Glass fiber reinforced polypropylene composite material as well as preparation method and application thereof

Abstract

The invention discloses a glass fiber reinforced polypropylene composite material as well as a preparation method and application thereof. The glass fiber reinforced polypropylene composite material is prepared from the following components in parts by mass: 12 to 23 parts of first polypropylene, 27 to 73 parts of second polypropylene, 17 to 53 parts of glass fiber and 3 to 18 parts of graft, the melt flow rate of the first polypropylene is 700 to 2000g / 10min under the conditions that the temperature is 230 DEG C and the weight is 2.16 kg; the melt flow rate of the second polypropylene at 230 DEG C and 2.16 kg is 20-200 g / 10 min; the graft is a graft of a hydrogenated styrene-butadiene block copolymer and glycidyl methacrylate. According to the invention, the first polypropylene and the second polypropylene with specific melt flow rate are compounded and combined with the specific graft, so that the composite material has good mechanical properties, anti-floating fiber effect and formability.

Description

Technical Field

[0001] This invention belongs to the field of polymer technology, and particularly relates to a glass fiber reinforced polypropylene composite material, its preparation method, and its application. Background Technology

[0002] Glass fiber reinforced polypropylene (GFRPP) composites possess advantages such as high rigidity, high impact resistance, good fatigue creep resistance, short molding cycle, and recyclability, largely overcoming the shortcomings of pure polypropylene (PP) such as low rigidity and poor fatigue creep. They have been widely used in numerous fields including home appliances, electronics, construction, aerospace, shipbuilding, and automobiles. However, in engineering applications, the exposed glass fibers significantly limit the use of GFRPP composites. In recent years, with increasing demands for the environmental friendliness and aesthetics of polymer materials, higher requirements have been placed on the surface fiber exposure of GFRPP composites.

[0003] Many current studies have explored various methods for creating anti-buoyancy fiber masterbatches using glass fiber and PB-1, which are then added to the finished product. However, this method involves a second processing of the glass fiber in the masterbatch, resulting in a reduced retention length and impacting the product's mechanical properties. Another approach uses zinc oxide as an anti-buoyancy fiber masterbatch, but this white masterbatch cannot be applied to dark-colored products. Additionally, various anti-buoyancy fiber agents are added to the product, such as a combination of high melt flow index PP (MFR > 500 g / 10 min), ethylene bis-stearamide dispersant, and TAF lubricant. However, both ethylene bis-stearamide dispersant and TAF are small molecules, posing a risk of precipitation and stickiness.

[0004] Styrene-ethylene-butylene-styrene block copolymer (SEBS) is an important thermoplastic elastomer (TPE) produced by block copolymerization of styrene (S) and butadiene (B) followed by hydrogenation. Its structural characteristics endow it with unique properties, combining the elasticity of rubber with the processability of plastics, making it one of the most widely used high-performance elastomer materials. Its core properties include: 1. Excellent elasticity: Its elasticity at room temperature is close to that of natural rubber, with low compression set and resistance to repeated bending and twisting; 2. Aging resistance: Due to the absence of unsaturated double bonds in its molecular chain (it is hydrogen-saturated), its resistance to ozone, ultraviolet radiation, and high and low temperatures is significantly better than that of traditional rubbers (such as SBS and natural rubber), and its operating temperature range is typically -60℃ to 120℃; 3. Thermoplastic processability: It can be processed using plastic processing techniques such as injection molding, extrusion, and blow molding without vulcanization, resulting in high production efficiency. Scrap materials can be recycled and reused, meeting environmental protection requirements; 4. Compatibility and modification potential: It has good compatibility with plastics such as polystyrene (PS) and polypropylene (PP). Hardness can be adjusted by adding oils (such as white oil), or costs can be reduced by adding fillers (such as calcium carbonate and talc); 5. Surface properties: It has a soft, non-sticky feel, can be in direct contact with the skin, and has good chemical resistance (water resistance, dilute acid resistance, alkali resistance, etc.). Summary of the Invention

[0005] In order to overcome at least one of the problems existing in the prior art, one of the objectives of the present invention is to provide a glass fiber reinforced polypropylene composite material, which has a good appearance, excellent anti-fiber buoyancy, and good mechanical and performance properties.

