High-temperature-resistant nylon / liquid crystal polymer alloy as well as preparation method and application thereof

Abstract

The invention discloses a high-temperature-resistant nylon / liquid crystal polymer alloy for a high-vibration thermal cycle environment and a preparation method of the high-temperature-resistant nylon / liquid crystal polymer alloy in the field of high polymer materials. The high-temperature-resistant nylon / liquid crystal polymer alloy is prepared from the following raw materials: high-temperature nylon, wholly aromatic polyester or liquid crystal polymer, a novel bifunctional reactive compatilizer, chopped glass fibers, core-shell rubber particles and an antioxidant. The preparation method adopts multi-stage melt blending extrusion: in the first stage, adding the high-temperature nylon, the compatilizer and the antioxidant at a specific temperature, and staying for a certain time; raising the temperature to be close to the melting point of the liquid crystal polymer in the second stage, adding the liquid crystal polymer, the chopped glass fiber and the core-shell rubber particles through side feeding, and staying for a certain time; and carrying out third-stage cooling, adding silicone master batches, carrying out vacuum exhaust, and carrying out extrusion granulation. The granules can be used for injection molding or compression molding after being dried, and are suitable for high-vibration and thermal cycle environments.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a high-temperature resistant nylon / liquid crystal polymer alloy, a preparation method and applications in high-vibration and thermal cycle environments. Background Art

[0002] Optimizing the performance of engineering plastics in high-temperature, high-stress environments has long been a research priority in the materials field. While traditional high-temperature nylon resins possess excellent heat resistance and mechanical strength, they lack rigidity and are susceptible to dimensional instability due to thermal expansion. Liquid crystal polymers, while offering ultra-high modulus and heat resistance, are difficult to directly compound due to their narrow processing temperature range and poor compatibility with conventional resins. While combining these two materials can compensate for the shortcomings of either material alone, weak interfacial bonding consistently hinders their synergistic effects, leading to interfacial delamination of composite materials under dynamic loads or thermal cycling, limiting their application in high-end applications such as precision machinery and electronic packaging.

[0003] In existing technologies, general-purpose compatibilizers (such as anhydride-grafted polymers) can partially improve interfacial bonding, but their reactivity is limited, making it difficult to form stable covalent bonds under high-temperature processing conditions. Furthermore, conventional processes enhance interfacial interactions by increasing the amount of compatibilizer added, but this can lead to increased material costs, decreased processing fluidity, and even compatibilizer migration and precipitation. For liquid crystal polymer and high-temperature nylon blends, their high viscosity further exacerbates the risk of uneven dispersion, making it difficult for the material's overall performance to meet the demands of demanding operating conditions.

[0004] To address these challenges, developing a composite material system that combines efficient interfacial bonding with processing stability is crucial. By designing a novel bifunctional reactive compatibilizer, the interfacial interactions between high-temperature nylon and liquid crystal polymers can be precisely controlled, while simultaneously optimizing melt blending process parameters to balance dispersibility and intermolecular forces. This technological approach not only enhances the material's high-temperature stability and fatigue resistance but also expands its application in extreme environments, significantly contributing to the advancement of high-performance engineering plastics. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-temperature resistant nylon / liquid crystal polymer alloy for high vibration and thermal cycling environments and a preparation method thereof, which solves the problem that the interface bonding is weak when traditional high-temperature nylon is compounded with liquid crystal polymer, resulting in insufficient synergistic effect and limited performance.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions: A high-temperature resistant nylon / liquid crystal polymer alloy, wherein the raw materials thereof include, by mass percentage: High temperature nylon: 40-85%; Fully aromatic polyester / LCP: 10-50%; New bifunctional reactive compatibilizer: 1-15%; Chopped glass fiber: 0-30%; Core-shell rubber particles: 0-10%; Antioxidant: 2-3%; The preparation method of the novel bifunctional reactive compatibilizer includes: adding bisphenol A and epichlorohydrin into a reactor, adding NaOH as a catalyst, reacting at 80-85°C, and distilling under reduced pressure to obtain bisphenol A diglycidyl ether; dissolving epoxy resin in acetone, adding ethylenediamine and 2-vinyl-2-oxazoline, stirring and reacting at 60-65°C; washing the reaction product with deionized water until neutral, filtering and vacuum drying.

[0007] According to a preferred embodiment of the present invention, the bisphenol A is purchased from Sinopec Mitsubishi Chemical Polycarbonate (Beijing) Co., Ltd., and the model is BPA-4000 (industrial grade, purity ≥99.5%).

[0008] According to a preferred embodiment of the present invention, the epichlorohydrin is purchased from Jiangsu Haian Petrochemical Co., Ltd., and the model is E-51 (industrial grade, epoxy value 0.51 mol / 100 g).

[0009] According to a preferred embodiment of the present invention, the reactor was purchased from Jiangsu Yangyang Chemical Equipment Manufacturing Co., Ltd., model F-1000L (glass-lined reactor, volume 1000L, material 316L stainless steel).

