Thermoplastic polyphenylene ether containing reticular phosphorus crosslinked structure, and preparation method and application thereof

Abstract

The application provides thermoplastic polyphenyl ether containing a reticular phosphorus crosslinking structure and a preparation method and application thereof. The preparation method of the thermoplastic TPV crosslinking polyphenyl ether provided by the application constructs part of PPO resins into a reticular structure through the reaction of phosphorus oxychloride and the end hydroxyl group of polyphenyl ether. The modified polyether can not only rely on an external flame retardant to improve the flame retardant property of the material, but also further improve the heat resistance and rigidity of the polyphenyl ether material under the premise of excellent flame retardant property.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to a thermoplastic polyphenylene ether containing a network phosphated polyphenylene ether crosslinking structure, its preparation method, and its application. Background Technology

[0002] The automotive industry has increasingly stringent requirements for material performance. The engine compartment, exhaust system, and other components of automobiles operate at extremely high temperatures, necessitating materials with excellent heat resistance and rigidity to prevent deformation, degradation, or failure under high-temperature conditions. Furthermore, these materials are highly flammable and release toxic fumes in fires, thus requiring excellent flame-retardant properties. However, adding flame retardants during the blending process typically reduces the material's heat resistance, making it impossible to simultaneously achieve both flame retardancy and heat resistance.

[0003] It is evident that the automotive industry currently has extremely high comprehensive requirements for materials in terms of heat resistance, flame retardancy, and mechanical properties. In particular, it faces severe challenges in key electronic components such as power battery systems and electric vehicle control units. There is still an urgent problem to be solved in how to improve the heat resistance and rigidity of materials without sacrificing flame retardancy. Summary of the Invention

[0004] In view of the above-mentioned problems in the prior art, one of the objectives of the present invention is to provide a modified polyphenylene ether that can not only rely on the addition of flame retardants to improve the flame retardant properties of the material, but also further improve the heat resistance and rigidity of the polyphenylene ether material while maintaining excellent flame retardancy.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0006] A modified polyphenylene ether, wherein the polyphenylene ether contains a partially cross-linked network phosphating polyphenylene ether structure obtained by reacting excess polyphenylene ether (PPO) with phosphorus oxychloride; wherein the mass ratio of phosphorus oxychloride to polyphenylene ether is 1:(9-30).

[0007] In this invention, the introduction of phosphorus through reaction serves two purposes: firstly, it provides a precursor for subsequent char formation; at high temperatures, phosphorus promotes the formation of a stable char layer, which effectively isolates oxygen and heat transfer, thereby slowing down the combustion process; secondly, the semi-crosslinked network structure established through the reaction promotes a denser char layer formed at high temperatures and prevents it from collapsing during combustion, significantly improving the material's flame-retardant properties. Furthermore, the addition of phosphorus oxychloride to polyphenylene ether before blending reduces the amount of flame retardant required at the blending end, while the semi-crosslinked network structure obtained after polyphenylene ether modification significantly enhances the material's mechanical strength and heat resistance.

[0008] Another object of the present invention is to provide a method for preparing modified polyphenylene ether.

[0009] A method for preparing the above-mentioned modified polyphenylene ether, wherein the polyphenylene ether reacts with phosphorus oxychloride in a solvent, and after cooling, washing, and separation, the precipitate is washed and dried to obtain a phosphorinated polyphenylene ether resin containing a network crosslinking structure.

[0010] In one embodiment of the present invention, the mass ratio of phosphorus oxychloride to polyphenylene ether in the reaction is 1:(9-30), preferably 1:(12-20).

[0011] In one embodiment of the present invention, the reaction is carried out under alkaline conditions, preferably with a pH of 7-9; preferably, the mass ratio of phosphorus oxychloride to alkali is 1:(1-2).

[0012] In one embodiment of the present invention, the solvent is a halogenated hydrocarbon and / or an aromatic hydrocarbon, preferably 1,2,4-trichlorobenzene and / or o-dichlorobenzene.

[0013] In one embodiment of the present invention, the reaction temperature is 100-140°C and the time is 1-3 hours.

[0014] The reaction formula is shown below:

[0015]

[0016] Another object of the present invention is to provide a thermoplastic polyphenylene ether composition containing a partially cross-linked structure.