[0006] The second objective of this invention is to provide a method for preparing the above-mentioned glass fiber reinforced polypropylene composite material.

[0007] A third objective of this invention is to provide an application of the above-mentioned glass fiber reinforced polypropylene composite material.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A first aspect of the present invention provides a glass fiber reinforced polypropylene composite material comprising the following components in parts by weight: First polypropylene 12-23 parts, Second polypropylene 27-73 parts 17-53 parts glass fiber 3-18 portions of graft material; The first polypropylene has a melt flow rate (MFR) of 700~2000 g / 10 min at 230℃ and 2.16 kg; the second polypropylene has a melt flow rate (MFR) of 20~200 g / 10 min at 230℃ and 2.16 kg; the graft is a graft of hydrogenated styrene-butadiene block copolymer and glycidyl methacrylate (SEBS-g-GMA).

[0009] This invention reveals that a first polypropylene with a high melt flow rate (700~2000g / 10min) can better coat glass fibers and reduce shear during extrusion, resulting in a better finished product appearance and a longer glass fiber retention length. When combined with a second polypropylene with a low melt flow rate (20~200g / 10min), it can effectively reduce costs while maintaining good mechanical properties and anti-floating fiber effects, and ensure that the glass fiber retention length is not too long, thus preventing molding defects such as warping. Utilizing the fact that SEBS has a lower melting range (96~112℃) than PP (167℃), its melt viscosity is lower at the same temperature, allowing for better wetting of the glass fiber surface. Furthermore, SEBS has good compatibility with PP, and GMA can bond well with glass fibers. Therefore, adding SEBS-g-GMA can simultaneously act as an anti-floating fiber and compatibilizer.

[0010] In this invention, the melt flow rate (MFR) of the first polypropylene and the second polypropylene can be measured according to the ISO 1133-1-2022 standard.

[0011] In some embodiments of the present invention, the melt flow rate of the first polypropylene at 230°C and 2.16 kg can be any value or a range between 700 g / 10 min, 800 g / 10 min, 1000 g / 10 min, 1200 g / 10 min, 1500 g / 10 min, 1800 g / 10 min, or 2000 g / 10 min.

[0012] In some embodiments of the present invention, the melt flow rate of the second polypropylene at 230°C and 2.16 kg can be any value or a range between any two of 20 g / 10 min, 30 g / 10 min, 50 g / 10 min, 60 g / 10 min, 80 g / 10 min, 100 g / 10 min, 120 g / 10 min, 150 or 200 g / 10 min.

[0013] In this invention, the first polypropylene and the second polypropylene are used as the main resins, accounting for more than 50 wt% of the glass fiber reinforced polypropylene composite material.

[0014] Preferably, the glass fiber reinforced polypropylene composite material comprises the following components in parts by weight: First, 15-20 parts of polypropylene. Second polypropylene 31-70 parts, 20-50 parts glass fiber 5-15 portions of graft material.

[0015] By controlling the amount of each component in the glass fiber reinforced polypropylene composite material within the above range, the resulting glass fiber reinforced polypropylene composite material exhibits higher mechanical properties and better anti-fiber floating effect.

[0016] Preferably, the melt flow rate of the first polypropylene at 230°C and 2.16 kg is 800~1950 g / 10 min; more preferably, the melt flow rate of the first polypropylene at 230°C and 2.16 kg is 1000~1900 g / 10 min; even more preferably, the melt flow rate of the first polypropylene at 230°C and 2.16 kg is 1500~1850 g / 10 min.

[0017] By controlling the melt flow rate of the first polypropylene within the above range, the resulting glass fiber reinforced polypropylene composite material exhibits higher mechanical properties and better anti-fiber floating effect.

[0018] Preferably, the melt flow rate of the second polypropylene at 230°C and 2.16 kg is 30~150 g / 10 min.

