules, and Polyamide Foamed Molded Articles and Manufacturing Methods Thereof," reflecting that existing technologies typically obtain foam products through granule pre-foaming and subsequent molding. However, most existing technologies focus on improving a single objective, making it difficult to simultaneously address multiple performance requirements. For basic foaming routes, material weight reduction often results in decreased melt support, coarsened cells, and reduced mechanical properties. For flame-retardant routes, flame-retardant modification can easily interfere with the foaming process, increase melt viscosity, damage cell structure, and reduce molding stability. For low-dielectric routes, adding low-dielectric functional components can help reduce the dielectric constant, but it may also cause uneven system dispersion, reduced structural continuity, or weakened mechanical properties. When flame-retardant and low-dielectric requirements are put forward simultaneously, the above contradictions will be further superimposed, making it difficult to achieve the technical challenges of material systems that must meet both foaming molding requirements and flame-retardant safety and electrical performance control.

[0004] Therefore, there is an urgent need for a technical solution for high-performance engineering plastic foam materials to address the problem of balancing lightweight and mechanical properties during basic foaming in existing systems, the problem of the foam structure and molding stability being easily affected after flame retardant modification alone, the problem of insufficient structural integrity and mechanical properties after low dielectric modification alone, and further the problem of the difficulty in achieving flame retardant and low dielectric properties synergistically in the same material system. This would result in a foam material and its preparation method that combines low density, good structural integrity, high flame retardancy, and low dielectric constant. Summary of the Invention

[0005] To achieve the aforementioned objectives and address the aforementioned technical problems, this invention provides a lightweight PPO / PA foam material and its functionalization solution, the technical solution of which is as follows: The foam material is obtained by supercritical carbon dioxide foaming of a composition comprising polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether and epoxy reactive additives.

[0006] Based on the above technical solutions, the present invention also provides a flame-retardant lightweight PPO / PA foam material. The flame-retardant foam material is obtained by supercritical carbon dioxide foaming of a composition comprising polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, epoxy reactive additives, and flame-retardant fillers; the flame-retardant filler is composed of bisphenol A bis(diphenyl phosphate), melamine cyanurate amide, and zinc borate.

[0007] Based on the above technical solution, the present invention also provides a low-dielectric lightweight PPO / PA foam material. The low-dielectric foam material is obtained by supercritical carbon dioxide foaming of a composition comprising polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, epoxy reactive additives, and a low-dielectric filler; the low-dielectric filler is either SiO2 aerogel or PTFE.

[0008] Based on the above technical solution, the present invention also provides a flame-retardant, low-dielectric, lightweight PPO / PA foam material. The flame-retardant, low-dielectric foam material is obtained by supercritical carbon dioxide foaming of a composition comprising polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, epoxy reactive additives, flame-retardant fillers, and low-dielectric fillers; the flame-retardant filler is composed of bisphenol A bis(diphenyl phosphate), melamine cyanurate amide, and zinc borate; and the low-dielectric filler is either SiO2 aerogel or PTFE.

[0009] Furthermore, the epoxy reactive additive is selected from one of ADR, TGIC, SMG4108 and epoxy linseed oil.

[0010] Furthermore, in some embodiments, the mass parts of polyphenylene ether, polyamide 6, and maleic anhydride-grafted polyphenylene ether in the composition are 60-85 parts, 10-30 parts, and 5-10 parts, respectively, and the amount of epoxy reactive additive added is 0.2-0.6 parts.

[0011] Furthermore, for the flame-retardant lightweight PPO / PA foam material and the flame-retardant low-dielectric lightweight PPO / PA foam material, the mass ratio of bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate is 2:1:1-9:3:4, and the total amount of the three is 18-30 parts.

[0012] Furthermore, for the low-dielectric lightweight PPO / PA foam material and the flame-retardant low-dielectric lightweight PPO / PA foam material, the amount of low-dielectric filler added is 1-3 parts.

[0013] The present invention also provides a method for preparing the above-mentioned lightweight PPO / PA foam material, comprising the following steps: (1) Add polyphenylene ether and polyamide 6 to the torque rheometer, and add maleic anhydride-grafted polyphenylene ether; For flame-retardant lightweight PPO / PA foam materials, add bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate; For low-dielectric lightweight PPO / PA foam materials, add low-dielectric fillers; For flame-retardant, low-dielectric lightweight PPO / PA foam materials, add bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate, and then add low-dielectric filler. After uniform mixing, epoxy reactive additives are added to obtain a mixed sample.