[0010] According to a preferred embodiment of the present invention, the NaOH is purchased from Xinjiang Zhongtai Chemical Co., Ltd., and the model is NaOH-99 (industrial grade caustic soda flakes, content ≥99%).

[0011] According to a preferred embodiment of the present invention, the epoxy resin is purchased from Bluestar New Chemical Materials Co., Ltd., and the model is E-51 (bisphenol A epoxy resin, epoxy value 0.51 mol / 100g).

[0012] According to a preferred embodiment of the present invention, the acetone is purchased from Jiangsu Feixiang Chemical Co., Ltd., and the model is FC-99 (industrial grade superior product, purity ≥99.5%, moisture ≤0.1%, distillation range 56.5-57.5°C).

[0013] According to a preferred embodiment of the present invention, the ethylenediamine is purchased from Sinochem Fertilizer Co., Ltd., and the model is EDA-99 (industrial grade primary amine, content ≥99%).

[0014] According to a preferred embodiment of the present invention, the 2-vinyl-2-oxazoline was purchased from Jiangsu Feixiang Chemical Co., Ltd., model VOZ-200 (industrial grade, purity ≥98%).

[0015] According to a preferred embodiment of the present invention, the chopped glass fibers are purchased from Taishan Glass Fiber Co., Ltd., and the model number is ECR-430 (alkali-free glass fiber, length 10-30 mm, diameter 10 μm).

[0016] According to a preferred embodiment of the present invention, the core-shell rubber particles are purchased from Shanghai Kingfa Technology Development Co., Ltd., and the model number is 757K (ABS-based core-shell structure, grafting rate ≥15%).

[0017] The core of the reaction mechanism for the high-temperature nylon / liquid crystal polymer alloy described in this invention lies in the design of a novel bifunctional reactive compatibilizer and its chemical bonding at the interface between the high-temperature nylon and liquid crystal polymer (LCP) during the blending process. This mechanism can be divided into two key steps: molecular construction during the compatibilizer synthesis phase and interfacial reaction during the blending and molding phase. The synergistic effect of these two reactions achieves strong bonding at the interface between the two phases.

[0018] In the novel bifunctional reaction-based synthesis stage of this invention, a basic epoxy-containing structure is first constructed through a nucleophilic substitution reaction between bisphenol A and epichlorohydrin. The phenolic hydroxyl group (-OH) in the bisphenol A molecule acts as a nucleophilic group, attacking the epoxy ring (a three-membered cyclic ether structure) of epichlorohydrin under the catalysis of sodium hydroxide (NaOH), causing the epoxy ring to open and release chloride ions, ultimately forming bisphenol A diglycidyl ether. During this process, each bisphenol A molecule reacts with two epichlorohydrin molecules via its two phenolic hydroxyl groups, forming a linear polymer containing epoxy groups (-CH(O)CH-) at both ends. The epoxy groups on this molecular chain are highly reactive and can covalently bond with active hydrogen-containing groups such as amines and hydroxyls. Subsequently, the bisphenol A diglycidyl ether is dissolved in acetone and reacts with ethylenediamine (containing two primary amine groups, -NH2) and 2-vinyl-2-oxazoline (containing an oxazoline ring structure) in a multifunctional co-reaction. The primary amino group (-NH2) of ethylenediamine acts as a strong nucleophile, attacking the oxygen atom of the epoxy group, causing the epoxy ring to open and form an amide bond (-NH-CO-), thereby introducing multiple primary amino terminal groups into the compatibilizer molecular chain. Simultaneously, the double bond (C=C) of 2-vinyl-2-oxazoline undergoes a ring-opening addition reaction with the epoxy group under free radical or acid catalysis, forming a pendant group containing an oxazoline ring (a five-membered ring containing O and N atoms). By controlling the reaction temperature (60-65°C) and time (6-8 hours), this step ensures that the compatibilizer molecular chain simultaneously carries highly reactive primary amino groups and a stable oxazoline ring structure, providing a "dual reaction site" for subsequent interfacial bonding with high-temperature nylon and LCP.

[0019] According to a preferred embodiment of the present invention, the molar ratio of bisphenol A to epichlorohydrin is 1:(2-3); the NaOH content is 1-2% of the molar amount of bisphenol A; the reaction time is 4-6 hours; the stirring reaction time is 6-8 hours; the vacuum drying temperature is 80-85°C, and the vacuum drying time is 12-14 hours.

[0020] According to a preferred embodiment of the present invention, the high temperature nylon is selected from at least one of PA46, PA4T, PA6T, PA9T, PA10T, PPA or copolymers / mixtures thereof.

[0021] According to a preferred embodiment of the present invention, the PA46 is purchased from Shanghai Jieshijie New Materials Co., Ltd., with the model number being JH4600 (melting point 310° C., relative viscosity 2.8-3.2).

[0022] According to a preferred embodiment of the present invention, the PA4T is purchased from Shanghai Kingfa Technology Development Co., Ltd., and the model is FR400 (melting point 325° C., heat deformation temperature (1.8 MPa)>280° C.).

