Polyamide / polyphenyl ether alloy and fiber reinforced composite material and preparation method thereof

Abstract

The invention discloses a polyamide / polyphenyl ether alloy as well as a fiber reinforced composite material and a preparation method thereof, and belongs to the technical field of high polymer materials, after an incompatible system of polyamide PA and polyphenyl ether PPO is compatibilized by using a polystyrene-polyamide comb copolymer as a non-reactive compatibilizer, the compatibility of PA and PPO can be obviously improved, and the compatibility between PA and PPO is improved. The average particle size of a PPO dispersed phase is reduced, and the two-phase interface action strength is enhanced, so that the polyamide / polyphenyl ether alloy with excellent performance is prepared. The fiber-reinforced polyamide / polyphenyl ether alloy composite material is further prepared, glass fibers, an antioxidant and a light stabilizer are added on the basis of polyamide / polyphenyl ether alloy, and the fiber-reinforced polyamide / polyphenyl ether alloy composite material has the characteristics of high temperature resistance, low moisture absorption, high resistance and thermal oxidation / light aging resistance; the glass fiber reinforced PA66 can partially replace the existing 30% glass fiber reinforced PA66 to be used for producing a high-performance extreme-environment-resistant gauge apron.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a polyamide / polyphenylene ether alloy and a fiber-reinforced composite material thereof and a preparation method thereof. Background Art

[0002] Polyamide (PA) is a semicrystalline engineering thermoplastic with abundant amide bonds in its backbone. It boasts advantages such as wear resistance, corrosion resistance, easy processing, and high mechanical strength, making it widely used in the automotive, electronics, textile, aerospace, and medical device industries. However, its high hygroscopicity, large dielectric constant and dissipation factor, and high molding shrinkage limit its application in high-voltage electrical components, microwave communication equipment, and precision injection-molded parts. While polyphenylene ether (PPO), an amorphous engineering plastic, possesses a high glass transition temperature, excellent mechanical properties, low hygroscopicity, dimensional stability, and good electrical insulation, its large-scale application is hampered by poor solvent resistance and insufficient processing properties. Therefore, the development of PA / PPO blends that combine the properties of both materials through melt blending has attracted widespread attention from both academia and industry. However, the significant differences in polarity and solubility parameters between PA and PPO can lead to severe phase separation in uncompatibilized blends, resulting in deterioration in mechanical properties and stability.

[0003] Traditional PA / PPO blend compatibilization strategies typically employ reactive grafted polymers as compatibilizers. For example, the polyphenylene ether / polyamide alloy material disclosed in Chinese patent publication CN103613918A employs maleic anhydride-grafted polyphenylene ether and / or fumaric anhydride-grafted polyphenylene ether as compatibilizers. However, the grafting rate of such compatibilizers is generally low, typically less than 2%, and residual initiators and unreacted monomers from the synthesis process can affect the stability of the blend, limiting the efficiency of such compatibilizers.

[0004] Chinese patent publication CN116875049A discloses a high-temperature nylon and polyphenylene ether alloy and a preparation method thereof. The invention uses a copolymeric compatibilizer or a grafted compatibilizer to compatibilize the PA / PPO blend system. The copolymeric compatibilizer is selected from one or a combination of styrene-maleic anhydride copolymer, styrene-glycidyl methacrylate copolymer, and styrene-3-isopropenyl-α,α-dimethylbenzyl isocyanate copolymer, and the grafted compatibilizer is selected from one or a combination of maleic anhydride-grafted hydrogenated styrene-butadiene-styrene copolymer and glycidyl methacrylate-grafted hydrogenated styrene-butadiene-styrene copolymer. However, the copolymeric compatibilizer or grafted compatibilizer in this invention requires a chemical reaction during the melt blending process to produce the compatibilizer that actually works. However, the chemical reaction efficiency is affected by process parameters such as processing temperature, screw speed, and residence time, resulting in an unstable actual compatibilizer yield, further affecting the blend performance. In addition, the corresponding chemical reaction may also cause chain extension, partial cross-linking or even severe cross-linking of the matrix resin to cause gelation, resulting in an increase in the melt viscosity of the blend and deterioration of its processing performance.

