A high-gloss, high-glass-fiber-content nylon 66 composite material and its preparation method

Abstract

The present invention relates to a high-gloss high-glass-fiber-content nylon 66 composite material and a preparation method thereof, and belongs to the technical field of polymer composite materials. The components of the composite material are: 50-60wt% of alkali-free glass fiber, 2.2-3.5wt% of a high-gloss compatibilizer, 3.5-5wt% of a toughening agent, 0.15-0.2wt% of an antioxidant, and 0.6-0.9wt% of a processing aid, with the remainder being nylon 66 resin; the high-gloss compatibilizer is substituted by n-alkyl alcohol and vinyl trichlorosilane to form intermediate 1, and then intermediate 2 is prepared by initiating addition of methyl thioglycolate and the unsaturated double bond of intermediate 1, and finally amine transesterification is carried out by γ-aminopropyl triethoxysilane and the terminal methyl ester of intermediate 2; the high-gloss compatibilizer effectively reduces the high-crystalline region-low-crystalline region interface content in the composite system, reduces the scattering of light, and thus allows the composite material to maintain a higher gloss.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite fabrics, and in particular relates to a high-gloss and high-glass-fiber-content nylon 66 composite material and a preparation method thereof. Background Art

[0002] Nylon 66, an engineering plastic with excellent comprehensive properties, is widely used in industries such as aerospace, automotive, and electronics. However, its relatively low strength and modulus limit its further development in demanding applications. To overcome this limitation, efforts are underway to develop new composite materials that enhance the performance of nylon 66. Glass fiber (hereafter referred to as glass fiber) is a reinforcing fiber material characterized by high strength, high modulus, and low weight. Combining glass fiber with nylon 66 effectively improves its mechanical properties and is cost-effective, making it an ideal choice for structural materials.

[0003] Due to the addition of glass fiber, the physical and mechanical properties of nylon 66 have been effectively improved, and the mechanical strength, wear resistance and dimensional stability have been greatly improved. However, the glossiness of the composite material has been seriously reduced, which has greatly limited its application in appearance parts. In long-term research, it was found that the reasons for this defect include: the addition of glass fiber forms a large number of nylon-glass fiber interfaces in the composite system, and light is scattered on the inhomogeneous interface, thereby reducing the glossiness. This defect cannot be fundamentally eliminated, and the glossiness decreases more seriously with the increase of glass fiber content. More importantly, the introduction of glass fiber hinders the movement and arrangement of nylon molecules on its surface, inhibits the crystallization of nylon during the molding process, and forms a large number of uneven low-crystalline areas on the glass fiber surface. From the perspective of the entire composite system, a wide high-crystalline area-low-crystalline area inhomogeneous interface is formed from the nylon matrix to the glass fiber surface, forming serious light scattering in this area, resulting in a sharp deterioration of glossiness. Summary of the Invention

[0004] In order to solve the technical problems mentioned in the background technology, the purpose of the present invention is to provide a high-gloss and high-glass fiber content nylon 66 composite material and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A high-gloss, high-glass-fiber-content nylon 66 composite material, comprising:

[0007] 50-60wt% of alkali-free glass fiber, 2.2-3.5wt% of high-gloss compatibilizer, 3.5-5wt% of toughening agent, 0.15-0.2wt% of antioxidant and 0.6-0.9wt% of processing aid, and the balance is nylon 66 resin.

[0008] The high-gloss compatibilizer is prepared by the following method:

[0009] Step A1: Premix n-alkyl alcohol, sodium hydroxide, and anhydrous tetrahydrofuran, introduce dry gas protection, control the temperature of the water bath at 0-10°C, apply stirring at 120-150 rpm, slowly add vinyltrichlorosilane and react for 2-3 hours, then raise the temperature to 60-70°C and reflux for 1-1.5 hours. After the reaction is completed, filter and dry by rotary evaporation to obtain intermediate 1.

[0010] Furthermore, the feed ratio of vinyltrichlorosilane, n-alkyl alcohol, sodium hydroxide and anhydrous tetrahydrofuran is 10mmol:30mmol:0.2-0.4g:55-90mL, n-alkyl alcohol is substituted with vinyltrichlorosilane to introduce alkyl side chains, and the specific reaction route is as follows:

[0011]

[0012] Preferably, the n-alkyl alcohol is one of n-butanol, n-octanol and n-decanol.

