Polyether-ether-ketone resin processing aid as well as preparation method and application thereof

Abstract

The invention relates to the technical field of polyether-ether-ketone materials, in particular to a polyether-ether-ketone resin processing aid and a preparation method and application thereof.The polyether-ether-ketone resin processing aid comprises, by weight, 10-30 parts of main antioxidants, 10-20 parts of auxiliary antioxidants, 7-15 parts of modified organic silicon and the balance lubricants, and 100 parts of the polyether-ether-ketone resin processing aid is prepared from, by weight, 10-30 parts of main antioxidants, 10-20 parts of auxiliary antioxidants, 7-15 parts of modified organic silicon and the balance lubricants. The polyether-ether-ketone resin processing aid prepared by the invention can improve the thermal stability of polyether-ether-ketone in the polyether-ether-ketone processing process.

Description

Technical Field

[0001] This invention relates to the field of polyetheretherketone (PEEK) materials technology, specifically to a PEEK resin processing aid, its preparation method, and its application. Background Technology

[0002] Currently, polyetheretherketone (PEEK) is widely used in high-end fields such as aerospace and medical. However, it suffers from problems such as a narrow processing window, high melt viscosity, and easy thermal degradation and crosslinking at high temperatures, which can reduce the toughness and high-temperature resistance of the prepared products. The core root causes of these pain points lie in the improper control of the alkalinity of the reaction system in traditional synthesis processes, the easy branching and crosslinking of phenoxy end groups, insufficient precision in molecular weight control, and frequent side reactions caused by unreasonable selection of salt-forming agents. These factors severely restrict the application expansion of PEEK in more advanced scenarios.

[0003] In the prior art, patent CN103467681B discloses a method for synthesizing a high-thermal-stability polyetheretherketone resin. This method uses 4,4-difluorobenzophenone and hydroquinone as polymerization chain-promoting reactants in a nucleophilic polycondensation reaction. Sodium bicarbonate is used as the salt-forming agent, while 4,4-dihydroxybenzophenone is used as a molecular weight regulator, and 4-fluorobiphenyl is used as a capping agent. This invention selects sodium bicarbonate as the salt-forming agent to lower the pH of the reaction system, which is beneficial for inhibiting hydroquinone oxidation. Furthermore, the design uses an excess of 4,4-difluorobenzophenone relative to hydroquinone to inhibit phenoxy branching during the reaction. The addition of the molecular weight regulator ensures that the polymer's molecular weight meets the application requirements. Benzene end-capping reduces the concentration of phenoxy end groups in the polymer, preventing branching and cross-linking of phenoxy end groups at high temperatures and improving the product's thermal stability. However, the introduced end-capping agents or regulators may lead to various complex reaction processes, affecting the uniformity of molecular weight distribution, which in turn affects the regularity of polymer chains and crystallization rate, thus having an uncertain impact on the mechanical and processing properties of the final product.

[0004] Patent CN110527247B discloses a dual-network polyetheretherketone (PEEK) composite material, its preparation method, and its applications. The dual-network PEEK composite material provided by this invention includes a PEEK / multi-walled carbon nanotube (MWC) composite material and graphene nanosheets. The PEEK / MWC composite material consists of MWC nanotubes dispersed in PEEK, and the PEEK / MWC nanotube composite material is distributed within the network structure formed by the graphene nanosheets. The dual-network PEEK composite material of this invention exhibits good thermal conductivity. However, the poor compatibility between MWC nanotubes, graphene nanosheets, and PEEK resin causes a sharp increase in the melt viscosity of the PEEK resin, resulting in extremely poor flowability. This may prevent secondary molding using conventional injection molding, extrusion, and other melt processing methods, severely limiting its practical applications.

[0005] Adding processing aids can adjust melt viscosity and improve the thermal stability of polyetheretherketone resin. However, conventional processing aids often have disadvantages such as poor high-temperature resistance and poor compatibility with polyetheretherketone, which has spurred the research and development of special processing aids for polyetheretherketone.

[0006] Therefore, there is an urgent need in the market for a processing aid that can improve the thermal stability of polyetheretherketone during processing. Summary of the Invention

[0007] To address the problems existing in the prior art, the purpose of this invention is to obtain a processing aid that can improve the thermal stability of polyether ether ketone resin and has a simple preparation method.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of the present invention provides a polyetheretherketone resin processing aid, comprising the following components in 100 parts by weight: 10-30 parts of a primary antioxidant, 10-20 parts of an auxiliary antioxidant, 7-15 parts of a modified organosilicon, and the balance being a lubricant.

