A modified polyetheretherketone composite material and its preparation method

Abstract

The present invention discloses a modified polyetheretherketone composite material and a preparation method thereof, belonging to the technical field of polymer materials. The modified polyetheretherketone composite material comprises the following raw materials in parts by weight: polyetheretherketone resin matrix: 60-85 parts; carbon fiber: 5-15 parts; modified nano-silica: 5-20 parts; hydroxyapatite: 5-10 parts; coupling agent: 0.5-2 parts; compatibilizer: 2-4 parts; In the present invention, a nucleophilic substitution reaction occurs between 4'-hydroxyacetophenone and 2-chloro-5-nitrobenzotrifluoride to obtain intermediate 1; intermediate 1 undergoes a benzene cyclization reaction to obtain a trinitro compound; then, under the action of hydrazine hydrate, it is reduced to a fluorine-containing triamine monomer; thereafter, the fluorine-containing triamine monomer reacts with 4,4'-(hexafluoroisopropylidene) diphthalic anhydride to prepare a modified compatibilizer. The modified polyetheretherketone composite material prepared by the present invention has excellent tensile strength, corrosion resistance and wear resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly relates to a modified polyetheretherketone composite material and a preparation method thereof. Background Art

[0002] Polyetheretherketone (PEEK) is a semi-crystalline thermoplastic polymer, known for its high temperature resistance (melting temperature 334 °C), chemical stability, mechanical strength, and self-lubrication, and is widely used in the fields of aerospace, automotive, electronics, and medical. Its linear aromatic molecular structure endows it with high wear resistance and dimensional stability, especially having important potential in the field of tribology. However, the performance of pure PEEK materials still has limitations under friction conditions, such as a relatively high friction coefficient, insufficient wear resistance, and it is difficult to achieve complex shape customization with traditional processing techniques. Existing PEEK modification technologies mainly improve its performance by adding fillers (such as carbon fiber, glass fiber, nanoparticles, etc.), but there are problems such as poor compatibility between PEEK and fillers, poor filler dispersion, weak interfacial bonding, and insufficient bioactivity. Therefore, it is of great significance to develop a modified PEEK composite material with better comprehensive performance.

[0003] Chinese invention patent with publication number CN109851989A discloses a polyetheretherketone composite material, a preparation method and an application thereof. The polyetheretherketone composite material includes the following components: 60 - 75 parts of polyetheretherketone; 5 - 10 parts of polytetrafluoroethylene; 5 - 15 parts of polyimide; 5 - 10 parts of carbon fiber; 0.1 - 1 part of graphene; 0.5 - 4 parts of nano-silica. The prepared polyetheretherketone composite material has good high temperature resistance, but its tensile performance and friction performance are poor. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a modified polyetheretherketone composite material and a preparation method thereof.

[0005] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0006] A modified polyetheretherketone composite material, comprising the following raw materials in parts by weight:

[0007] Polyetheretherketone resin: 60 - 85 parts; carbon fiber: 5 - 15 parts; modified nano-silica: 5 - 20 parts; hydroxyapatite: 5 - 10 parts; coupling agent: 0.5 - 2 parts; modified compatibilizer: 2 - 4 parts;

[0008] The modified compatibilizer is prepared by the following method:

[0009] S1: p-Hydroxyacetophenone and 2-chloro-5-nitro-trifluoromethylbenzene in the presence of a catalyst anhydrous K 2 CO 3Under the action of [nucleophilic substitution reaction occurs to obtain intermediate 1;

[0010] S2: Intermediate 1 undergoes a three-molecule condensation and benzene ring formation reaction under the action of the catalyst silicon tetrachloride to obtain a trinitro compound;

[0011] S3: The trinitro compound is reduced to a fluorine-containing triamine monomer under the action of the catalyst Pd / C and the reducing agent hydrazine hydrate;

[0012] S4: Under nitrogen protection, add DMAc and the fluorine-containing triamine monomer to the reactor, slowly dropwise add 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, stir and react for 12 - 24 h, then add the acetic anhydride / pyridine mixture, and carry out a ring-closure reaction at room temperature to obtain the modified compatibilizer.

[0013] In the step S1, the feeding mass ratio of 4-hydroxyacetophenone to 2-chloro-5-nitro-trifluoromethylbenzene is 1:(1 - 1.25).

[0014] In the step S2, the feeding mass ratio of intermediate 1 to silicon tetrachloride is 20:(4 - 6).

[0015] In the step S3, the feeding mass ratio of the trinitro compound, Pd / C, and hydrazine hydrate is 20:(0.6 - 0.8):(5 - 8).

[0016] In the step S4, the feeding mass ratio of DMAc, the fluorine-containing triamine monomer, and 4,4'-(hexafluoroisopropylidene) diphthalic anhydride is 50:(12 - 16):(8 - 10).

[0017] The coupling agent is one or a combination of vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, and methylvinyldimethoxysilane.