[0019] Preferably, the melt flow rate of the hydrogenated styrene-butadiene block copolymer (SEBS) in the grafted product is 0.8~6 g / 10 min at 230°C and 5 kg; for example, it can be any value or a range between any two of 0.8 g / 10 min, 0.91 g / 10 min, 1 g / 10 min, 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, 5 g / 10 min or 6 g / 10 min; the melt flow rate of the hydrogenated styrene-butadiene block copolymer (SEBS) can be measured according to ISO 1133-1-2022 standard.

[0020] More preferably, the melt flow rate of the hydrogenated styrene-butadiene block copolymer (SEBS) in the grafted compound is 0.91~5 g / 10 min at 230°C and 5 kg; even more preferably, the melt flow rate of the hydrogenated styrene-butadiene block copolymer (SEBS) in the grafted compound is 2~5 g / 10 min at 230°C and 5 kg.

[0021] By controlling the melt flow rate of the hydrogenated styrene-butadiene block copolymer within the above range, the resulting graft can better wet the glass fiber and bond with the polypropylene matrix, thereby resulting in glass fiber reinforced polypropylene composites with higher mechanical properties and better anti-fiber floating effect.

[0022] Preferably, in the grafted compound, the mass ratio of hydrogenated styrene-butadiene block copolymer to glycidyl methacrylate is 1:(0.01~0.1); for example, it can be any value or a range between 1:0.01, 1:0.02, 1:0.05, 1:0.08 or 1:0.1; more preferably, in the grafted compound, the mass ratio of hydrogenated styrene-butadiene block copolymer to glycidyl methacrylate is 1:(0.02~0.09); even more preferably, in the grafted compound, the mass ratio of hydrogenated styrene-butadiene block copolymer to glycidyl methacrylate is 1:(0.03~0.08).

[0023] Adjusting the mass ratio of hydrogenated styrene-butadiene block copolymer to glycidyl methacrylate can improve the bonding effect between the resulting graft and the glass fiber and polypropylene matrix. In particular, using a higher content of glycidyl methacrylate (GMA) can further enhance the bonding effect, resulting in higher mechanical properties and better anti-fiber buoyancy of the glass fiber reinforced polypropylene composite material.

[0024] Preferably, the grafted material is obtained by melt grafting reaction of hydrogenated styrene-butadiene block copolymer, glycidyl methacrylate, comonomer and initiator.

[0025] More preferably, the grafted material is obtained by melt grafting reaction of 40-50 parts by weight of hydrogenated styrene-butadiene block copolymer, 1-3 parts by weight of glycidyl methacrylate, 0.2-1 parts by weight of comonomer and 0.02-0.15 parts by weight of initiator.

[0026] Preferably, the comonomer includes divinylbenzene, styrene, or a combination thereof; more preferably, the comonomer is selected from divinylbenzene (DVB).

[0027] Preferably, the initiator comprises at least one selected from 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane (DHBP), di-tert-butylperoxide (DTBP), dicumyl peroxide (DCP), benzoyl peroxide (BPO), or di-tert-butylperoxide isopropylbenzene (BIPB); more preferably, the initiator is selected from 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane (DHBP).

[0028] Preferably, the grafted material is prepared by a method comprising the following steps: mixing hydrogenated styrene-butadiene block copolymer, glycidyl methacrylate, comonomer, initiator and solvent to obtain solution A; mixing solution A with polybutene (PB), and after the solvent evaporates, melting and extruding the mixture to undergo a melt grafting reaction to obtain a graft roughened material; purifying the graft roughened material to obtain the grafted material.

[0029] Preferably, in the preparation method of the graft, the melt extrusion temperature is 100~130℃.

[0030] Preferably, in the method for preparing the graft, the solvent is selected from acetone.

