A kind of anti-aging polypropylene composite material and its preparation method and application

Abstract

The present invention belongs to the technical field of polymer modified materials, and specifically relates to an aging-resistant polypropylene composite material, a preparation method thereof and an application thereof. An aging-resistant polypropylene composite material comprises the following raw materials in parts by weight: 35 to 65 parts of polypropylene resin; 2 to 20 parts of EPDM rubber recycling material; 20 to 40 parts of glass fiber; 0.1 to 1 part of light stabilizer; 0.1 to 1 part of antioxidant; the glass fiber comprises chopped glass fiber and continuous glass fiber. The present invention selects continuous glass fiber and chopped glass fiber for compounding, which can effectively reduce the orientation of glass fiber, reduce warping, and reduce costs; selects EPDM rubber recycling material as a toughening agent, which can effectively enhance the impact resistance of the material, is not easily damaged by falling, and realizes the recycling of waste rubber; is matched with light stabilizer and antioxidant, and the dosage of each component is scientifically matched, so that the comprehensive performance of the obtained polypropylene composite material is excellent.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer modified materials, and in particular relates to an aging-resistant polypropylene composite material and a preparation method and application thereof. Background Art

[0002] Polypropylene (PP) is one of the five general-purpose resins. It has excellent properties such as light weight, easy processing, and chemical corrosion resistance. It is widely used in chemical, electrical, packaging and other industrial fields. However, polypropylene itself still has many defects and needs to be modified to meet the needs of more application fields. Among them, glass fiber reinforced polypropylene is an important modification method, which enables it to "replace steel with plastic" and "replace wood with plastic".

[0003] Existing construction formwork is generally made of wooden boards. The disadvantage of this operation is that a large amount of wood needs to be cut down, and the wooden boards spliced ​​with nails are easily damaged and need to be constantly repaired. This requires the development of a new formwork material to replace the existing wooden board formwork for application in the construction industry, so that it has high strength, good impact resistance, and is not easily damaged by falling. However, the problems of warping and aging resistance of glass fiber reinforced polypropylene injection molding need to be solved.

[0004] Therefore, developing a glass fiber reinforced polypropylene composite material that is both aging-resistant and has good formability is a technical problem that needs to be solved at present. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides an aging-resistant polypropylene composite material, which has excellent mechanical strength, impact resistance, is not easy to be damaged by falling, and has good light and heat aging resistance.

[0006] The invention also provides a preparation method and application of the ageing-resistant polypropylene composite material.

[0007] In a first aspect of the present invention, an aging-resistant polypropylene composite material is provided, comprising the following raw materials in parts by weight:

[0008] 35-65 parts of polypropylene resin;

[0009] 2-20 parts of EPDM recycled materials;

[0010] 20-40 parts of glass fiber;

[0011] Light stabilizer 0.1-1 part;

[0012] Antioxidant 0.1-1 part;

[0013] The glass fibers include chopped glass fibers and continuous glass fibers.

[0014] According to the first aspect of the present invention, there are at least the following beneficial effects:

[0015] The cost of using continuous glass fiber alone is low, but it cannot be guaranteed that the continuous glass fiber can be fully shredded during the production process, and glass fibers of suitable length cannot be obtained, so the reinforcement effect of continuous glass fiber is not as good as that of chopped glass fiber; however, the cost of using chopped glass fiber alone is high, and the length is uniform, the orientation is obvious, and the composite material warps seriously. The present invention selects continuous glass fiber and chopped glass fiber for compounding, which can effectively reduce the orientation of glass fiber, reduce warping, and reduce costs; selects EPDM rubber recycled material as a toughening agent, which can effectively enhance the impact resistance of the material, is not easy to be damaged by falling, and realizes the recycling of waste rubber; with light stabilizers and antioxidants, and the dosage of each component is scientifically matched, the obtained polypropylene composite material has excellent comprehensive performance, excellent mechanical strength, impact resistance, and light and heat aging resistance.

[0016] In some preferred embodiments of the present invention, the aging-resistant polypropylene composite material further comprises the following raw materials in parts by weight:

[0017] Compatibilizer 2-8 parts;

[0018] 0.1 to 1 part of hydrotalcite;

[0019] Lubricant 0.1 to 1 part.