[0014] (2) The compounded sample is molded into a sheet.

[0015] (3) The plate is placed in a supercritical reactor and foamed in a carbon dioxide atmosphere.

[0016] (4) Shape the foamed board to obtain lightweight PPO / PA foam material.

[0017] Furthermore, in some embodiments, before step (1), polyphenylene ether and polyamide 6 are dried at 80-100°C for 2 hours.

[0018] Furthermore, in some embodiments, in step (2), the mixed sample is placed in a flat vulcanizing machine mold and pressed at 220-240°C for 5-10 minutes to prepare a sheet material with a thickness of 8 mm.

[0019] Furthermore, in some embodiments, in step (3), the board is foamed after being saturated at 140-160°C for 2-4 hours in a carbon dioxide atmosphere.

[0020] Furthermore, in some embodiments, in step (4), the foamed board is removed and cooled to set its shape.

[0021] Preferably, in some embodiments, in step (4), the foamed board is taken out and placed in cold water to set.

[0022] The beneficial effects of the technical solution provided by this invention are as follows: This invention first addresses the problems of high brittleness and insufficient foaming stability in PPO foam materials by introducing maleic anhydride-grafted polyphenylene ether and epoxy reactive additives into the PPO / PA system, combined with supercritical carbon dioxide foaming technology. Test results show that this system maintains good mechanical properties while achieving a lower density, indicating that maleic anhydride-grafted polyphenylene ether improves the interfacial compatibility between PPO and PA, while the epoxy reactive additives help improve melt strength and structural stability during foaming, resulting in more uniform and complete cell structure and improved overall material mechanical properties.

[0023] This invention further employs bisphenol A bis(diphenyl phosphate), melamine cyanurate amide, and zinc borate to construct a ternary synergistic flame retardant system, achieving good flame retardant effects at relatively low addition levels. Test results show that this system can improve the flame retardancy level of the material and reduce heat release and smoke production during combustion, indicating that this flame retardant system can simultaneously promote char formation, inhibit heat release, and reduce smoke generation during combustion. Specifically, bisphenol A bis(diphenyl phosphate) improves the processing fluidity of the system, while melamine cyanurate amide and zinc borate, in addition to their flame retardant effects, also provide nucleation sites for the foaming process, thus achieving a balance between flame retardant performance and cell structure stability.

[0024] The invention also achieves effective control of the dielectric properties of the material by introducing PTFE or SiO2 aerogel. Test results show that the dielectric constant of the material decreases both before and after foaming after the addition of low-dielectric filler, with a more significant decrease after foaming. This indicates that the low polarization characteristics of the low-dielectric filler itself and the microporous structure formed by foaming have a superimposed effect on reducing dielectric constant.

[0025] Furthermore, when flame-retardant fillers and low-dielectric fillers are used together, the material can still maintain a high level of flame retardancy and a low dielectric constant, indicating that the two have a good synergistic or balanced effect in the system of this invention. Among them, SiO2 aerogel shows a more obvious flame-retardant-low-dielectric synergistic trend, while the PTFE route shows a better overall balance.

[0026] Furthermore, this invention employs an integrated molding-supercritical foaming process, resulting in a more complete overall structure and more uniform cell distribution in the material, avoiding problems such as insufficient interfacial bonding and poor structural continuity encountered in granular foaming. Thus, this invention achieves a comprehensive balance between lightweight, mechanical properties, flame retardant properties, and low dielectric properties. Attached Figure Description

[0027] Figure 1 This is a SEM image of Embodiment 1 of the present invention.

[0028] Figure 2 This is a SEM image of Embodiment 2 of the present invention.

[0029] Figure 3 This is a SEM image of Embodiment 6 of the present invention.

[0030] Figure 4 This is a SEM image of Embodiment 7 of the present invention.

[0031] Figure 5 This is a SEM image of Embodiment 8 of the present invention.

[0032] Figure 6 This is a SEM image of Embodiment 9 of the present invention.

[0033] Figure 7 This is a SEM image of Embodiment 10 of the present invention.

[0034] Figure 8 SEM images of Comparative Example 2 of the present invention: (a) before foaming; (b) after foaming.