[0013] Step A2: Mix the intermediate 1, methyl thioglycolate, benzophenone and ethanol, raise the temperature to 45-60°C, apply stirring at 60-90 rpm and 150-200 W / m 2 The mixture was irradiated with ultraviolet light and reacted for 3.5-5 h. After the reaction was completed, ethanol was removed to obtain intermediate 2.

[0014] Furthermore, the feed ratio of intermediate 1, methyl thioglycolate, benzophenone and ethanol is 10 mmol: 10 mmol: 10-20 mg: 50-80 mL, and methyl thioglycolate initiates addition with the unsaturated double bond of intermediate 1 to introduce a terminal methyl ester structure. The specific reaction route is as follows:

[0015]

[0016] Step A3: Intermediate 2, γ-aminopropyltriethoxysilane and dimethyl sulfoxide are mixed, and dry gas protection is introduced. The temperature is raised to 80-100°C, and stirring is applied at 60-120 rpm. Trimethylaluminum is added intermittently and the reaction is carried out for 4-5 hours. After the reaction is completed, dimethyl sulfoxide is removed under reduced pressure to obtain a high-gloss compatibilizer.

[0017] Furthermore, the feed ratio of intermediate 2, γ-aminopropyltriethoxysilane, trimethylaluminum and dimethyl sulfoxide is 10 mmol: 10 mmol: 25-50 mg: 60-80 mL, and γ-aminopropyltriethoxysilane is subjected to amine ester exchange with the terminal methyl ester of intermediate 2 to introduce ethoxysilane for modification. The specific reaction route is as follows:

[0018]

[0019] Preferably, the length of the alkali-free glass fiber is 1.5-4.5 mm and the diameter is 9-14 μm.

[0020] Preferably, the toughening agent is compounded from POE-g-MAH (maleic anhydride grafted POE) and E-GMA (ethylene-glycidyl methacrylate copolymer).

[0021] A method for preparing a high-gloss, high-glass-fiber-content nylon 66 composite material comprises the following steps:

[0022] Step S1: impregnating the alkali-free glass fiber with an ethanol aqueous solution to control the liquid content to 4.5-6 wt %, then mixing with the remaining raw materials, heating to 220±10° C. and mixing for 25-30 min, and drying the discharged material until the moisture content is no more than 0.1 wt % to obtain a batch;

[0023] Step S2: melt-extrude the compounded material through a twin-screw extruder, and the extrusion temperature zones are set as follows: the temperature of the first zone is 200±10°C, the temperature of the second zone is 260±10°C, the temperature of the third zone is 270±10°C, the temperature of the fourth zone is 280±10°C, the temperature of the fifth zone is 270±10°C, the temperature of the sixth zone is 270±10°C, the temperature of the seventh zone is 270±10°C, the temperature of the eighth zone is 270±10°C, the temperature of the ninth zone is 270±10°C, and the temperature of the die is 265±10°C; then, the compounded material is stretched, cooled and shaped, and pelletized to obtain a composite material.

[0024] Beneficial effects of the present invention:

[0025] The alkali-free glass fiber content in the nylon 66 composite material disclosed in the present invention reaches more than 50wt%, has high mechanical strength, and can be applied to some load-bearing products;

[0026] The composite system of the present invention introduces a self-developed high-gloss compatibilizer to effectively improve the gloss of the composite material. The intermediate 1 is prepared by substitution of n-alkyl alcohol and vinyl trichlorosilane, and then methyl thioglycolate and the unsaturated double bond of the intermediate 1 are added to prepare the intermediate 2. Finally, γ-aminopropyl triethoxysilane and the terminal methyl ester of the intermediate 2 are subjected to amine ester exchange to prepare the high-gloss compatibilizer. During the temperature rising and mixing process, the ethoxysilane structure of the high-gloss compatibilizer is fully hydrolyzed and coupled on the surface of the alkali-free glass fiber after impregnation, and a silicon-containing multi-branched alkyl chain is introduced to the surface of the alkali-free glass fiber. On the one hand, the alkyl The introduction of the chain reduces the entanglement between the nylon macromolecular chains on the surface of the alkali-free glass fiber, making the nylon macromolecules easier to orient and crystallize. On the other hand, the silicon-containing alkyl chain acts as a heterogeneous component, providing nucleation sites, promoting the nucleation and crystallization of nylon molecular chains on the surface of the alkali-free glass fiber, thereby greatly reducing the high-crystalline region-low-crystalline region interface content in the composite system, effectively reducing the scattering of light, and thus allowing the composite material to maintain a high gloss; in addition, the alkyl chain on the surface of the alkali-free glass fiber plays an in-situ toughening role, compensating for the increased brittleness caused by the increase in crystallinity, so that the composite material maintains a high impact toughness. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] Example 1: Preparation of a high-gloss, high-glass-fiber-content nylon 66 composite material, specifically as follows:

[0029] (1) Preparation of high-gloss compatibilizer

[0030] Step A1: Premix n-alkyl alcohol, sodium hydroxide, and anhydrous tetrahydrofuran, introduce dry nitrogen protection, control the temperature of the water bath at 0°C, apply stirring at 120 rpm, slowly add vinyltrichlorosilane and react for 2 hours, then raise the temperature to 60°C and reflux for 1 hour, wherein the n-alkyl alcohol is n-butanol, and the feed ratio of vinyltrichlorosilane, n-butanol, sodium hydroxide, and anhydrous tetrahydrofuran is 10 mmol:30 mmol:0.2 g:55 mL. After the reaction is completed, filter and dry by rotary evaporation to obtain intermediate 1.

[0031] Step A2: Mix the intermediate 1, methyl thioglycolate, benzophenone and ethanol, raise the temperature to 45°C, apply stirring at 60 rpm and 150 W / m 2 The reaction was carried out under ultraviolet irradiation for 3.5 h, wherein the feed ratio of intermediate 1, methyl thioglycolate, benzophenone and ethanol was 10 mmol:10 mmol:10 mg:50 mL. After the reaction was completed, ethanol was removed to obtain intermediate 2.

[0032] Step A3: Mix intermediate 2, γ-aminopropyltriethoxysilane and dimethyl sulfoxide, introduce dry gas protection, heat to 80°C, apply stirring at 60 rpm, take equal amounts of trimethylaluminum and divide it into three parts, add it intermittently for 30 minutes, and control the total reaction time to be 4 hours. Among them, the feed ratio of intermediate 2, γ-aminopropyltriethoxysilane, trimethylaluminum and dimethyl sulfoxide is 10 mmol: 10 mmol: 25 mg: 60 mL. After the reaction, remove dimethyl sulfoxide under reduced pressure to obtain a high-gloss compatibilizer.

[0033] (2) Preparation of composite materials

[0034] Ingredients: 50wt% of alkali-free glass fiber, specifications: straight 9um, length 1.5mm; 2.2wt% of high-gloss compatibilizer, homemade in this embodiment; 5wt% of toughening agent, selected N413 type POE-g-MAH and BF-7M type E-GMA in an equal weight ratio; 0.2wt% of antioxidant, selected antioxidant 1010 and antioxidant 168 in an equal weight ratio; 0.6wt% of processing aid, selected Hyper C181 lubricating agent; the balance EPR27 type nylon 66 resin is added to 100wt%.

[0035] Step S1: prepare a 20% volume fraction ethanol aqueous solution, immerse the alkali-free glass fiber in the ethanol aqueous solution, drain and control the liquid content to 4.5wt%, then mix with the remaining raw materials, mix at 220±10℃ for 25min, and dry the material until the moisture content is no more than 0.1wt% to obtain a batch.

[0036] Step S2: melt-extrude the compounded material through a twin-screw extruder, and the extrusion temperature zones are set as follows: the temperature of the first zone is 200±10°C, the temperature of the second zone is 260±10°C, the temperature of the third zone is 270±10°C, the temperature of the fourth zone is 280±10°C, the temperature of the fifth zone is 270±10°C, the temperature of the sixth zone is 270±10°C, the temperature of the seventh zone is 270±10°C, the temperature of the eighth zone is 270±10°C, the temperature of the ninth zone is 270±10°C, and the temperature of the die is 265±10°C; then, the compounded material is stretched, cooled and shaped, and pelletized to obtain a composite material.

