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

Abstract

The invention discloses a glass fiber reinforced polypropylene material as well as a preparation method and application thereof. The glass fiber reinforced polypropylene material comprises the following components in parts by weight: 55-95 parts of polypropylene resin, 10-35 parts of glass fibers and 1-5 parts of a compatilizer, wherein the polypropylene resin contains block co-polypropylene A and block co-polypropylene B in a weight ratio of (2-4): 1; the average molecular weight Mw of the block copolymerized polypropylene A is 200000-290000, and the mass fraction of the copolymerized ethylene propylene rubber phase content is 10%-20%; the average molecular weight Mw of the block co-polypropylene B is greater than or equal to 34 million, and the mass fraction of the copolymerized ethylene propylene rubber phase content is 11-17%. The glass fiber reinforced polypropylene material prepared from the block co-polypropylene A and the block co-polypropylene B with specific average molecular weight and ethylene propylene rubber phase content has relatively high tensile property, bending property and unnotched impact property under a low-temperature condition.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and more specifically, to a glass fiber reinforced polypropylene material and a preparation method and application thereof. Background Art

[0002] Polypropylene materials are widely used due to their advantages such as low density, excellent heat and chemical corrosion resistance, easy processing and molding, high cost performance and easy recycling, especially in the fields of automobiles and home appliances. In order to meet different application scenarios and further improve the performance of polypropylene materials, technicians usually modify polypropylene. For example, among the various parts of a car, only a small number of parts are processed with pure polypropylene materials without adding any other substances, while most parts are processed with modified polypropylene materials with enhanced performance. In the low-temperature working scene in winter, the performance of automobile parts made of polypropylene materials will change, such as becoming brittle and easy to be damaged, which will affect the performance of the car and bring major safety hazards to the low-temperature driving of the car. Improving the mechanical properties of polypropylene materials such as tensile properties, bending properties and notch-free impact properties under low temperature conditions can greatly reduce the probability of automobile parts becoming brittle and damaged in low temperatures in winter, and reduce the impact of low temperatures in winter on the use of cars.

[0003] Therefore, it is of great economic value to develop a glass fiber reinforced polypropylene material with strong tensile properties, bending properties and unnotched impact properties under low temperature conditions. Summary of the invention

[0004] The object of the present invention is to solve the deficiencies of the prior art and to provide a glass fiber reinforced polypropylene material and a preparation method and application thereof. The glass fiber reinforced polypropylene material improves its tensile properties, bending properties and unnotched impact properties under low temperature conditions by selecting two specific types of block copolymer polypropylenes and controlling the usage ratio of the two specific types of block copolymer polypropylenes.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides a glass fiber reinforced polypropylene material, comprising the following components in parts by weight:

[0007] Polypropylene resin 55-95 parts, glass fiber 10-35 parts, compatibilizer 1-5 parts;

[0008] in:

[0009] The polypropylene resin contains block copolymer polypropylene A and block copolymer polypropylene B in a weight ratio of (2-4):1;

[0010] The average molecular weight M of the block copolymer polypropylene Aw The mass fraction of the copolymerized EPR phase (ethylene propylene rubber phase) is 10%-20%;

[0011] The average molecular weight M of the block copolymer polypropylene B w ≥340,000, the mass fraction of the copolymer EPR phase (ethylene propylene rubber phase) is 11%-17%.

