Thermoplastic polyimide polyether sulfone alloy and preparation method thereof

Abstract

The invention provides a thermoplastic polyimide polyethersulfone alloy and a preparation method thereof, and relates to the technical field of high polymer materials. According to the polymer alloy, the compatibility of a blending system can be remarkably improved by introducing similar structural units. When two phases in a blending system both contain ether sulfone structures, the interface energy is reduced, and the interphase adhesive force is enhanced; the molecular-level structural similarity can promote interface diffusion, form a thick interface transition layer and effectively transfer stress, the Tg of the obtained alloy is no longer two independent values but is fused into a new Tg temperature, and it can be proved that the two high polymer materials are fused on the molecular chain level instead of being mixed simply.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly to a thermoplastic polyimide polyethersulfone alloy and a preparation method thereof. Background Art

[0002] Due to its three core advantages of high temperature resistance, dimensional stability, and flame retardant safety, polyethersulfone (PES) has become one of the most important special engineering plastics, especially suitable for medical devices, electronic insulation, and high-temperature fluid components. With its good solubility and processing properties, it can form composite materials or alloys with a variety of other materials including polyimide (PI).

[0003] Compared with traditional thermosetting PI or other thermoplastic polyimides (TPI), bisphenol A type TPI has significantly improved solubility and can be dissolved in strong polar solvents (such as DMF, NMP, DMAC) and low boiling point solvents (such as THF). This characteristic greatly broadens its solution processing window. At the same time, it has a good balance of mechanical properties. Bisphenol A type TPI maintains the inherent high strength and high modulus characteristics of the polyimide family. Its tensile strength is usually in the range of 90 - 115 MPa, and the tensile modulus is between 2.8 - 3.5 GPa, which can meet the requirements of most structural applications. The flexible ether bond structure of the bisphenol A unit endows the material with better toughness than other highly rigid PIs and is an ideal substance for compounding with PES.

[0004] In view of this, it is necessary to design an improved thermoplastic polyimide polyethersulfone alloy and a preparation method thereof to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a thermoplastic polyimide polyethersulfone alloy and a preparation method thereof.

[0006] To achieve the above invention purpose, the present invention provides a preparation method of a thermoplastic polyimide polyethersulfone alloy, which is characterized by including the following steps:

[0007] S1. In an inert gas atmosphere, mix a solvent, 4,4'-bis(3-aminophenoxy) diphenyl sulfone, and a catalyst, and after fully mixing evenly at 0 - 10°C, add bisphenol A type dianhydride and react at 0 - 10°C for 4 - 8 h;

[0008] S2. Add toluene to the reaction system of step S1, react at 135°C for 2 - 3 h, and then react at 180°C for 6 - 12 h; after the reaction is completed, TPI powder is obtained;

[0009] S3. After uniformly mixing the TPI powder obtained in step S2 with polyethersulfone, a thermoplastic polyimide polyethersulfone alloy is obtained.

[0010] Preferably, in step S3, the mass ratio of TPI powder to polyethersulfone is (1 - 9):(1 - 9).

[0011] Preferably, the mass ratio of TPI powder to polyethersulfone is 1:9. At this time, the T of the prepared thermoplastic polyimide polyethersulfone alloy g is 191.7 °C.

[0012] Preferably, the mass ratio of TPI powder to polyethersulfone is 9:1. At this time, the T of the prepared thermoplastic polyimide polyethersulfone alloy g is 222.8 °C.

[0013] Preferably, in step S1, the molar ratio of 4,4'-bis(3-aminophenoxy)diphenyl sulfone to bisphenol A dianhydride is 100:101 - 100:105, and the total mass ratio of 4,4'-bis(3-aminophenoxy)diphenyl sulfone and bisphenol A dianhydride to the solvent mass is 10:90 - 30:70.

[0014] Preferably, in step S1, the catalyst is isoquinoline, and its molar amount is 0.5 - 3% of the molar amount of bisphenol A dianhydride.

[0015] Preferably, in step S1, the solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and m-cresol.

[0016] Preferably, in step S1, the inert gas is nitrogen or argon.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The preparation method of the thermoplastic polyimide polyethersulfone alloy provided by the present invention realizes the multi-level fusion and performance optimization of TPI and PES materials through the combination of molecular-level structural hybridization design and macroscopic-scale blending modification. By introducing an ether sulfone structural unit into the TPI molecular chain, the high-temperature resistance of polyimide and the excellent processability of polyethersulfone can be combined. The sulfone group in the ether sulfone structure can increase the molecular chain rigidity, while the ether bond provides appropriate chain segment flexibility, improving the melt fluidity. At the same time, the bisphenol A structure is retained to utilize its function of improving solubility and toughness, forming a "rigid-flexible combination" molecular structure.