[0031] More preferably, the grafted material is prepared by a method comprising the following steps: mixing 40-50 parts by weight of hydrogenated styrene-butadiene block copolymer, 1-3 parts by weight of glycidyl methacrylate, 0.2-1 parts by weight of comonomer, 0.02-0.15 parts by weight of initiator, and 30-40 parts by weight of acetone to obtain solution A; mixing solution A with 40-50 parts by weight of polybutene (PB), and after the solvent evaporates, melting and extruding the mixture at 100-130°C to induce a melt grafting reaction, thereby obtaining a grafted roughened material; purifying the grafted roughened material to obtain the grafted material. Specifically, the purification step may be: mixing the grafted roughened material with xylene at a mass ratio of 1:(10-20) at 60-90°C to obtain solution B, and mixing solution B with acetone while hot to obtain a purified product; the purification step may be performed 1-5 times.

[0032] Preferably, the glass fiber is selected from alkali-free glass fiber; more preferably, the glass fiber is selected from alkali-free chopped glass fiber.

[0033] Preferably, the diameter of the glass fiber monofilament is 8~15μm; more preferably, the diameter of the glass fiber monofilament is 10~13μm.

[0034] Preferably, the glass fiber reinforced polypropylene composite material further includes 0.1 to 2 parts by weight of additives.

[0035] Preferably, the additive includes at least one of a lubricant, an antioxidant, or a light stabilizer; more preferably, the additive includes a lubricant, an antioxidant, and a light stabilizer.

[0036] Preferably, the lubricant comprises amides, stearates, or combinations thereof; more preferably, the lubricant comprises at least one of vinyl bis-stearamide (EBS), calcium stearate, or zinc stearate.

[0037] Preferably, in the glass fiber reinforced polypropylene composite material, the lubricant comprises 0.1 to 0.3 parts by weight.

[0038] Preferably, the antioxidant includes hindered phenols, phosphites, or combinations thereof; more preferably, the antioxidant includes hindered phenols and phosphites; even more preferably, the antioxidant includes antioxidant 1010 and antioxidant 168.

[0039] Preferably, in the glass fiber reinforced polypropylene composite material, the antioxidant comprises 0.2 to 0.6 parts by weight.

[0040] Preferably, the light stabilizer is selected from hindered amines.

[0041] Preferably, in the glass fiber reinforced polypropylene composite material, the light stabilizer comprises 0.1 to 0.3 parts by mass.

[0042] A second aspect of the present invention provides a method for preparing a glass fiber reinforced polypropylene composite material as described in the first aspect of the present invention, comprising the following steps: mixing the components, performing melt extrusion and granulation to obtain the glass fiber reinforced polypropylene composite material.

[0043] Preferably, the temperature of the melt extrusion is 205~250℃; for example, it can be any value or a range between any two of 205, 210, 215, 220, 225, 230, 235, 240, 245 or 250; more preferably, the temperature of the melt extrusion is 210~245℃; even more preferably, the temperature of the melt extrusion from the feeding section to the die head is 210℃, 230℃, 240℃, 240℃, 245℃, 245℃, 245℃, 240℃, 230℃.

[0044] The extrusion temperature of existing glass fiber reinforced polypropylene materials is generally 200~230℃, while the melt extrusion temperature of this invention is relatively high. By utilizing the low melt viscosity of the material at high temperature, the polypropylene and graft can better impregnate the glass fiber and reduce shear, thereby resulting in a composite material with good anti-floating fiber effect, long glass fiber retention length and high mechanical properties.

[0045] Preferably, the rotation speed of the melt extrusion is 200~300 rpm.

[0046] Preferably, in the preparation method of the glass fiber reinforced polypropylene composite material, the glass fiber is added from the side feed port for melt extrusion, and other components are added from the main feed port for melt extrusion.

[0047] A third aspect of the present invention provides the application of glass fiber reinforced polypropylene composite material as described in the first aspect of the present invention in the preparation of household appliances, electronic appliances, building industrial products, aerospace products, land and water transportation vehicles or office supplies.