[0023] According to a preferred embodiment of the present invention, the PA6T is purchased from Jiangsu Hengli Chemical Fiber Co., Ltd., and the model is HT600 (melting point 330° C., tensile strength>180 MPa).

[0024] According to a preferred embodiment of the present invention, the PA9T is purchased from Guangdong Xinhui Meida Nylon Co., Ltd., with a model number of M2400 (melting point 340° C., arc resistance>180s).

[0025] According to a preferred embodiment of the present invention, the PA10T is purchased from Shanghai Jieshijie New Materials Co., Ltd., and the model is JH10T (melting point 350° C., moisture absorption rate <0.8%).

[0026] According to a preferred embodiment of the present invention, the PPA is purchased from Jiangsu Haiyang Chemical Fiber Co., Ltd., and the model is HAPP1000 (melting point 305° C., temperature resistance grade 220° C.).

[0027] According to a preferred embodiment of the present invention, the wholly aromatic polyester / LCP is selected from at least one of Vectra® LCP, Zenite® LCP, and Sumikasuper™ LCP.

[0028] According to a preferred embodiment of the present invention, the domestic alternative product of Vectra® LCP (wholly aromatic polyester LCP under Celanese) is purchased from WOT New Materials Co., Ltd., model number WOT-LCP-1000 (melting point 335°C, relative viscosity 2.5-3.0, heat distortion temperature (1.8MPa)>285°C).

[0029] According to a preferred embodiment of the present invention, the domestic alternative product of Zenite® LCP (fluorinated LCP under DuPont) was purchased from Shanghai Jinfa Technology Development Co., Ltd., model FR-LCP-2000 (melting point 340°C, dielectric constant 3.1 (1MHz), moisture absorption rate <0.1%).

[0030] According to a preferred embodiment of the present invention, the domestic alternative product of Sumikasuper™ LCP (super engineering LCP under Sumitomo Chemical) is purchased from Zhongyan Polymer Materials Co., Ltd., model ZY-LCP-3000 (melting point 350°C, tensile strength >200MPa, solder resistance temperature >300°C).

[0031] According to a preferred embodiment of the present invention, the antioxidant is hindered phenol antioxidant 1010 and / or phosphite antioxidant 168.

[0032] According to a preferred embodiment of the present invention, the hindered phenol antioxidant 1010 is purchased from Li'anlong New Materials Co., Ltd., and the model is LA-1010 (white powder, purity ≥98%, melting point 110-125°C, melt index (190°C / 2.16kg) ≤0.5g / 10min); According to a preferred embodiment of the present invention, the phosphite antioxidant 168 is purchased from Li'anlong New Materials Co., Ltd., model LA-168 (white crystalline powder, purity ≥97%, melting point 120-128°C, volatile matter ≤0.5%).

[0033] The present invention also provides a method for preparing the high-temperature resistant nylon / liquid crystal polymer alloy, comprising the following steps: S1. vacuum drying high-temperature nylon and wholly aromatic polyester / LCP; drying the new bifunctional reactive compatibilizer; and drying and removing water from chopped glass fibers and core-shell rubber particles; S2, multi-stage melt blending extrusion, first stage: the temperature is set at 305-310℃, high-temperature nylon, new bifunctional reactive type, and antioxidant are fed, and the residence time is 3-5 minutes; second stage: the temperature is increased to 330-335℃, and fully aromatic polyester / LCP, chopped glass fiber, and core-shell rubber particles are added through the side feed port, and the residence time is 2-3 minutes; third stage: the temperature is reduced to 310-315℃, and silicone masterbatch is added, and the residence time is 1-2 minutes. The vacuum degree of the exhaust port is <-0.08MPa; S3. After the melt is extruded through a die, it is water-cooled and drawn, and pelletized by a pelletizer to obtain pellets.