[0018] The preparation method of the modified nano-silica is as follows:

[0019] S1: Add toluene and nano-silica to the reactor, ultrasonically vibrate for 20 - 30 min, then add γ-methacryloxypropyltrimethoxysilane and triethylamine, react at 100 - 120 °C for 3 - 5 h, and perform post-treatment to obtain silane-grafted nano-silica;

[0020] S2: Under nitrogen protection, add toluene, silane-grafted nano-silica, styrene, and the initiator AIBN to the reactor, stir and mix evenly, heat up to 80 - 100 °C, react for 12 - 16 h, and perform post-treatment to obtain the modified nano-silica.

[0021] In step S1, the feeding mass ratio of toluene, nano-silica, and γ-methacryloxypropyltrimethoxysilane is 50:(12 - 16):(4 - 6).

[0022] In step S2, the feeding mass ratio of toluene, silane-grafted nano-silica, styrene, and initiator AIBN is 50:(8 - 10):(2 - 3):(0.02 - 0.05).

[0023] A preparation method of a modified polyetheretherketone composite material includes the following steps:

[0024] S1: Weigh by weight parts: 60 - 85 parts of polyetheretherketone resin; 5 - 15 parts of carbon fiber; 5 - 20 parts of modified nano-silica; 5 - 10 parts of hydroxyapatite; 0.5 - 2 parts of coupling agent; 2 - 4 parts of modified compatibilizer;

[0025] S2: Add the polyetheretherketone resin, carbon fiber, modified nano-silica, hydroxyapatite, coupling agent, and modified compatibilizer into a high-speed mixer in proportion and mix evenly; add the mixed material into a twin-screw extruder, set the melting temperature at 360 - 400°C, the screw speed at 200 - 400 rpm, and extrude and pelletize; inject the pellet material, set the injection temperature at 350 - 380°C, and the mold temperature at 160 - 180°C to obtain the modified polyetheretherketone composite material.

[0026] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include:

[0027] (1) In the present invention, a nucleophilic substitution reaction occurs between hydroxyacetophenone and 2-chloro-5-nitro-trifluoromethylbenzene to obtain intermediate 1; intermediate 1 undergoes a benzene cyclization reaction to obtain a trinitro compound; the trinitro compound is reduced to a fluorine-containing triamine monomer under the action of hydrazine hydrate; then the fluorine-containing triamine monomer reacts with 4,4'-(hexafluoroisopropylidene) diphthalic anhydride to prepare a modified compatibilizer.

[0028] (2) In the present invention, silane-grafted nano-silica is prepared by grafting a silane coupling agent - γ-methacryloxypropyltrimethoxysilane on the surface of nano-silica, and then modified nano-silica is prepared by grafting styrene.

[0029] (3) The structural units such as fluorine-containing triamine monomers in the modified compatibilizer prepared by the present invention have good flexibility and reactivity, can form a "bridge" between polyetheretherketone and other components, reduce the interfacial energy between phases, enhance the interfacial bonding force, make the distribution of each phase inside the composite material more uniform, and improve the overall performance. The modified compatibilizer can reduce the surface tension between each phase, prevent particle agglomeration, promote the good dispersion of the reinforcing phase (such as carbon fiber, etc.) in the polyetheretherketone matrix, make the composite material more uniform in microstructure, and thus improve the mechanical properties and physical properties of the material.

[0030] (4) Through the graft treatment with silane coupling agent and styrene, the surface hydroxyl groups are replaced by hydrophobic groups, resulting in a decrease in polarity and an improvement in the compatibility with the polyether ether ketone matrix. After the modified nano-silica is uniformly dispersed, a three-dimensional network is formed with the matrix molecular chains through physical entanglement or chemical cross-linking, which can effectively disperse the external load and increase the tensile strength of the material. Detailed implementation manners

[0031] The following is further described in conjunction with embodiments, but the present invention is not limited to these embodiments.

[0032] Example 1 Preparation of modified compatibilizer:

[0033] S1: Under nitrogen protection, add 400 ml of DMAc, 40 g of p-hydroxyacetophenone, and 50 g of anhydrous K 2 CO 3 to the reactor, stir and mix evenly, heat up to 120 °C, then slowly dropwise add 40 g of 2-chloro-5-nitro-trifluoromethylbenzene, dropwise add for 10 min, react for 10 h, cool down to 40 °C, add 100 ml of anhydrous ethanol and 600 ml of deionized water, stir, precipitate, filter, then wash three times with deionized water (50 ml of deionized water each time), and then add 300 ml of anhydrous ethanol for recrystallization, and vacuum dry at 70 °C for 2 h to obtain intermediate 1;

[0034] S2: Add 200 ml of anhydrous ethanol and 20 g of intermediate 1 to the reactor, stir, and slowly and uniformly dropwise add 4 g of silicon tetrachloride at room temperature, dropwise add for 2 min, react at room temperature for 12 h after dropping, then add 100 ml of deionized water, continue to stir for 30 min, slowly add 10 wt% NaOH solution to adjust the solution to neutral, filter, add 80 ml of deionized water for washing, and vacuum dry at 60 °C for 2 h to obtain a trinitro compound;