[0009] This application describes a processing aid obtained by mixing a primary antioxidant, an auxiliary antioxidant, a lubricant, and a modified organosilicon. When used in the processing of polyetheretherketone (PEEK), it can reduce melt viscosity and improve the thermal stability of PEEK, and the preparation method is simple.

[0010] In some embodiments, the primary antioxidant is a hindered phenolic antioxidant; the secondary antioxidant is a thioester or phosphite antioxidant.

[0011] Preferably, the primary antioxidant is antioxidant 1010; the secondary antioxidant is antioxidant 608.

[0012] In some embodiments, the lubricant is one or more of calcium stearate, zinc stearate, pentaerythritol stearate, N,N-ethylene bis-stearamide, and PE wax.

[0013] Preferably, the lubricant is calcium stearate.

[0014] In some embodiments, the method for preparing the modified organosilicon includes the following steps: A1. Add hydrogen-containing silicone oil and platinum catalyst to the reaction vessel, purge with nitrogen for 20-40 min, heat to 60-70℃ and stir for 5-15 min, add methyl methacrylate dropwise, react under nitrogen protection for 4-6 h after the addition is complete, and distill under reduced pressure to obtain PDMS-MMA. A2. Add the PDMS-MMA obtained in step A1 to tetrahydrofuran, stir at room temperature for 20-30 min, add LiOH aqueous solution with a concentration of 4-6 mol / L dropwise, react at room temperature for 4-6 h after the addition is complete, add dilute hydrochloric acid to adjust the pH to 3-4, separate the liquids, take the upper organic phase and wash until neutral, rotary evaporate, and vacuum dry to obtain carboxylated PDMS. A3. Add the carboxylated PDMS and 1,5-naphthyldiamine obtained in step A2 to DMF, add activator and catalyst to the solution, activate at 0-5℃ for 30 min, heat to 25-40℃ and react for 12-24 h, cool to room temperature, pour into ice-cold methanol to obtain a precipitate, wash the precipitate with deionized water 3-4 times, then wash with anhydrous ethanol 1-2 times, dry to obtain modified organosilicon.

[0015] Preferably, the ratio of PDMS-MMA and tetrahydrofuran in step A2 is 1g:(5-10)ml.

[0016] Preferably, the concentration of the dilute hydrochloric acid in step A2 is 0.8-1.2 mol / L.

[0017] Preferably, the ratio of carboxylated PDMS and DMF in step A2 is 1g: (5-10)ml.

[0018] Preferably, the activator is 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride.

[0019] Preferably, the catalyst is 4-dimethylaminopyridine and / or 1-hydroxybenzotriazole.

[0020] More preferably, the catalyst is 4-dimethylaminopyridine.

[0021] In some embodiments, the hydrogen content of the hydrogen-containing silicone oil is 0.1-1.0 mmol / g.

[0022] In some embodiments, the mass ratio of the hydrogen-containing silicone oil to methyl methacrylate is 1:(0.7-1.1).

[0023] This application presents a modified organosilicon with a unique "flexible PDMS backbone + carboxyl reaction site + rigid aromatic amine terminus" structure, synthesized in three steps. Applying this modified organosilicon to the processing of polyetheretherketone (PEEK) can improve the thermal stability of PEEK. This is likely because: firstly, the flexible PDMS segments in the modified organosilicon act as a "lubricating core," effectively reducing melt viscosity, while the terminal 1,5-naphthyldiamine segments act as "compatibility anchors." The rigid aromatic ring structure within these segments can generate strong π-π interactions or co-crystallization effects with the PEEK backbone, significantly improving the compatibility between the modified organosilicon and PEEK. This solves the industry problem of poor compatibility and easy migration and precipitation between traditional silicone oils and PEEK, achieving long-lasting and stable lubrication. Secondly, the aromatic amine terminus of the modified organosilicon also possesses free radical scavenging capabilities, providing auxiliary antioxidant effects and generating additional synergistic effects with the main antioxidant system.

[0024] In some embodiments, the mass ratio of PDMS-MMA to LiOH is 1:(0.1-0.15).

[0025] In some embodiments, the mass ratio of the carboxylated PDMS to 1,5-naphthyldiamine is 1:(0.4-0.7).