[0017] A thermoplastic polyphenylene ether composition containing a partially cross-linked structure, the composition containing the above-described modified polyphenylene ether, or containing the modified polyphenylene ether prepared by the above method, the composition being prepared from raw materials comprising the following parts by weight:

[0018] 20-80 parts of modified polyphenylene ether resin;

[0019] 20-80 parts of polymer are used for blending;

[0020] 1-5 parts flame retardant.

[0021] In one embodiment of the present invention, the polymer used for blending is a high-flow thermoplastic polymer, preferably one or more of high-impact polystyrene, nylon, polypropylene, and polyester.

[0022] In one embodiment of the present invention, the flame retardant comprises one or more of halogenated flame retardants, phosphorus-based flame retardants, nitrogen-based flame retardants, and inorganic flame retardants; wherein, the phosphorus-based flame retardant is preferably an organophosphorus flame retardant and / or an inorganic phosphorus flame retardant, more preferably one or more of phosphate esters, phosphites, phosphonates, organic phosphorus salts, phosphorus heterocyclic compounds, and polymeric phosphorus / phosphonates. The above-mentioned flame retardants and their dosages are well known in the art.

[0023] In one embodiment of the present invention, the composition further comprises the following adjuvants in parts by weight: 0.01-1 part of a primary antioxidant and 0.01-1 part of a secondary antioxidant; preferably, the primary antioxidant comprises one or more hindered phenolic antioxidants; and the secondary antioxidant comprises one or more phosphite antioxidants. The above adjuvants and their dosages are well known in the art.

[0024] Another object of the present invention is to provide a method for preparing a thermoplastic polyphenylene ether composition containing a partially cross-linked structure.

[0025] A method for preparing a thermoplastic polyphenylene ether composition containing a partially cross-linked structure, wherein the composition contains the modified polyphenylene ether described above, or contains the modified polyphenylene ether prepared by the above method, or is the above composition, the preparation method comprising the following steps: premixing the modified polyphenylene ether resin, blending polymer, flame retardant, primary antioxidant, and secondary antioxidant in a high-speed mixer, then adding the mixture to a twin-screw extruder, and melt extruding and granulating to obtain granules of the polyphenylene ether composition.

[0026] In one embodiment of the present invention, the process conditions for melt extrusion are: premixing in a high-speed mixer for 10-20 minutes, extrusion temperature of 250-280℃, and extrusion speed of 400-600 r / min.

[0027] Another object of the present invention is to provide a use for modified polyphenylene ether.

[0028] A use of a modified polyphenylene ether, wherein the modified polyphenylene ether is the modified polyphenylene ether described above, or a modified polyphenylene ether prepared by the above method, wherein the modified polyphenylene ether is used to prepare a thermoplastic processable, high heat-resistant, flame-retardant polyphenylene ether resin.

[0029] Another object of the present invention is to provide an application of a thermoplastic polyphenylene ether composition containing a partially cross-linked structure.

[0030] Application of a thermoplastic polyphenylene ether composition containing a partially cross-linked structure, wherein the composition contains the modified polyphenylene ether described above, or contains the modified polyphenylene ether prepared by the method described above, or is the composition described above, or is the composition prepared by the method described above, wherein the composition is used to prepare automotive exterior parts and internal structural parts, preferably for automotive fuel tank caps, air intake pipes, battery structural parts, and engine structural parts.

[0031] Compared with existing technologies, the advantages of this technical solution are:

[0032] By introducing phosphorus oxychloride at the reaction end, the amount of flame retardant added at the blending end can be reduced without decreasing the flame retardant effect, while improving the heat resistance and rigidity of the modified polyphenylene ether material, thus achieving the preparation of a polyphenylene ether material with excellent flame retardant properties, heat resistance, and rigidity. Attached Figure Description

[0033] Figure 1 The image shows the infrared absorption spectrum of PPO-1 obtained after modification in Example 1. Detailed Implementation

[0034] The present invention will be further described below with reference to the embodiments. It should be noted that the embodiments do not constitute a limitation on the scope of protection of the present invention.

[0035] The main raw material sources in the embodiments and comparative examples of this invention are as follows; unless otherwise specified, all other raw materials were obtained through ordinary commercial channels:

[0036] Polyphenylene oxide (PPO): purchased from China Bluestar Group Co., Ltd., grades LXN045 and LXN040;

[0037] High-impact polystyrene (HIPS): Purchased from Chi Mei Industrial Co., Ltd., grade PH-88;

[0038] Nylon 66 (PA66): Purchased from Shenma Industrial Co., Ltd., grade EPR27;

[0039] Polypropylene (PP): Purchased from Taiwan Plastics Industries Co., Ltd., grade 3354;

[0040] Flame retardants: purchased from Wansheng Co., Ltd., including TPP, RDP, and PX220;

[0041] Antioxidants: Both 1076 and 168 antioxidants were purchased from BASF.