[0035] Figure 9 SEM images of Comparative Example 3 of the present invention: (a) before foaming; (b) after foaming.

[0036] Figure 10 This is the SEM image of Comparative Example 4 of the present invention.

[0037] Figure 11 This is a cross-sectional photograph of the product in Embodiment 10 of the present invention.

[0038] Figure 12 This is a cross-sectional photograph of the product of Comparative Example 2 of the present invention.

[0039] Figure 13 This is a cross-sectional photograph of the product of Comparative Example 5 of the present invention. Detailed Implementation

[0040] The purpose of this invention is to provide a high-performance engineering plastic foam material and its preparation method, so as to solve the technical problems in the prior art that it is difficult to balance the lightweight and mechanical properties of the basic foaming system, the foaming structure and molding stability are easily affected after flame retardant modification alone, the structural integrity and mechanical properties are insufficient after low dielectric modification alone, and the flame retardant properties and low dielectric properties are difficult to achieve synergistically in the same material system.

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Of course, the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0042] Example 1 This embodiment provides a lightweight PPO / PA foam material.

[0043] Specifically, the steps include the following: S1, dry polyphenylene ether and polyamide 6 at 80°C for 2 hours.

[0044] S2, weigh out 60 parts of polyphenylene ether, 30 parts of polyamide 6, and 10 parts of maleic anhydride-grafted polyphenylene ether according to the mass ratio. First, add polyphenylene ether and polyamide 6 to a torque rheometer for mixing, then add maleic anhydride-grafted polyphenylene ether, mix evenly, add 0.6 parts of ADR, and continue mixing until the reaction is complete to obtain the mixed sample.

[0045] S3. Place the mixed sample in a flat vulcanizing machine mold and press it at 230°C for 5 minutes to prepare a sheet.

[0046] S4. The plate is placed in a supercritical reactor and foamed at 16 MPa and 160°C for 2 hours under a carbon dioxide atmosphere.

[0047] S5. The foamed board is removed and placed in cold water to set, resulting in lightweight PPO / PA foam material.

[0048] Example 2 This embodiment provides a flame-retardant, lightweight PPO / PA foam material.

[0049] The procedure is the same as in Example 1, except that: In step S2, after adding maleic anhydride-grafted polyphenylene ether, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate are added. After mixing evenly, SMG4108 is added and mixing is continued to obtain a mixed sample.

[0050] Foaming conditions: 16MPa, 155℃.

[0051] In this embodiment, the mass parts of polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, SMG4108, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate are 60 parts, 30 parts, 10 parts, 0.6 parts, 11.25 parts, 3.75 parts and 10 parts, respectively.

[0052] Example 3 This embodiment provides a flame-retardant, lightweight PPO / PA foam material.

[0053] The procedure is the same as in Example 1, except that: In step S2, after adding maleic anhydride-grafted polyphenylene ether, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate are added. After mixing evenly, ADR is added and mixing is continued to obtain a mixed sample.

[0054] Foaming conditions: 18MPa, 160℃.

[0055] In this embodiment, the mass parts of polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, ADR, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate are 70 parts, 20 parts, 10 parts, 0.4 parts, 10 parts, 3 parts and 5 parts, respectively.

[0056] Example 4 This embodiment provides a flame-retardant, lightweight PPO / PA foam material.

[0057] The procedure is the same as in Example 1, except that: In this embodiment, the mass parts of polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, TGIC, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide, and zinc borate are 85 parts, 10 parts, 5 parts, 0.2 parts, 11.25 parts, 3.75 parts, and 5 parts, respectively.

[0058] Foaming conditions: 16MPa, 160℃.

[0059] In step S2, after adding maleic anhydride-grafted polyphenylene ether, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate are added. After mixing evenly, TGIC is added and mixing is continued to obtain a mixed sample.

[0060] Example 5 This embodiment provides a flame-retardant, lightweight PPO / PA foam material.

[0061] The procedure is the same as in Example 1, except that: In step S2, after adding maleic anhydride-grafted polyphenylene ether, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate are added. After mixing evenly, epoxidized linseed oil is added and mixing is continued to obtain a mixed sample.

[0062] Foaming conditions: 20MPa, 140℃.

[0063] In this embodiment, the mass parts of polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, epoxidized linseed oil, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide, and zinc borate are 65 parts, 25 parts, 10 parts, 0.5 parts, 15 parts, 5 parts, and 10 parts, respectively.