[0005] Non-reactive compatibilizers improve the compatibility of multiphase systems through physical effects such as polarity similarity, hydrogen bonding, and van der Waals forces. Their molecular chains usually do not contain reactive groups such as epoxy, carboxyl, maleic anhydride, and amino groups that can participate in chemical reactions. They mainly act as a "bridge" at the interface between the two phases, reducing interfacial tension and promoting uniform distribution and interfacial adhesion of the dispersed phase, but they do not chemically bond with the blending components. This type of compatibilizer has the following advantages: (1) Simple process: They can be used directly through melt blending or physical mixing without considering chemical reaction conditions; (2) High stability: There is no risk of chemical reaction, and the system performance will not be affected by byproducts (such as bubbles and cross-linking); (3) Wide range of applications: They can be used in incompatible blending systems where none of the components contain reactive groups; (4) Repeated processing stability: No chemical reaction will occur during subsequent reprocessing or recycling after physical action, causing performance changes, making the material more recyclable and stable. Therefore, designing and synthesizing copolymers with similar physical properties to both PA and PPO, and using them as non-reactive compatibilizers to improve the compatibility of the PA / PPO system, is a key technology for developing PA / PPO alloy materials with high mechanical strength, high melt fluidity and stable performance. Summary of the Invention

[0006] The present invention provides the use of a polystyrene-polyamide comb copolymer as a non-reactive compatibilizer for an incompatible system of polyamide and polyphenylene ether. The polystyrene-polyamide comb copolymer does not contain active groups that react with PA and PPO, and can effectively reduce the interfacial tension between the PA and PPO phases. This allows the development of a series of PA / PPO alloys and fiber-reinforced composite materials thereof with excellent comprehensive performance.

[0007] The specific technical solutions adopted are as follows:

[0008] The application of polystyrene-polyamide comb copolymer as a non-reactive compatibilizer for incompatible systems of polyamide and polyphenylene ether. The structure of polystyrene-polyamide comb copolymer includes polystyrene main chain and polyamide side chain, with a number average molecular weight of 2.0×10 4 -10.0×10 4 g / mol, and its structural formula is as follows:

[0009]

[0010] Wherein, x=0.01-0.1, y is 3, 5 or 11, n and m are integers, 50≤n≤8000, 20≤m≤8000.

[0011] Furthermore, the polystyrene-polyamide comb copolymer is synthesized by the following method ("one-pot method"), comprising the steps of:

[0012] Under an inert gas atmosphere, a copolymerization reaction is carried out in an organic solvent using styrene, an unsaturated isocyanate and a free radical initiator at 50-150° C. for 4-48 hours to obtain a prepolymer solution; under an inert gas atmosphere, a lactam and a lactam metal salt catalyst are added to the above prepolymer solution, and an anionic ring-opening polymerization reaction is carried out at a temperature of ≥120° C. for 1-24 hours to separate and obtain the polystyrene-polyamide comb copolymer.

[0013] Preferably, the unsaturated isocyanate is 3-isopropyl-α,α-dimethylbenzyl isocyanate.

[0014] Preferably, the free radical initiator is at least one of azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, cyclohexanone peroxide, and tert-butyl hydroperoxide.

[0015] Preferably, the organic solvent has a boiling point higher than 120°C and does not react with the lactam metal salt catalyst, and is further selected from at least one of xylene, trimethylbenzene, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl silicone oil, and a saturated hydrocarbon compound with a carbon number ≥8.

[0016] The organic solvent is an organic compound having a boiling point higher than 120° C. and not reacting with the sodium lactam catalyst, and is further preferably at least one selected from xylene, trimethylbenzene, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl silicone oil, and a saturated hydrocarbon compound having a carbon number ≥8.