[0020] In some preferred embodiments of the present invention, the aging-resistant polypropylene composite material further comprises the following raw materials in parts by weight:

[0021] 4-6 parts of compatibilizer;

[0022] 0.4-0.6 parts of hydrotalcite;

[0023] Lubricant 0.2-0.5 parts.

[0024] In the present invention, hydrotalcite is an anionic layered compound. The hydrotalcite utilizes the intercalation property of the layered compound body under the action of strong polar molecules and the exchangeability of interlayer ions to introduce some functional guest substances into the interlayer gaps and expand the distance between the layers to form a layered column compound. During the thermal oxidation aging process, some decomposed free radicals can be adsorbed to slow down the aging process. The addition of a lubricant can improve the internal and external lubricity of the material, increase the dispersibility of the glass fiber, and improve the surface brightness of the material, while taking into account the economy.

[0025] In some embodiments of the present invention, the mass ratio of the chopped glass fibers to the continuous glass fibers is 1:1-5, preferably 1:1-3, including but not limited to 1:1, 1:2, 1:2.5, 1:3, etc.

[0026] In some embodiments of the present invention, the length of the chopped glass fibers is 2 to 10 mm, more preferably 4 to 6 mm, and the diameter is 2 to 8 μm, more preferably 4 to 5 μm.

[0027] In some embodiments of the present invention, the diameter of the continuous glass fiber is 4-5 μm.

[0028] In some embodiments of the present invention, the EPDM rubber is a copolymer of ethylene, propylene and a small amount of a third monomer which is a non-conjugated diene; the EPDM rubber recycled material has a third monomer ethylidene norbornene content of ≥2%, preferably a mass content of ethylidene norbornene of ≥4%. In the present invention, the EPDM rubber with a higher third monomer ethylidene norbornene content has a lower compression deformation, and the EPDM rubber with a high ethylene content has good aging resistance and impact properties, high Mooney viscosity, good fluidity, and is suitable for injection molding.

[0029] In some embodiments of the present invention, the mass ratio of ethylene to propylene in the EPDM rubber recycling material is 1 to 4:1 (i.e., 80:20 to 50:50), preferably 2 to 3:1, including but not limited to 2:1, 2.3:1, 2.6:1, 3:1, etc.; the Mooney viscosity of the EPDM rubber is greater than 30MU, preferably the Mooney viscosity is greater than 50MU.

[0030] In some preferred embodiments of the present invention, the EPDM rubber recycled material is EPDM rubber black recycled particles, and the EPDM rubber black recycled particles are obtained by sorting, magnetically filtering and dyeing EPDM rubber recycled materials from sports equipment or sports tracks.

[0031] In some preferred embodiments of the present invention, the melt index of the polypropylene resin is greater than 70g / 10min (230°C, 2.16Kg), and more preferably the melt index of the polypropylene is greater than 80g / 10min (230°C, 2.16Kg); the bending modulus of the polypropylene resin is greater than 1200MPa, and more preferably the bending modulus of the polypropylene resin is greater than 1500MPa. The present invention uses high-fluidity and high-crystalline polypropylene, which can reduce film filling resistance, better molding of large injection molded parts, avoid glue shortage, high crystallinity, shorten molding cooling time, improve efficiency, and high bending modulus, which can improve deformation resistance and load-bearing capacity.

[0032] In some preferred embodiments of the present invention, the compatibilizer includes ethylene-butene copolymer (POE) grafted maleic anhydride, and the grafting rate of the POE grafted maleic anhydride is ≥0.6%, and more preferably the grafting rate is ≥0.8%. In the present invention, the POE grafted maleic anhydride can be used as a compatibilizer for glass fiber and polypropylene, and can also improve the impact strength.

[0033] In some preferred embodiments of the present invention, the light stabilizer is a compound light stabilizer, including a combination of light stabilizer 622 and light stabilizer 228; preferably, the mass ratio of the light stabilizer 622 to the light stabilizer 228 is 1:1-4, more preferably 1:1-3, including but not limited to 1:1, 1:2, 1:3, etc.