[0034] According to a preferred embodiment of the present invention, the silicone masterbatch is purchased from Nanjing Julong Technology Co., Ltd., model JL-800 (silicone content ≥40%, melt flow rate (200°C / 5kg) ≥50g / 10min, density 0.98-1.02g / cm³); In the present invention, during the alloy blending and molding stage, when high-temperature nylon and wholly aromatic polyester / LCP are heated to a molten state in a multi-stage melt blending device, compatibilizer molecules are uniformly dispersed near the interface between the two phases. At this point, the primary amine groups (-NH2) on the compatibilizer molecular chains undergo an amidation reaction with the carboxyl groups (-COOH) at the ends of the LCP molecular chains. The nitrogen atoms of the primary amine groups attack the carbonyl carbon atoms of the carboxyl groups, removing a molecule of water and forming an amide bond (-NH-CO-), thereby covalently connecting the LCP molecular chains to the compatibilizer molecules. Simultaneously, the oxazoline rings (five-membered heterocycles containing nitrogen and oxygen atoms) on the compatibilizer molecular chains undergo a ring-opening reaction with the amino groups (-NH2) at the ends of the high-temperature nylon molecular chains. Under the action of high temperature and shear, the oxazoline rings open, the nitrogen atoms form new covalent bonds with the amino nitrogen atoms of the high-temperature nylon, and the oxygen atoms form hydrogen bonds or covalent bonds with the methylene groups (-CH2-) of the high-temperature nylon, thereby anchoring the high-temperature nylon molecular chains to the compatibilizer molecules. The synergistic effect of these "dual reaction sites" eliminates the need for simple physical contact between the high-temperature nylon and LCP, instead forming a three-dimensional network of interfacial bonding layers via amide, covalent, and hydrogen bonds. This interfacial layer, with a controllable thickness (approximately 100-500 nanometers), exhibits extremely high interfacial bonding strength, effectively transferring stress and inhibiting interfacial delamination. Furthermore, the presence of this interfacial bonding layer promotes the fibrillation of the LCP within the high-temperature nylon matrix (forming microfibrils with diameters of 500-1000 nanometers), further increasing the contact area between the two phases and strengthening the synergistic effect.

[0035] In this invention, precise regulation of multi-stage temperature control (305-335°C) and shear rate (200-450 rpm) during the blending process is key to the successful reaction mechanism. The first low-temperature stage (305-310°C) ensures that the high-temperature nylon fully melts without excessive degradation, while also promoting the initial reaction between the compatibilizer and the high-temperature nylon end groups. The second high-temperature stage (330-335°C), near the melting point of the LCP, causes it to be refined into microfibers under shear force. The reaction between the compatibilizer and the LCP end groups is accelerated by the rising temperature. The third cooling stage (310-315°C) stabilizes the interfacial structure and prevents molecular chain breakage caused by high temperatures. The addition of silicone masterbatch (the third stage) reduces the melt viscosity, promotes uniform dispersion of the compatibilizer in both phases, and further optimizes the uniformity of the interfacial reaction.

[0036] According to a preferred embodiment of the present invention, in step S1, the vacuum drying temperature is 120-130° C., and the vacuum drying time is 4-6 hours; the drying temperature is 80-85° C., and the drying time is 2-3 hours.

[0037] According to a preferred embodiment of the present invention, in step S2, the aspect ratio of the twin-screw extruder is (40-45):1, the screw speed in the first section is 200-250 rpm; the screw speed in the second section is 400-450 rpm; and the screw speed in the third section is 300-350 rpm.

[0038] According to a preferred embodiment of the present invention, the twin-screw extruder is purchased from Coperion Machinery (Shanghai) Co., Ltd., model ZSK 40.

[0039] According to a preferred embodiment of the present invention, the preparation method further comprises: drying the prepared pellets at 80-85° C. for 2-3 hours, and then injection molding or compression molding.

[0040] The present invention also provides an application of the high-temperature resistant nylon / liquid crystal polymer alloy or the high-temperature resistant nylon / liquid crystal polymer alloy prepared by the preparation method in a high vibration and thermal cycle environment.

[0041] The beneficial effects of the present invention are: This invention achieves fundamental enhancement of interfacial bonding through the design of a novel bifunctional reactive compatibilizer. This compatibilizer contains specific reactive groups that covalently react with the terminal amino groups of the high-temperature nylon and the terminal carboxyl groups of the liquid crystal polymer during melt blending, forming a stable interfacial bonding structure. This effectively inhibits interfacial debonding and creates an "interlocking" reinforcement effect between the two phases, fundamentally resolving the performance degradation problem caused by interfacial defects in traditional systems.

[0042] Improved interfacial bonding significantly enhances the overall performance of the material. The toughness of high-temperature nylon and the high modulus and low thermal expansion properties of liquid crystal polymers are fully synergistic, significantly improving the material's mechanical indicators such as tensile strength, flexural modulus, and impact toughness. At the same time, heat resistance properties such as heat deformation temperature and oxidation induction period at high temperatures are significantly enhanced. Dimensional stability can be maintained in continuous thermal cycles or alternating hot and cold environments, effectively resisting vibration fatigue and stress cracking. Compared to traditional systems that rely solely on general compatibilizers, the service life of the alloy of the present invention in high-temperature and high-stress scenarios is extended by more than 30%, and its comprehensive performance advantages are outstanding.

[0043] The combination of a multi-stage melt blending process and a specialized compatibilizer further optimizes processing performance. By precisely controlling the temperature, shear, and residence time at each stage, the compatibilizer and components fully react while avoiding material degradation or excessive shear. This ensures the fluidity and uniformity of the melt, reducing the difficulty of molding. The resulting alloys can be widely used in high-vibration equipment, thermal management components, and other applications with stringent requirements for heat resistance and reliability. This will promote the expanded application of high-performance engineering plastics in extreme environments and provide key material support for the lightweight and long-life performance of high-end equipment. DETAILED DESCRIPTION

[0044] The following specific implementation methods are only used to further illustrate the present application and should not be understood as limiting the scope of protection of the present application. Technicians in this field may make some non-essential improvements and adjustments to the present application based on the above application content.

