A reactive thermoplastic resin having a large free volume, a preparation method and a bismaleimide resin composition

Abstract

The application discloses a reaction type thermoplastic resin with a large free volume, a preparation method and a bismaleimide resin composition, and belongs to the technical field of polymer material toughening. N 2 a nucleophilic polycondensation reaction to obtain a polyaryletherketone / sulfone copolymer containing a reaction type group, wherein the bisphenol compound is selected from one or more of phenolphthalein, thymolphthalein, bisphenol fluorene and isoindolinone-based bisphenol. The application introduces a bisphenol compound with a large side group into the molecular chain of the thermoplastic resin to construct a large free volume structure, and simultaneously utilizes TGSH to provide an active propenyl group, so that the resin can participate in the curing and cross-linking reaction of bismaleimide. The bismaleimide resin composition using the resin as a toughening agent has a significantly improved toughness after curing.

Description

Technical Field

[0001] This invention belongs to the field of polymer toughening agent technology, specifically relating to a reactive thermoplastic resin with a large free volume, a preparation method, and a bismaleimide resin composition, which is particularly suitable for high-end materials with high requirements for toughness and heat resistance. Background Technology

[0002] Bismaleimide (BMI) resin possesses higher heat resistance than epoxy resins and superior molding and processing properties compared to polyimides. It also exhibits good resistance to damp heat and aging, making it a hot research topic in matrix resins across various fields. It is widely used in high-tech areas such as aerospace and electronic packaging. However, the high melting point, high curing temperature, high crosslinking density, and certain brittleness of bismaleimide limit its application in structural materials.

[0003] Traditional thermoplastic toughening agents such as polyethersulfone (PES) and polyaryletherketone (PEK) can improve the toughness of BMI resin to some extent, but their effectiveness is limited due to poor interfacial compatibility between thermoplastic and thermosetting resins, which easily leads to phase separation. Patent CN103602066A discloses a method for toughening BMI resin using polyethersulfone (PES), which involves thermally melting PES into diallyl bisphenol A (DABPA) and then blending and curing it with bismaleimide. This method utilizes the high toughness of PES itself; however, as a non-reactive toughening agent, PES has limited compatibility with the BMI resin matrix, making it prone to phase separation. This results in uneven stress transmission, hindering further improvement in toughening effect and negatively impacting the material's heat resistance.

[0004] Reactive thermoplastic resins, by introducing active groups (such as propylene and carboxyl groups) into the molecular chain, can participate in the curing and crosslinking reaction of BMI resin, forming covalent bonds, significantly improving interfacial compatibility and enhancing toughening effect. Simultaneously, the free volume of the resin has a significant impact on toughening performance. A large free volume structure provides more space for molecular chain movement, and upon impact, it can disperse impact energy through molecular chain slippage and hole absorption, further improving toughness. Patents CN118185012A and CN118184995A disclose propylene-containing polyarylether sulfone and polyarylether ketone toughening agents, respectively. By introducing allyl bisphenol A (DABPA) as a third monomer into the polymer backbone, the toughening agent molecular chain carries propylene group reaction sites, which can undergo a Diels-Alder reaction with BMI, thereby anchoring it in the crosslinking network and inhibiting phase separation. However, because the DABPA monomer contains methyl groups, it lowers the polymer's glass transition temperature (Tg). g This further reduces the operating temperature of the bismaleimide curing system. Summary of the Invention

[0005] To overcome the problems existing in the prior art, this invention provides a reactive thermoplastic resin with a large free volume, a preparation method, and a bismaleimide resin composition. This resin utilizes bisphenol monomers with large side groups (such as the Cardo structure of phenolphthalein, the isopropyl-substituted benzene ring of thymolphthalein, the fluorene ring of bisphenol fluorene, etc.) to construct the main chain, and combines it with a reactive third monomer TGSH, enabling the resin to simultaneously possess large free volume and active propylene groups at the molecular level. When used to toughen BMI resin, the large free volume is beneficial for stress dispersion and energy absorption, while the active propylene groups can chemically react with BMI to anchor the molecular chain. Thus, while inhibiting phase separation, a superior toughening effect is achieved through the synergistic effect of physical dissipation and chemical bonding.