[0034] In the present invention, the light stabilizer UV622 is a low-alkalinity polymerized high molecular weight hindered amine light stabilizer. Since it is a polymer compound, it has good processing thermal stability and good compatibility with polypropylene. It can effectively prevent the degradation of polypropylene by light, heat climate and moisture. During the light aging process, polypropylene degrades and presents an acidic environment. If too much alkaline light stabilizer is used, the light aging resistance effect cannot be achieved. When used with the neutral hindered amine ultraviolet light stabilizer 228, this problem can be perfectly solved, so that the material can achieve a long-term light aging resistance effect.

[0035] In some preferred embodiments of the present invention, the antioxidant is a compound antioxidant, which is a combination of antioxidant 168, antioxidant 1010, and antioxidant DSTDP. The mass ratio of the antioxidant 168, antioxidant 1010, and antioxidant DSTDP is 1-4:1:1-5, more preferably 1-3:1:2-4, and further preferably 2:1:2.5.

[0036] In the present invention, the addition of compound antioxidants can improve the aging resistance of glass fiber reinforced polypropylene composite materials. Antioxidants 168 and 1010 are conventional antioxidants, which can not only protect PP from degradation during the processing process, but also make the material have long-term aging resistance. The compound thioester antioxidant DSTDP has a synergistic effect with antioxidant 1010, which can prevent the thermal oxidation aging degradation of the polypropylene composite material during the long-term aging process, has a long effectiveness, and has high economy.

[0037] The second aspect of the present invention provides a method for preparing the aging-resistant polypropylene composite material, comprising the following steps: mixing the raw materials of the aging-resistant polypropylene composite material, and melt-extruding to obtain the aging-resistant polypropylene composite material.

[0038] In some preferred embodiments of the present invention, the preparation method of the aging-resistant polypropylene composite material comprises the following steps: mixing polypropylene resin, EPDM rubber recycled material, compatibilizer, light stabilizer, antioxidant, compatibilizer, hydrotalcite, and lubricant, adding them from the main feed port of the extruder, adding chopped glass fiber from the side feed port, adding continuous glass fiber from the exhaust port, and melt-extruding to obtain the aging-resistant polypropylene composite material.

[0039] In some preferred embodiments of the present invention, the melt extrusion temperature is 200-230°C, and a more preferred melt extrusion temperature is 200°C / 220°C / 220°C / 220°C / 225°C / 225°C / 225°C / 230°C / 230°C / 230°C / 210°C.

[0040] In some more preferred embodiments of the present invention, the screw assembly used in the extruder is independently designed, and the screw design parameters of the screw assembly from the exhaust port to the discharge film head end are 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, 90° / 5 / 56, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, transition Block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, 56 / 56, 56 / 28L, 96 / 96, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 56 / 56, 56 / 56, 56 / 56, 56 / 56. The above data are the parameters of screw design, for example, "96 / 96" means that this is a thread block with a lead of 96mm and a length of 96mm; "45° / 5 / 56" means that 45° represents the angle of the kneading block, 5 is the number of pieces, and 56 is the length; "Transition block 12 / 12" is a link block between the toothed disk and the threaded block or shear block, and its length is 12mm; "Tooth group 57 / 57" means that the length of the toothed thread element is 57mm; "56 / 28L" means that 56 refers to the lead of the conveying block, 28 represents the length of this conveying block, and L represents the direction. The others are just length changes, and the meanings are similar.

[0041] The third aspect of the present invention proposes the use of the ageing-resistant polypropylene composite material in the preparation of building formwork materials.

[0042] Compared with the prior art, the present invention has at least the following beneficial effects:

[0043] 1. The aging-resistant reinforced polypropylene composite material of the present invention has excellent mechanical properties, tensile strength>90MPa, bending modulus>5500MPa, cantilever beam notched impact strength>150J / m, and strength is higher than that of wood. The injection-molded building formwork will not break when dropped vertically from a height of 3m.

[0044] 2. The aging-resistant glass fiber reinforced polypropylene composite material of the present invention has excellent aging resistance. After baking at 150°C for 1000 hours, the tensile strength, flexural modulus and cantilever beam notched impact strength are all maintained above 70%. After UV irradiation for 1500 hours, the tensile strength, flexural modulus and cantilever beam notched impact strength are all maintained above 70%.