[0037] Example 2: Preparation of high gloss and high glass fiber content nylon 66 composite material, specifically as follows:

[0038] (1) Preparation of high-gloss compatibilizer

[0039] Step A1: Premix n-alkyl alcohol, sodium hydroxide, and anhydrous tetrahydrofuran, introduce dry nitrogen protection, control the temperature of the water bath at 10°C, apply stirring at 150 rpm, slowly add vinyltrichlorosilane and react for 3 hours, then raise the temperature to 70°C and reflux for 1.5 hours, wherein n-alkyl alcohol is n-decanol, and the feed ratio of vinyltrichlorosilane, n-decanol, sodium hydroxide, and anhydrous tetrahydrofuran is 10 mmol:30 mmol:0.4 g:90 mL. After the reaction is completed, filter and dry by rotary evaporation to obtain intermediate 1.

[0040] Step A2: Mix the intermediate 1, methyl thioglycolate, benzophenone and ethanol, raise the temperature to 60°C, apply stirring at 90 rpm and 200 W / m 2 The reaction was carried out under ultraviolet irradiation for 5 h, wherein the feed ratio of intermediate 1, methyl thioglycolate, benzophenone and ethanol was 10 mmol: 10 mmol: 20 mg: 80 mL. After the reaction was completed, ethanol was removed to obtain intermediate 2.

[0041] Step A3: Mix intermediate 2, γ-aminopropyltriethoxysilane and dimethyl sulfoxide, introduce dry gas protection, heat to 100°C, apply stirring at 120 rpm, take equal amounts of trimethylaluminum and divide it into three parts, add it intermittently for 30 minutes, and control the total addition reaction time to be 5 hours. Among them, the feed ratio of intermediate 2, γ-aminopropyltriethoxysilane, trimethylaluminum and dimethyl sulfoxide is 10 mmol: 10 mmol: 50 mg: 80 mL. After the reaction is completed, dimethyl sulfoxide is removed under reduced pressure to obtain a high-gloss compatibilizer.

[0042] (2) Preparation of composite materials

[0043] Ingredients: 60wt% of alkali-free glass fiber, specifications: straight 14um, length 4.5mm; 3.5wt% of high-gloss compatibilizer, homemade in this embodiment; 4wt% of toughening agent, N413 type POE-g-MAH and BF-7M type E-GMA are selected and compounded in an equal weight ratio; 0.15wt% of antioxidant, antioxidant 1010 and antioxidant 168 are selected and compounded in an equal weight ratio; 0.9wt% of processing aid, Hyper C181 lubricating agent is selected; the balance EPR27 type nylon 66 resin is supplemented to 100wt%.

[0044] Step S1: prepare a 20% volume fraction ethanol aqueous solution, immerse the alkali-free glass fiber in the ethanol aqueous solution, drain and control the liquid content to 6wt%, then mix with the remaining raw materials, mix at 220±10℃ for 30min, and dry the material until the moisture content is no more than 0.1wt% to obtain a batch.

[0045] Step S2: melt-extrude the compounded material through a twin-screw extruder, and the extrusion temperature zones are set as follows: the temperature of the first zone is 200±10°C, the temperature of the second zone is 260±10°C, the temperature of the third zone is 270±10°C, the temperature of the fourth zone is 280±10°C, the temperature of the fifth zone is 270±10°C, the temperature of the sixth zone is 270±10°C, the temperature of the seventh zone is 270±10°C, the temperature of the eighth zone is 270±10°C, the temperature of the ninth zone is 270±10°C, and the temperature of the die is 265±10°C; then, the compounded material is stretched, cooled and shaped, and pelletized to obtain a composite material.

[0046] Example 3: Preparation of high gloss and high glass fiber content nylon 66 composite material, specifically as follows:

[0047] (1) Preparation of high-gloss compatibilizer

[0048] Step A1: Premix n-alkyl alcohol, sodium hydroxide, and anhydrous tetrahydrofuran, introduce dry nitrogen protection, control the temperature of the water bath at 5°C, apply stirring at 150 rpm, slowly add vinyltrichlorosilane and react for 2.2 hours, then raise the temperature to 65°C and reflux for 1.5 hours, wherein n-octanol is selected as the n-alkyl alcohol, and the feed ratio of vinyltrichlorosilane, n-octanol, sodium hydroxide, and anhydrous tetrahydrofuran is 10 mmol:30 mmol:0.3 g:80 mL. After the reaction is completed, filter and dry by rotary evaporation to obtain intermediate 1.