[0017] Preferably, the lactam is at least one of caprolactam and laurolactam; and the lactam metal salt is the sodium, potassium, magnesium or calcium salt corresponding to butyrolactam, caprolactam or laurolactam.

[0018] More preferably, the lactam is ε-caprolactam, and the lactam metal salt is sodium caprolactam.

[0019] The present invention also provides a polyamide / polyphenylene ether alloy, which uses the polystyrene-polyamide comb copolymer as a non-reactive compatibilizer and specifically comprises the following components in parts by weight:

[0020] Polyamide: 60-90 parts;

[0021] Polyphenylene ether: 10-40 parts;

[0022] Polystyrene-polyamide comb copolymer: 0.5-10 parts.

[0023] The main chain of the polyamide contains an amide bond, has a melting point of 100-350° C., and a molecular weight of 10,000-500,000, and includes at least one of polyamide 11, polyamide 12, polyamide 6, polyamide 6 / 12 copolymer, polyamide 46, polyamide 56, polyamide 612, polyamide 610, polyamide 66, polyamide 6T, polyamide 9T, polyamide 10T, polyamide 12T, and polyamide MXD6.

[0024] Furthermore, the polyamide is a semi-aromatic polyamide with a melting point of 280-350° C., and is selected from at least one of polyamide 6T, polyamide 9T, polyamide 10T, polyamide 12T, and polyamide MXD6.

[0025] Furthermore, the polyamide is polyamide 10T.

[0026] The present invention also provides a method for preparing the polyamide / polyphenylene ether alloy, comprising the following steps:

[0027] S11: drying the polyamide and polyphenylene ether at 60-160° C. for 2-24 hours, and premixing them with a non-reactive compatibilizer, polystyrene-polyamide comb copolymer, in corresponding proportions;

[0028] S12: melt-blending the premix through a twin-screw extruder to prepare a polyamide / polyphenylene ether alloy, with a screw speed of 100-600 rpm and a processing temperature higher than the glass transition temperature of PPO and the melting point of polyamide and lower than 350°C.

[0029] The present invention also provides a fiber-reinforced polyamide / polyphenylene ether alloy composite material, which uses the polystyrene-polyamide comb copolymer as a non-reactive compatibilizer and specifically comprises the following components in parts by weight:

[0030]

[0031] The mechanical properties of the composite material obtained by reinforcing the polyamide / polyphenylene ether system compatibilized with polystyrene-polyamide comb copolymer using glass fiber are better than those of the polyamide / polyphenylene ether system compatibilized with a reactive compatibilizer.

[0032] Further preferably, the fiber-reinforced polyamide / polyphenylene ether alloy composite material comprises the following components in parts by weight:

[0033]

[0034] The present invention also provides a method for preparing the fiber-reinforced polyamide / polyphenylene ether alloy composite material, comprising the following steps:

[0035] S21: drying polyamide and polyphenylene ether at 60-160°C for 2-24 hours, and then premixing with a non-reactive compatibilizer, polystyrene-polyamide comb copolymer, glass fiber, antioxidant, and light stabilizer;

[0036] S22 The above premixes are melt-blended in corresponding proportions through a twin-screw extruder to prepare the fiber-reinforced polyamide / polyphenylene ether alloy composite material, the screw speed is 100-600 rpm (further preferably 300-500 rpm), and the processing temperature is higher than the glass transition temperature of PPO and the melting point of polyamide and lower than 350°C (further preferably 300-340°C).

[0037] The present invention also provides a gauge baffle component, which comprises the gauge baffle component obtained by injection molding the fiber reinforced polyamide / polyphenylene ether alloy composite material.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The present invention uses styrene and unsaturated isocyanates such as 3-isopropyl-dimethylbenzyl isocyanate to undergo free radical copolymerization to prepare a prepolymer, and uses it as a macromolecular activator to initiate lactam anionic ring-opening polymerization to obtain a polystyrene-polyamide comb copolymer with polystyrene as the main chain and polyamide as the side chain. The synthesis method of the polystyrene-polyamide comb copolymer is simple, the yield is high, the product is high in purity, and the heat resistance is good. In addition, compared with the two commonly used reactive compatibilizers, maleic anhydride grafted hydrogenated styrene-butadiene-styrene copolymer (SEBS-g-MAH) and styrene / methacrylate glycidyl ester (PSG), the compatibilization efficiency of the PA / PPO system is higher.