[0045] 3. The surface of the aging-resistant glass fiber reinforced polypropylene composite material of the present invention is relatively smooth without obvious warping.

[0046] 4. The preparation method of the present invention is relatively simple, easy to realize large-scale production, low cost, uses a self-designed screw assembly, the material has high mechanical properties, and the product quality is stable. DETAILED DESCRIPTION

[0047] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0048] The raw materials used in the following examples, unless otherwise specified, can be obtained from conventional commercial sources; the processes used, unless otherwise specified, are conventional processes in the art; the operating temperatures used, unless otherwise specified, are room temperature (20±5° C.).

[0049] Example 1

[0050] This embodiment prepares an aging-resistant glass fiber reinforced polypropylene composite material, which is specifically implemented as follows:

[0051] According to the proportion, 53.1 parts of the polypropylene resin (SK, South Korea, BX3920), 5 parts of POE grafted maleic anhydride (Coais Chemical Co., Ltd., plastic additive: W1), 5 parts of EPDM rubber black recycled particles (commercially available, the third monomer ethylidene norbornene content is 5%, the ratio of ethylene to propylene is 70:30, and the Mooney viscosity is 60MU), 0.5 parts of compound light stabilizer (light stabilizer 622: light stabilizer 228 = 1:2, commercially available), and 0.4 parts of polyethylene wax (Qingdao Bangni, BN500) were added. , 0.5 parts of hydrotalcite (commercially available), and 0.5 parts of compound antioxidant (antioxidant 168: antioxidant 1010: antioxidant DSTDP = 2:1:2.5, commercially available) were mixed evenly in proportion, fed into a twin-screw extruder from the main feed, 25 parts of chopped glass fiber (TCR438G-13-4.5, Chongqing Composite Materials) were added from the side feed port, and 10 parts of continuous glass fiber (EDR14-2000-988A, China Jushi) were added from the exhaust port, and extrusion granulation was carried out in a self-designed screw combination. , an aging-resistant glass fiber reinforced polypropylene composite material is obtained; the extrusion temperature of the extrusion granulation is 200℃ / 220℃ / 220℃ / 220℃ / 225℃ / 225℃ / 225℃ / 230℃ / 230℃ / 230℃ / 210℃, and the independently designed screw combination is 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, 90° / 5 / 56, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, 56 / 56, 56 / 28L, 96 / 96, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 56 / 56, 56 / 56, 56 / 56, 56 / 56.

[0052] Example 2

[0053] This embodiment prepares an aging-resistant glass fiber reinforced polypropylene composite material, which is specifically implemented as follows:

[0054] According to the proportion, 43.1 parts of the polypropylene resin (SK, Korea, BX3920), 5 parts of POE grafted maleic anhydride (Coais Chemical Co., Ltd., plastic additive: W1), 15 parts of EPDM rubber black recycled particles (commercially available, the third monomer ethylidene norbornene content is 5%, the ratio of ethylene to propylene is 70:30, and the Mooney viscosity is 60MU), 0.5 parts of compound light stabilizer (light stabilizer 622: light stabilizer 228 = 1:2, commercially available), 0.4 parts of polyethylene wax (Qingdao Bangni, BN500 ), 0.5 parts of hydrotalcite (commercially available), and 0.5 parts of compound antioxidant (antioxidant 168: antioxidant 1010: antioxidant DSTDP = 2:1:2.5, commercially available) were mixed evenly in proportion, fed into a twin-screw extruder from the main feed, 25 parts of chopped glass fiber (TCR438G-13-4.5, Chongqing Composite Materials) were added from the side feed port, and 10 parts of continuous glass fiber (EDR14-2000-988A, China Jushi) were added from the exhaust port, and extruded in a self-designed screw combination. The granules are prepared to obtain an aging-resistant glass fiber reinforced polypropylene composite material; the extrusion temperature of the extrusion granulation is 200°C / 220°C / 220°C / 220°C / 225°C / 225°C / 225°C / 230°C / 230°C / 230°C / 210°C, and the independently designed screw combination is 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, 90° / 5 / 56, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, 56 / 56, 56 / 28L, 96 / 96, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 56 / 56, 56 / 56, 56 / 56, 56 / 56.