[0049] Step A2: Mix the intermediate 1, methyl thioglycolate, benzophenone and ethanol, heat to 50°C, stir at 60 rpm and 180 W / m 2 The reaction was carried out under ultraviolet irradiation for 4 h, wherein the feed ratio of intermediate 1, methyl thioglycolate, benzophenone and ethanol was 10 mmol: 10 mmol: 20 mg: 70 mL. After the reaction was completed, ethanol was removed to obtain intermediate 2.

[0050] Step A3: Mix intermediate 2, γ-aminopropyltriethoxysilane and dimethyl sulfoxide, pass dry gas protection, heat to 90°C, apply 90rpm stirring, take equal amounts of trimethylaluminum and divide it into three parts, add it intermittently for 30 minutes, and control the total addition reaction time to be 4.5 hours. Among them, the feed ratio of intermediate 2, γ-aminopropyltriethoxysilane, trimethylaluminum and dimethyl sulfoxide is 10mmol:10mmol:30mg:70mL. After the reaction is completed, dimethyl sulfoxide is removed under reduced pressure to obtain a high-gloss compatibilizer.

[0051] (2) Preparation of composite materials

[0052] Ingredients: 55wt% of alkali-free glass fiber, specifications: straight 10um, length 3.5mm; 3wt% of high-gloss compatibilizer, homemade in this embodiment; 3.5wt% of toughener, selected N413 type POE-g-MAH and BF-7M type E-GMA in an equal weight ratio; 0.18wt% of antioxidant, selected antioxidant 1010 and antioxidant 168 in an equal weight ratio; 0.8wt% of processing aid, selected Hyper C181 lubricating agent; the balance EPR27 type nylon 66 resin is added to 100wt%.

[0053] Step S1: prepare a 20% volume fraction ethanol aqueous solution, immerse the alkali-free glass fiber in the ethanol aqueous solution, drain and control the liquid content to 5wt%, then mix with the remaining raw materials, mix at 220±10℃ for 30min, and dry the material until the moisture content is no more than 0.1wt% to obtain a batch.

[0054] Step S2: melt-extrude the compounded material through a twin-screw extruder, and the extrusion temperature zones are set as follows: the temperature of the first zone is 200±10°C, the temperature of the second zone is 260±10°C, the temperature of the third zone is 270±10°C, the temperature of the fourth zone is 280±10°C, the temperature of the fifth zone is 270±10°C, the temperature of the sixth zone is 270±10°C, the temperature of the seventh zone is 270±10°C, the temperature of the eighth zone is 270±10°C, the temperature of the ninth zone is 270±10°C, and the temperature of the die is 265±10°C; then, the compounded material is stretched, cooled and shaped, and pelletized to obtain a composite material.

[0055] Example 4: Preparation of a high-gloss, high-glass-fiber-content nylon 66 composite material, specifically as follows:

[0056] (1) Preparation of high-gloss compatibilizer

[0057] Step A1: Premix n-alkyl alcohol, sodium hydroxide, and anhydrous tetrahydrofuran, introduce dry nitrogen protection, control the temperature of the water bath at 10°C, apply stirring at 150 rpm, slowly add vinyltrichlorosilane and react for 2.5 hours, then raise the temperature to 60°C and reflux for 1.5 hours, wherein n-alkyl alcohol is n-octanol, and the feed ratio of vinyltrichlorosilane, n-octanol, sodium hydroxide, and anhydrous tetrahydrofuran is 10 mmol:30 mmol:0.3 g:80 mL. After the reaction is completed, filter and dry by rotary evaporation to obtain intermediate 1.

[0058] Step A2: Mix the intermediate 1, methyl thioglycolate, benzophenone and ethanol, raise the temperature to 55°C, apply stirring at 90 rpm and 200 W / m 2 The reaction was carried out under ultraviolet irradiation for 4.5 h, wherein the feed ratio of intermediate 1, methyl thioglycolate, benzophenone and ethanol was 10 mmol: 10 mmol: 15 mg: 70 mL. After the reaction was completed, ethanol was removed to obtain intermediate 2.