[0035] S3: Under nitrogen protection, add 200 ml of anhydrous ethanol, 20 g of trinitro compound, and 0.6 g of Pd / C to the reactor, stir and mix evenly, heat up to reflux, then slowly dropwise add 5 g of hydrazine hydrate, dropwise add for 30 min, react for 12 h, then cool down to room temperature, add 200 ml of deionized water, stir, precipitate, filter, then wash three times with deionized water (50 ml of deionized water each time), and vacuum dry at 50 °C for 4 h to obtain a fluorinated triamine monomer, and its structural formula is as follows:

[0036]

[0037] The nuclear magnetic resonance hydrogen spectrum data thereof are as follows:

[0038] 11H NMR (500 MHz, Chloroform-d) δ 7.81 (s, 3H), 7.59 - 7.46 (m, 6H), 7.24 (dt, J = 1.9, 0.9 Hz, 3H), 7.20 - 7.13 (m, 6H), 7.00 (d, J = 8.1 Hz, 3H), 6.62 (dd, J = 8.1, 2.2 Hz, 3H), 4.73 (s, 6H).

[0039] S4: Under nitrogen protection, add 500 g of DMAc and 120 g of fluorinated triamine monomer into the reactor. Add 80 g of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride in batches (20 g per batch, with a 5-minute interval between batches), stir, and react at room temperature for 12 h. Then add 300 ml of acetic anhydride / pyridine mixture (acetic anhydride:pyridine (V:V) = 4:5), react at room temperature for 12 h, then add 500 ml of absolute ethanol to produce precipitation, filter, wash with 35 ml of deionized water, and dry in vacuum at 60 °C for 3 h to obtain the modified compatibilizer.

[0040] Example 2: Preparation of the modified compatibilizer:

[0041] S1: Under nitrogen protection, add 400 ml of DMAc, 40 g of p-hydroxyacetophenone, and 55 g of anhydrous K 2 CO 3 to the reactor, stir and mix evenly, heat up to 110 °C, then slowly dropwise add 45 g of 2-chloro-5-nitro-trifluoromethylbenzene dropwise for 12 min, react for 11 h, cool down to 40 °C, then add 100 ml of absolute ethanol and 600 ml of deionized water, stir to precipitate, filter, then wash with deionized water three times (50 ml of deionized water each time), then add 300 ml of absolute ethanol for recrystallization, and dry in vacuum at 60 °C for 3 h to obtain Intermediate 1;

[0042] S2: Add 200 ml of absolute ethanol and 20 g of Intermediate 1 to the reactor, stir, and slowly and uniformly dropwise add 5 g of silicon tetrachloride at room temperature dropwise for 2 min. After dropping, react at room temperature for 13 h, then add 100 ml of deionized water, continue to stir for 30 min, slowly add 10 wt% NaOH solution to adjust the solution to neutral, filter, add 80 ml of deionized water for washing, and dry in vacuum at 50 °C for 3 h to obtain the trinitro compound;

[0043] S3: Under nitrogen protection, add 200 ml of absolute ethanol, 20 g of trinitro compound, and 0.7 g of Pd / C into the reactor, stir to mix evenly, heat up to reflux, then slowly dropwise add 6 g of hydrazine hydrate over 45 min. After reacting for 11 h, cool to room temperature, add 200 ml of deionized water, stir, precipitate out, filter, and then wash three times with deionized water (50 ml of deionized water each time), and vacuum dry at 60 °C for 3 h to obtain the fluorine-containing triamine monomer;

[0044] S4: Under nitrogen protection, add 500 g of DMAc and 140 g of fluorine-containing triamine monomer into the reactor, add 90 g of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride in batches (30 g each batch, with a 5-min interval between batches), stir, and react at room temperature for 14 h. Then add 300 ml of acetic anhydride / pyridine mixture (acetic anhydride:pyridine (V:V) = 4:5), react at room temperature for 14 h, then add 500 ml of absolute ethanol to produce precipitation, filter, wash with 35 ml of deionized water, and vacuum dry at 50 °C for 4 h to obtain the modified compatibilizer.

[0045] Example 3 Preparation of the modified compatibilizer:

[0046] S1: Under nitrogen protection, add 400 ml of DMAc, 40 g of 4-hydroxyacetophenone, and 60 g of anhydrous K 2 CO 3 into the reactor, stir to mix evenly, heat up to 100 °C, then slowly dropwise add 50 g of 2-chloro-5-nitro-trifluoromethylbenzene over 15 min. After reacting for 12 h, cool to 40 °C, then add 100 ml of absolute ethanol and 600 ml of deionized water, stir, precipitate out, filter, and then wash three times with deionized water (50 ml of deionized water each time), then add 300 ml of absolute ethanol for recrystallization, and vacuum dry at 50 °C for 4 h to obtain Intermediate 1;