[0012] The present invention selects a specific average molecular weight M w The block copolymer polypropylene A and B with EPR phase (ethylene propylene rubber phase) content as the matrix polypropylene resin of glass fiber reinforced polypropylene material can, on the one hand, destroy the regularity and tightness of the molecular chain arrangement in the crystallization area, make the polypropylene resin easy to deform and absorb energy, reduce the rigidity of the polypropylene resin, enhance the toughness of the polypropylene resin, and make the polypropylene resin in a rigid-toughness balance state even under low temperature conditions, which is beneficial to improve the tensile properties, bending properties and unnotched impact properties of glass fiber reinforced polypropylene materials under low temperature conditions; on the other hand, when the block copolymer polypropylene A and B with specific different average molecular weights are used in combination, due to the molecular At the same time, they can build bridges for glass fibers, strengthen the connection between glass fibers, and improve the strength of the network structure, so that the polypropylene resin can be in a rigid-toughness balance state even under low temperature conditions, which is beneficial to improving the tensile properties, bending properties and unnotched impact properties of glass fiber reinforced polypropylene materials under low temperature conditions; moreover, the network structure formed by the entanglement of block copolymer polypropylenes A and B with different average molecular weights and bridged with glass fibers can improve the melt strength of glass fiber reinforced polypropylene materials, which is beneficial to improving the foaming rate of glass fiber reinforced polypropylene materials.

[0013] Preferably, the weight percentage of the polypropylene resin in the glass fiber reinforced polypropylene material is ≥ 60.0%.

[0014] More preferably, the weight percentage of the polypropylene resin in the glass fiber reinforced polypropylene material is ≥ 65.0%.

[0015] In the present invention, the test method for the average molecular weight of the block copolymer polypropylene A and / or B is as follows: the average molecular weight M of the block copolymer polypropylene A or B is measured by gel permeation chromatography (GPC, size exclusion chromatography) according to GB / T36214.4-2018 standard. w .

[0016] In the present invention, the test method for the copolymerized EPR phase content of the block copolymerized polypropylene A and / or B is:

[0017] Add M1g of block copolymer polypropylene A or block copolymer polypropylene B to xylene, heat and reflux at 135-140°C for 50-100min, cool and crystallize, filter, take the filtrate, evaporate and dry, the mass of the dried material is recorded as M2, then the copolymer EPR phase (ethylene propylene rubber phase) content of block copolymer polypropylene A or block copolymer polypropylene B = M2 / M1×100%.

[0018] Preferably, the weight ratio of the block copolymer polypropylene A to the block copolymer polypropylene B is in the range of one or any two of 2:1, 2.3:1, 2.5:1, 2.6:1, 2.9:1, 3:1, 3.3:1, 3.5:1, 3.6:1, 3.9:1, and 4:1.

[0019] Preferably, the average molecular weight M of the block copolymer polypropylene A is w The mass fraction of the copolymerized EPR phase content of the block copolymerized polypropylene A is 10%, 10.3%, 11%, 12%, 13%, 14%, 15%, 16%, 16.9%, 17%, 18%, 19%, 19.7%, 20%, or any two of the range values.

[0020] More preferably, the average molecular weight M of the block copolymer polypropylene A is w It is 205,000-285,000.

[0021] More preferably, the mass fraction of the copolymerized EPR phase (ethylene propylene diene rubber phase) of the block copolymerized polypropylene A is 10.3%-19.7%.

[0022] Preferably, the average molecular weight M of the block copolymer polypropylene B is w The mass fraction of the copolymerized EPR phase content of the block copolymerized polypropylene B is 11%, 11.9%, 12%, 13%, 14%, 15%, 15.8%, 16%, 16.6%, 17% or any two of the range values.

[0023] More preferably, the average molecular weight M of the block copolymer polypropylene B is wIt is between RMB 340,000 and RMB 600,000.

[0024] More preferably, the average molecular weight M of the block copolymer polypropylene B is w It is 380,000-560,000.

[0025] More preferably, the mass fraction of the copolymerized EPR phase (ethylene propylene diene rubber phase) of the block copolymerized polypropylene B is 11.9%-16.6%.

[0026] Preferably, the glass fibers have an average length of 0.40-1.00 mm and an average diameter of 10-15 μm.

[0027] More preferably, the average length of the glass fibers is 0.60-0.90 mm.