[0048] The beneficial effects of this invention are: by compounding a first polypropylene and a second polypropylene with a specific melt flow rate, the composite material has good mechanical properties, anti-fiber floating effect and molding performance. By combining a specific grafting material, the compatibility between raw materials is improved and the anti-fiber floating effect is further improved. The final glass fiber reinforced polypropylene composite material has good mechanical properties, anti-fiber floating effect and molding performance. Detailed Implementation

[0049] The following specific embodiments further illustrate the content of the present invention in detail. It should also be understood that the following embodiments are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the principles described herein are all within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make selections within a suitable range based on the description herein, and are not intended to be limited to the specific data in the examples below. Unless otherwise specified, the raw materials, reagents, or apparatus used in the following embodiments and comparative examples can be obtained from conventional commercial sources or by existing known methods.

[0050] (1) The reagents used in the various embodiments and comparative examples of the present invention are described below: SEBS-1: Model: G1650 (230℃, 5kg, MFR=0.91g / 10min), Manufacturer: Kraton S.p.A., Inc., USA; SEBS-2: Model: G1652 (230℃, 5kg, MFR=5g / 10min), Manufacturer: Kraton S.A., USA; Glycidyl methacrylate (GMA), Manufacturer: Nanjing Rong'an Chemical Technology Co., Ltd. 2,5-Dimethyl-2,5-bis(tert-butylperoxide)hexane: DHBP, Manufacturer: Zhejiang Shangyu Shaofeng Chemical Co., Ltd.; Divinylbenzene (DVB), Manufacturer: Hubei Xinkang Pharmaceutical Chemical Co., Ltd. First Polypropylene-1: Model: HP560X (230℃, 2.16kg, MFR=800g / 10min), Manufacturer: LyondellBasell; First Polypropylene-2: Model: MF650X (230℃, 2.16kg, MFR=1200g / 10min), Manufacturer: LyondellBasell; First Polypropylene-3: Model: MF650Y (230℃, 2.16kg, MFR=1800g / 10min), Manufacturer: LyondellBasell; Second polypropylene-1: Model: N-Z30S (230℃, 2.16kg, MFR=30g / 10min), Manufacturer: Sinopec Maoming Petrochemical; Second polypropylene-2: Model: H9018 (230℃, 2.16kg, MFR=60g / 10min), Manufacturer: Sinopec Maoming Petrochemical; Second polypropylene-3: Model: MH7900 (230℃, 2.16kg, MFR=150g / 10min), Manufacturer: LG Chem; Compatibilizer-1: POE-g-GMA, Model: W5D, Manufacturer: Cosmax Chemical Co., Ltd. Compatibilizer-2: PP-g-MAH, Model: B1, Manufacturer: Cosmax Chemical Co., Ltd.; Alkali-free glass fiber-1: Model: E7CS13-03-508A (monofilament diameter 13μm), Manufacturer: Jushi Group; Alkali-free glass fiber-2: Model: E7CS10-03-508A (monofilament diameter 10μm), Manufacturer: Jushi Group; Antioxidant-1: Hindered phenols, 1010, Manufacturer: Shandong Sanfeng; Antioxidant-2: Phosphite, 168, Manufacturer: Shandong Sanfeng; Light stabilizer: hindered amine, model: T-81, manufacturer: Beijing Tiangang Additives Co., Ltd.; Lubricant-1: Amide, EBS, Manufacturer: Tianjin Dadu International Business Co., Ltd. Lubricant-2: Calcium stearate, model: BS-3818, manufacturer: Huamingtai Chemical; Lubricant-3: Zinc stearate, model: BS-2818, manufacturer: Huamingtai Chemical.

[0051] (2) The preparation processes of the GFRPP composite materials in each embodiment and comparative example of the present invention are as follows: Weigh each component according to the formula and mix them in a high-speed mixer for 3-5 minutes at a speed of 200-300 rpm. Add the mixed particles to a twin-screw extruder for melt extrusion, granulation, drying, cooling, and packaging. Glass fiber is fed into the extrusion process from the side. The temperatures of the twin-screw extruder from the feeding section to the die head are 210℃, 230℃, 240℃, 240℃, 245℃, 245℃, 245℃, 245℃, 240℃, and 230℃ respectively.