[0026] In some embodiments, the mass ratio of the 1,5-naphthyldiamine to the activator is 1:(0.03-0.06).

[0027] In some embodiments, the mass ratio of the 1,5-naphthyldiamine to the catalyst is 1:(0.005-0.01).

[0028] The second aspect of the present invention provides a method for preparing a polyether ether ketone resin processing aid, comprising the following steps: adding a primary antioxidant, an auxiliary antioxidant, a lubricant, and a modified organosilicon into a mixer and stirring at room temperature for 10-20 minutes to obtain the product.

[0029] The third aspect of the present invention provides an application of a polyetheretherketone resin processing aid, wherein the amount of the polyetheretherketone resin processing aid added is 2-5 wt‰.

[0030] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses a processing aid obtained by mixing a main antioxidant, an auxiliary antioxidant, a lubricant and a modified organosilicon in the processing of polyether ether ketone to reduce the melt viscosity and improve the thermal stability of polyether ether ketone. The preparation method is simple.

[0031] (2) This invention develops a modified organosilicon with a structure of “flexible PDMS backbone + carboxyl reaction site + rigid aromatic amine end” through three-step synthesis. The flexible PDMS segment in the modified organosilicon can reduce the melt viscosity, while the rigid aromatic ring structure contained in the 1,5-naphthyldiamine segment at its end can generate strong π-π interaction or co-crystallization effect with the PEEK backbone, which greatly improves the compatibility between the modified organosilicon and PEEK.

[0032] (3) The aromatic amine end of the modified organosilicon prepared by the present invention also has the function of free radical scavenging, which can produce additional synergistic effect with the main antioxidant system. Detailed Implementation

[0033] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0034] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0035] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of the invention. Various modifications and variations to the specific embodiments described in this specification are apparent to those skilled in the art without departing from the scope or spirit of the invention. Other embodiments derived from this specification will be apparent to those skilled in the art. This application specification and embodiments are merely exemplary.

[0036] It should be noted that the operations described in this invention, such as "rotary evaporation," "drying," "vacuum drying," "reduced pressure distillation," and "liquid separation," are routine operations for those skilled in the art, and should be selected according to actual operation.

[0037] In the following examples and comparative examples, except for the modified organosilicon, all other compounds and related reagents used were commercially available. The hydrogen-containing silicone oil had a hydrogen content of 0.5 mmol / g and was purchased from Hubei Langbowan Biomedical Co., Ltd.; the platinum catalyst had a platinum content of 700 ppm and was purchased from Jining Fangyu Chemical Co., Ltd.

[0038] Preparation Example 1 The preparation method of modified organosilicon-1 includes the following steps: A1. Add 10g of hydrogen-containing silicone oil and 0.001g of platinum catalyst to a reaction vessel, purge with nitrogen for 30min, heat to 65℃ and stir for 10min, add 9g of methyl methacrylate dropwise at a rate of 1 drop / s, react under nitrogen protection for 5h, and distill under reduced pressure to obtain PDMS-MMA. A2. Add 10g of PDMS-MMA obtained in step A1 to 70g of tetrahydrofuran, stir at room temperature for 25min, add 12ml of 5mol / L LiOH aqueous solution dropwise, react at room temperature for 5h after the addition is complete, add 1mol / L hydrochloric acid dropwise to adjust the pH to 3, separate the liquid and liquid, take the upper organic phase and wash until neutral, rotary evaporate, and vacuum dry to obtain carboxylated PDMS; A3. Add 10g of carboxylated PDMS obtained in step A2 and 6.5g of 1,5-naphthyldiamine to 70g of DMF. Add 0.29g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.052g of 4-dimethylaminopyridine to the solution. Activate at 3℃ for 30min, raise the temperature to 35℃ and react for 18h. Cool to room temperature and pour into ice-cold methanol to obtain a precipitate. Wash the precipitate three times with deionized water and then twice with anhydrous ethanol. Dry to obtain modified organosilicon-1.

[0039] Preparation Example 2 The preparation method of modified organosilicon-2 is the same as that in preparation example 1, except that the amount of 5 mol / L LiOH aqueous solution added is 20 ml.

[0040] Preparation Example 3 The preparation method of modified organosilicon-3 is the same as that in preparation example 1, except that the amount of 1,5-naphthyldiamine added is 8g.