[0019] 2. The thermoplastic polyimide polyethersulfone alloy provided by the present invention can significantly improve the compatibility of the blend system by introducing similar structural units. When both phases in the blend system contain an ether sulfone structure, the interfacial energy is reduced, and the interfacial adhesion force is enhanced; the molecular-level structural similarity can promote interfacial diffusion, forming a thick interfacial transition layer to effectively transfer stress. The T of the obtained alloy g is no longer two independent values, but merges into a new Tg The temperature can prove that the two polymer materials in the present invention have undergone molecular chain-level fusion rather than simple mixing. Detailed implementation manners

[0020] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail below with reference to specific embodiments.

[0021] Here, it should also be noted that in order to avoid obscuring the present invention due to unnecessary details, only the structures and / or processing steps closely related to the solution of the present invention are shown in the text, while other details less related to the present invention are omitted.

[0022] In addition, it should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0023] The present invention provides a method for preparing a thermoplastic polyimide polyethersulfone alloy, comprising the following steps:

[0024] S1. Under an inert gas atmosphere, a solvent, 4,4'-bis(3-aminophenoxy) diphenyl sulfone (m-BAPS), and a catalyst are mixed and sufficiently mixed at 0-10 °C. After mixing evenly, bisphenol A dianhydride (BPADA) is added, and the reaction is carried out at 0-10 °C for 4-8 h;

[0025] S2. Toluene is added to the reaction system of step S1, and the reaction is carried out at 135 °C for 2-3 h, and then at 180 °C for 6-12 h; after the reaction is completed, when the system is cooled to room temperature, the reaction solution obtained is poured into anhydrous ethanol, washed and dried to obtain TPI powder;

[0026] S3. The TPI powder obtained in step S2 is mixed evenly with polyethersulfone (PES) in a certain proportion to obtain a thermoplastic polyimide polyethersulfone alloy.

[0027] In some embodiments, the inert gas is nitrogen or argon.

[0028] In some embodiments, in step S1, the solvent is one or more of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), N-methylpyrrolidone (NMP), and m-cresol.

[0029] In some embodiments, in step S1, the catalyst is isoquinoline, and its amount of substance is 0.5-3% of the amount of substance of BPADA.

[0030] In some embodiments, in step S1, the molar ratio of m-BAPS to BPADA is 100:101 - 100:105, and the ratio of the total mass of m-BAPS and BPADA to the mass of the solvent is 10:90 - 30:70.

[0031] In some embodiments, in step S3, the mass ratio of TPI powder to PES is (1 - 9):(1 - 9).

[0032] The following further illustrates the thermoplastic polyimide polyethersulfone alloy and its preparation method proposed by the present invention with specific embodiments:

[0033] Example 1

[0034] S1. Under an inert gas atmosphere, 387 g of DMF (analytical pure), 0.1 mol of m-BAPS, and isoquinoline were mixed, and fully mixed at 0 °C. After mixing evenly, 0.103 mol of BPADA was added, and the reaction was carried out at 0 °C for 6 h; among them, the amount of substance of isoquinoline was 1% of the amount of substance of BPADA.

[0035] S2. Toluene (analytical pure) was added to the reaction system of step S1, and the reaction was carried out at 135 °C for 2 - 3 h, and then at 180 °C for 6 - 12 h; after the reaction ended, when the system was cooled to room temperature, the reaction solution obtained was poured into anhydrous ethanol, washed and dried to obtain TPI powder.

[0036] S3. The TPI powder obtained in step S2 was mixed with PES at a mass ratio of 1:9, dissolved in DMF at room temperature, stirred until the materials were fully solvated and the solution was stable and homogeneous, and finally the solvent was removed and dried to obtain the thermoplastic polyimide polyethersulfone alloy. It should be noted that toluene in step S2 was used as a water-carrying agent to remove water in the system. The addition of DMF in step S3 was only used to mix and dissolve TPI powder and PES. As long as this purpose can be achieved, the amounts of toluene and DMF are not limited. In addition, the reagents used in the examples of the present invention can all be obtained by purchasing in the market.

[0037] Example 2

[0038] The difference between Example 2 and Example 1 is only that: in step S3, the mass ratio of TPI powder to PES is 5:5, and the other experimental parameters are the same as those in Example 1, and will not be repeated here.

[0039] Example 3

[0040] The difference between Example 3 and Example 1 is only that: in step S3, the mass ratio of TPI powder to PES is 9:1, and the other experimental parameters are the same as those in Example 1, and will not be repeated here.