[0040] (2) The present invention uses polystyrene-polyamide comb copolymer as a non-reactive compatibilizer to compatibilize the PA / PPO incompatible system, thereby improving the compatibility of PA and PPO, reducing the average particle size of the PPO dispersed phase, and enhancing the interfacial interaction strength of the two phases, thereby improving the tensile strength of the PA / PPO alloy. The tensile strength and melt index of the polyamide / polyphenylene ether alloy prepared using the polystyrene-polyamide comb copolymer as a non-reactive compatibilizer are significantly better than those of the polyamide / polyphenylene ether alloy prepared using a reactive compatibilizer.

[0041] (3) The present invention further adds glass fiber, antioxidant and light stabilizer to the polystyrene-polyamide comb copolymer compatibilized PA / PPO alloy system to prepare a fiber-reinforced polyamide / polyphenylene ether alloy composite material and its molded railway gauge baffle product, which has the advantages of high temperature resistance, low moisture absorption, high electrical resistance and resistance to heat oxygen / light aging compared with the existing glass fiber reinforced PA66 material and its products. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a scanning electron microscope image of the polyamide / polyphenylene ether alloy of Comparative Example 1 after freeze-fracture, tetrahydrofuran etching, and gold plating of the cross section.

[0043] Figure 2 This is a scanning electron microscope image of the polyamide / polyphenylene ether alloy of Comparative Example 4 after freeze-fracture, tetrahydrofuran etching, and gold plating of the cross section.

[0044] Figure 3 This is a scanning electron microscope image of the polyamide / polyphenylene ether alloy of Example 3 after freeze-fracture, tetrahydrofuran etching, and gold plating of the cross section.

[0045] Figure 4 This is a scanning electron microscope image of the polyamide / polyphenylene ether alloy of Example 6 after freeze-fracture, tetrahydrofuran etching, and gold plating of the cross section. DETAILED DESCRIPTION

[0046] In order to make the objects, features and advantages of the present invention more clearly understood, a detailed description is given below using specific embodiments. In the following description, many specific details are set forth to fully understand the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. The technical features in the various embodiments of the present invention can be combined accordingly without conflicting with each other.

[0047] The procedures for the following examples, in which specific conditions are not specified, generally follow conventional conditions or those recommended by the manufacturer. Any material not described in detail in this specification belongs to the prior art known to those skilled in the art. The experimental materials used in the following examples, unless otherwise specified, can be purchased from conventional biochemical reagent companies.

[0048] Example 1

[0049] The raw material information involved in the comparative examples and embodiments of the present invention is as follows:

[0050] Chemically pure styrene (St), 3-isopropenyl-α,α-dimethylbenzyl isocyanate (TMI), tetrahydrofuran (THF), sodium methoxide (CH3ONa), and analytically pure anhydrous xylene and ethanol were purchased from Anhui Zesheng Technology Co., Ltd. Industrial-grade ε-caprolactam (CL) was purchased from Nanjing Dongfang Chemical Co., Ltd. Polyamide 6 pellets (PA6, brand J2000) and polyphenylene ether powder (PPO, brand LXR 035) were provided by Polyshun New Materials Co., Ltd. and Nantong Xingchen Synthetic Materials Co., Ltd., respectively.

[0051] The reactive compatibilizer SEBS-MAH (brand name Kraton FG1901X, Kraton High Performance Polymers Co., Ltd.) is a block copolymer with a styrene content of 29% and a hydrogenated butadiene content of 71%. The hydrogenated butadiene block is grafted with 1.4%-2.0% maleic anhydride.