[0028] In the glass fiber reinforced polypropylene material of the present invention, the glass fibers are connected to each other by a mesh structure formed by entanglement of block copolymer polypropylene A and B with different average molecular weights, so that the polypropylene resin can be in a rigid-tough balance state even under low temperature conditions, and at the same time, the melt strength of the glass fiber reinforced polypropylene material can be improved, thereby achieving the effect of improving the tensile properties, bending properties and unnotched impact properties of the glass fiber reinforced polypropylene material under low temperature conditions, and improving the foaming rate of the glass fiber reinforced polypropylene material. The effect of the glass fiber is related to the average length of the glass fiber and the dispersibility of the glass fiber in the polypropylene resin.

[0029] The present invention can make glass fiber have better dispersibility in polypropylene resin by adjusting the average length of glass fiber, and the stress in the system is more easily transmitted to the glass fiber, which is more conducive to improving the tensile property, bending property and notchless impact property of glass fiber reinforced polypropylene material under low temperature conditions, and is more conducive to improving the foaming rate of glass fiber reinforced polypropylene material. In addition, when the average length of glass fiber is too short, the stress in the system is difficult to be transmitted to the glass fiber, and the tensile property, bending property and notchless impact property of glass fiber reinforced polypropylene material under low temperature conditions cannot be better improved, and the foaming rate of glass fiber reinforced polypropylene material cannot be better improved. When the average length of glass fiber is too long, glass fiber is more difficult to be evenly dispersed in the polypropylene resin, resulting in less glass fiber in the local part of the system, more easily forming performance weak points, more easily inducing the formation and fracture of cracks, thereby better improving the tensile property, bending property and notchless impact property of glass fiber reinforced polypropylene material under low temperature conditions, and cannot better improve the foaming rate of glass fiber reinforced polypropylene material.

[0030] More preferably, the average length of the glass fiber is 0.40mm, 0.42mm, 0.45mm, 0.46mm, 0.48mm, 0.49mm, 0.50mm, 0.52mm, 0.54mm, 0.55mm, 0.56mm, 0.58mm, 0.60mm, 0.62mm, 0.64mm, 0.65mm, 0.66mm, 0.68mm, 0.70mm, 0.71mm, 0.72mm, 0.73mm, 0.74mm, 0.75mm , 0.76mm, 0.78mm, 0.80mm, 0.82mm, 0.84mm, 0.85mm, 0.86mm, 0.87mm, 0.88mm, 0.90mm, 0.92mm, 0.94mm, 0.95mm, 0.96mm, 0.97mm, 0.98mm, 1.00mm or any two of the range values; the diameter of the glass fiber is 10μm, 11μm, 12μm, 13μm, 14μm, 15μm or any two of the range values.

[0031] More preferably, the average length of the glass fiber is 0.65-0.87 mm, specifically 0.65-0.87 mm.

[0032] In the present invention, the method for measuring the average length of glass fibers in the glass fiber reinforced polypropylene material is as follows: the glass fiber reinforced polypropylene material is calcined at 625°C ± 25°C for 30-90 minutes, cooled, 150-500 glass fibers are taken out, the lengths of the glass fibers are measured and the arithmetic average thereof is calculated as the average length of the glass fibers in the glass fiber reinforced polypropylene material.

[0033] Preferably, in the components of the glass fiber reinforced polypropylene material, the weight proportion of the polypropylene resin is one of 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, 95 parts or any two of the range values; the weight proportion of the glass fiber is one of 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts or any two of the range values; the weight proportion of the compatibilizer is one of 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts or any two of the range values.

[0034] Preferably, the glass fiber reinforced polypropylene material comprises the following components in parts by weight:

[0035] 60-90 parts of polypropylene resin, 10-30 parts of glass fiber, and 1-3 parts of compatibilizer.

[0036] Preferably, the compatibilizer is at least one of maleic anhydride grafted polypropylene (PP-g-MAH) and maleic anhydride grafted POE (POE-g-MAH).