[0047] S2: Add 200 ml of absolute ethanol and 20 g of Intermediate 1 into the reactor, stir, and slowly and uniformly dropwise add 6 g of silicon tetrachloride at room temperature over 2 min. After dropping, react at room temperature for 14 h, then add 100 ml of deionized water, continue to stir for 30 min, slowly add 10 wt% NaOH solution to adjust the solution to neutral, filter, add 80 ml of deionized water for washing, and vacuum dry at 40 °C for 4 h to obtain the trinitro compound;

[0048] S3: Under nitrogen protection, add 200 ml of absolute ethanol, 20 g of trinitro compound, and 0.8 g of Pd / C into the reactor, stir to mix evenly, heat up to reflux, then slowly dropwise add 8 g of hydrazine hydrate over 1 h. After reacting for 10 h, cool down to room temperature, add 200 ml of deionized water, stir to precipitate, filter, and then wash three times with deionized water (50 ml of deionized water is used each time), and dry in vacuum at 70 °C for 2 h to obtain the fluorine-containing triamine monomer;

[0049] S4: Under nitrogen protection, add 500 g of DMAc and 160 g of fluorine-containing triamine monomer into the reactor, add 100 g of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride in batches (25 g each batch, with a 5-min interval between batches), stir, and react at room temperature for 16 h. Then add 300 ml of acetic anhydride / pyridine mixture (acetic anhydride:pyridine (V:V) = 4:5), react at room temperature for 16 h, then add 500 ml of absolute ethanol to produce precipitation, filter, wash with 35 ml of deionized water, and dry in vacuum at 70 °C for 2 h to obtain the modified compatibilizer.

[0050] Example 4 Preparation of modified nano-silica:

[0051] S1: Add 500 g of toluene and 120 g of nano-silica into the reactor, ultrasonically vibrate for 20 min, then add 40 g of γ-methacryloxypropyltrimethoxysilane and 60 ml of triethylamine, react at 100 °C for 5 h, centrifuge and wash, wash successively with 100 ml of toluene, 100 ml of absolute ethanol, and 100 ml of 50 wt% ethanol, and then dry in vacuum at 80 °C for 2 h to obtain silane-grafted nano-silica;

[0052] S2: Under nitrogen protection, add 500 g of toluene, 80 g of silane-grafted nano-silica, 20 g of styrene, and 0.2 g of initiator AIBN into the reactor, stir to mix evenly, heat up to 80 °C, after reacting for 16 h, cool down to room temperature, add 500 ml of methanol, let it stand for precipitation, filter, and dry in vacuum at 80 °C for 5 h to obtain modified nano-silica.

[0053] Example 5 Preparation of modified nano-silica:

[0054] S1: Add 500 g of toluene and 140 g of nano-silica into the reactor, ultrasonically vibrate for 25 min, then add 50 g of γ-methacryloxypropyltrimethoxysilane and 65 ml of triethylamine, react at 110 °C for 4 h, centrifuge and wash, wash successively with 100 ml of toluene, 100 ml of absolute ethanol, and 100 ml of 50 wt% ethanol, and then dry in vacuum at 90 °C for 1 h to obtain silane-grafted nano-silica;

[0055] S2: Under nitrogen protection, add 500 g of toluene, 90 g of silane-grafted nano-silica, 25 g of styrene, and 0.3 g of initiator AIBN into the reactor. Stir to mix evenly, heat up to 90 °C, react for 14 h, then cool down to room temperature. Add 500 ml of methanol, let it stand for precipitation, filter, and dry in vacuum at 70 °C for 6 h to obtain modified nano-silica.

[0056] Example 6 Preparation of modified nano-silica:

[0057] S1: Add 500 g of toluene and 160 g of nano-silica into the reactor, ultrasonically oscillate for 30 min, then add 60 g of γ-methacryloxypropyltrimethoxysilane and 70 ml of triethylamine, react at 120 °C for 3 h, centrifuge and wash, wash successively with 100 ml of toluene, 100 ml of absolute ethanol, and 100 ml of 50 wt% ethanol, then dry in vacuum at 100 °C for 40 min to obtain silane-grafted nano-silica;

[0058] S2: Under nitrogen protection, add 500 g of toluene, 100 g of silane-grafted nano-silica, 30 g of styrene, and 0.5 g of initiator AIBN into the reactor. Stir to mix evenly, heat up to 100 °C, react for 12 h, then cool down to room temperature. Add 500 ml of methanol, let it stand for precipitation, filter, and dry in vacuum at 60 °C for 7 h to obtain modified nano-silica.

[0059] Example 7 Preparation of modified polyetheretherketone composite:

[0060] S1: Weigh polyetheretherketone resin: 600 g; carbon fiber: 50 g; modified nano-silica (prepared in Example 4): 50 g; hydroxyapatite: 50 g; coupling agent (3-glycidoxypropyltrimethoxysilane): 5 g; modified compatibilizer (prepared in Example 1): 20 g;

[0061] S2: Add polyetheretherketone resin, carbon fiber, modified nano-silica, hydroxyapatite, coupling agent, and modified compatibilizer into a high-speed mixer in proportion and mix evenly; add the mixed material into a twin-screw extruder, set the melting temperature at 360 °C, screw speed at 200 rpm, and extrude and pelletize; inject the pellet material into a mold, set the injection temperature at 350 °C and the mold temperature at 160 °C to obtain the modified polyetheretherketone composite.