[0045] 1. Implementation Example 1 50 g of PA6T, 30 g of Vectra® LCP, and a new bifunctional reactive compatibilizer (prepared as follows: 2 mol of analytically pure bisphenol A (Shanghai Aladdin Biochemical Technology Co., Ltd., purity ≥99.8%, melting point 155-158°C), 5 mol of industrial-grade epichlorohydrin (Jiangsu Haian Petrochemical Co., Ltd., model E-51, epoxy value 0.51 mol / 100 g, purity ≥98%), and 20% by mass NaOH solution (Xinjiang Zhongtai Chemical Co., Ltd., concentration 20%, containing 0.3 mol of NaOH, which is 1.5% of the molar amount of bisphenol A)) were added to a 1000 L glass-lined reactor (Jiangsu Yangyang Chemical Equipment Manufacturing Co., Ltd., model F-10 00L, material 316L stainless steel, stirring speed 200rpm, jacket heating), react at 80℃ for 5h (during which time, sampling is taken every 30min to detect the conversion rate of epichlorohydrin, until the conversion rate is ≥95%), and unreacted epichlorohydrin is recovered by vacuum distillation (vacuum degree -0.09MPa, temperature 80℃) to obtain bisphenol A diglycidyl ether (epoxy value 0.8-1.0mol / 100g); the above product is dissolved in acetone (Jiangsu Feixiang Chemical Co., Ltd., model FC-99, purity ≥99.5%, moisture ≤0.1%) (solid-liquid ratio 1:5), and ethylenediamine (Sinochem Fertilizer Co., Ltd., model EDA-99, purity ≥99%) is added. The reaction mixture was stirred at 60 ° C for 7 h (nitrogen was introduced during the reaction, and the stirring speed was 150 rpm). After the reaction, the mixture was washed with deionized water (resistivity ≥18.2 MΩ·cm) until neutral (pH = 6.5-7.5), filtered, and vacuum-dried at 80 ° C for 13 h (vacuum degree -0.09 MPa) to obtain a mixture containing epoxy groups (residual epoxy value 0.1-0.2 mol / 100 g) and oxazoline. The ingredients included: 10 g of a bifunctional reactive compatibilizer (containing 18% by mass) of 1% ethanol (100 g), 5 g of chopped glass fiber (Taishan Glass Fiber Co., Ltd., model ECR-430, alkali-free glass fiber, length 10-30 μm, diameter 10 μm, tensile strength ≥ 3000 MPa), 3 g of core-shell rubber particles (Shanghai Kingfa Technology Development Co., Ltd., model 757K, ABS-based core-shell structure, grafting rate ≥ 15%, particle size 2-5 μm), and hindered phenol antioxidant 1010 (Li'anlong New Materials Co., Ltd., model LA-1010, white powder, purity ≥ 98%, melting point 110-125°C, melt index (190°C / 2.16 kg) ≤ 0.5g / 10min), 1g of phosphite antioxidant 168 (Lianlong New Materials Co., Ltd., model LA-168, white crystalline powder, purity ≥97%, melting point 120-128°C, volatile matter ≤0.5%), and 1g of silicone masterbatch (Nanjing Julong Technology Co., Ltd., model JL-800, silicone content ≥40%, melt flow rate (200°C / 5kg) ≥50g / 10min, density 0.98-1.02g / cm³).

[0046] S1. Drying treatment: PA6T and Vectra® LCP were placed in a DZF-6020 vacuum drying oven (Shanghai Yiheng Scientific Instrument Co., Ltd.) at 120°C and a vacuum degree of -0.09 MPa for 4 h (water content was measured every h using a Karl Fischer titrator until the moisture content was <0.05%). The new bifunctional reactive compatibilizer was placed in a vacuum drying oven (same model as above) at 80°C and a vacuum degree of -0.08 MPa for 2 h (water content <0.1%). Chopped glass fiber and core-shell rubber particles were placed in a blast drying oven (DHG-9070A, Shanghai Yiheng Scientific Instrument Co., Ltd.) at 80°C for 2 h (the material thickness was ≤2 cm and the material was turned over every 30 min to ensure uniform drying and a moisture content <0.1%).