[0037] Preferably, the glass fiber reinforced polypropylene material further includes an antioxidant.

[0038] More preferably, the weight portion of the antioxidant is 0.1-2 parts.

[0039] More preferably, the antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant.

[0040] In the present invention, commonly used hindered phenol antioxidants in the art can be used in the present invention, such as: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (antioxidant 1010, CAS No.: 6683-19-8), 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione (antioxidant TH-1790, CAS No.: 40601-76-1), and the like.

[0041] In the present invention, commonly used phosphite antioxidants in the art can be used in the present invention, such as tris(2,4-di-tert-butyl)phenyl phosphite (antioxidant 168, CAS No.: 31570-04-4) and the like.

[0042] Those skilled in the art can reasonably select the average length of the glass fiber raw material. Generally speaking, the average length of the glass fiber raw material is greater than the average length of the glass fibers in the glass fiber reinforced polypropylene material.

[0043] Preferably, the glass fiber raw material has an average length of 1-6 mm and an average diameter of 10-15 μm.

[0044] More preferably, the glass fiber raw material has an average length of 2-4.5 mm and an average diameter of 13 μm.

[0045] In a second aspect, the present invention provides a method for preparing a glass fiber reinforced polypropylene material, comprising the following steps:

[0046] S1. Take the raw materials of the glass fiber reinforced polypropylene material except the glass fiber raw material, mix them to obtain a premix;

[0047] S2. Add glass fiber raw material when the premix is ​​melt-extruded to obtain glass fiber reinforced polypropylene material.

[0048] In the present invention, those skilled in the art can adjust the average length of the glass fiber raw material to the desired average length of the glass fiber in the glass fiber reinforced polypropylene material through the above preparation method.

[0049] Preferably, in step S1, the mixing speed is 400-800 rpm and the mixing time is 1-3 min.

[0050] Preferably, in step S2, the conditions for melt extrusion are:

[0051] The temperature of zone 1 is 80-120°C, the temperature of zone 2 is 180-200°C, the temperature of zone 3 is 180-220°C, the temperature of zone 4 is 180-220°C, the temperature of zone 5 is 180-220°C, the temperature of zone 6 is 180-220°C, the temperature of zone 7 is 180-220°C, the temperature of zone 8 is 180-220°C, and the temperature of zone 9 is 180-220°C; the aspect ratio of the screw extruder is (40-48):1.

[0052] More preferably, the length-to-diameter ratio of the screw extruder is 40:1.

[0053] In the present invention, the screw extruder is a twin-screw extruder commonly used in the art.

[0054] In a third aspect, the present invention provides an application of a glass fiber reinforced polypropylene material in an automobile.

[0055] In the present invention, the glass fiber reinforced polypropylene material can be used to prepare various brackets in automobiles, such as front end frames, sunroof frames, and instrument panel frames.

[0056] When the glass fiber reinforced polypropylene material of the present invention is used to prepare the instrument panel frame, due to its high unnotched impact strength under low temperature conditions and the balanced rigidity and toughness inside the material, the frame of the instrument panel can be opened along the weakened line during the airbag explosion process without causing the generation of fragments.

[0057] In a fourth aspect, the present invention provides a foamed polypropylene material, which is obtained by foaming and molding the glass fiber reinforced polypropylene material described in the first aspect.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] The present invention selects a specific average molecular weight M wThe block copolymer polypropylene A and B with EPR phase (ethylene propylene rubber phase) content as the matrix polypropylene resin of glass fiber reinforced polypropylene material can, on the one hand, destroy the regularity and tightness of the molecular chain arrangement in the crystallization area, make the polypropylene resin easy to deform and absorb energy, reduce the rigidity of the polypropylene resin, enhance the toughness of the polypropylene resin, and make the polypropylene resin in a rigid-toughness balance state even under low temperature conditions, which is beneficial to improve the tensile properties, bending properties and unnotched impact properties of glass fiber reinforced polypropylene materials under low temperature conditions; on the other hand, when the block copolymer polypropylene A and B with specific different average molecular weights are used in combination, due to the molecular At the same time, they can build bridges for glass fibers, strengthen the connection between glass fibers, and improve the strength of the network structure, so that the polypropylene resin can be in a rigid-toughness balance state even under low temperature conditions, which is beneficial to improving the tensile properties, bending properties and unnotched impact properties of glass fiber reinforced polypropylene materials under low temperature conditions; moreover, the network structure formed by the entanglement of block copolymer polypropylenes A and B with different average molecular weights and bridged with glass fibers can improve the melt strength of glass fiber reinforced polypropylene materials, which is beneficial to improving the foaming rate of glass fiber reinforced polypropylene materials. DETAILED DESCRIPTION