[0006] The first objective of this invention is to provide a reactive thermoplastic resin with a large free volume, having a structural unit as shown in Formula I, where m+n=1, and m and n are molar percentages:

[0007] In Formula I, X is selected from one of the structures shown in Formula I-1, Formula I-2, Formula I-3, and Formula I-4:

[0008] In formula I, Y is selected from one of the structures shown in formulas II-1, II-2, and II-3:

[0009] The reactive thermoplastic resins described above have an intrinsic viscosity of 0.3~0.6 dL / g.

[0010] Another object of the present invention is to provide a method for preparing the above-mentioned reactive thermoplastic resin, comprising the following steps: Under an inert atmosphere, bisphenol compound, 4,4'-sulfonylbis[2-(2-allyl)]phenol, and dihalogen compound are dissolved in a polar aprotic solvent at a certain molar ratio. A salt-forming agent and a dehydrating agent are added, followed by dehydration and polymerization. After the reaction is completed, the mixture is cooled, a diluent is added, and the mixture is poured into a water-organic solvent mixture. After precipitation and vacuum drying, the reactive thermoplastic resin is obtained.

[0011] In the preparation method described above, the dihalogen compound is selected from one of the structures shown in Formula II-1, Formula II-2, and Formula II-3; In formulas II-1, II-2, and II-3, R is independently selected from fluorine and / or chlorine; The bisphenol compound is selected from the structures shown in Formula IV-1, Formula IV-2, Formula IV-3, and Formula IV-4. .

[0012] In the preparation method described above, the molar ratio of the total bisphenol compound to the dihalogen compound is 1:1 to 1.3.

[0013] In the preparation method described above, the molar ratio of the bisphenol compound to TGSH is 0.99~0.8:0.01~0.2.

[0014] In the preparation method described above, the salt-forming agent is selected from one or more of sodium hydroxide, potassium hydroxide, potassium carbonate, and sodium carbonate.

[0015] In the preparation method described above, the molar ratio of the bisphenol compound to the salt-forming agent is 1:1 to 1.5.

[0016] In the preparation method described above, the dehydrating agent is selected from toluene and / or xylene.

[0017] In the preparation method described above, the polar aprotic solvent is selected from one or more of sulfolane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and N-methylpyrrolidone.

[0018] In the preparation method described above, the temperature for water inclusion is 140–160°C, and the water inclusion time is 2–3 hours.

[0019] In the preparation method described above, the temperature of the water is independently selected from any value of 140°C, 145°C, 150°C, 155°C, 160°C, or a range between any two of the above.

[0020] In the preparation method described above, the water-carrying time is independently selected from any value of 2h, 3h, or a range between any two of the above.

[0021] In the preparation method described above, the polymerization reaction temperature is 180–200°C, and the polymerization reaction time is 1–4 h.

[0022] In the preparation method described above, the temperature of the polymerization reaction is independently selected from any value of 180°C, 185°C, 190°C, 195°C, 200°C, or a range between any two of the above.

[0023] In the preparation method described above, the time of the polymerization reaction is independently selected from any value of 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h or a range between any two of the above.

[0024] A third objective of this invention is to provide a bismaleimide resin composition obtained by blending and curing bismaleimide monomer, the above-mentioned reactive thermoplastic resin, allyl bisphenol A.

[0025] In the bismaleimide resin composition described above, the bismaleimide monomer is selected from one or more of N,N′-(4,4′-methylenediphenyl)bismaleimide, diisocyanate bismaleimide, polyether bismaleimide, and m-phenylenediamine bismaleimide.

[0026] The preparation method of the above-mentioned bismaleimide resin composition includes the following steps: A reactive thermoplastic resin, allyl bisphenol A (DABPA), and bismaleimide monomer are mixed in a certain molar ratio to obtain a blended resin prepolymer. The blended resin prepolymer is poured into a mold, degassed, and cured by gradient temperature increase to obtain the bismaleimide resin composition.

[0027] The reactive thermoplastic resin is selected from the above-mentioned reactive thermoplastic resins with large free volume.

[0028] In the preparation method of the bismaleimide resin composition as described above, the molar ratio of bismaleimide monomer to DABPA is 1:0.87.

[0029] In the preparation method of the bismaleimide resin composition as described above, the amount of reactive thermoplastic resin added is 1-20 phr of the total mass of BDM and DABPA.

[0030] The preparation method of the bismaleimide resin composition as described above involves a reaction temperature of 200℃~250℃ and a reaction time of 2h~8h.