[0064] Example 6 This embodiment provides a low dielectric lightweight PPO / PA foam material.

[0065] The procedure is the same as in Example 1, except that: In step S2, after adding maleic anhydride-grafted polyphenylene ether, PTFE is added, and after mixing evenly, ADR is added and mixing is continued to obtain a mixed sample.

[0066] Foaming conditions: 16MPa, 160℃.

[0067] In this embodiment, the mass parts of polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, ADR, and PTFE are 60 parts, 30 parts, 10 parts, 0.6 parts, and 1 part, respectively.

[0068] Example 7 This embodiment provides a low dielectric lightweight PPO / PA foam material.

[0069] The procedure is the same as in Example 3, except that: In step S2, after adding maleic anhydride-grafted polyphenylene ether, PTFE is added, and after mixing evenly, ADR is added and mixing is continued to obtain a mixed sample.

[0070] Foaming conditions: 18MPa, 160℃.

[0071] In this embodiment, the mass parts of polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, ADR, and PTFE are 70 parts, 20 parts, 10 parts, 0.4 parts, and 3 parts, respectively.

[0072] Example 8 This embodiment provides a low dielectric lightweight PPO / PA foam material.

[0073] The procedure is the same as in Example 4, except that: In step S2, after adding maleic anhydride-grafted polyphenylene ether, SiO2 aerogel is added, and after mixing evenly, TGIC is added and mixing is continued to obtain a mixed sample.

[0074] Foaming conditions: 16MPa, 160℃.

[0075] In this embodiment, the mass parts of polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, TGIC and SiO2 aerogel are 85 parts, 10 parts, 5 parts, 0.2 parts and 3 parts, respectively.

[0076] Example 9 This embodiment provides a flame-retardant, low-dielectric, lightweight PPO / PA foam material.

[0077] The procedure is the same as in Example 3, except that: In step S2, after adding 10 parts of bisphenol A bis(diphenyl phosphate), 3 parts of melamine cyanurate amide and 5 parts of zinc borate, 3 parts of PTFE are added, and after mixing evenly, 0.4 parts of ADR are added and mixing is continued to obtain a mixed sample.

[0078] Example 10 This embodiment provides a flame-retardant, low-dielectric, lightweight PPO / PA foam material.

[0079] The procedure is the same as in Example 4, except that: In step S2, after adding 11.25 parts of bisphenol A bis(diphenyl phosphate), 3.75 parts of melamine cyanurate amide and 5 parts of zinc borate, 3 parts of SiO2 aerogel are added, and after mixing evenly, 0.2 parts of TGIC are added and mixing is continued to obtain a mixed sample.

[0080] Comparative Example 1 This comparative example provides a foam material.

[0081] The procedure is the same as in Example 2, except that: In step S2, only polyphenylene ether is added, excluding polyamide 6, maleic anhydride-grafted polyphenylene ether, epoxy reactive additives, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide, and zinc borate. The remaining steps are the same.

[0082] Foaming conditions: 16MPa, 140℃.

[0083] In this comparative example, the mass fraction of polyphenylene ether is 100 parts.

[0084] Comparative Example 2 This comparative example provides a foam material.

[0085] The procedure is the same as in Example 2, except that: In step S2, after adding polyphenylene ether and polyamide 6, maleic anhydride-grafted polyphenylene ether, epoxy reactive additives, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide, and zinc borate are not added; the remaining steps are the same.

[0086] In this comparative example, the mass parts of polyphenylene ether and polyamide 6 are 70 parts and 30 parts, respectively.

[0087] Comparative Example 3 The procedure is the same as in Example 2, except that: Bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate were not added, and the remaining components and steps were consistent with those in Example 2.

[0088] In this comparative example, the mass parts of polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, and SMG4108 were 60 parts, 30 parts, 10 parts, and 0.6 parts, respectively.

[0089] Foaming conditions: 16MPa, 160℃.

[0090] Comparative Example 4 This comparative example provides a lightweight PPO / PA foam material.

[0091] The procedure is the same as in Example 4, except that: In step S2, after adding maleic anhydride-grafted polyphenylene ether, zinc borate is not added. After mixing evenly, TGIC is added and mixing is continued to obtain a mixed sample.