[0041] Preparation Example 4 The preparation method of modified organosilicon-4 includes the following steps: A1. Add 10g of hydrogen-containing silicone oil and 0.001g of platinum catalyst to a reaction vessel, purge with nitrogen for 30min, heat to 65℃ and stir for 10min, add 9g of methyl methacrylate dropwise at a rate of 1 drop / s, react under nitrogen protection for 5h, and distill under reduced pressure to obtain PDMS-MMA. A2. Add 10g of PDMS-MMA obtained in step A1 to 70g of tetrahydrofuran, stir at room temperature for 25min, add 12ml of 5mol / L LiOH aqueous solution dropwise, react at room temperature for 5h after the addition is complete, add 1mol / L hydrochloric acid dropwise to adjust the pH to 3, separate the liquid, take the upper organic phase and wash until neutral, rotary evaporate, and vacuum dry to obtain modified organosilicon-4.

[0042] Example 1 A polyetheretherketone resin processing aid, comprising the following raw materials in 100 parts by weight: 20 parts of antioxidant 1010, 15 parts of antioxidant 608, 54 parts of calcium stearate, and 11 parts of modified organosilicon-1.

[0043] The preparation method of the polyether ether ketone resin processing aid in this embodiment includes the following steps: adding antioxidant 1010, antioxidant 608, calcium stearate, and modified organosilicon-1 into a mixer, stirring at room temperature for 15 minutes at a speed of 100 rpm, and the product is obtained.

[0044] Example 2 A polyetheretherketone resin processing aid, comprising the following raw materials in 100 parts by weight: 10 parts of antioxidant 1010, 10 parts of antioxidant 608, 73 parts of calcium stearate, and 7 parts of modified organosilicon-1.

[0045] The preparation method of the polyether ether ketone resin processing aid in this embodiment includes the following steps: adding antioxidant 1010, antioxidant 608, calcium stearate, and modified organosilicon-1 into a mixer, stirring at room temperature for 10 minutes at a speed of 100 rpm, and the product is obtained.

[0046] Example 3 A polyetheretherketone resin processing aid, comprising the following raw materials in 100 parts by weight: 30 parts of antioxidant 1010, 20 parts of antioxidant 608, 35 parts of calcium stearate, and 15 parts of modified organosilicon-1.

[0047] The preparation method of the polyether ether ketone resin processing aid in this embodiment includes the following steps: adding antioxidant 1010, antioxidant 608, calcium stearate, and modified organosilicon-1 into a mixer, stirring at room temperature for 20 minutes at a speed of 100 rpm, and the product is obtained.

[0048] Example 4 A polyether ether ketone resin processing aid and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that modified organosilicon-1 is replaced with modified organosilicon-2 in equal amounts.

[0049] Example 5 A polyether ether ketone resin processing aid and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that modified organosilicon-1 is replaced with modified organosilicon-3 in an equal amount.

[0050] Example 6 A polyether ether ketone resin processing aid and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that modified organosilicon-1 is replaced with modified organosilicon-4 in equal amounts.

[0051] Comparative Example 1 A processing aid and its preparation method are described. The specific implementation method is the same as in Example 1, except that the modified organosilicon-1 is replaced with an equal amount of hydrogen-containing silicone oil.

[0052] Performance testing The processing aids obtained in the above embodiments and comparative examples were tested: (1) Sample preparation 100g of polyetheretherketone resin (injection molding grade, general type, self-made by Tangyuan County Hairuit Engineering Plastics Co., Ltd.) and 0.3g of processing aids obtained in each example and comparative example were mixed at room temperature to obtain initial samples. Each initial sample was repeatedly extruded three times at 400℃ using a twin-screw extruder to obtain processed samples.

[0053] (2) Test method 1. Melt Index Change Rate: The melt index was tested according to GB / T 3682-2018 standard. Test conditions: 380℃, 5Kg weight. The melt index change rate was tested for both the initial sample (polyetheretherketone resin) and the processed sample. The melt index change rate for each sample was then calculated using the following formula: Initial melt flow rate change (%) = [(MFR)] 初始30min－ MFR 初始4min ) / MFR 4min [×100%, MFR is the melt flow rate]

[0054] Melt Flow Index Change Rate (%) after Processing = [(MFR)] 加工后30min－ MFR 加工后4min ) / MFR 加工后4min [×100%, MFR is the melt flow rate]