[0042] Example 1

[0043] The preparation steps of modified polyphenylene ether resin are as follows:

[0044] 180g of LXN045 polyphenylene ether was dissolved in 360g of 1,2,4-trichlorobenzene, 20g of sodium bicarbonate was added, and after dissolution, 20g of phosphorus oxychloride was added dropwise for reaction. Under high-purity nitrogen protection, the reaction was carried out at 140℃ for 1h. The solution was cooled to room temperature, and then anhydrous methanol was added for washing and separation to obtain the final precipitate. The precipitate was washed and dried three times, and then vacuum dried to obtain polyphenylene ether resin PPO-1 containing phosphorus.

[0045] (2) Prepare a partially cross-linked polyphenylene ether that can be thermoplastically processed. The raw material formula is as follows:

[0046] PPO-11600g;

[0047] HIPS 400g;

[0048] Flame retardant TPP 20g;

[0049] Main antioxidant 10760.2g;

[0050] 1680.2g of co-antioxidant;

[0051] S1: Powdered PPO-1, HIPS, flame retardant, primary antioxidant, and secondary antioxidant are premixed in a high-speed mixer for 20 minutes and then added to the barrel of a twin-screw extruder.

[0052] S2: The extruder is set to an extrusion temperature of 280℃ and a rotation speed of 400r / min. The thermoplastic partially cross-linked polyphenylene ether particles are obtained by melt extrusion under a nitrogen atmosphere.

[0053] S3: Prepare the corresponding test specimens by injection molding at a temperature of 280℃ and an injection pressure of 180MPa, and keep them for testing.

[0054] The infrared characterization results of the modified PPO-1 are as follows: Figure 1 As shown, Figure 1 This indicates that a partially cross-linked structure has been formed in the polyphenylene ether.

[0055] Example 2

[0056] (1) The preparation steps of the modified polyphenylene ether resin are as follows:

[0057] 300g of LXN045 polyphenylene ether was dissolved in 1200g of o-dichlorobenzene, and then 30g of sodium bicarbonate was added. After the solution was fully dissolved, 20g of phosphorus oxychloride was slowly added dropwise to carry out the reaction. The reaction was carried out under the protection of high-purity nitrogen and at a temperature of 120℃ for 2 hours. The solution was cooled to room temperature, and then anhydrous methanol was added for washing and separation to obtain the final precipitate. The precipitate was washed and dried three times, and then vacuum dried to obtain polyphenylene ether resin PPO-2 containing phosphorus.

[0058] (2) Prepare thermoplastic processable TPV crosslinked polyphenylene ether, the raw material formula is as follows:

[0059] PPO-21000g;

[0060] PA66 1000g;

[0061] Flame retardant RDP 40g;

[0062] 10762g of main antioxidant;

[0063] 16810g of co-antioxidant;

[0064] S1: Powdered PPO-2, HIPS, flame retardant, primary antioxidant, and secondary antioxidant are premixed in a high-speed mixer for 15 minutes and then added to the barrel of a twin-screw extruder.

[0065] S2: The extruder barrel temperature is set to a maximum of 260℃ and the rotation speed is 500r / min. The thermoplastic TPV cross-linked polyphenylene ether particles are produced by melt extrusion under a nitrogen atmosphere.

[0066] S3: Prepare the corresponding test specimens by injection molding at a temperature of 280℃ and an injection pressure of 180MPa, and keep them for testing.

[0067] Example 3

[0068] (1) The preparation steps of the modified polyphenylene ether resin are as follows:

[0069] 600g of LXN040 polyphenylene ether was dissolved in 4800g of o-dichlorobenzene, and then 40g of sodium bicarbonate was added. After the solution was fully dissolved, 20g of phosphorus oxychloride was slowly added dropwise to carry out the reaction. The reaction was carried out under the protection of high-purity nitrogen and at 100℃ for 3 hours. The solution was cooled to room temperature, and then anhydrous methanol was added for washing and separation to obtain the final precipitate. The precipitate was washed and dried 4 times, and then vacuum dried to obtain polyphenylene ether resin PPO-3 containing phosphorus.