[0055] Comparative Example 1

[0056] In this comparative example, a glass fiber reinforced polypropylene composite material was prepared. The main difference from Example 1 is that the polypropylene resin (SK, BX3920, Korea, MI is 100g / 10min, the test conditions are 2.16Kg, 230°C) is changed to polypropylene resin (EP548R, CNOOC Shell, MI is 28g / 10min, the test conditions are 2.16Kg, 230°C), the raw material proportions are shown in Table 1, and the preparation process refers to Example 1.

[0057] Comparative Example 2

[0058] In this comparative example, a glass fiber reinforced polypropylene composite material was prepared. The main difference from Example 1 is that the compatibilizer was changed to PP grafted maleic anhydride (KT-1, Shenyang Ketong). The raw material proportions are shown in Table 1. The preparation process refers to Example 1.

[0059] Comparative Example 3

[0060] This comparative example prepares a glass fiber reinforced polypropylene composite material. The main difference from Example 1 is that 5 parts of EPDM rubber black recycled particles are replaced with 5 parts of polypropylene resin (SK, BX3920, South Korea). The raw material proportions are shown in Table 1. The preparation process refers to Example 1.

[0061] Comparative Example 4

[0062] In this comparative example, a glass fiber reinforced polypropylene composite material was prepared. The main difference from Example 2 is that the compounded light stabilizer 0.5 parts (light stabilizer 622: light stabilizer 228 = 1:2, commercially available) was changed to 0.5 parts of light stabilizer (light stabilizer 622). The raw material proportions are shown in Table 1. The preparation process refers to Example 2.

[0063] Comparative Example 5

[0064] This comparative example prepared a glass fiber reinforced polypropylene composite material, which is different from Example 2 in that 0.5 parts of hydrotalcite (commercially available) is replaced by 0.5 parts of polypropylene resin (SK, BX3920, South Korea). The raw material ratios are shown in Table 1. The preparation process is referenced to

[0065] Comparative Example 6

[0066] In this comparative example, a glass fiber reinforced polypropylene composite material is prepared. The main difference from Example 2 is that 0.5 parts of the compound antioxidant (antioxidant 168: antioxidant 1010: antioxidant DSTDP = 2:1:2.5, commercially available) is changed to 0.5 parts of antioxidant B215. The raw material proportions are shown in Table 1. The preparation process refers to Example 2.

[0067] Comparative Example 7

[0068] In this comparative example, a glass fiber reinforced polypropylene composite material was prepared. The main difference from Example 1 was that 25 parts of chopped glass fibers (TCR438G-13-4.5, Chongqing Composite Materials) were added from the side feed port, and 10 parts of continuous glass fibers (EDR14-2000-988A, China Jushi) were added from the exhaust port. Instead, 35 parts of chopped glass fibers (TCR438G-13-4.5, Chongqing Composite Materials) were added from the side feed port, and 0 parts of continuous glass fibers (EDR14-2000-988A, China Jushi) were added from the exhaust port. The proportion of raw materials is shown in Table 1. The preparation process refers to Example 1.

[0069] Comparative Example 8

[0070] In this comparative example, a glass fiber reinforced polypropylene composite material was prepared. The main difference from Example 2 was that 25 parts of chopped glass fibers (TCR438G-13-4.5, Chongqing Composite Materials) were added from the side feed port, and 10 parts of continuous glass fibers (EDR14-2000-988A, China Jushi) were added from the exhaust port, while 0 parts of chopped glass fibers (TCR438G-13-4.5, Chongqing Composite Materials) were added from the side feed port, and 35 parts of continuous glass fibers (EDR14-2000-988A, China Jushi) were added from the exhaust port. The proportion of raw materials is shown in Table 1. The preparation process refers to Example 2.

[0071] Comparative Example 9

[0072] This comparative example prepared a glass fiber reinforced polypropylene composite material, which was mainly different from Example 1 in that the independently designed screw combination (the screw designs from the exhaust port to the discharge die end were 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, 90° / 5 / 56, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, 56 / 56, 56 / 28L, 96 / 96, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 56 / 56, 56 / 56 , 56 / 56, 56 / 56) are changed to the screw combination design commonly used in the field of ordinary materials. The screw designs from the exhaust port to the discharge die head are 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, 90° / 5 / 56, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, 60° / 4 / 56 , 45° / 5 / 56, 72 / 72, 56 / 56, 45° / 5 / 56, 60° / 4 / 56, 56 / 56, 56 / 56, 56 / 28L, 96 / 96, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 56 / 56, 56 / 56, 56 / 56, 56 / 56, and other ingredients remain unchanged. The proportion of raw materials is shown in Table 1. The preparation process refers to Example 1.