[0047] S2. Multi-stage melt blending extrusion: A Coperion ZSK 40 twin-screw extruder (Coperion Group, Germany, length-to-diameter ratio 40:1, screw diameter 40 mm, compression ratio 3.5) was used. The temperature of the first section (feeding zone Z1-Z3, corresponding to screw position 0-12D) was set to 305°C (temperature deviation of each zone ±2°C), the screw speed was 200 rpm, and PA6T, compatibilizer, and antioxidant (1010 and 168 mixed in a mass ratio of 1:1) were added at the main feed port (left) at a rate of 100 g / min. The residence time was 3 min (calculated by feeding rate and screw speed). The temperature of the second section (melt mixing zone Z4-Z6, corresponding to screw position 12-24D) was increased to 330°C (temperature deviation of each zone ±1°C), the screw speed was increased to 400 rpm, and the side feed port (right, 1000 mm from the left) was used to feed PA6T. LCP, chopped glass fiber, and core-shell rubber particles (mass ratio of 10:5:3) were added to the feed port (18D) at a rate of 50 g / min, with a residence time of 2 min (the average residence time of the melt in the mixing zone was determined by the tracer method). In the third section (homogenization / exhaust zones Z7-Z8, corresponding to screw positions 24-36D), the temperature was lowered to 310°C (temperature deviation within each zone ±1°C), the screw speed was reduced to 300 rpm, and silicone masterbatch was added (at a rate of 10 g / min through the side feed port) with a residence time of 1 min. A vacuum pump (model 2SK-1.5, flow rate 1.5 m³ / h, vacuum degree <-0.08 MPa) was installed at the exhaust port (located at the end of zone Z7) to remove volatiles (primarily residual acetone and water vapor).

[0048] Example 2 The preparation method is the same as that in Example 1, except that 60 g of PA4T (Shanghai Jinfa Technology Development Co., Ltd., model FR400), 25 g of Zenite® LCP (Shanghai Jinfa Technology Development Co., Ltd., model FR-LCP-2000), 15 g of a novel bifunctional reactive compatibilizer, 10 g of chopped glass fibers, 5 g of core-shell rubber particles, 1.5 g of a hindered phenol antioxidant 1010, 1.5 g of a phosphite antioxidant 168, and 2 g of a silicone masterbatch are weighed. Step S1: Drying: The PA4T and Zenite® LCP are vacuum dried (125°C, 5 h); the compatibilizer is dried (82°C, 2.5 h); and the chopped glass fibers and core-shell rubber particles are dried (82°C, 2.5 h). S2. Multi-stage melt blending extrusion: the twin-screw extruder had an aspect ratio of 45:1, the temperature of the first section was 308°C, the screw speed was 220 rpm, PA4T, compatibilizer, and antioxidant were added at the main feed port with a residence time of 4 min; the temperature of the second section was 333°C, the screw speed was 420 rpm, LCP, chopped glass fiber, and core-shell rubber particles were added at the side feed port with a residence time of 2.5 min; the temperature of the third section was 312°C, the screw speed was 320 rpm, silicone masterbatch was added with a residence time of 1.5 min, and the vacuum degree of the exhaust port was <-0.08 MPa.

[0049] S3. Extrusion granulation: After water cooling and traction, pelletizing is performed to obtain pellets.

[0050] Example 3 The preparation method is the same as that in Example 1, except that 70 g of PA10T, 15 g of Sumikasuper™ LCP, 5 g of a novel bifunctional reactive compatibilizer, 20 g of chopped glass fibers, 0 g of core-shell rubber particles, 2 g of hindered phenol antioxidant 1010, 1 g of phosphite antioxidant 168, and 2 g of silicone masterbatch are weighed by mass. S1. Drying: The PA10T and Sumikasuper™ LCP are vacuum dried (130°C, 6 h); the compatibilizer is dried (85°C, 3 h); and the chopped glass fibers are dried (85°C, 3 h). S2. Multi-stage melt blending extrusion: The twin-screw extruder has an aspect ratio of 42:1, a temperature of 310°C in the first stage, a screw speed of 250 rpm, and PA10T, a compatibilizer, and an antioxidant are added through the main feed port with a residence time of 5 minutes. The temperature of the second stage is 335°C, a screw speed of 450 rpm, and LCP and chopped glass fiber are added through the side feed port with a residence time of 3 minutes. The temperature of the third stage is 315°C, a screw speed of 350 rpm, and silicone masterbatch is added with a residence time of 2 minutes. The vacuum degree at the exhaust port is <-0.08 MPa. S3. Extrusion granulation: After water cooling and traction, pelletization is performed to obtain pellets.

[0051] Comparative Example 1 The preparation method is the same as that of Example 1, except that the new bifunctional reactive compatibilizer is not added (the amount of the compatibilizer is 0 g), and the other components are adjusted to 55 g of PA6T, 30 g of LCP, 5 g of chopped glass fiber, 3 g of core-shell rubber particles, 2 g of antioxidant, and 5 g of silicone masterbatch.

[0052] Comparative Example 2 The preparation method is the same as that of Example 2, except that the amount of LCP is less than 10% (8 g), and the other components are adjusted to 60 g of PA4T, 8 g of LCP, 15 g of compatibilizer, 10 g of chopped glass fiber, 5 g of core-shell rubber particles, 3 g of antioxidant, and 9 g of silicone masterbatch.

[0053] Comparative Example 3 The preparation method is the same as that of Example 3, except that the amount of high-temperature nylon is less than 40% (35 g), the amount of LCP is greater than 50% (25 g), and the other components are adjusted to 35 g of PA10T, 25 g of LCP, 5 g of compatibilizer, 20 g of chopped glass fiber, 3 g of antioxidant, and 12 g of silicone masterbatch.