[0070] (2) Prepare thermoplastic processable TPV crosslinked polyphenylene ether, the raw material formula is as follows:

[0071] PPO-3400g;

[0072] PP 1600g;

[0073] Flame retardant PX220 100g;

[0074] Main antioxidant 107620g;

[0075] 16820g of co-antioxidant;

[0076] S1: Powdered PPO-3, HIPS, flame retardant, primary antioxidant, and secondary antioxidant are premixed in a high-speed mixer for 10 minutes and then added to the barrel of a twin-screw extruder.

[0077] S2: The extruder barrel temperature is set to a maximum of 250℃ and the rotation speed is 600r / min. The thermoplastic TPV cross-linked polyphenylene ether particles are produced by melt extrusion under a nitrogen atmosphere.

[0078] S3: Prepare the corresponding test specimens by injection molding at a temperature of 280℃ and an injection pressure of 180MPa, and keep them for testing.

[0079] Comparative Example 1

[0080] The thermoplastic processable TPV crosslinked polyphenylene ether was prepared according to Example 1, except that the PPO powder was not modified and the polyphenylene ether was directly extruded and granulated with other components and additives. Other operations and conditions remained unchanged, and the thermoplastic processable TPV crosslinked polyphenylene ether was obtained.

[0081] Comparative Example 2

[0082] The thermoplastic TPV crosslinked polyphenylene ether was prepared according to Example 1, except that no flame retardant was added to the PPO blending modification formulation, and other operations and conditions remained unchanged, thus obtaining the thermoplastic TPV crosslinked polyphenylene ether.

[0083] Comparative Example 3

[0084] Refer to step 1) of Example 1 to prepare thermoplastic TPV crosslinked polyphenylene ether, the only difference being that: during PPO modification, the mass ratio of phosphorus oxychloride to polyphenylene ether is 1:8, and other operations and conditions remain unchanged, thus obtaining thermoplastic TPV crosslinked polyphenylene ether.

[0085] Comparative Example 4

[0086] The thermoplastic TPV crosslinked polyphenylene ether was prepared according to Example 1, except that the mass ratio of phosphorus oxychloride to polyphenylene ether was 1:40, and other operations and conditions remained unchanged, thus obtaining the thermoplastic TPV crosslinked polyphenylene ether.

[0087] The main performance testing methods used in the embodiments of this invention are as follows:

[0088] Infrared testing: The infrared absorption spectrum of the sample was tested using a Fourier transform infrared spectrometer, with a scanning range of 4000-500 cm⁻¹.

[0089] Heat resistance test: Vicat temperature was tested according to GB / T1633-2000 method;

[0090] Flame retardancy test: The flame retardancy rating is tested according to the UL94 method;

[0091] Mechanical property testing: Tensile modulus was tested according to ISO 527-3 method, with a tensile speed of 0.5 mm / min;

[0092] Crosslinking density test: swelling method, using tetrahydrofuran as solvent, the ratio of the mass of the gel after swelling to the mass in the dry state is the degree of swelling.

[0093] Table 1. Performance Comparison of PPO

[0094] Performance indicators Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Vicat temperature (°C) 150 145 140 130 149 152 136 Flame retardant rating: 0.75mm V-0 V-0 V-0 V-2 V-2 V-2 V-1 Tensile modulus (MPa) 2810 2500 2250 2430 2800 3020 2580 swelling degree 1 3 8 soluble 1 0.2 15

[0095] A higher degree of swelling indicates less cross-linking. If it is directly soluble, it indicates no cross-linking. If the degree of swelling is close to 0, it indicates high cross-linking. Based on the above experimental data, Examples 1-3 all adopted the modification method of the present invention. The flame retardant effect of PPO was greatly improved after modification. Only a small amount of flame retardant is needed to achieve excellent flame retardant performance, and the heat resistance of the material is also improved. Examples 1 and Comparative Example 1 show that when PPO is not modified, its flame retardant performance cannot reach the V-0 level, and the lack of a constructed network structure significantly reduces its heat resistance. Examples 1 and Comparative Example 2 show that without adding a flame retardant at the blending end, excellent flame retardant performance cannot be achieved. Examples 1 and Comparative Example 3 show that adding excessive phosphorus oxychloride to PPO modification does not improve flame retardant performance, but instead leads to excessive cross-linking and difficulty in processing. Examples 1 and Comparative Example 4 show that when insufficient phosphorus oxychloride is added for PPO modification, the network structure is too small, and it is also impossible to achieve both excellent heat resistance and flame retardant effects.