[0060] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0061] In each embodiment and comparative example of the present invention, the use of reagents is as follows:

[0062] Block copolymer polypropylene A-1, PP EP548R, CNOOC Shell, average molecular weight M w is 264969, and the mass fraction of copolymer EPR phase is 16.9%;

[0063] Block copolymer polypropylene A-2, PP K7227, Sinopec Guangzhou, average molecular weight M w is 206488, and the mass fraction of copolymer EPR phase is 10.3%;

[0064] Block copolymer polypropylene A-3, PP 7033N, ExxonMobil, average molecular weight M w is 281963, and the mass fraction of copolymer EPR phase is 19.7%;

[0065] Block copolymer polypropylene A-4, PP BX3920, South Korea SK, average molecular weight M w is 161495, and the mass fraction of copolymer EPR phase is 8.7%;

[0066] Block copolymer polypropylene A-5, PP SP179, Lanzhou Petrochemical, average molecular weight M w is 280024, and the mass fraction of copolymer EPR phase is 24.5%;

[0067] Block copolymer polypropylene B-1, PP 3010, Formosa Plastics Corporation, Taiwan, China, average molecular weight M w is 387474, and the mass fraction of copolymer EPR phase is 11.9%;

[0068] Block copolymer polypropylene B-2, PP B8101, Yanshan Petrochemical, average molecular weight M w is 552125, and the mass fraction of copolymer EPR phase is 15.8%;

[0069] Block copolymer polypropylene B-3, PP K8003, China Taiwan Chemical Fiber (China Taiwan Chemical Fiber Co., Ltd.), average molecular weight M w is 341408, and the mass fraction of copolymer EPR phase is 16.6%;

[0070] Block copolymer polypropylene B-4, PP 7032E3, ExxonMobil, average molecular weight M w is 332845, and the mass fraction of copolymer EPR phase is 16.5%;

[0071] Glass fiber raw material-1, ECS13-04-508A, China Jushi Co., Ltd., glass fiber with an average length of 4 mm and an average diameter of 13 μm;

[0072] Glass fiber raw material-2, ECS13-03-508A, China Jushi Co., Ltd., glass fiber with an average length of 3 mm and an average diameter of 13 μm;

[0073] Glass fiber raw material-3, ECS13-4.5-T538D, Taishan Glass Fiber Co., Ltd., glass fiber with an average length of 4.5 mm and an average diameter of 13 μm;

[0074] Glass fiber raw material-4, glass fibers with an average length of 2 mm and an average diameter of 13 μm, obtained by shearing and shredding glass fiber raw material-1 (ECS13-04-508A, China Jushi Co., Ltd.);

[0075] Glass fiber raw material-5, ECS13-06-558, China Jushi Co., Ltd., glass fiber with an average length of 6 mm and an average diameter of 13 μm;

[0076] Maleic anhydride grafted polypropylene (PP-g-MAH), commercially available;

[0077] Pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Antioxidant 1010), commercially available;

[0078] Tris(2,4-di-tert-butyl)phenyl phosphite (Antioxidant 168), commercially available;

[0079] In each embodiment and comparative example of the present invention:

[0080] (1) Test method for average molecular weight of block copolymer polypropylene A and / or B: The average molecular weight M of block copolymer polypropylene A or B is measured by gel permeation chromatography (GPC, size exclusion chromatography) according to GB / T36214.4-2018 standard. w ;

[0081] (2) Test method for the copolymerized EPR phase content of block copolymerized polypropylene A and / or B: add 2 g of block copolymerized polypropylene A or block copolymerized polypropylene B to 200 mL of xylene, heat and reflux at 135-140° C. for 60 min, cool and crystallize at 25° C., filter, take the filtrate, rotary evaporate, and dry to constant weight. The mass of the substance after drying to constant weight is recorded as M2, and the copolymerized EPR phase (ethylene propylene rubber phase) content of block copolymerized polypropylene A or block copolymerized polypropylene B = M2 / 2 g×100%;

[0082] (3) The method for measuring the average length of glass fibers in glass fiber reinforced polypropylene materials is as follows: place the glass fiber reinforced polypropylene material in a crucible, calcine it in a muffle furnace at 625°C ± 25°C for 60 minutes, take it out and cool it, place the calcined solid in an evaporating dish (a small amount of clean water can be added to the evaporating dish to help disperse the glass fibers after gentle stirring), take 300 glass fibers from it, measure the length of the glass fibers with a two-dimensional microscope and calculate the arithmetic mean value, which is used as the average length of the glass fibers in the glass fiber reinforced polypropylene material.

[0083] Examples 1-18 and Comparative Examples 1-10

[0084] Examples 1-18 and Comparative Examples 1-10 provide different glass fiber reinforced polypropylene materials, the only difference between them is that the types and amounts of the components are different. Calculated by weight, Examples 1-18 and Comparative Examples 1-10 include the components shown in Table 1;

[0085] The preparation method of the glass fiber reinforced polypropylene material comprises the following steps:

[0086] S1. Take the raw material of the glass fiber reinforced polypropylene material except the glass fiber raw material, and mix it with a high mixer at a speed of 600 rpm for 2 min to obtain a premix;

[0087] S2. When the premix is ​​placed in the main feed port of a twin-screw extruder for melt extrusion, a glass fiber raw material is added through the side feed port of the twin-screw extruder to obtain a glass fiber reinforced polypropylene material;

[0088] Wherein, in step S2, the conditions for melt extrusion are:

[0089] The temperature of zone 1 is 90℃, the temperature of zone 2 is 180℃, the temperature of zone 3 is 200℃, the temperature of zone 4 is 200℃, the temperature of zone 5 is 200℃, the temperature of zone 6 is 200℃, the temperature of zone 7 is 200℃, the temperature of zone 8 is 200℃, the temperature of zone 9 is 200℃, the main engine speed is 450r / min; the aspect ratio of the twin-screw extruder is 40:1;

[0090] In addition, before and after the above-mentioned preparation method is implemented, the average diameter of the glass fiber remains substantially unchanged, that is, the average diameter of the glass fiber raw material is substantially consistent with the average diameter of the glass fiber;

[0091] Table 1 Weight percentage of each component of glass fiber reinforced polypropylene materials of Examples 1-18 and Comparative Examples 1-10

[0092]

[0093]

[0094]

[0095]

[0096] Performance Testing

[0097] The following performance tests were performed on the glass fiber reinforced polypropylene materials of each embodiment and comparative example:

[0098] (1) Tensile properties test at low temperature

[0099] The low temperature tensile performance is carried out according to ISO527-2012, using 1A specimens, the test temperature is -30℃, and the tensile rate is 10mm / min;

[0100] (2) Bending performance test at low temperature

[0101] The low temperature bending performance is carried out according to ISO178-2010, using 80×10×4mm injection molded specimens, the test temperature is -30℃, the bending rate is 2mm / min, and the span is 64mm;