[0062] Example 8 Preparation of modified polyetheretherketone composite:

[0063] S1: Weigh polyetheretherketone resin: 700 g; carbon fiber: 80 g; modified nano-silica (prepared in Example 5): 120 g; hydroxyapatite: 80 g; coupling agent (vinyltriethoxysilane): 10 g; modified compatibilizer (prepared in Example 2): 30 g;

[0064] S2: Add polyetheretherketone resin, carbon fiber, modified nano-silica, hydroxyapatite, coupling agent, and modified compatibilizer into a high-speed mixer in proportion and mix evenly; add the mixed material into a twin-screw extruder, set the melting temperature at 380 °C, the screw speed at 300 rpm, and extrude and pelletize; inject and mold the pellet material at an injection temperature of 360 °C and a mold temperature of 170 °C to obtain the modified polyetheretherketone composite material.

[0065] Example 9 Preparation of modified polyetheretherketone composite material:

[0066] S1: Weigh polyetheretherketone resin: 850 g; carbon fiber: 150 g; modified nano-silica (prepared in Example 6): 200 g; hydroxyapatite: 100 g; coupling agent (methylvinyl dimethoxysilane): 20 g; modified compatibilizer (prepared in Example 3): 40 g;

[0067] S2: Add polyetheretherketone resin, carbon fiber, modified nano-silica, hydroxyapatite, coupling agent, and modified compatibilizer into a high-speed mixer in proportion and mix evenly; add the mixed material into a twin-screw extruder, set the melting temperature at 400 °C, the screw speed at 400 rpm, and extrude and pelletize; inject and mold the pellet material at an injection temperature of 380 °C and a mold temperature of 180 °C to obtain the modified polyetheretherketone composite material.

[0068] Comparative Example 1

[0069] A modified polyetheretherketone composite material, the raw material composition and process are basically the same as those in Example 8, the difference is that the modified compatibilizer is not added in the components.

[0070] Comparative Example 2

[0071] A modified polyetheretherketone composite material, the raw material composition and process are basically the same as those in Example 8, the difference is that the modified compatibilizer added in the components is replaced with polyimide of equal weight.

[0072] Comparative Example 3

[0073] A modified polyetheretherketone composite material, the raw material composition and process are basically the same as those in Example 8, the difference is that the modified compatibilizer is replaced with a compatibilizer prepared by the following method:

[0074] S1: Under nitrogen protection, add 400 ml of DMAc, 40 g of p-hydroxyacetophenone, and 55 g of anhydrous K 2 CO 3, stir and mix evenly, heat up to 110 °C, then add 45 g of 4-nitrochlorobenzene, react for 11 h, cool down to 40 °C, then add 100 ml of absolute ethanol and 600 ml of deionized water, stir, precipitate, filter, and then wash three times with deionized water (50 ml of deionized water each time), then add 300 ml of absolute ethanol for recrystallization, and vacuum dry at 60 °C for 3 h to obtain Intermediate 1;

[0075] S2: Add 200 ml of absolute ethanol and 20 g of Intermediate 1 to the reactor, stir, slowly and evenly dropwise add 5 g of silicon tetrachloride at room temperature, the dropping time is 2 min, after dropping, react at room temperature for 13 h, then add 100 ml of deionized water, continue to stir for 30 min, slowly add 10 wt% NaOH solution to adjust the solution to neutral, filter, add 80 ml of deionized water for washing, and vacuum dry at 50 °C for 3 h to obtain the trinitro compound;

[0076] S3: Under nitrogen protection, add 200 ml of absolute ethanol, 20 g of trinitro compound, and 0.7 g of Pd / C to the reactor, stir and mix evenly, heat up to reflux, then slowly dropwise add 6 g of hydrazine hydrate, the dropping time is 45 min, after reacting for 11 h, cool down to room temperature, add 200 ml of deionized water, stir, precipitate, filter, and then wash three times with deionized water (50 ml of deionized water each time), and vacuum dry at 60 °C for 3 h to obtain the fluorine-containing triamine monomer;

[0077] S4: Under nitrogen protection, add 500 g of DMAc and 140 g of fluorine-containing triamine monomer to the reactor, add 90 g of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride in batches (30 g each batch, the batch interval is 5 min), stir, react at room temperature for 14 h, then add 300 ml of acetic anhydride / pyridine mixture (acetic anhydride:pyridine (V:V)=4:5), react at room temperature for 14 h, then add 500 ml of absolute ethanol to produce precipitation, filter, wash with 35 ml of deionized water, and vacuum dry at 50 °C for 4 h to obtain the modified compatibilizer.