[0059] Step A3: Mix intermediate 2, γ-aminopropyltriethoxysilane and dimethyl sulfoxide, introduce dry gas protection, heat to 80°C, apply stirring at 90 rpm, take equal amounts of trimethylaluminum and divide it into three parts, add it intermittently for 30 minutes, and control the total addition reaction time to be 5 hours. Among them, the feed ratio of intermediate 2, γ-aminopropyltriethoxysilane, trimethylaluminum and dimethyl sulfoxide is 10 mmol: 10 mmol: 35 mg: 70 mL. After the reaction is completed, dimethyl sulfoxide is removed under reduced pressure to obtain a high-gloss compatibilizer.

[0060] (2) Preparation of composite materials

[0061] Ingredients: 53wt% of alkali-free glass fiber, specifications: straight 10um, length 3.5mm; 3.2wt% of high-gloss compatibilizer, homemade in this embodiment; 4wt% of toughening agent, selected N413 type POE-g-MAH and BF-7M type E-GMA in an equal weight ratio; 0.15wt% of antioxidant, selected antioxidant 1010 and antioxidant 168 in an equal weight ratio; 0.7wt% of processing aid, selected Hyper C181 lubricating agent; the balance EPR27 type nylon 66 resin is added to 100wt%.

[0062] Step S1: prepare a 20% volume fraction ethanol aqueous solution, immerse the alkali-free glass fiber in the ethanol aqueous solution, drain and control the liquid content to 5.5wt%, then mix with the remaining raw materials, mix at 220±10℃ for 30min, and dry the material until the moisture content is no more than 0.1wt% to obtain a batch.

[0063] Step S2: melt-extrude the compounded material through a twin-screw extruder, and the extrusion temperature zones are set as follows: the temperature of the first zone is 200±10°C, the temperature of the second zone is 260±10°C, the temperature of the third zone is 270±10°C, the temperature of the fourth zone is 280±10°C, the temperature of the fifth zone is 270±10°C, the temperature of the sixth zone is 270±10°C, the temperature of the seventh zone is 270±10°C, the temperature of the eighth zone is 270±10°C, the temperature of the ninth zone is 270±10°C, and the temperature of the die is 265±10°C; then, the compounded material is stretched, cooled and shaped, and pelletized to obtain a composite material.

[0064] In a comparative example, referring to Example 4, no high-gloss compatibilizer was added to the composite system, and 1.5 wt% of lubricant TAF, 1.1 wt% of silane coupling agent KH-550 and 0.6 wt% of anti-glass fiber exposure agent PFE-A were added; the specific composite process was adjusted as follows: mixing, kneading, extruding, drawing, cooling and shaping the raw materials, and pelletizing, and the process parameters were set the same as in Example 4.

[0065] The composite material prepared as above was hot-pressed at a molding temperature of 280°C and a molding pressure of 12 MPa. Samples were taken after molding and subjected to a tensile test according to GB / T 1040.1-2018; a bending test according to GB / T 9341-2008; an impact test according to GB / T 1843-2008; and a 60° angle gloss test according to GB / T 8807-1988. The specific test results are shown in Table 1:

[0066] Table 1

[0067]

[0068] As can be seen from the test results in Table 1, the composite materials prepared in the examples have similar mechanical strengths to those of the comparative examples. The impact strength of the examples is slightly higher than that of the comparative examples. Analysis shows that this may be due to the toughening effect of the high-gloss compatibilizer between the glass fiber and the nylon resin, thereby improving the bonding toughness between the two. The glossiness of the examples is significantly higher than that of the comparative examples, showing excellent high gloss characteristics and having broad application prospects as appearance products.

[0069] Samples were taken from the composite material prepared as above and subjected to melt mass flow rate testing in accordance with ISO 1133-1-2011 standard, at a temperature of 280°C and a load of 5 kg. Samples were taken from the composite material prepared as above and subjected to crystallinity testing using DSC analysis. Specifically, under a nitrogen atmosphere, the sample was heated to 270°C at a rate of 10°C / min and held for 5 minutes to eliminate thermal history, then cooled to 220°C at a rate of 40°C / min for isothermal crystallization, then heated to 270°C at a rate of 10°C / min and held for 3 minutes, then cooled to room temperature at a rate of 20°C / min, and finally heated to 270°C at a rate of 10°C / min to measure the crystallinity of the sample. The specific test results are shown in Table 2:

[0070] Table 2

[0071]

[0072] From the test results in Table 2, it can be seen that the melt mass flow rate of the composite material prepared in the example is significantly higher than that of the comparative example, and the crystallinity is slightly higher than that of the comparative example.