[0054] 2. Performance Testing The high temperature resistant nylon / liquid crystal polymer alloys prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests according to the following method: 1. The tensile strength test was conducted using a universal material testing machine (Instron 5967, USA) in accordance with GB / T 1040.2-2006. The specimens were dumbbell type I (gauge length 50 mm, width 10 mm, thickness 4 mm), the tensile rate was 1 mm / min, and the average value of 5 specimens was taken.

[0055] 2. The flexural strength test was conducted using a three-point bending tester (model Zwick Z020, Zwick, Germany) in accordance with GB / T 9341-2008. The specimen size was 80 mm × 10 mm × 4 mm, the span was 10 mm, the loading rate was 2 mm / min, and the average value of 5 specimens was taken.

[0056] 3. The notched impact strength test was conducted using an Izod impact tester (Tinius Olsen H100K, USA) in accordance with GB / T 1843-2008. The specimen dimensions were 80 mm × 10 mm × 4 mm, the notch depth was 2 mm, the pendulum energy was 5.5 J, and the average value of five specimens was taken.

[0057] 4. The heat deformation temperature (HDT) test was conducted using a Vicat softening point tester (model CEAST HV-300, CEAST, Italy) in accordance with GB / T 1634.2-2019 standard, with a load of 1.8 MPa and a heating rate of 120°C / h. The temperature at which the specimen was bent 0.2 mm was recorded.

[0058] 5. The melt flow rate (MFR) test was conducted using a melt flow rate meter (model Zwick Z030, Zwick, Germany) in accordance with GB / T 3682-2018 standard, at a temperature of 275°C and a load of 2.16 kg. The average value of three tests was taken.

[0059] 6. Interface bonding strength test: A peel tester (Instron 3345, Instron Corporation, USA) was used to bond the alloy specimen to a 304 stainless steel plate (thickness 2 mm) using an epoxy resin adhesive (3M DP460, 3M Company, USA) (curing conditions: 25°C / 24 h). The T-peel strength was tested according to GB / T 3903.3-2011 (tensile rate 50 mm / min), and the average value of five specimens was taken.

[0060] 7. Moisture absorption rate test: According to GB / T 1034-2008 standard, place the sample (size 50mm×50mm×2mm) in a constant temperature and humidity chamber (temperature 85℃, humidity 85%RH) for 24 hours, weigh it and calculate the moisture absorption rate (moisture absorption rate = (wet weight - dry weight) / dry weight × 100%).

[0061] 8. Performance test results: Table 1: Performance test results of various embodiments and comparative examples

[0062] When conventional high-temperature nylon is composited with liquid crystal polymers, problems such as interfacial delamination and insufficient synergistic effects often occur due to significant differences in their chemical structures and weak interfacial forces. This limits the material's mechanical properties (such as tensile, flexural, and impact strength), heat resistance (heat deformation temperature), and processing performance (melt flow rate). The present invention significantly improves interfacial bonding by adding a novel bifunctional reactive compatibilizer. A detailed analysis is as follows: As can be seen in Table 1, a comparison of Examples 1-3 with Comparative Example 1 shows that, in the absence of a compatibilizer (Comparative Example 1), the material exhibits a tensile strength of only 185 MPa (22% lower than Example 1), a flexural strength of 240 MPa (23% lower), a notched impact strength of 4.2 kJ / m² (38% lower), a heat deformation temperature of 250°C (35°C lower), an interfacial bonding strength of only 4.5 N / mm² (43% lower), a moisture absorption rate of 1.2% (25% higher), and a melt flow rate of 15 g / 10 min (30% lower). These data indicate that, in the absence of a compatibilizer, the interfacial bonding is extremely weak, preventing effective stress transfer, leading to a significant decrease in mechanical properties. Furthermore, the increased number of interfacial defects increases hygroscopicity and deteriorates melt flowability. In Examples 1-3, a novel bifunctional reactive compatibilizer (containing epoxy and oxazoline groups) was added. During the high-temperature blending process, it covalently reacted with the terminal amine groups (-NH2) of the high-temperature nylon and the terminal carboxyl groups (-COOH) of the LCP, forming a stable interfacial bonding layer (interfacial bonding strength of 6.8-8.2 N / mm, a 42%-82% increase over Comparative Example 1). This interfacial layer effectively inhibited interfacial debonding and enabled the coordinated transmission of stresses between the two phases, significantly improving mechanical properties: tensile strength of 225-245 MPa (16%-32% higher than Comparative Example 1), flexural strength of 285-310 MPa (19%-29% higher), and notched impact strength of 5.5-6.8 kJ / m² (31%-62% higher). At the same time, the enhanced interfacial bonding reduces interfacial defects, reduces moisture absorption to 0.8-1.0% (17%-33% lower than Comparative Example 1), and increases the melt flow rate to 18-22 g / 10 min (20%-47% higher than Comparative Example 1), improving processing performance. The performance degradation in Comparative Example 2 (LCP dosage less than 10%) and Comparative Example 3 (high-temperature nylon dosage less than 40%) further demonstrates the critical role of the compatibilizer: when the LCP dosage is insufficient (Comparative Example 2), the interfacial bonding area is reduced, the tensile strength drops to 210 MPa (14% lower than Example 1), and the interfacial bonding strength is 6.0 N / mm (27% lower). When the high-temperature nylon dosage is insufficient (Comparative Example 3), the matrix's ability to support the LCP is weakened, with the tensile strength dropping to 198 MPa (20% lower) and the interfacial bonding strength to 5.2 N / mm (37% lower). This shows that only by optimizing the interface bonding between the two phases through compatibilizers can the synergistic effect of the toughness of high-temperature nylon and the high modulus of LCP be fully utilized, and the performance limitation problem of the traditional system caused by the weak interface be solved.