[0096] The above embodiments are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived within the scope of the technology disclosed in the present invention, the scope covered by the claims, and other easily conceived changes or substitutions should be included within the scope of protection of the present invention.

Claims

1. A modified polyphenylene ether, characterized in that, The polyphenylene ether contains a partially cross-linked network phosphated polyphenylene ether structure obtained by reacting excess polyphenylene ether (PPO) with phosphorus oxychloride. The mass ratio of phosphorus oxychloride to polyphenylene ether is 1:(9-30).

2. A method for preparing the modified polyphenylene ether of claim 1, characterized in that, In the method described, polyphenylene ether reacts with phosphorus oxychloride in a solvent, and after cooling, washing, and separation, the precipitate is washed and dried to obtain a phosphorinated polyphenylene ether resin with a network cross-linked structure.

3. The method according to claim 3, characterized in that, In the reaction, the mass ratio of phosphorus oxychloride to polyphenylene ether is 1:(9-30), preferably 1:(12-20); And / or, the reaction is carried out under alkaline conditions, preferably at a pH of 7-9; Preferably, the mass ratio of phosphorus oxychloride to alkali is 1:(1-2); And / or, the solvent is a halogenated hydrocarbon and / or an aromatic hydrocarbon, preferably 1,2,4-trichlorobenzene and / or o-dichlorobenzene; And / or, the reaction is carried out at a temperature of 100-140°C for 1-3 hours.

4. A thermoplastic polyphenylene ether composition containing a partially cross-linked structure, said composition containing the modified polyphenylene ether of claim 1, or containing the modified polyphenylene ether prepared by the method of claim 2 or 3, characterized in that, The composition is prepared from raw materials comprising the following parts by weight: 20-80 parts of modified polyphenylene ether resin; 20-80 parts of polymer are used for blending; 1-5 parts flame retardant.

5. The composition according to claim 4, characterized in that, The polymer used for blending is a high-flow thermoplastic polymer, preferably one or more of high-impact polystyrene, nylon, polypropylene, and polyester; And / or, the flame retardant comprises one or more of halogenated flame retardants, phosphorus-based flame retardants, nitrogen-based flame retardants, and inorganic flame retardants; wherein, the phosphorus-based flame retardant is preferably an organic phosphorus-based flame retardant and / or an inorganic phosphorus-based flame retardant, more preferably one or more of phosphate esters, phosphites, phosphonates, organic phosphorus salts, phosphorus heterocyclic compounds, and polymeric phosphorus / phosphonates.

6. The composition according to claim 4 or 5, characterized in that, The composition also contains the following parts by weight of additives: Primary antioxidant 0.01-1 part, 0.01-1 part of co-antioxidant; Preferably, the primary antioxidant comprises one or more hindered phenolic antioxidants; the secondary antioxidant comprises one or more phosphite antioxidants.

7. A method for preparing a thermoplastic polyphenylene ether composition containing a partially cross-linked structure, wherein the composition contains the modified polyphenylene ether according to claim 1, or contains the modified polyphenylene ether prepared by the method according to claim 2 or 3, or is the composition according to any one of claims 4-6, characterized in that, The preparation method includes the following steps: Modified polyphenylene ether resin, blending polymer, flame retardant, primary antioxidant, and secondary antioxidant are premixed in a high-speed mixer, then added to a twin-screw extruder for melt extrusion granulation to obtain polyphenylene ether composition granules.

8. The preparation method according to claim 7, characterized in that, The process conditions for melt extrusion are: premixing in a high-speed mixer for 10-20 minutes, extrusion temperature of 250-280℃, and extrusion speed of 400-600 r / min.

9. A use of a modified polyphenylene ether, wherein the modified polyphenylene ether is the modified polyphenylene ether according to claim 1, or the modified polyphenylene ether prepared by the method according to claim 2 or 3, wherein the modified polyphenylene ether is used to prepare a thermoplastic processable, high heat-resistant, flame-retardant polyphenylene ether resin.

10. Application of a thermoplastic polyphenylene ether composition containing a partially cross-linked structure, said composition containing the modified polyphenylene ether of claim 1, or containing the modified polyphenylene ether prepared by the method of claim 2 or 3, or the composition of any one of claims 4-6, or the composition prepared by the preparation method of claim 7 or 8, said composition being used to prepare automotive exterior parts, internal structural parts, preferably for automotive fuel tank caps, air intake pipes, battery structural parts, and engine structural parts.

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