[0052] The reactive compatibilizer styrene-glycidyl methacrylate (PSG) was prepared by copolymerization of styrene (St) and 4 mol% glycidyl methacrylate (GMA). The synthesis method can be found in the literature Xia et al. J. Appl. Polym Sci., 2023, 140(44), e54604.

[0053] Polystyrene-polyamide comb copolymers are prepared by a two-step "one-pot" method of free radical copolymerization and anionic ring-opening polymerization. Step 1: Anhydrous xylene, purified styrene (St) and 3-isopropenyl-α,α-dimethylbenzyl isocyanate (TMI) are added to a four-necked flask equipped with a reflux condenser, a nitrogen inlet (0.5L / min), a mechanical stirrer (200rpm) and a thermocouple. The above-mentioned mixed system is heated to 80±1°C under continuous nitrogen protection, and then azobisisobutyronitrile (AIBN) is added to initiate the copolymerization reaction for 24 hours to obtain a viscous PST macroinitiator / xylene solution (marked as component A). Step 2: ε-caprolactam (CL) is placed in a three-necked flask equipped with a condenser and a vacuum system (<10kPa) and pre-dehydrated at 120°C for 10 minutes. Sodium methoxide is added for further degassing for 30 minutes to prepare a sodium-activated ε-caprolactam catalyst (Na+ A component containing CL (sodium caprolactam) (labeled as component B) was prepared. Under strict nitrogen protection, component B was transferred to the flask containing component A. Anionic ring-opening polymerization of CL was carried out at 130°C with vigorous mechanical stirring at 500 rpm for 3 hours. After cooling to 80°C, the resulting slurry was vacuum filtered through a Buchner funnel, washed sequentially with ethanol and deionized water, and dried under vacuum at 60°C (<100 Pa) for 24 hours to obtain the final product, a polystyrene-polyamide comb copolymer. By adjusting the TMI feed ratio in the first step (1, 2, and 4 mol%, respectively, based on the total molar amount of St and TMI), while maintaining the same mass ratio of PST, CL monomer, and xylene solvent, three samples (T1, T2, and T3) were prepared. The specific synthesis formulas and physical properties are shown in Table 1.

[0054] Table 1 Ratios of raw materials and properties of polystyrene-polyamide comb copolymers

[0055]

[0056] [a] The yield and conversion were determined and calculated by gravimetric method using the formula: ratio of product polymer mass to total mass of initial monomers × 100%;

[0057] [b] Thermogravimetric analysis was performed using a STA 449F3 simultaneous thermal analyzer (Netzsch, Germany) under the following test conditions: nitrogen atmosphere (flow rate 20 mL / min), sample amount 5–10 mg, heating from room temperature (RT) to 700 °C at a heating rate of 10 °C / min;

[0058] [c] The number average molecular weight of the PS-g-PA6 copolymer after N-trifluoroacetylation pretreatment was determined using a Waters ACQUITY APC system equipped with a differential refractive index detector (RI). The sample solution was prepared at a concentration of 3 mg / mL (THF solvent) and filtered through a 0.45 μm PTFE membrane before injection of 100 μL.

[0059] The polystyrene-polyamide comb copolymer structure obtained by the above method includes a polystyrene main chain and a polyamide side chain, and its structural formula is as follows:

[0060]

[0061] Wherein x=0.01-0.04, y=3, 5 or 11, and n and m can be obtained by calculation of molecular weight.

[0062] By adopting the method of the present invention, the yield of the obtained PST macromolecular initiator is high, the conversion rate of ε-caprolactam CL is high, and the product polystyrene-polyamide comb-shaped copolymer has good thermal stability and excellent comprehensive performance.

[0063] The equipment and testing instrument information involved in the comparative examples and embodiments of the present invention are as follows:

[0064] PA / PPO alloy particles were prepared using a twin-screw extruder, model Nanjing Keya HK26-40D. Mechanical properties test specimens were injection molded using a Haitian PL860 injection molding machine equipped with ISO standard size molds. Mechanical properties tests were performed using a universal testing machine in accordance with ISO standards, model Shenzhen Sansi UTM4304.