[0102] (3) Unnotched impact performance test at low temperature

[0103] Low temperature simply supported beam unnotched impact performance is carried out according to ISO179-1993, using 80×10×4mm injection molded specimens, the test temperature is -30℃, and the span is 62mm;

[0104] (4) Foaming effect test

[0105] S1. Preparation of non-foaming sample

[0106] A BS800-III 80-ton injection molding machine was used to inject glass fiber reinforced polypropylene material, and a 10×10×3mm sample was cut out as a non-foaming sample. The injection molding process was as follows: injection temperature 200°C, injection speed 45g / s, injection pressure 45MPa, holding pressure 50MPa, holding time 15s, and cooling time 15s.

[0107] S2. Preparation of foaming sample

[0108] A BS800-III 80-ton injection molding machine was used. A foaming agent (EE25C, Japan Yonghe Fine Chemicals) was added to the glass fiber reinforced polypropylene material at a mass ratio of 100:1, and the mixture was mixed. Then, injection molding was performed, and a sample of 10×10×3 mm was cut out as a foaming sample. The injection molding process was as follows: injection temperature 200°C, injection speed 75g / s, injection pressure 75MPa, holding time 30s, and cooling time 30s.

[0109] S3. Calculation of weight loss ratio

[0110] Weigh the weight of the non-foamed sample m1 and the weight of the foamed sample m2, the weight loss ratio (%) = (m1-m2) / m1×100%, and use the weight loss ratio to characterize the foaming effect of the glass fiber reinforced polypropylene material. A large value of the weight loss ratio indicates that the foaming effect of the glass fiber reinforced polypropylene material is good;

[0111] The experimental results are shown in the following table:

[0112] Table 2 Performance test results of various embodiments and comparative examples

[0113]

[0114]

[0115] As can be seen from Table 2, the glass fiber reinforced polypropylene material of the present invention has strong tensile properties, bending properties and unnotched impact properties under low temperature conditions, and the tensile strength can reach more than 93MPa, the bending strength can reach more than 145MPa, and the unnotched impact property can reach 38 / KJ / m 2 The weight reduction ratio before and after foaming can reach more than 5.0%; specifically:

[0116] (1) By comparing Examples 1-7 and Comparative Examples 1-7, it can be seen that the present invention selects block copolymer polypropylenes A and B with specific average molecular weights and EPR phase (ethylene propylene rubber phase) contents as the base polypropylene resin of the glass fiber reinforced polypropylene material. On the one hand, the regularity and tightness of the molecular chain arrangement in the crystallization region can be destroyed, so that the polypropylene resin is easy to deform and absorb energy, the rigidity of the polypropylene resin is reduced, and the toughness of the polypropylene resin is enhanced, so that the polypropylene resin can be in a rigid-toughness balance state even under low temperature conditions, which is beneficial to improving the tensile properties, bending properties and unnotched impact properties of the glass fiber reinforced polypropylene material under low temperature conditions; on the other hand, the block copolymers A and B with specific average molecular weights and different EPR phase (ethylene propylene rubber phase) contents can be used as the base polypropylene resin of the glass fiber reinforced polypropylene material. When copolymer polypropylene A and B are used together, they are more likely to be entangled due to their different molecular sizes, chain lengths, etc. to form a stable, high-toughness network structure. At the same time, they can build bridges for glass fibers, strengthen the connection between glass fibers, and improve the strength of the network structure, so that the polypropylene resin can be in a rigid-toughness balance state even under low temperature conditions, which is beneficial to improving the tensile properties, bending properties and unnotched impact properties of glass fiber reinforced polypropylene materials under low temperature conditions; moreover, the network structure formed by the entanglement of different high-average molecular weight block copolymer polypropylenes A and B and bridged with glass fibers can improve the melt strength of glass fiber reinforced polypropylene materials, which is beneficial to improving the foaming rate of glass fiber reinforced polypropylene materials.