[0031] Preferably, the reaction temperature is selected from any value of 200℃, 220℃, 230℃, 240℃, 250℃ or a range between any two of the above.

[0032] Preferably, the reaction time is selected from any value of 2h, 4h, 6h, 8h, 10h or a range between any two of the above.

[0033] In the preparation method of the bismaleimide resin composition as described above, the degassing temperature is 110℃~130℃.

[0034] Preferably, the degassing temperature is selected from any value of 110℃, 115℃, 120℃, 125℃, 130℃ or a range between any two of the above.

[0035] By adopting the above technical solution, the present invention has the following beneficial effects: High synergistic toughening efficiency: This invention integrates a large free-volume physical structure with the chemical function of active propylene groups. The large side groups in the toughening agent molecule (such as phenolphthalein and thymolphthalein) provide excellent energy absorption and crack deflection capabilities; simultaneously, the propylene groups on the side chains can undergo a Diels-Alder reaction with bismaleimide (BDM), "anchoring" the toughening agent molecular chain in the cross-linked network. The synergistic effect of physical dissipation and chemical bonding results in a toughening efficiency that is significantly better than traditional toughening agents that only contain reactive groups or rely solely on physical miscibility at the same addition level (typically 5-10 phr).

[0036] Excellent interfacial compatibility and suppression of phase separation: Due to the similarity between the toughening agent's main chain structure and that of high-performance thermoplastic resins (such as polyarylether sulfone / ketone), and the introduction of large side groups, it exhibits good solubility with BDM / DABPA prepolymers, following the principle of "like dissolves like." Through the chemical reaction of the propylene groups, strong covalent bonds are formed between the thermosetting network and the thermoplastic segments, fundamentally suppressing macroscopic phase separation. This allows the cured system to form a homogeneous or nanoscale microphase structure, thereby avoiding stress concentration and performance degradation caused by interfacial defects.

[0037] Excellent heat resistance: The synthesized thermoplastic resin with a large free volume reactive main chain has a rigid aromatic ring structure, coupled with the large-volume side groups of the bisphenol compound, resulting in high TL temperature stability. g (230~250℃), and becomes part of the cross-linked network through chemical "anchoring", the T of the composite material after curing g It will not decrease and can completely maintain the high T of pure BDM / DABPA resin. g Characteristics (typically around 285℃).

[0038] Suitable for industrial production: Bisphenol compounds, dihalobenzophenone / sulfone and TGSH are all commercially available monomers, without complicated pre-synthesis or purification steps, and some bisphenol compounds can be derived from bio-based raw materials, which is green and economical. An industrial-grade supply system has been formed, which significantly reduces production costs. At the same time, the synthesis process is simple and controllable, easy to scale up, and suitable for large-scale industrial production.

[0039] Excellent processing performance and wide applicability: This toughening agent has good solubility in BDM / DABPA prepolymer, and the resulting blend system has moderate viscosity, good fluidity, and is easy to degas and inject. It is highly compatible with existing composite material molding processes (such as compression molding and resin transfer molding) and has good prospects for engineering applications.

[0040] High molecular designability: The molecular design of this invention offers high flexibility. By replacing bisphenol monomers with different structures and sizes (such as phenolphthalein, thymolphthalein, bisphenol fluorene, etc.), the free volume, polarity, and reactivity of the toughening agent can be systematically controlled. This allows for the preparation of high-performance reactive toughening agents to meet different performance requirements (such as ultra-toughness, high heat resistance, low dielectric constant, etc.). The application scope is not limited to bismaleimide but can also be extended to other thermosetting systems such as epoxy resins.

[0041] Highly adaptable to various processes and easy to scale up: Resin synthesis utilizes mature S... N 2. The nucleophilic condensation reaction allows for blending, degassing, and curing processes of the BMI resin composition that are fully compatible with existing industrial molding systems for BMI resins (such as RTM and wet winding), requiring no additional specialized equipment. Furthermore, the resin viscosity is controllable (intrinsic viscosity 0.3~0.6 dL / g), facilitating the impregnation of reinforcing fibers and making it suitable for large-scale production applications. This reactive thermoplastic resin has promising application prospects in high-end fields such as aerospace and electronics. Attached Figure Description

[0042] Figure 1 The infrared spectrum (FT-IR) of the RPES-CT resin prepared in Example 1 of this invention; Figure 2 The ¹H NMR spectrum of the RPES-CT resin prepared in Example 1 of this invention is shown. Figure 3 Differential scanning calorimetry (DSC) image of the RPES-CT resin prepared in Example 1 of this invention; Figure 4 Thermogravimetric analysis (TGA) diagram of the RPES-CT resin prepared in Example 1 of this invention; Detailed Implementation

[0043] 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. The following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention.