[0078] Comparative Example 4

[0079] A modified polyetheretherketone composite material, the raw material composition and process are basically the same as those in Example 8, the difference is that the modified compatibilizer is replaced by a compatibilizer prepared by the following method:

[0080] S1: Under nitrogen protection, add 400 ml of DMAc, 40 g of 4-hydroxyacetophenone, and 55 g of anhydrous K 2 CO 3, Stir and mix evenly, heat up to 110 °C, then slowly add dropwise 45 g of 2-chloro-5-nitro-benzotrifluoride over 12 min, react for 11 h, cool down to 40 °C, then add 100 ml of absolute ethanol and 600 ml of deionized water, stir, precipitate, filter, then wash three times with deionized water (50 ml of deionized water each time), then add 300 ml of absolute ethanol for recrystallization, and dry in vacuum at 60 °C for 3 h to obtain Intermediate 1;

[0081] S2: Add 200 ml of absolute ethanol and 20 g of Intermediate 1 to the reactor, stir, slowly and uniformly add dropwise 5 g of silicon tetrachloride at room temperature over 2 min, after dropping, react at room temperature for 13 h, then add 100 ml of deionized water, continue to stir for 30 min, slowly add 10 wt% NaOH solution to adjust the solution to neutral, filter, add 80 ml of deionized water for washing, and dry in vacuum at 50 °C for 3 h to obtain the trinitro compound;

[0082] S3: Under nitrogen protection, add 200 ml of absolute ethanol, 20 g of the trinitro compound, and 0.7 g of Pd / C to the reactor, stir and mix evenly, heat up to reflux, then slowly add dropwise 6 g of hydrazine hydrate over 45 min, after reacting for 11 h, cool to room temperature, add 200 ml of deionized water, stir, precipitate, filter, then wash three times with deionized water (50 ml of deionized water each time), and dry in vacuum at 60 °C for 3 h to obtain the fluorine-containing triamine monomer;

[0083] S4: Under nitrogen protection, add 500 g of DMAc and 140 g of the fluorine-containing triamine monomer to the reactor, add 90 g of pyromellitic dianhydride in batches (30 g each batch, with a batch interval of 5 min), stir, react at room temperature for 14 h, then add 300 ml of acetic anhydride / pyridine mixture (acetic anhydride:pyridine (V:V)=4:5), react at room temperature for 14 h, then add 500 ml of absolute ethanol to produce precipitation, filter, wash with 35 ml of deionized water, and dry in vacuum at 50 °C for 4 h to obtain the modified compatibilizer.

[0084] Comparative Example 5

[0085] A modified polyetheretherketone composite material, the raw material composition and process are basically the same as those in Example 8, the difference is that the modified compatibilizer is replaced with a compatibilizer prepared by the following method:

[0086] (1) Dissolve 120 g of 4,4'-diaminodiphenyl ether in an appropriate amount of 500 g of N,N-dimethylformamide, then add 100 g of biphenyltetracarboxylic dianhydride, stir and react for 24 h to obtain a polyamic acid solution.

[0087] (2) Mix the solution obtained in step (1) with 200 g of melamine, seal and react at 200 °C for 8 h. After cooling, pour it into 200 ml of deionized water to precipitate. Filter by suction, and then wash three times with deionized water (80 ml of deionized water is used each time), and dry in vacuum at 60 °C for 3 h to obtain the modified compatibilizer.

[0088] Comparative Example 6

[0089] A modified polyetheretherketone composite material, the raw material composition and process are basically the same as those of Example 8, the difference is that the modified nano-silica is replaced with nano-silica of equal weight.

[0090] Comparative Example 7

[0091] A modified polyetheretherketone composite material, the raw material composition and process are basically the same as those of Example 8, the difference is that the modified nano-silica is replaced with the modified nano-silica prepared by the following method:

[0092] Add 500 g of toluene and 120 g of nano-silica to the reactor, ultrasonically vibrate for 20 min, then add 40 g of γ-methacryloxypropyltrimethoxysilane and 60 ml of triethylamine, react at 100 °C for 5 h, centrifuge and wash, wash successively with 100 ml of toluene, 100 ml of absolute ethanol, and 100 ml of 50 wt% ethanol, and then dry in vacuum at 80 °C for 2 h to obtain silane-grafted nano-silica.

[0093] Comparative Example 8

[0094] A polyetheretherketone composite material prepared with the raw material composition, ratio and the following method of Example 2 of the Chinese invention patent with the publication number CN109851989A.

[0095] The polyetheretherketone resin models used in Examples 7-9 and Comparative Examples 1-8 of this application are RTP 2205HF BK, purchased from RTP Company, USA; the carbon fiber model is SYT55, purchased from Zhongfu Shenying Carbon Fiber Co., Ltd.; the particle size of nano-silica is 15 nm, purchased from Shanghai Guipu Chemical Co., Ltd.; the hydroxyapatite model is Fluoro-HA, purchased from Zhejiang Yamei Nano Technology Co., Ltd. When 2-chloro-5-nitro-trifluoromethylbenzene is added dropwise, the temperature of 2-chloro-5-nitro-trifluoromethylbenzene is 35 °C.