[0073] Table 1 Raw material ratios of Examples 1 to 2 and Comparative Examples 1 to 9 (%)

[0074]

[0075]

[0076] Compound light stabilizer: light stabilizer 622: light stabilizer 228 = 1:2;

[0077] Compound antioxidant: antioxidant 168: antioxidant 1010: antioxidant DSTDP = 2:1:2.5.

[0078] Test example

[0079] The materials of Examples 1 to 2 and Comparative Examples 1 to 9 were injection molded using a horizontal injection molding machine to obtain standard samples. Molding process conditions: injection temperature (feeding port) 185 / 190 / 190 / 195°C (nozzle); injection pressure 55MPa; holding time 8s; cooling time 8s, and drying at 105°C for 2h before injection molding. Performance tests were carried out respectively, and the performance test standards are as follows. The results are shown in Table 2:

[0080] Melt index: tested according to ASTM D1238-2010 standard, 230℃, 2.16Kg, unit: g / 10min;

[0081] Tensile strength: tested according to ASTM D638-2010 standard, 3.0mm thick specimen, unit: MPa;

[0082] Bending performance: According to ASTM D790-2017 standard, thickness 3.0mm specimen, unit: MPa;

[0083] Izod notched impact performance: tested according to ASTM D256-2010 standard, 3.0mm thick specimen, unit: J / m;

[0084] Observe the extrusion and pelletizing conditions: visually;

[0085] High temperature aging test: The tensile specimens, bending specimens and cantilever beam notched impact specimens were placed in a 150°C oven for aging for 1000 hours to test various properties;

[0086] UV aging test: Place the tensile specimens, bending specimens and cantilever beam notched impact specimens in a UV box for 1500 hours to test various properties. Light source: UVA-340, light intensity: 0.76W, cycle conditions: 8h illumination (BPT: 60℃), 4h condensation (BPT: 50℃) (GB / T16422.3);

[0087] Drop test: Drop the molded building formwork (600mm*900mm) vertically from a height of 3m until it cracks, and count the number of drops;

[0088] Observe the injection molding condition: visually.

[0089] Table 2 Performance test results

[0090]

[0091]

[0092] As can be seen from Table 2, the aging-resistant glass fiber reinforced polypropylene composite materials of Examples 1 to 2 of the present invention have excellent mechanical properties. After aging at 150°C and after UV irradiation aging, the retention rates of various properties are all above 70%, the number of vertical drops also reaches more than 7 times without cracking, the extraction of particles is smooth, there is no cilia, the injection molding effect is good, and there is no warping; however, the glass fiber reinforced polypropylene composite material of Comparative Example 1 has a decreased melt index and poor processing performance due to the replacement of the PP substrate, resulting in difficulty in injection molding and easy lack of glue; the glass fiber reinforced polypropylene composite materials of Comparative Examples 2 to 3 have increased tensile strength and flexural modulus due to the replacement of the compatibilizer or the removal of the black recycled particles of EPDM rubber, but the impact strength is significantly reduced, resulting in a decrease in the number of vertical drops, and due to the strong rigidity, there is a slight deformation during injection molding; the glass fiber reinforced polypropylene composite material of Comparative Example 4 has a changed light stabilizer model, resulting in a tensile strength and impact strength of less than 70% after UV aging, lacking the neutral hindered amine ultraviolet light stabilizer 228, and after UV irradiation, polypropylene produces Degradation, presenting an acidic environment, if only the alkaline light stabilizer 622 is used, a good light aging resistance effect cannot be achieved, so the retention rate decreases; the glass fiber reinforced polypropylene composite materials of comparative examples 5 to 6 are not added with hydrotalcite or replaced with antioxidants. During the thermal oxidative aging process, the lack of hydrotalcite or antioxidant DSTDP leads to poor high temperature aging stability and poor heat aging resistance, so the retention rate is significantly lower than that of Example 2; the glass fiber reinforced polypropylene composite material of comparative example 7 is changed to pure short-cut glass fiber, and various mechanical properties are significantly improved, but because the independently designed screw combination has little damage to the glass fiber, it causes slight warping after injection molding; the glass fiber reinforced polypropylene composite material of comparative example 8 is changed to 35 parts of pure continuous glass fiber, resulting in the glass fiber not being fully shredded, resulting in uneven particle extraction, easy breaking, and cilia, and the mechanical properties are significantly lower than those of Example 2; the glass fiber reinforced polypropylene composite material of comparative example 9 changes the screw combination to strengthen the shear strength of the combination, resulting in significantly lower mechanical properties than Example 1, and a reduction in the number of vertical drops.