[0092] In this comparative example, the mass parts of polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, TGIC, bisphenol A bis(diphenyl phosphate), and melamine cyanurate amide were 85 parts, 10 parts, 5 parts, 0.2 parts, 11.25 parts, and 3.75 parts, respectively.

[0093] Foaming conditions: 16MPa, 160℃.

[0094] Comparative Example 5 This comparative example provides a low-dielectric-weight PPO / PA foam material.

[0095] The procedure is the same as in Example 7, except that: In step S2, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate are not added; only PTFE is added. After mixing evenly, ADR is added and mixing is continued to obtain a mixed sample.

[0096] In this comparative example, the mass parts of polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, ADR, and PTFE were 70 parts, 20 parts, 10 parts, 0.4 parts, and 5 parts, respectively.

[0097] Experimental test: 1. Tensile strength: Tested according to ISO 1926:2009.

[0098] 2. Bending strength: Tested according to ISO 1209-1:2007.

[0099] 3. Impact strength: The impact strength is evaluated using an impact testing machine according to ISO 179-1, with sample dimensions of 80 mm × 10 mm × 4 mm.

[0100] 4. Density: The density of the foamed material sample was tested using the water displacement method with a GT-XB320M densitometer.

[0101] 5. Oxygen Index: The flame-retardant PPO foam material was tested using an HC-2 type oxygen index tester, referring to the standard GB / T2406.2-2009.

[0102] 6. Cone Calorimetry (pHRR, THR, TSP): Test standard is GB / T 16172-2007. Thermal radiation power is 25 Kw / m². 2 The sample size is 100 × 100 × 10 mm.

[0103] 7. Dielectric Constant (Before and After Foaming): The dielectric constant at 10 GHz was measured using a vector network analyzer to calibrate the single-frequency dielectric resonator settings. The specimens consisted of disk-shaped specimens with a diameter of 25 mm and a thickness of 2 mm. Each specimen system was measured 5 times, and the average value was taken. Table 1 Mechanical Performance Data

[0104] Test results show that the PPO / PA foaming system constructed in this invention, after introducing maleic anhydride-grafted polyphenylene ether and epoxy reactive additives, can maintain good mechanical properties while achieving material lightweighting, indicating that the constructed basic system has good compatibility, melt strength, and foaming stability. Furthermore, the flame-retardant example did not show significant instability in overall mechanical properties after the addition of flame-retardant fillers, indicating good interfacial compatibility between the flame-retardant fillers and the matrix, and will not significantly damage the cell structure and overall load-bearing capacity. The low-dielectric example, after introducing PTFE or SiO2 aerogel, still maintains good mechanical support and low density, indicating that the low-dielectric fillers have good dispersibility and structural compatibility in the system of this invention. Further, the flame-retardant and low-dielectric combined example, under the condition of using bifunctional fillers, still maintains a high level of overall mechanical properties, indicating that the flame-retardant fillers and low-dielectric fillers in the foaming platform constructed in this invention do not simply overlap and weaken each other, but rather exhibit a good synergistic matching relationship in the process of interface control, cell nucleation, and cell retention. As can be seen from the SEM morphology and cross-sectional photographs in the attached figures, the bubble structure formed by the embodiment of the present invention is more uniform and has better integrity, while the comparative sample is more prone to uneven bubble structure, loose structure or insufficient cross-sectional integrity. Therefore, it can be shown that the solution of the present invention can achieve a good comprehensive balance between lightweight, mechanical properties and structural stability.