[0052] (3) The performance of the GFRPP composite materials provided in the embodiments and comparative examples of the present invention was determined according to the following test methods: Tensile strength: Tested according to ISO 527-2-2025, tensile speed 10 mm / min; Bending strength and bending modulus: tested according to ISO 178-2019, bending speed 2 mm / min; Notched impact strength of cantilever beam: tested according to ISO 180-2023; Fiberglass retention length: The following evaluation criteria are used: the extruded particles are fully burned in a muffle furnace at 650℃ for 4 hours, and the retention length of the fiberglass residue after burning is tested. The average retention length of 500 fibers is calculated and analyzed, in mm.

[0053] Appearance and fiber resistance: Evaluated according to the evaluation criteria in Table 1 below (customer acceptable level ≤ 3): Table 1 Appearance Anti-buoyancy Fiber Grade

[0054] Preparation Examples 1-4 Preparation Examples 1-4 provide a series of grafts, namely SEBS-grafted glycidyl methacrylate (abbreviated as SEBS-g-GMA), the formulations of which are shown in Table 2.

[0055] Table 2 Formulations for Preparation Examples 1-4 (parts by mass)

[0056] The preparation process of the grafted SEBS-g-GMA in Examples 1-4 above is as follows: 1) Weigh out the hydrogenated styrene-butadiene block copolymer (SEBS), glycidyl methacrylate monomer (GMA), initiator 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane (DHBP), and comonomer divinylbenzene (DVB) according to the formula, and dissolve them in 35 parts of acetone at 40°C to obtain mixed solution A for later use.

[0057] 2) Add the above mixed solution A to 45 parts of poly-1-butene (PB-1) and mix thoroughly at room temperature. After all the acetone has evaporated, add the material to a twin-screw extruder for melt extrusion grafting reaction to obtain SEBS-g-GMA roughened material. The temperature of the twin-screw extruder is 100~130℃.

[0058] 3) Take 1 part of the SEBS-g-GMA crude compound and add it to 15 parts of xylene. Stir at 75°C until completely dissolved to obtain mixed solution B. Then, pour mixed solution B into 40 parts of acetone solution while hot and stir continuously with a glass rod to generate a white flocculent precipitate. Wash with acetone 4 times to obtain the first purified product. Then, place the white flocculent precipitate in a fume hood and dry to constant weight. Repeat the above steps for the second and third purification. Finally, place the obtained SEBS-g-GMA purified product in a vacuum drying oven and dry for 24 hours to constant weight for later use.

[0059] The grafted compound SEBS-g-GMA obtained in the above preparation example was used to prepare the GFRPP composite materials in the following examples and comparative examples.

[0060] Examples 1-10 and Comparative Examples 1-5 Examples 1-10 and Comparative Examples 1-5 provide a series of GFRPP composite materials, the formulations of which are shown in Tables 3 and 4.

[0061] Table 3. Formulations for Examples 1-7 (unit: parts by mass)

[0062] Table 4. Formulations of Examples 8-10 and Comparative Examples 1-5 (parts by mass)

[0063] The properties of the GFRPP composite materials of each embodiment and comparative example were determined according to the test methods mentioned above, and the test results are shown in Table 5.

[0064] Table 5 Performance test results of GFRPP composite materials in each embodiment and comparative example

[0065] As shown in Table 5, the tensile strength of Examples 1-10 is all above 88 MPa, the flexural strength is all above 146 MPa, the flexural modulus is all above 5250 MPa, and the notched impact strength of the cantilever beam is all above 14 kJ / m. 2 The fiber buoyancy resistance rating of the composite material is Grade 1, the glass fiber retention length is within the range of 0.723~0.673mm, and no warping occurred during the molding process. This indicates that the GFRPP composite material of the present invention has good mechanical properties, fiber buoyancy resistance, and molding performance, which can meet the current development trends of lightweighting, olefinification, and high performance required by the automotive industry. Moreover, the production process of the GFRPP composite material of the present invention is simple and suitable for mass production.