[0055] The test results are shown in Table 1: Table 1

[0056] As shown in Table 1, the processing aids in Examples 1-3 of this invention can improve the thermal stability of polyetheretherketone resin during processing. A comparison between Example 4 and Example 1 shows that changing the ratio of PDMS-MMA to LiOH may cause hydrolysis of the ester bonds in PDMS-MMA and may also attack the Si-O bonds of the polysiloxane backbone, leading to a decrease in polymer molecular weight and chain breakage, resulting in a deterioration in the effectiveness of the processing aid and an increase in the melt index change rate of the sample. A comparison between Example 5 and Example 1 shows that changing the ratio of carboxylated PDMS to 1,5-naphthyldiamine may result in a large number of free amine groups in the system, causing cross-linking of the polyetheretherketone resin and an increase in the melt index change rate of the sample. A comparison between Example 6 and Example 1 shows that the melt index change rate of the sample increases when 1,5-naphthyldiamine is not used to modify the carboxylated PDMS. A comparison between Comparative Example 1 and Example 1 shows that the melt index change rate of the sample is large when the organosilicon is not modified, indicating that the processing aid has limited effect on improving the thermal stability of the polyetheretherketone resin.

[0057] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A processing aid for polyetheretherketone resin, characterized in that, Based on 100 parts by weight, it includes the following components: 10-30 parts of primary antioxidant, 10-20 parts of secondary antioxidant, 7-15 parts of modified organosilicon, and the balance being lubricant.

2. The polyetheretherketone resin processing aid according to claim 1, characterized in that, The primary antioxidant is a hindered phenolic antioxidant; the secondary antioxidant is a thioester or phosphite antioxidant.

3. The polyetheretherketone resin processing aid according to claim 1, characterized in that, The lubricant is one or more of calcium stearate, pentaerythritol stearate, N,N-ethylene bis-stearamide, and PE wax.

4. The polyetheretherketone resin processing aid according to claim 1, characterized in that, The method for preparing the modified organosilicon includes the following steps: A1. Add hydrogen-containing silicone oil and platinum catalyst to the reaction vessel, purge with nitrogen for 20-40 min, heat to 60-70℃ and stir for 5-15 min, add methyl methacrylate dropwise, react under nitrogen protection for 4-6 h after the addition is complete, and distill under reduced pressure to obtain PDMS-MMA. A2. Add the PDMS-MMA obtained in step A1 to tetrahydrofuran, stir at room temperature for 20-30 min, add LiOH aqueous solution with a concentration of 4-6 mol / L dropwise, react at room temperature for 4-6 h after the addition is complete, add dilute hydrochloric acid to adjust the pH to 3-4, separate the liquids, take the upper organic phase and wash until neutral, rotary evaporate, and vacuum dry to obtain carboxylated PDMS. A3. Add the carboxylated PDMS and 1,5-naphthyldiamine obtained in step A2 to DMF, add activator and catalyst to the solution, activate at 0-5℃ for 30 min, heat to 25-40℃ and react for 12-24 h, cool to room temperature, pour into ice-cold methanol to obtain a precipitate, wash the precipitate with deionized water 3-4 times, then wash with anhydrous ethanol 1-2 times, dry to obtain modified organosilicon.

5. The polyetheretherketone resin processing aid according to claim 4, characterized in that, The hydrogen content of the hydrogen-containing silicone oil is 0.1-1.0 mmol / g.

6. The polyetheretherketone resin processing aid according to claim 4, characterized in that, The mass ratio of the hydrogen-containing silicone oil to methyl methacrylate is 1:(0.7-1.1).

7. The polyetheretherketone resin processing aid according to claim 4, characterized in that, The mass ratio of PDMS-MMA to LiOH is 1:(0.1-0.15).

8. The polyetheretherketone resin processing aid according to claim 4, characterized in that, The mass ratio of the carboxylated PDMS to 1,5-naphthyldiamine is 1:(0.4-0.7).

9. A method for preparing the polyetheretherketone resin processing aid according to any one of claims 1-8, characterized in that, The process includes the following steps: adding the main antioxidant, auxiliary antioxidant, lubricant, and modified organosilicon into a mixer and stirring at room temperature for 10-20 minutes to obtain the final product.

10. The application of a polyetheretherketone resin processing aid according to any one of claims 1-8 or a polyetheretherketone resin processing aid obtained by the preparation method according to claim 9, characterized in that, The amount of the polyetheretherketone resin processing aid added is 2-5 wt‰.

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