[0065] Examples 1-6 and Comparative Examples 1-6

[0066] All raw materials, except the polystyrene-polyamide comb copolymer, reactive compatibilizers SEBS-MAH, and reactive compatibilizer PSG, were dried in a circulating hot air oven at 120°C for 8 hours. PA resin, PPO powder, and compatibilizer were premixed according to the proportions in Table 2 and melt-blended using a twin-screw extruder at 300 rpm. The extruded strands were dried at 100°C for 12 hours and then molded into ISO-standard specimens using an injection molding machine equipped with a mold temperature control system to produce polyamide / polyphenylene ether alloys. For the PA6 / PPO system, extrusion and injection molding temperatures were 210-240°C, and the injection mold temperature was room temperature. For the PA10T / PPO system, extrusion and injection molding temperatures were 310-330°C, and the injection mold temperature was 150±1°C.

[0067] Tensile strength was measured according to ISO 527 at a rate of 10 mm / min; flexural strength was measured according to ISO 178 at a rate of 2 mm / min; and notched Izod impact strength was measured according to ISO 180. Melt flow rate (MFR) was tested according to ISO 1133-1:2011 for PA6 / PPO alloys at 230°C and a load of 2.16 kg, and for PA10T / PPO alloys at 330°C and a load of 1.2 kg.

[0068] Table 2. Formulations of Examples 1-6 and Comparative Examples 1-6 and their product tensile strength and melt index

[0069]

[0070] Examples 1-3 of the present invention demonstrate the effects of non-reactive compatibilizers (PSA-P) (T1, T2, and T3) synthesized using the aforementioned steps on the properties of PA6 / PPO alloys. Increasing the TMI monomer content in the PST macromolecular activator used to synthesize the PSA-P copolymers increases the compatibilization efficiency of the corresponding PSA-P copolymers, leading to higher tensile strengths in the PA6 / PPO alloys. The T3-compatibilized alloy achieved a maximum tensile strength of 56.5 MPa, a 43.8% increase compared to the uncompatibilized PA6 / PPO alloy. Furthermore, compared to two other reactive compatibilizers, SBS-g-MAH and PSG, the tensile strength also increased by 13.5% and 12.5%, respectively, demonstrating that the compatibilization efficiency of the non-reactive PSA-P copolymers is significantly higher than that of commonly used reactive compatibilizers. Most importantly, the melt index (MFR) value of the PA6 / PPO alloy compatibilized with the polystyrene-polyamide comb copolymer is significantly higher than that of the uncompatibilized and reactive compatibilizer systems (Comparative Examples 1-3), indicating that the polystyrene-polyamide comb copolymer comb polymer not only improves the compatibility of PA6 and PPO, but also does not participate in chain extension or cross-linking reactions that cause a decrease in the melt index. Therefore, it is very suitable for processing and molding methods such as injection molding, and is also more suitable for further melt blending or compounding with glass fiber or carbon fiber to prepare high-performance composite materials.

[0071] To demonstrate the versatility of polystyrene-polyamide comb copolymers as efficient compatibilizers for PA / PPO systems, Examples 4-6 of the present invention used different types of polystyrene-polyamide comb copolymers to compatibilize PA10T / PPO alloys. Comparative Examples 4-6, respectively, used uncompatibilized, SEBS-g-MAH-compatibilized, and PSG-compatibilized PA10T / PPO alloys. The PA10T / PPO alloy compatibilized with the T3 sample achieved the highest tensile strength of 69.5 MPa, a 33.1% increase over the uncompatibilized PA6 / PPO alloy. Furthermore, compared to systems with equivalent addition amounts of two reactive compatibilizers, SBS-g-MAH and PSG, the tensile strength increased by 30.4% and 29.2%, respectively, demonstrating that the compatibilization efficiency of the non-reactive polystyrene-polyamide comb copolymer for PA10T and PPO is significantly higher than that of conventional reactive compatibilizers. Similarly, the MFR value of the PA10T / PPO alloy compatibilized with the polystyrene-polyamide comb copolymer is also much higher than that of the uncompatibilized and reactive compatibilizer systems (Comparative Examples 4-6), indicating that the polystyrene-polyamide comb copolymer comb polymer not only improves the compatibility of PA10T and PPO, but also makes the compatibilized PA10T / PPO alloy have very good processing fluidity, which is very suitable for further melt blending or compounding with glass fiber or carbon fiber to prepare high-performance composite materials.