[0117] (2) By comparing Examples 1 and 8-11, it can be seen that in the glass fiber reinforced polypropylene material of the present invention, the glass fibers are connected to each other by a mesh structure formed by entanglement of block copolymer polypropylenes A and B of different average molecular weights, so that the polypropylene resin can be in a rigid-tough balance state even under low temperature conditions, and at the same time, the melt strength of the glass fiber reinforced polypropylene material can be improved, thereby achieving the effect of improving the tensile properties, bending properties and unnotched impact properties of the glass fiber reinforced polypropylene material under low temperature conditions, and improving the foaming rate of the glass fiber reinforced polypropylene material. When the average length of the glass fiber is preferably 0.60-0.90 mm, the glass fiber has better dispersibility in the polypropylene resin, and the stress in the system is more easily transmitted to the glass fiber, which is more conducive to improving the tensile properties, bending properties and unnotched impact properties of the glass fiber reinforced polypropylene material under low temperature conditions, and is more conducive to improving the foaming rate of the glass fiber reinforced polypropylene material.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A glass fiber reinforced polypropylene material, characterized in that: The composition comprises the following components in parts by weight: Polypropylene resin 55-95 parts, glass fiber 10-35 parts, compatibilizer 1-5 parts; in: The polypropylene resin contains block copolymer polypropylene A and block copolymer polypropylene B in a weight ratio of (2-4):1; The average molecular weight M of the block copolymer polypropylene A w The mass fraction of the copolymerized EPDM rubber phase is 10%-20%; The average molecular weight M of the block copolymer polypropylene B w ≥340,000, the mass fraction of the copolymer EPDM rubber phase is 11%-17%.

2. The glass fiber reinforced polypropylene material according to claim 1, characterized in that: Include at least one of the following (1)-(2): (1) The average molecular weight M of the block copolymer polypropylene B w 340,000-600,000; (2) The glass fibers have an average length of 0.40-1.00 mm and an average diameter of 10-15 μm.

3. The glass fiber reinforced polypropylene material according to claim 2, characterized in that: Include at least one of the following (1)-(2): (1) The average molecular weight Mw of the block copolymer polypropylene B is 380,000-560,000; (2) The average length of the glass fiber is 0.60-0.90 mm.

4. The glass fiber reinforced polypropylene material according to claim 1, characterized in that: Including at least one of the following (1)-(3): (1) The average molecular weight M of the block copolymer polypropylene A w 205,000-285,000; (2) the mass fraction of the copolymerized EPDM rubber phase of the block copolymerized polypropylene A is 10.3%-19.7%; (3) The mass fraction of the copolymerized EPDM rubber phase in the block copolymerized polypropylene B is 11.9%-16.6%.

5. The glass fiber reinforced polypropylene material according to claim 1, characterized in that: The compatibilizer is at least one of maleic anhydride grafted polypropylene and maleic anhydride grafted POE.

6. The glass fiber reinforced polypropylene material according to claim 1, characterized in that: The glass fiber reinforced polypropylene material also includes an antioxidant.

7. The glass fiber reinforced polypropylene material according to claim 1, characterized in that: The glass fiber reinforced polypropylene material comprises the following components in parts by weight: 60-90 parts of polypropylene resin, 10-30 parts of glass fiber, and 1-3 parts of compatibilizer.

8. The method for preparing the glass fiber reinforced polypropylene material according to any one of claims 1 to 7, characterized in that: The steps include: S1. Take the raw materials of the glass fiber reinforced polypropylene material except the glass fiber raw material, mix them to obtain a premix; S2. Add glass fiber raw material when the premix is ​​melt-extruded to obtain glass fiber reinforced polypropylene material.

9. Use of the glass fiber reinforced polypropylene material according to any one of claims 1 to 7 in automobiles.

10. A foamed polypropylene material, characterized in that: The glass fiber reinforced polypropylene material according to any one of claims 1 to 7 is prepared by foaming and molding.

Images