[0093] It can be seen that compared with the comparative example, the aging-resistant glass fiber reinforced polypropylene composite material of the technical solution of the present invention adds a compatibilizer and EPDM rubber recycled particles in a suitable proportion, and is used together with a compound lubricant, a light stabilizer, a compound antioxidant and two different types of glass fibers. The components work synergistically, so that the aging-resistant glass fiber reinforced polypropylene composite material of the present invention has excellent mechanical strength, good impact resistance, is not easy to be damaged by falling, and has good light and heat aging resistance.

[0094] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. An aging-resistant polypropylene composite material, characterized in that: The invention comprises the following raw materials in parts by weight: 35-65 parts of polypropylene resin; 2~20 parts of EPDM recycled materials; Glass fiber 20~40 parts; Light stabilizer 0.1~1 part; Antioxidant 0.1~1 part; Compatibilizer 2~8 parts; 0.1~1 part of hydrotalcite; Lubricant 0.1~1 part; The glass fibers include chopped glass fibers and continuous glass fibers; The mass ratio of the chopped glass fibers to the continuous glass fibers is 1:1-5; The melt index of the polypropylene resin at 230°C and 2.16Kg is greater than 70 g / 10min; The antioxidant is a compound antioxidant, including antioxidant 168, antioxidant 1010 and antioxidant DSTDP; The compatibilizer includes ethylene butene copolymer grafted with maleic anhydride; The light stabilizer is a compound light stabilizer, including light stabilizer 622 and light stabilizer 228; The preparation method of the aging-resistant polypropylene composite material comprises the following steps: The raw materials of the aging-resistant polypropylene are mixed and melt-extruded to obtain the aging-resistant polypropylene composite material; The melt extrusion is carried out by an extruder; the screw design parameters of the screw combination of the extruder from the exhaust port to the head end of the discharge film are 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, 90° / 5 / 56, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 45° / 5 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, transition block 12 / 12, tooth group 57 / 57, transition block 12 / 12, 72 / 72, 56 / 56, 56 / 56, 56 / 28L, 96 / 96, 96 / 96, 96 / 96, 72 / 72, 72 / 72, 56 / 56, 56 / 56, 56 / 56, 56 / 56, 56 / 56; 96 / 96 means that this is a threaded block with a lead of 96mm and a length of 96mm; 45° / 5 / 56 means that 45° represents the angle of the kneading block, 5 is the number of pieces, and 56 is the length; the transition block 12 / 12 is the linking block between the toothed disk and the threaded block or shear block, and its length is 12mm; the tooth group 57 / 57 means that the length of the toothed threaded element is 57mm; 56 / 28L means that 56 refers to the lead of the conveying block, 28 represents the length of this conveying block, and L represents the direction; the other parameters only change in length, and the meanings they represent are similar.

2. The aging-resistant polypropylene composite material according to claim 1, characterized in that: The mass content of the third monomer ethylidene norbornene in the EPDM rubber recycled material is ≥2%.

3. The method for preparing the aging-resistant polypropylene composite material according to any one of claims 1 to 2, characterized in that: The method comprises the following steps: mixing the raw materials of the aging-resistant polypropylene and melt-extruding to obtain the aging-resistant polypropylene composite material.

4. Use of the aging-resistant polypropylene composite material according to any one of claims 1 to 2 in the preparation of building formwork materials.

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