[0072] The samples of Comparative Examples 1, 4 and Examples 3, 6 were further subjected to liquid nitrogen brittle fracture and tetrahydrofuran etching and SEM morphology observation was performed. The results are as follows: Figure 1-Figure 4 As shown. Tetrahydrofuran is a good solvent for PPO, and the pores left by etching reflect the micromorphology of the PPO phase in the PA / PPO alloy. The average particle sizes of the PPO dispersed phase in the uncompatibilized PA6 / PPO alloy and PA10T / PPO alloy were 17.1 μm and 1.9 μm, respectively. The average particle sizes of the PPO dispersed phase in the PA6 / PPO alloy and PA10T / PPO alloy compatibilized with the polystyrene-polyamide comb copolymer were 14.0 μm and 1.2 μm, respectively. These results demonstrate that the comb polymer of the polystyrene-polyamide comb copolymer can effectively compatibilize the PA / PPO alloy.

[0073] In addition, the PA10T / PPO alloys prepared in Comparative Examples 5, 6 and Example 6 were further modified by glass fiber reinforcement, and ~30% glass fiber (GF) 301HP, ~0.5% antioxidant JYANOX-1330 and ~0.5% light stabilizer CHIGUARD-234 were added (PA10T / PPO alloy: GF: antioxidant: light stabilizer mass ratio of 70:30:0.5:0.5), and PA10T / PPO / GF composite materials were prepared by granulation using a twin-screw extruder (screw speed of 300-500 rpm, processing temperature of 300-340°C), and the tensile strengths thereof were 138 MPa, 145 MPa and 156 MPa, respectively. The results show that the tensile strength of the polystyrene-polyamide comb copolymer compatibilized composite material is the highest. The applicant speculates that this beneficial effect is not only due to the better tensile strength of the polystyrene-polyamide comb copolymer compatibilized PA10T / PPO alloy material, but also due to the high melt index (low melt viscosity) of the alloy, which is conducive to the surface wetting of the glass fiber and the maintenance of the glass fiber length (the low melt viscosity PA10T / PPO matrix transfers low shear stress to the glass fiber).

[0074] A series of tests on the PA10T / PPO / GF composite material compatibilized with the polystyrene-polyamide comb copolymer demonstrated its high-temperature resistance, low moisture absorption, high electrical resistance, and resistance to thermal, oxygen, and light aging (Table 3). This material can partially replace existing 30% glass fiber-reinforced PA66 in the production of high-performance, extreme-environment-resistant track gauge plates.

[0075] Table 3 Characterization of polystyrene-polyamide comb copolymer-compatibilized PA10T / PPO / GF composites

[0076]

[0077] The embodiments described above provide a detailed description of the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements or similar substitutions made within the scope of the principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Application of polystyrene-polyamide comb copolymer as non-reactive compatibilizer for incompatible systems of polyamide and polyphenylene ether, characterized in that: The polystyrene-polyamide comb copolymer structure consists of a polystyrene main chain and a polyamide side chain, with a number average molecular weight of 2.0×10 4 -10.0×10 4 g / mol, and its structural formula is as follows: Wherein, x=0.01-0.1, y is 3, 5 or 11, n and m are integers, 50≤n≤8000, 20≤m≤8000.