[0044] Unless otherwise specified, all raw materials used in the examples are commercially available products.

[0045] Testing and characterization methods: 1. Proton NMR spectroscopy: A 400MHz NMR spectrometer (Bruker, Switzerland) was used for proton NMR spectroscopy measurements with deuterated chloroform (CDCl3) as the solvent. 1 H NMR).

[0046] 2. Fourier transform infrared spectroscopy: FT-IR spectrometer (Tracer-100, Japan) was used, KBr pellet method.

[0047] 3. Impact performance test: According to the national standard GB / T 1843-2023, a cantilever beam simply supported beam combined impact testing machine was used. The test conditions were: pendulum energy 7.5J, span 60mm, impact rate 3.5m / s, and the specimen size was 80mm×10mm×4mm. The toughness of the bismaleimide resin composition was characterized.

[0048] 4. Glass transition temperature: Measured using differential scanning calorimetry (DSC) under nitrogen atmosphere, heating rate of 10℃ / min, and temperature range of room temperature to 300℃. The inflection point temperature of the two-stage heating curve was taken as the glass transition temperature (T0) of the sample. g .

[0049] 5. Thermogravimetric analysis (TGA): Tested using a thermogravimetric analyzer (TGA) under a nitrogen atmosphere at a heating rate of 10℃ / min. The temperature range was room temperature to 500℃. The temperature corresponding to a 5% sample mass loss was recorded as T. d5% .

[0050] 6. Intrinsic viscosity: At room temperature, a certain amount of polymer powder was placed in a volumetric flask and dissolved with DMAc to prepare a solution of 0.5 g / dL. The intrinsic viscosity of the polymer was measured using an Ubbelohde viscometer (Ø=0.63 mm) in a constant temperature water bath at 25℃.

[0051] In one specific implementation, this application achieves its purpose through the following technical solution: A method for preparing reactive polyarylene ether sulfone is as follows: Difluorodiphenyl sulfone, 4,4'-sulfonylbis[2-(2-allyl)]phenol (TGSH), and phenolphthalein were dissolved in a polar aprotic solvent and reacted under nitrogen atmosphere with xylene as a dehydrating agent in the presence of potassium carbonate catalyst.

[0052] The unit content of TGSH in the propylene-based polyarylether sulfone (RPES-CT) molecular chain segment does not exceed 20%.

[0053] The TGSH unit content in the propylene-based polyarylene ether sulfone (RPES-CT) molecular chain segment is selected from any value of 0%, 2%, 5%, 7%, 10%, 12%, 15%, 17%, 20%, or any value between the two.

[0054] A method for preparing RPES-CT / DABPA / BDM blend resin is as follows: S1. A blended resin is prepared by hot-melting propylene-based polyarylether sulfone (RPES-CT) into DABPA and then adding bismaleimide (BDM), resulting in a blended resin prepolymer with a BDM:DABPA molar ratio of 1:0.87. S2. The blended resin prepolymer obtained in the previous step is used to make a casting plate through a mold; S3. Degas the prepolymer; S4. The composite material sheets are manufactured in an oven according to the process requirements. The sheets are then cut and post-processed to obtain the composite material.

[0055] Example 1: Preparation of bismaleimide resin composition Step 1 involves reacting three monomers—phenolphthalein (PHT), 4,4'-sulfonylbis[2-(2-allyl)]phenol (TGSH), and difluorodiphenyl sulfone (DFDPS)—with S... N 2. Nucleophilic polymerization reaction to obtain reactive polyarylether sulfone with a large free volume.