[0096] Conduct tests such as tensile strength, elongation at break, friction coefficient, and heat distortion temperature on the modified polyetheretherketone composite materials prepared in Examples 7-9 and Comparative Examples 1-8.

[0097] The tensile strength was carried out according to GB / T 1040.2-2006; the elongation at break was carried out according to GB / T 1040.2-2006; the coefficient of friction was carried out according to GB / T 3960-2016; the heat distortion temperature was carried out according to GB / T 1634.1-2019; the salt spray test was carried out according to ASTM G85 standard, the sample size: 50×100×3 mm (ISO 3167 standard dumbbell specimen), and the dilute electrolyte circulating spray / drying test method of Annex A5 was adopted, with the number of cycles being 50 times. The test results are shown in Table 1.

[0098] Table 1

[0099]

[0100] It can be seen from Examples 7, 8, and 9 in Table 1 that the tensile strength of the modified polyetheretherketone composite material prepared by the present invention is greater than 112 MPa, the elongation at break is greater than 22%, the coefficient of friction is less than 0.15, and the heat distortion temperature is about 310 °C, having excellent tensile properties, wear resistance, and corrosion resistance.

[0101] Comparative Example 1 is a comparative example without adding a modified compatibilizer. It can be seen from the data in Table 1 that its tensile strength is 81 MPa, the elongation at break is 16.4%, the coefficient of friction is 0.26, the heat distortion temperature is 266 °C, and the salt spray resistance performance is poor.

[0102] Comparative Example 2 is a comparative example different from Example 8. The difference is that the modified compatibilizer is replaced with polyimide of equal weight. It can be seen from the data in Table 1 that its tensile strength is 85 MPa, the elongation at break is 17.2%, the coefficient of friction is 0.24, and the heat distortion temperature is 274 °C. Since the hyperbranched structure introduces physical crosslinking of the molecular chain, and at the same time the hyperbranched polyimide has good solubility to promote its uniform dispersion in the polyetheretherketone matrix and reduce defects, the tensile strength and elongation at break of the composite material can be improved.

[0103] Comparative Example 3 is a comparative example different from Example 8. The difference lies in replacing 2-chloro-5-nitro-trifluoromethylbenzene in step S1 during the preparation of the modified compatibilizer with 4-nitrochlorobenzene. It can be seen from the data in Table 1 that its tensile strength is 96 MPa, the elongation at break is 18.6%, the coefficient of friction is 0.22, and the heat distortion temperature is 297 °C. This is because structural units such as fluorinated triamine monomers have good flexibility and reactivity, can form a "bridge" between polyetheretherketone and other components, reduce the interfacial energy between phases, enhance the interfacial bonding force, make the distribution of each phase inside the composite material more uniform, and improve the overall performance.

[0104] Comparative Example 4 is a comparative example different from Example 8. The difference lies in that pyromellitic dianhydride is used to replace 4,4'-(hexafluoroisopropylidene) diphthalic anhydride in step S4 of the preparation process of the modified compatibilizer. It can be seen from the data in Table 1 that its tensile strength is 101 MPa, elongation at break is 20.7%, coefficient of friction is 0.18, and heat distortion temperature is 302 °C. This is because the benzene rings, fluorine atoms, etc. contained in the modified compatibilizer itself have relatively high thermal stability. In the composite material, it can interact with the molecular chains of polyether ether ketone, improve the rigidity and thermal stability of the molecular chains, and then increase the heat distortion temperature of the composite material, enabling it to maintain good performance in a higher temperature environment. At the same time, the introduction of fluorine atoms endows the material with excellent chemical corrosion resistance. Further, the fluorine-containing structure in the modified compatibilizer can form a stable protective film on the surface or interface of the composite material, resist the erosion of chemical substances, and improve the stability and durability of the composite material in a chemical environment.

[0105] Comparative Example 5 is a comparative example different from Example 8. The difference lies in that the preparation process of the modified compatibilizer is different. It can be seen from the data in Table 1 that its tensile strength is 92 MPa, elongation at break is 17.8%, coefficient of friction is 0.20, and heat distortion temperature is 283 °C.

[0106] Comparative Example 6 is a comparative example different from Example 8. The difference lies in that the modified nano-silica added in the components is replaced by unmodified nano-silica. It can be seen from the data in Table 1 that its tensile strength is 100 MPa, elongation at break is 20.3%, coefficient of friction is 0.19, and heat distortion temperature is 301 °C. The surface of nano-silica is rich in hydroxyl groups (Si-OH), which are prone to agglomerate through hydrogen bonds and van der Waals forces to form micron-sized aggregates, resulting in an increase in stress concentration points and a decrease in material strength. Through treatment with γ-methacryloxypropyltrimethoxysilane, the surface hydroxyl groups are replaced by hydrophobic groups, the polarity is reduced, the compatibility with the polyether ether ketone matrix is improved, and a three-dimensional network is formed through physical entanglement or chemical cross-linking, which can effectively disperse external loads and increase the tensile strength of the composite material.