[0066] Comparative Example 1 did not include any grafting agent, while Comparative Examples 2 and 3 used existing compatibilizers (POE-g-GMA, PP-g-MAH). The mechanical properties, anti-floating fiber effect, and molding performance of the resulting GFRPP composite materials were all inferior to those of the examples. This indicates that the invention, by adding specific SEBS-g-GMA, can exert both the anti-floating fiber effect and the compatibilizer effect, thereby increasing the glass fiber retention length to a certain level, improving mechanical properties, and ensuring good molding performance.

[0067] Comparative Example 4, lacking the addition of a high melt flow rate first polypropylene, relied solely on a low melt flow rate second polypropylene, resulting in poor coating of the glass fibers and inadequate shear reduction. This significantly reduced the retained glass fiber length, impacting the mechanical properties of the finished product and exacerbating the fiber floating problem. Comparative Example 5, while incorporating a high melt flow rate first polypropylene, omitted the low melt flow rate second polypropylene. This drastically increased production costs and, due to the excessively long retained glass fiber length, resulted in a significant difference in thermal shrinkage rates between the glass fibers and the PP matrix. Consequently, the product underwent uneven shrinkage during molding, leading to warping and poor molding performance.

[0068] In summary, this invention, through the compounding of a first polypropylene and a second polypropylene with a specific melt flow rate, enables the composite material to possess excellent mechanical properties, anti-fiber floating effect, and molding performance. By combining specific grafting materials, the compatibility between raw materials is improved and the anti-fiber floating effect is further enhanced. The final glass fiber reinforced polypropylene composite material possesses excellent mechanical properties, anti-fiber floating effect, and molding performance.

Claims

1. A glass fiber reinforced polypropylene composite material, characterized in that, The components include the following parts by weight: First polypropylene 12-23 parts, Second polypropylene 27-73 parts 17-53 parts glass fiber 3-18 portions of graft material; The first polypropylene has a melt flow rate of 700~2000g / 10min at 230℃ and 2.16kg; the second polypropylene has a melt flow rate of 20~200g / 10min at 230℃ and 2.16kg; the graft is a graft of hydrogenated styrene-butadiene block copolymer and glycidyl methacrylate.

2. The glass fiber reinforced polypropylene composite material according to claim 1, characterized in that, In the grafted material, the melt flow rate of the hydrogenated styrene-butadiene block copolymer at 230°C and 5 kg is 0.8~6 g / 10 min.

3. The glass fiber reinforced polypropylene composite material according to claim 1, characterized in that, In the grafted material, the mass ratio of hydrogenated styrene-butadiene block copolymer to glycidyl methacrylate is 1:(0.01~0.1).

4. The glass fiber reinforced polypropylene composite material according to claim 1, characterized in that, The grafted material is obtained by melt grafting reaction of hydrogenated styrene-butadiene block copolymer, glycidyl methacrylate, comonomer and initiator.

5. The glass fiber reinforced polypropylene composite material according to claim 1, characterized in that, The glass fiber is selected from alkali-free glass fiber; And / or, the diameter of the glass fiber monofilament is 8~15μm.

6. The glass fiber reinforced polypropylene composite material according to claim 1, characterized in that, The glass fiber reinforced polypropylene composite material further includes 0.1 to 2 parts by weight of additives; the additives include at least one of lubricant, antioxidant or light stabilizer.

7. The glass fiber reinforced polypropylene composite material according to claim 1, characterized in that, The lubricant includes amides, stearates, or combinations thereof; And / or, the antioxidants include hindered phenols, phosphites, or combinations thereof; And / or, the light stabilizer is selected from hindered amines.

8. A method for preparing a glass fiber reinforced polypropylene composite material as described in any one of claims 1 to 7, characterized in that, Includes the following steps: The components are mixed, melt extruded, and granulated to obtain the glass fiber reinforced polypropylene composite material.

9. The preparation method according to claim 8, characterized in that, The temperature of the melt extrusion is 205~250℃; And / or, the rotation speed of the melt extrusion is 200~300 rpm.

10. The application of a glass fiber reinforced polypropylene composite material as described in any one of claims 1 to 7 in the preparation of household appliances, electronic appliances, building industrial products, aerospace products, land and water transportation vehicles, or office supplies.

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