2. The use according to claim 1, characterized in that The polystyrene-polyamide comb copolymer is synthesized by the following method, comprising the steps of: Under an inert gas atmosphere, a copolymerization reaction is carried out in an organic solvent using styrene, an unsaturated isocyanate and a free radical initiator at 50-150° C. for 4-48 hours to obtain a prepolymer solution; under an inert gas atmosphere, a lactam and a lactam metal salt catalyst are added to the above prepolymer solution, and an anionic ring-opening polymerization reaction is carried out at a temperature of ≥120° C. for 1-24 hours to separate and obtain the polystyrene-polyamide comb copolymer.

3. The use according to claim 2, characterized in that The unsaturated isocyanate is 3-isopropyl-α,α-dimethylbenzyl isocyanate; and / or the free radical initiator is at least one of azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, cyclohexanone peroxide, and tert-butyl hydroperoxide; and / or the boiling point of the organic solvent is higher than 120° C. and does not react with the lactam metal salt catalyst.

4. The use according to claim 2, characterized in that The lactam is at least one of caprolactam and laurolactam; and / or the lactam metal salt is the sodium, potassium, magnesium or calcium salt corresponding to butyrolactam, caprolactam or laurolactam.

5. A polyamide / polyphenylene ether alloy, characterized in that: The polystyrene-polyamide comb copolymer according to claim 1 is used as a non-reactive compatibilizer, and specifically comprises the following components in parts by weight: Polyamide: 60-90 parts; Polyphenylene ether: 10-40 parts; Polystyrene-polyamide comb copolymer: 0.5-10 parts.

6. The polyamide / polyphenylene ether alloy according to claim 5, characterized in that The main chain of the polyamide contains an amide bond, has a melting point of 100-350° C., and a molecular weight of 10,000-500,000, and includes at least one of polyamide 11, polyamide 12, polyamide 6, polyamide 6 / 12 copolymer, polyamide 46, polyamide 56, polyamide 612, polyamide 610, polyamide 66, polyamide 6T, polyamide 9T, polyamide 10T, polyamide 12T, and polyamide MXD6.

7. The method for preparing a polyamide / polyphenylene ether alloy according to claim 5 or 6, characterized in that: The following steps are involved: S11: drying the polyamide and polyphenylene ether at 60-160° C. for 2-24 hours, and premixing them with a non-reactive compatibilizer, polystyrene-polyamide comb copolymer, in corresponding proportions; S12: melt-blending the premix through a twin-screw extruder to prepare a polyamide / polyphenylene ether alloy, with a screw speed of 100-600 rpm and a processing temperature higher than the glass transition temperature of PPO and the melting point of polyamide and lower than 350°C.

8. A fiber-reinforced polyamide / polyphenylene ether alloy composite material, characterized in that: The polystyrene-polyamide comb copolymer according to claim 1 is used as a non-reactive compatibilizer, and specifically comprises the following components in parts by weight: Polyamide: 40-90 parts; Polyphenylene ether: 10-40 parts; Polystyrene-polyamide comb copolymer: 0.5-10 parts; Glass fiber: 10-50 parts; Antioxidant: 0-2 parts; Light stabilizer: 0-2 parts.

9. The method for preparing the fiber-reinforced polyamide / polyphenylene ether alloy composite material according to claim 8, characterized in that: The following steps are involved: S21: drying polyamide and polyphenylene ether at 60-160°C for 2-24 hours, and then premixing with a non-reactive compatibilizer, polystyrene-polyamide comb copolymer, glass fiber, antioxidant, and light stabilizer; S22: melt-blending the premixes in corresponding proportions through a twin-screw extruder to prepare the fiber-reinforced polyamide / polyphenylene ether alloy composite material, with a screw speed of 100-600 rpm and a processing temperature higher than the glass transition temperature of PPO and the melting point of polyamide and lower than 350°C.

10. A gauge baffle component, characterized in that: The fiber-reinforced polyamide / polyphenylene ether alloy composite material according to claim 8 is injection-molded to obtain a gauge baffle component.

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