[0063] The above-described embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A high temperature resistant nylon / liquid crystal polymer alloy, characterized in that: In terms of mass percentage, the raw materials include: High temperature nylon: 40-85%; Fully aromatic polyester / LCP: 10-50%; New bifunctional reactive compatibilizer: 1-15%; Chopped glass fiber: 0-30%; Core-shell rubber particles: 0-10%; Antioxidant: 2-3%; The preparation method of the novel bifunctional reactive compatibilizer includes: adding bisphenol A and epichlorohydrin into a reactor, adding NaOH as a catalyst, reacting at 80-85°C, and distilling under reduced pressure to obtain bisphenol A diglycidyl ether; dissolving epoxy resin in acetone, adding ethylenediamine and 2-vinyl-2-oxazoline, stirring and reacting at 60-65°C; washing the reaction product with deionized water until neutral, filtering and vacuum drying.

2. The high temperature resistant nylon / liquid crystal polymer alloy according to claim 1, characterized in that: The molar ratio of bisphenol A to epichlorohydrin is 1:(2-3); the NaOH content is 1-2% of the molar amount of bisphenol A; the reaction time is 4-6 hours; the stirring reaction time is 6-8 hours; the vacuum drying temperature is 80-85° C., and the vacuum drying time is 12-14 hours.

3. The high temperature resistant nylon / liquid crystal polymer alloy according to claim 1, characterized in that: The high temperature nylon is selected from at least one of PA46, PA4T, PA6T, PA9T, PA10T, PPA or copolymers / mixtures thereof.

4. The high temperature resistant nylon / liquid crystal polymer alloy according to claim 1, characterized in that: The wholly aromatic polyester / LCP is selected from at least one of Vectra® LCP, Zenite® LCP, and Sumikasuper™ LCP.

5. The high temperature resistant nylon / liquid crystal polymer alloy according to claim 1, characterized in that: The antioxidant is a hindered phenol antioxidant 1010 and / or a phosphite antioxidant 168.

6. A method for preparing a high temperature resistant nylon / liquid crystal polymer alloy according to any one of claims 1 to 5, characterized in that the steps include: S1, vacuum drying high temperature nylon and fully aromatic polyester / LCP; New bifunctional reactive compatibilizer drying; The chopped glass fibers and core-shell rubber particles are dried to remove water; S2, multi-stage melt blending extrusion, first stage: the temperature is set at 305-310℃, high-temperature nylon, new bifunctional reactive type, and antioxidant are fed, and the residence time is 3-5 minutes; second stage: the temperature is increased to 330-335℃, and fully aromatic polyester / LCP, chopped glass fiber, and core-shell rubber particles are added through the side feed port, and the residence time is 2-3 minutes; third stage: the temperature is reduced to 310-315℃, and silicone masterbatch is added, and the residence time is 1-2 minutes. The vacuum degree of the exhaust port is <-0.08MPa; S3. After the melt is extruded through a die, it is water-cooled and drawn, and pelletized by a pelletizer to obtain pellets.

7. The preparation method according to claim 6, characterized in that In step S1, the vacuum drying temperature is 120-130° C., and the vacuum drying time is 4-6 hours; the drying temperature is 80-85° C., and the drying time is 2-3 hours.

8. The preparation method according to claim 6, characterized in that In step S2, the aspect ratio of the twin-screw extruder is (40-45):1, the screw speed in the first section is 200-250 rpm; the screw speed in the second section is 400-450 rpm; and the screw speed in the third section is 300-350 rpm.

9. The preparation method according to claim 6, characterized in that The preparation method further comprises: drying the prepared pellets at 80-85° C. for 2-3 hours, and then injection molding or compression molding.

10. An application of the high-temperature resistant nylon / liquid crystal polymer alloy according to any one of claims 1 to 5 or the high-temperature resistant nylon / liquid crystal polymer alloy prepared by the preparation method according to any one of claims 6 to 9, characterized in that: The high temperature resistant nylon / liquid crystal polymer alloy is used in high vibration and thermal cycle environments.

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