[0056] Under N2 protection, 11.460 g (36.0 mmol) PHT, 10.322 g (40.6 mmol) DFDPS, 1.322 g (4.0 mmol) TGSH (dissolved in xylene), 6.358 g (46.0 mmol) potassium carbonate powder, and 65 mL of NMP solvent were added sequentially to a three-necked flask equipped with a dehydrating device. The mixture was heated to dissolve the xylene, which served as the dehydrating agent, and reacted at 140°C for 2 h. The solution was then heated above the boiling point of xylene to remove xylene, and the mixture was continuously heated to 185°C for isothermal polymerization for 3 h. During the heating to 185°C, a small amount of xylene was also removed. After the reaction was complete, the mixture was cooled to below 100°C, diluted with 58 mL of DMAc, and the diluted liquid was poured into a mixed solvent of ethanol and water (Vol. 3:1). After precipitation for 24 hours, the product was filtered, crushed, washed repeatedly with boiling water, and vacuum dried to obtain the target product: a reactive polyarylene ether sulfone copolymer (RPES-CT) with a large free volume, an intrinsic viscosity of 0.42 dL / g, a TGSH content of 10% of the total bisphenol content, and a light pink powder.

[0057] Appendix Figure 1-4 The images shown are the infrared spectrum, nuclear magnetic resonance spectrum, DSC image, and TGA image of RPES-CT.

[0058] Step 2: Dissolve RPES-CT in allyl bisphenol A at 150°C. After complete dissolution and homogenization, add N,N′-(4,4′-methylenediphenyl)bismaleimide (BDM). Mix BDM and DABPA at a molar ratio of 1:0.87 and mechanically stir at 115°C for 30 minutes until homogeneous. Pour the mixture into a preheated mold and place it in a vacuum oven. Degas under vacuum at 120°C until all air bubbles disappear. Then, place the mold in a high-temperature oven for temperature gradient curing: cure at 130°C for 2 hours, 160°C for 2 hours, 180°C for 2 hours, 200°C for 2 hours, and 230°C for 5 hours. Finally, cut and polish the cured template to obtain the test specimen. The amount of RPES-CT added is 7.5 phr of the total mass of BDM and DABPA.

[0059] Example 2 Preparation of bismaleimide resin composition The three monomers thymolphthalein (TP), TGSH, and difluorodiphenyl sulfone (DFDPS) were subjected to S... N 2. Nucleophilic polymerization reaction yielded reactive polyarylene sulfone with a large free volume and an intrinsic viscosity of 0.38 dL / g.

[0060] Under N2 protection, 15.499 g (36.0 mmol) of thymolphthalein (TP), 10.170 g (40.0 mmol) of DFDPS, 1.322 g (4.0 mmol) of TGSH (dissolved in xylene), 6.910 g of potassium carbonate (K2CO3) fine powder (50.0 mmol), and NMP solvent (65 mL) were added sequentially to a three-necked flask equipped with a dehydration device. Subsequent dehydration, polymerization, precipitation, washing, and drying steps were the same as in step one of Example 1, yielding a light pink powdered resin.

[0061] The preparation method of the BDM composition is the same as step two of Example 1.

[0062] Example 3 Preparation of bismaleimide resin composition Bisphenol fluorene (BPF), TGSH, and difluorobenzophenone (DFBP) were subjected to S... N 2. Nucleophilic polymerization reaction yielded reactive polyarylether ketone with a large free volume and an intrinsic viscosity of 0.45 dL / g.

[0063] Under N2 protection, 12.610 g (36.0 mmol) of bisphenol fluorene (BPF), 8.860 g (40.6 mmol) of DFBP, 1.322 g (4.0 mmol) of TGSH (dissolved in xylene), 6.358 g of potassium carbonate (K2CO3) fine powder (46.0 mmol), and 65 mL of NMP solvent were added sequentially to a three-necked flask equipped with a dehydration device. Subsequent dehydration, polymerization, precipitation, washing, and drying steps were the same as in step one of Example 1, yielding a light pink powdered resin.

[0064] The preparation method of the BDM composition is the same as step two of Example 1.

[0065] Example 4 Preparation of bismaleimide resin composition The three monomers, isoindololinone bisphenol, TGSH, and difluorodiphenyl sulfone (DFDPS), were subjected to S... N 2. Nucleophilic polymerization reaction yielded reactive polyarylene sulfone with a large free volume and an intrinsic viscosity of 0.40 dL / g.