[0073] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0074] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A high gloss and high glass fiber content nylon 66 composite material, characterized in that: The composition is: 50-60wt% of alkali-free glass fiber, 2.2-3.5wt% of high-gloss compatibilizer, 3.5-5wt% of toughening agent, 0.15-0.2wt% of antioxidant and 0.6-0.9wt% of processing aid, and the balance is nylon 66 resin; The high-gloss compatibilizer is prepared by the following method: Step A1: premix n-alkyl alcohol, sodium hydroxide, and anhydrous tetrahydrofuran, introduce dry gas protection, control the water bath temperature at 0-10°C, stir, and slowly add vinyltrichlorosilane to react for 2-3 hours, then raise the temperature to 60-70°C and reflux for 1-1.5 hours to obtain intermediate 1; Step A2: Mix the intermediate 1, methyl thioglycolate, benzophenone and ethanol, heat to 45-60°C, stir and heat at 150-200W / m 2 UV irradiation reaction for 3.5-5h to obtain intermediate 2; Step A3: Intermediate 2, γ-aminopropyltriethoxysilane and dimethyl sulfoxide are mixed, and dry gas is introduced into the mixture. The temperature is raised to 80-100°C, and trimethylaluminum is added intermittently while stirring for 4-5 hours to obtain a high-gloss compatibilizer. The n-alkyl alcohol is one of n-butanol, n-octanol and n-decanol.

2. The high gloss and high glass fiber content nylon 66 composite material according to claim 1, characterized in that: The feeding ratio of vinyltrichlorosilane, n-alkyl alcohol, sodium hydroxide and anhydrous tetrahydrofuran is 10 mmol: 30 mmol: 0.2-0.4 g: 55-90 mL.

3. The high gloss and high glass fiber content nylon 66 composite material according to claim 2, characterized in that: The feed ratio of intermediate 1, methyl thioglycolate, benzophenone and ethanol is 10 mmol: 10 mmol: 10-20 mg: 50-80 mL.

4. The high-gloss, high-glass-fiber-content nylon 66 composite material according to claim 3, characterized in that: The charging ratio of intermediate 2, γ-aminopropyltriethoxysilane, trimethylaluminum and dimethyl sulfoxide is 10 mmol: 10 mmol: 25-50 mg: 60-80 mL.

5. A method for preparing the high-gloss and high-glass-fiber-content nylon 66 composite material according to any one of claims 1 to 4, characterized in that: The steps include: Step S1: impregnating the alkali-free glass fiber with an ethanol aqueous solution to control the liquid content to 4.5-6wt%, then mixing with the remaining raw materials, heating to 220±10°C and mixing for 25-30 minutes, and drying the discharged material until the moisture content is no more than 0.1wt% to obtain a batch; Step S2: melt-extrude the compounded material through a twin-screw extruder, and the extrusion temperature zones are set as follows: the temperature of the first zone is 200±10°C, the temperature of the second zone is 260±10°C, the temperature of the third zone is 270±10°C, the temperature of the fourth zone is 280±10°C, the temperature of the fifth zone is 270±10°C, the temperature of the sixth zone is 270±10°C, the temperature of the seventh zone is 270±10°C, the temperature of the eighth zone is 270±10°C, the temperature of the ninth zone is 270±10°C, and the temperature of the die is 265±10°C; then, the compounded material is stretched, cooled and shaped, and pelletized to obtain a composite material.

6. The method for preparing a high-gloss and high-glass-fiber-content nylon 66 composite material according to claim 5, characterized in that: The length of alkali-free glass fiber is 1.5-4.5mm and the diameter is 9-14um.

7. The method for preparing a high-gloss and high-glass-fiber-content nylon 66 composite material according to claim 5, characterized in that: The toughening agent is compounded by POE-g-MAH and E-GMA.

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