[0041] Comparative Example 1

[0042] The difference between Comparative Example 1 and Example 1 is that: TPI was prepared using m-phenylenediamine (m-PDA) and 4,4'-bis(4-aminophenoxy)diphenyl ether (PBADA), and the remaining experimental parameters were the same as those in Example 1, which will not be elaborated here.

[0043] Comparative Example 2

[0044] The difference between Comparative Example 2 and Example 1 is that: TPI was prepared using m-phenylenediamine (m-PDA) and 4,4'-bis(4-aminophenoxy)diphenyl ether (PBADA), and the mass ratio of TPI powder to PES was 5:5, and the remaining experimental parameters were the same as those in Example 1.

[0045] The thermal performance data of the thermoplastic polyimide polyethersulfone alloys prepared in Examples 1-3 and Comparative Examples 1-2 are shown in Table 1. Comparing the T g data, it can be found that under the conditions of 10% PES content or 10% TPI content, the two materials' T g are completely fused, the values are close and greater than the component with a content of 90%. This is because the molecular chain structures of the two materials are similar, achieving a uniform mixing at the molecular chain level. And the increase in T g values is because this uniform mixing at the molecular chain level hinders the original molecular chain movement, increasing the temperature of the amorphous part of the polymer from the frozen state to the thawed state. However, this mixing is not an unlimited mutual solubility. In Example 2 (i.e., the mass ratio of PES to TPI is 1:1), the alloy shows a common double T g , and both T g values are greater than those of the corresponding pure resins. The increase in T g proves that a uniform mixing at the molecular chain level is still achieved at this ratio, but the appearance of the double T g proves that this mixing is a situation where one material can be partially dissolved in the other, rather than an unlimited mutual solubility of the two materials.

[0046] The difference in the molecular structure of TPI synthesized in Comparative Examples 1-2 compared to that in the examples is that it does not contain an ether sulfone group. Therefore, after the two materials are mixed, there is no fusion of T g or an increase in T g . The lower T d5% of the alloy is because the TPI prepared by m-PDA + PBADA itself has lower thermal stability than the TPI prepared by m-BAPS + PBADA.

[0047] Table 1 Thermal performance data of the thermoplastic polyimide polyethersulfone alloys prepared in Examples 1 to 3 and Comparative Examples 1 to 2

[0048]

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A preparation method of a thermoplastic polyimide polyethersulfone alloy, characterized in that It includes the following steps: S1. Under an inert gas atmosphere, mix a solvent, 4,4'-bis(3-aminophenoxy)diphenyl sulfone, and a catalyst. After fully mixing evenly at 0 - 10°C, add bisphenol A dianhydride and react at 0 - 10°C for 4 - 8 h; S2. Add toluene to the reaction system in step S1, react at 135°C for 2 - 3 h, and then react at 180°C for 6 - 12 h; after the reaction ends, TPI powder is obtained; S3. Mix the TPI powder obtained in step S2 with polyethersulfone evenly to obtain a thermoplastic polyimide - polyethersulfone alloy.

2. The preparation method according to claim 1, characterized in that, In step S3, the mass ratio of the TPI powder to the polyethersulfone is (1 - 9):(1 - 9).

3. The preparation method according to claim 2, characterized in that, The mass ratio of the TPI powder to the polyethersulfone is 1:

9.

4. The preparation method according to claim 2, wherein The mass ratio of the TPI powder to the polyethersulfone is 9:

1.

5. The preparation method according to claim 1, wherein In step S1, the molar ratio of 4,4'-bis(3-aminophenoxy)diphenyl sulfone to bisphenol A dianhydride is 100:101 - 100:105, and the ratio of the total mass of 4,4'-bis(3-aminophenoxy)diphenyl sulfone and bisphenol A dianhydride to the mass of the solvent is 10:90 - 30:

70.

6. The preparation method according to claim 1, characterized in that, In step S1, the catalyst is isoquinoline, and its amount of substance is 0.5 - 3% of the amount of substance of bisphenol A dianhydride.

7. The preparation method according to claim 1, wherein, In step S1, the solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and m-cresol.

8. The preparation method according to claim 1, characterized in that, In step S1, the inert gas is nitrogen or argon.

9. A thermoplastic polyimide-polyethersulfone alloy prepared by the preparation method according to claim 3, characterized in that, The T of the thermoplastic polyimide polyethersulfone alloy g is 191.7 °C.

10. A thermoplastic polyimide polyethersulfone alloy prepared by the preparation method according to claim 4, characterized in that, The T of the thermoplastic polyimide polyethersulfone alloy g is 222.8 °C.

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