[0066] Under N2 protection, 11.460 g (36.0 mmol) of isoindololinone bisphenol, 10.322 g (40.6 mmol) of DFDPS, 1.322 g (4.0 mmol) of TGSH (dissolved in xylene), 6.358 g of potassium carbonate powder (46.0 mmol), and 65 mL of NMP solvent were added sequentially to a three-necked flask equipped with a dehydration device. Subsequent dehydration, polymerization, precipitation, washing, and drying steps were the same as in step one of Example 1, yielding a light pink powdered resin.

[0067] The preparation method of the BDM composition is the same as step two of Example 1.

[0068] Comparative Example 1 Pure polyethersulfone (PES) toughened BDM PES was dissolved in DABPA at 150°C. After complete dissolution and homogenization, N,N′-(4,4′-methylenediphenyl)bismaleimide (BDM) was added. BDM and DABPA were mixed at a molar ratio of 1:0.87 and mechanically stirred at 115°C for 30 minutes until homogeneous. The mixture was poured into a preheated mold and placed in a vacuum oven. Vacuum degassing was performed at 120°C until all air bubbles disappeared. Then, the mold was placed in a high-temperature oven for temperature gradient curing: 130°C for 2 hours, 160°C for 2 hours, 180°C for 2 hours, 200°C for 2 hours, and 230°C for 5 hours. Finally, the cured mold was cut and polished to obtain the test specimen, which is the control sample 1. The amount of PES added was 7.5 phr of the total mass of BDM and DABPA.

[0069] Comparative Example 2 Pure PES-C toughened BDM PES-C was dissolved in DABPA at 150°C. After complete dissolution and homogenization, N,N′-(4,4′-methylenediphenyl)bismaleimide (BDM) was added. BDM and DABPA were mixed at a molar ratio of 1:0.87 and mechanically stirred at 115°C for 30 minutes until homogeneous. The mixture was poured into a preheated mold and placed in a vacuum oven. Vacuum degassing was performed at 120°C until all air bubbles disappeared. Then, the mold was placed in a high-temperature oven for temperature gradient curing: 130°C for 2 hours, 160°C for 2 hours, 180°C for 2 hours, 200°C for 2 hours, and 230°C for 5 hours. Finally, the cured mold was cut and polished to obtain the test specimen, resulting in control sample 2. The amount of PES-C added was 7.5 phr of the total mass of BDM and DABPA.

[0070] Comparative Example 3 A blank sample was obtained by curing pure BDM resin using the same curing process as in Example 1.

[0071] Impact performance tests were conducted on the samples prepared in the examples and comparative examples, and the results are shown in Table 1: Table 1 Impact Resistance Test Table of Toughened Resin

[0072] Generally, free volume (FFV) is positively correlated with the toughness of a material. Within a certain range, the toughness of polymer resins increases with increasing FFV. Molecular chains with larger FFVs are anchored in thermosetting resin systems and are theoretically more likely to intercept impact cracks. The FFV values ​​of polymers calculated using molecular dynamics simulations are listed in Table 2.

[0073] Table 2 Sample FFV data sample Example 1 Example 2 Example 3 Example 4 FFV (%) 14.58 19.21 16.52 13.28 As shown in Tables 1 and 2, within a certain range, the larger the FFV, the better the toughness; however, an excessively large FFV (such as TP) may lead to chain segment aggregation and phase separation, which is not conducive to anchoring and toughening.

[0074] Table 3. Comparison of thermal properties of thermoplastic resins and corresponding toughened BMI systems in this invention and comparative patents. <![CDATA[T g (℃)]]> <![CDATA[T d5% (℃)]]> Example 1 249.5 440.5 Example 2 237.6 418.2 Example 3 252.8 455.7 Example 4 248.5 442.1 Patent CN 118185012A (RPES-10) 227.7 438.5 Patent CN 118184995A(RPEK-C-10) 221.5 433.4 As can be seen from Table 3, the bisphenol monomers (PHT, BPF, etc.) selected in this invention all contain aromatic ring structures with large free volumes, resulting in high molecular chain rotational resistance. In contrast, the RPES-10 and RPEK-C-10 of the comparative patents use conventional bisphenol monomers with a higher proportion of flexible segments, leading to their higher T... g Too low.

[0075] The intrinsic viscosity of the reactive polyarylether sulfone copolymers prepared in Examples 1-4 of this application was tested, and the results are shown in the table below.