[0105] Table 2 Flame retardant and dielectric properties data

[0106] As shown in Table 2, the test results demonstrate that the functional design of this invention can effectively regulate both flame retardant and dielectric properties. For the flame retardant pathway, the addition of bisphenol A bis(diphenyl phosphate), melamine cyanurate amide, and zinc borate resulted in a higher overall flame retardant level and lower heat release and smoke production tendency, indicating that this flame retardant system can promote char formation in the condensed phase and inhibit heat and smoke release during combustion, thereby improving the material's combustion safety. In the comparative example, the removal of key flame retardant components significantly weakened the aforementioned flame retardant effect, further demonstrating the stable synergistic flame retardant effect within the ternary flame retardant system. For the low-dielectric pathway, the addition of PTFE or SiO2 aerogel reduced the overall dielectric constant of the material before and after foaming, with a more significant decrease after foaming. This indicates a synergistic dielectric reduction effect between the low-polarity characteristics of the low-dielectric filler and the porous structure formed by foaming. Further analysis of the flame-retardant and low-dielectric composite embodiments reveals that while maintaining a high level of flame retardancy, the material still maintains a low dielectric constant after foaming. This indicates that the combined use of flame-retardant and low-dielectric fillers in the system of this invention can form a significant functional synergy or at least a stable synergistic effect. That is, the flame-retardant filler does not significantly offset the dielectric reduction effect of the low-dielectric filler, and the introduction of the low-dielectric filler does not significantly damage the smoke suppression ability of the flame-retardant system. Among them, the SiO2 aerogel route shows a more obvious flame-retardant-low-dielectric synergistic trend, while the PTFE route shows a better functional balance and comprehensive equilibrium effect. This demonstrates that this invention is not a simple mechanical superposition of flame-retardant and low-dielectric functions, but rather achieves a synergistic unity of flame retardancy, low dielectric constant, and foaming structure stability through compatibility structure regulation, reactive additives, and microporous structure construction.

[0107] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A lightweight PPO / PA foam material, characterized in that, The foam material is obtained by supercritical carbon dioxide foaming of a composition comprising polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether and epoxy reactive additives.

2. A flame-retardant lightweight PPO / PA foam material, characterized in that, The flame-retardant foam material is obtained by supercritical carbon dioxide foaming of a composition comprising polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, epoxy reactive additives, and flame-retardant filler composed of bisphenol A bis(diphenyl phosphate), melamine cyanurate amide, and zinc borate.

3. A low-dielectric lightweight PPO / PA foam material, characterized in that, The low-dielectric foam material is obtained by supercritical carbon dioxide foaming of polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, epoxy reactive additives and low-dielectric fillers. The low-dielectric filler is either SiO2 aerogel or PTFE.

4. A flame-retardant, low-dielectric, lightweight PPO / PA foam material, characterized in that, The flame-retardant low-dielectric foam material is obtained by supercritical carbon dioxide foaming of polyphenylene ether, polyamide 6, maleic anhydride-grafted polyphenylene ether, epoxy reactive additives, flame-retardant filler composed of bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate, and low-dielectric filler. The low-dielectric filler is either SiO2 aerogel or PTFE.

5. The lightweight PPO / PA foam material according to any one of claims 1-4, characterized in that, The epoxy reactive additive is selected from one of ADR, TGIC, SMG4108 and epoxy linseed oil.

6. The lightweight PPO / PA foam material according to any one of claims 1-4, characterized in that, The composition contains 60-85 parts by weight of polyphenylene ether, 10-30 parts by weight of polyamide 6 and 5-10 parts by weight of maleic anhydride-grafted polyphenylene ether, and the amount of epoxy reactive additive added is 0.2-0.6 parts by weight.

7. The lightweight PPO / PA foam material according to claim 2 or 4, characterized in that, The mass ratio of bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate is 2:1:1-9:3:4, and the total amount of the three is 18-30 parts.

8. The lightweight PPO / PA foam material according to claim 3 or 4, characterized in that, The amount of the low dielectric filler added is 1-3 parts.

9. A method for preparing the lightweight PPO / PA foam material according to any one of claims 1-4, characterized in that, Includes the following steps: (1) Add polyphenylene ether and polyamide 6 to the torque rheometer, and add maleic anhydride-grafted polyphenylene ether; For the material described in claim 2, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate are further added; For the material described in claim 3, a low-dielectric filler is further added; For the material described in claim 4, bisphenol A bis(diphenyl phosphate), melamine cyanurate amide and zinc borate are added, followed by the addition of a low dielectric filler. After uniform mixing, epoxy reactive additives are added to obtain the mixed sample; (2) The compounded sample is molded into a sheet; (3) The plate is placed in a supercritical reactor and foamed under a carbon dioxide atmosphere; (4) Shape the foamed board to obtain lightweight PPO / PA foam material.

10. The preparation method according to claim 9, characterized in that, Before step (1), the polyphenylene ether and polyamide 6 are dried at 80-100°C; In step (2), the mixed sample is placed in a flat vulcanizing machine mold and pressed at 220-240℃ for 5-10 minutes to prepare the sheet material; In step (3), the board is foamed after being saturated at 140-160℃ for 2-4 hours in a carbon dioxide atmosphere; In step (4), the foamed board is taken out and cooled to set.

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