[0107] In Comparative Example 7, the modified nano-silica added in the components is replaced by the nano-silica grafted with silane prepared in step S1. It can be seen from the data in Table 1 that its tensile strength is 102 MPa, elongation at break is 20.9%, coefficient of friction is 0.17, and heat distortion temperature is 308 °C.

[0108] Comparative Example 8 is a polyether ether ketone composite material prepared by using the raw materials of Example 2 of the Chinese invention patent with the publication number CN109851989A and the process of the present application. It can be seen from the data in Table 1 that its mechanical properties and salt spray resistance are poor.

[0109] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. However, for those of ordinary skill in the art, without departing from the scope of the technical solution of the present invention, any equivalent changes made by using the technical content disclosed above, such as slight modifications, refinements, and evolutions, are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications, and evolutions made to the above embodiments based on the substantial technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A modified polyetheretherketone composite material, characterized in that: The invention comprises the following raw materials in parts by weight: Polyetheretherketone resin: 60-85 parts; carbon fiber: 5-15 parts; modified nano-silicon dioxide: 5-20 parts; hydroxyapatite: 5-10 parts; Coupling agent: 0.5-2 parts; Modified compatibilizer: 2-4 parts; The modified compatibilizer is prepared by the following method: S1: p-Hydroxyacetophenone and 2-chloro-5-nitro-trifluoromethylbenzene undergo nucleophilic substitution reaction in the presence of anhydrous K2CO3 to give intermediate 1; S2: Under the action of catalyst silicon tetrachloride, three molecules of intermediate 1 are condensed to undergo benzene cyclization reaction to obtain a trinitro compound; S3: The trinitro compound is reduced to a fluorine-containing triamine monomer under the action of a catalyst Pd / C and a reducing agent hydrazine hydrate; S4: Under nitrogen protection, add DMAc and fluorinated triamine monomer to the reactor, add 4,4'-(hexafluoroisopropylene) diphthalic anhydride in batches, stir and react for 12-24 hours, then add acetic anhydride / pyridine mixture, and carry out ring-closing reaction at room temperature to obtain a modified compatibilizer; The preparation method of the modified nano silicon dioxide is as follows: A1: Add toluene and nano-silica into the reactor, perform ultrasonic vibration for 20-30 minutes, then add γ-methacryloxypropyltrimethoxysilane and triethylamine, react at 100-120°C for 3-5 hours, and post-treat to obtain silane-grafted nano-silica; A2: Under nitrogen protection, toluene, silane-grafted nano-silica, styrene and initiator AIBN were added to the reactor, stirred and mixed, heated to 80-100°C, reacted for 12-16 hours, and post-treated to obtain modified nano-silica; In the step A2, the feed mass ratio of toluene, silane-grafted nano-silica, styrene, and initiator AIBN is 50:(8-10):(2-3):(0.02-0.05).

2. A modified polyetheretherketone composite material according to claim 1, characterized in that: In the step S1, the mass ratio of p-hydroxyacetophenone to 2-chloro-5-nitro-trifluoromethylbenzene is 1:(1-1.25).

3. The modified polyetheretherketone composite material according to claim 1, characterized in that: In the step S2, the feed mass ratio of the intermediate 1 to silicon tetrachloride is 20:(4-6).

4. The modified polyetheretherketone composite material according to claim 1, characterized in that: In the step S3, the mass ratio of the trinitro compound, Pd / C and hydrazine hydrate is 20:(0.6-0.8):(5-8).

5. The modified polyetheretherketone composite material according to claim 1, characterized in that: In the step S4, the feed mass ratio of DMAc, fluorine-containing triamine monomer, and 4,4'-(hexafluoroisopropylene) diphthalic anhydride is 50:(12-16):(8-10).

6. The modified polyetheretherketone composite material according to claim 1, characterized in that: The coupling agent is one of vinyl triethoxysilane, 3-glycidyloxypropyl trimethoxysilane, and methyl vinyl dimethoxysilane, or a combination of several thereof.

7. The modified polyetheretherketone composite material according to claim 1, characterized in that: In step A1, the mass ratio of toluene, nano-silica and γ-methacryloxypropyltrimethoxysilane is 50:(12-16):(4-6).

8. A method for preparing the modified polyetheretherketone composite material according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Weigh 60-85 parts of polyetheretherketone resin, 5-15 parts of carbon fiber, and 5-20 parts of modified nano-silicon dioxide by weight; Hydroxyapatite: 5-10 parts; Coupling agent: 0.5-2 parts; Modified compatibilizer: 2-4 parts; S2: Add polyetheretherketone resin, carbon fiber, modified nano-silica, hydroxyapatite, coupling agent, and modified compatibilizer into a high-speed mixer in proportion and mix evenly; add the mixture into a twin-screw extruder, set the melt temperature to 360-400°C, the screw speed to 200-400rpm, and extrude granulation; injection mold the granular material, the injection temperature to 350-380°C, the mold temperature to 160-180°C, and obtain a modified polyetheretherketone composite material.

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