[0076] Table 4. Intrinsic viscosity data of samples

[0077] Example 1 Example 2 Example 3 Example 4 [η] (dL / g) 0.42 0.38 0.45 0.40

[0078] The above embodiments are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural modifications made based on the content of this specification, or direct or indirect applications in other related technical fields, are similarly included within the scope of protection of this invention.

Claims

1. A reactive thermoplastic resin with a large free volume, characterized in that: It has a structural unit as shown in Equation I, where m+n=1, and m and n are mole percentages: ； X is selected from one of the structures shown in Equation I-1, Equation I-2, Equation I-3, and Equation I-4: ； In formula I, Y is selected from one of the structures shown in formulas II-1, II-2, and II-3: 。 2. The reactive thermoplastic resin with a large free volume according to claim 1, characterized in that: The intrinsic viscosity of the reactive thermoplastic resin ranges from 0.3 to 0.6 dL / g.

3. A method for preparing a reactive thermoplastic resin with a large free volume as described in any one of claims 1-2, characterized in that, Includes the following steps: Under an inert atmosphere, bisphenol compound, 4,4'-sulfonylbis[2-(2-allyl)]phenol, and dihalogen compound are dissolved in a polar aprotic solvent in a certain molar ratio. Salt-forming agent and dehydrating agent are added, followed by dehydration and polymerization reaction. After the reaction is completed, the temperature is lowered, a diluent is added, and the mixture is poured into a water-organic solvent mixture. After precipitation and vacuum drying, the reactive thermoplastic resin is obtained. The dihalogen compound is selected from one of the structures shown in Formula II-1, Formula II-2, and Formula II-3. ； In formulas II-1, II-2, and II-3, R is independently selected from fluorine and / or chlorine; The bisphenol compound is selected from one or more of the structures shown in Formula IV-1, Formula IV-2, Formula IV-3, and Formula IV-4; 。 4. The method for preparing a reactive thermoplastic resin with a large free volume according to claim 3, characterized in that: The molar ratio of the bisphenol compound to 4,4'-sulfonylbis[2-(2-allyl)]phenol is 0.99~0.8:0.01~0.2; the molar ratio of the total amount of the bisphenol compound and 4,4'-sulfonylbis[2-(2-allyl)]phenol to the dihalogen compound is 1:1~1.3; and the molar ratio of the total amount of the bisphenol compound and 4,4'-sulfonylbis[2-(2-allyl)]phenol to the salt-forming agent is 1:1~1.

5.

5. The method for preparing a reactive thermoplastic resin with a large free volume according to claim 3, characterized in that: The dehydrating agent is selected from toluene and / or xylene; the polar aprotic solvent is selected from at least one of sulfolane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and N-methylpyrrolidone; and the salt-forming agent is selected from one or more of potassium hydroxide, sodium hydroxide, potassium carbonate, and sodium carbonate.

6. The method for preparing a reactive thermoplastic resin with a large free volume according to claim 3, characterized in that: The temperature of the water-containing reaction is 140–160°C, and the water-containing time is 2–3 hours; the temperature of the polymerization reaction is 180–200°C, and the polymerization reaction time is 1–4 hours.

7. A bismaleimide resin composition, characterized in that: It is obtained by blending and curing bismaleimide monomer, reactive thermoplastic resin according to any one of claims 1-2, and allyl bisphenol A; wherein the bismaleimide monomer is selected from one or more of N,N′-(4,4′-methylenediphenyl)bismaleimide, diisocyanate bismaleimide, polyether bismaleimide, and m-phenylenediamine bismaleimide.

8. A method for preparing a bismaleimide resin composition according to claim 7, characterized in that: A reactive thermoplastic resin was dissolved in allyl bisphenol A, and bismaleimide monomer was added and mixed evenly to obtain a prepolymer. After degassing the prepolymer, it was cured by step temperature increase to obtain the bismaleimide resin composition.

9. The method for preparing a bismaleimide resin composition according to claim 8, characterized in that: The molar ratio of the bismaleimide monomer to allyl bisphenol A is 1:0.87, and the amount of the reactive thermoplastic resin added is 1-20 phr of the total mass of bismaleimide and allyl bisphenol A.

10. A method for preparing a bismaleimide resin composition according to claim 8, characterized in that: The degassing temperature is 110-130℃, and the degassing time is 1-2h; the temperature gradient curing method is: 130℃ for 2h, 160℃ for 2h, 180℃ for 2h, 200℃ for 2h, and 230℃ for 5h.

Images