Low-carbon-value halogen-free flame-retardant high-transmittance polypropylene composite material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of polypropylene materials, and particularly relates to a low-carbon-value halogen-free flame-retardant high-transmittance polypropylene composite material as well as a preparation method and application thereof. The low-carbon-value halogen-free flame-retardant high-transmittance polypropylene composite material is prepared from the following components in parts by weight: 60 to 78 parts of homo-polypropylene, 10 to 15 parts of silane coupling agent modified phytic acid piperazine compound, 10 to 20 parts of low-crystallinity bio-based elastomer and 2 to 5 parts of high-molecular-weight multi-block compatilizer. The low-carbon-value halogen-free flame-retardant high-light-transmittance polypropylene composite material has excellent flame retardance and high light transmittance and good rigid-tough mechanical balance, the GWP carbon value of the composite material is obviously reduced, and the composite material conforms to the development direction of carbon reaching peak and carbon neutralization in the industry and is very suitable for application requirements of interior and exterior trimming parts of new energy vehicles in the future.

Description

Technical Field

[0001] This invention belongs to the field of polypropylene material technology. More specifically, it relates to a low-carbon, halogen-free, flame-retardant, high-transmittance polypropylene composite material, its preparation method, and its applications. Background Technology

[0002] In recent years, with the development of the automotive industry, more and more plastic materials have been used in automotive interior and exterior parts. Among them, polypropylene, due to its excellent comprehensive performance, wide availability, and high quality and low price, occupies a large proportion of automotive plastics. Now, with the widespread adoption of new energy vehicles, the flame retardant safety performance of automotive materials is receiving increasing attention. Many mainstream automakers are now requiring specific flame retardant properties in automotive interior and exterior parts and battery-related functional components, which places higher demands on the technological development of automotive materials. Previously commonly used halogenated flame retardants have high mechanical property retention and excellent flame retardant effects, but environmental regulations favor the development of halogen-free flame retardants for the automotive materials industry. While traditional halogen-free flame retardants such as nitrogen-phosphorus based and inorganic oxides have excellent flame retardant effects, their poor compatibility with the matrix resin composed of polypropylene and elastomers leads to a significant decrease in the mechanical properties of composite materials, especially a severe reduction in toughness.

[0003] In addition, with the development of new energy vehicles, the design of technological and comfortable features has received increasing attention from the industry. In particular, the large-scale promotion of light-transmitting components in recent years has placed higher demands on light-transmitting polypropylene composite materials. Traditional polypropylene composite materials have low light transmittance, especially after the addition of traditional halogen-free flame retardants, the light transmittance of composite materials has decreased significantly, which cannot meet the requirements for the use of light-transmitting automotive parts.

[0004] In recent years, the concept of low carbon and environmental protection has gained widespread popularity, and countries around the world have issued their own carbon strategies. However, the carbon values ​​of traditional halogen-free flame retardants and elastomers are currently very high, posing significant challenges to energy and the environment. These shortcomings have hindered the rapid development of halogen-free flame retardant polypropylene materials in the automotive industry. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of existing halogen-free flame-retardant polypropylene composite materials, such as poor mechanical properties, low light transmittance and high carbon value, and to provide a halogen-free flame-retardant polypropylene composite material with high light transmittance.

[0006] Another object of the present invention is to provide a method for preparing the high-transmittance polypropylene composite material.

[0007] Another object of the present invention is to provide the application of the polypropylene composite material in the preparation of automotive interior parts.

[0008] The above-mentioned objective of this invention is achieved through the following technical solution: This invention protects a polypropylene composite material, which, by weight, comprises the following components: 60-78 parts of homopolymer polypropylene, 10-15 parts of silane coupling agent modified phytic acid piperazine compound, 10-20 parts of low-crystallinity bio-based elastomer, and 2-5 parts of high molecular weight multi-block compatibilizer. The crystallinity of the low-crystallinity bio-based elastomer is 5-16%. The weight-average molecular weight (Mw) of the high molecular weight multiblock compatibilizer is 20,000 to 60,000.

[0009] In the low-carbon, halogen-free, flame-retardant, and high-transmittance polypropylene composite material of this invention, the synergistic effect of the low-crystallinity bio-based elastomer and the high-molecular-weight multi-block compatibilizer is key to achieving a polypropylene composite material that simultaneously possesses high transmittance, excellent flame retardancy, and a good balance of rigidity and toughness. Regarding transmittance and mechanical properties, the selected elastomer has low crystallinity, enabling it to form a phase structure within the homopolymer polypropylene matrix that matches the matrix's refractive index, thereby effectively reducing light loss caused by light scattering at the two-phase interface. Meanwhile, the specific high-molecular-weight multi-block compatibilizer's molecular chain structure can deeply entangle and bridge the homopolymer polypropylene matrix and the elastomer dispersion phase, significantly improving the interfacial compatibility and adhesion between the two phases. This promotes the elastomer's dispersion in the homopolymer polypropylene in a finer and more uniform form, further reducing the phase interface size and density, greatly optimizing the light transmission path, and simultaneously exhibiting a good balance of rigidity and toughness.

[0010] In terms of flame retardant performance, this synergistic effect indirectly and powerfully improves flame retardant efficiency by optimizing the condensed-state structure of the system. The fine and uniform phase morphology promoted by the multi-block compatibilizer forms a more synergistic distribution network with the silane coupling agent-modified phytic acid piperazine compounds. The uniformly dispersed elastic phase helps the flame retardant to be distributed more continuously in the matrix, thereby enabling the formation of a dense and stable char layer or protective layer more quickly and completely under the action of an ignition source, effectively isolating heat and oxygen.

[0011] Furthermore, this synergistic system directly contributes to reducing the global warming potential (GWP) of composite materials. The selection of low-crystallinity bio-based elastomers may itself be based on raw materials or processes with lower carbon emissions. More importantly, by improving the overall efficiency of mechanical properties (such as toughness) and functional properties (such as light transmission and flame retardancy), they enable materials to achieve equivalent or better performance levels while reducing reliance on traditional high-carbon additives (such as petroleum-based elastomers or excessive flame retardants).

[0012] In summary, this invention uses homopolymer polypropylene as the resin matrix and precisely matches the crystallinity of the elastomer with the molecular structure and molecular weight of the compatibilizer. Combined with a specific flame retardant silane coupling agent to modify phytic acid piperazine compounds, a highly compatible multiphase system is created. This system not only improves light transmittance through optical matching and phase refinement but also enhances the synergistic effect of the flame retardant by optimizing the phase structure, thereby simultaneously achieving high flame retardancy, high light transmittance, and good mechanical properties. In other words, this material design strategy not only reduces the carbon footprint of the composite material from the source but also effectively improves the efficiency of the material's overall performance.

[0013] Specifically, the homopolymer polypropylene resin can be 60 parts, 63 parts, 65 parts, 70 parts, 75 parts, 76 parts, 78 parts, etc., or any specific point value between the above values, or any range of these values. For the sake of simplicity, not all possible point values ​​or range values ​​are listed here.

[0014] Specifically, the silane coupling agent modified phytic acid piperazine compound can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, etc., or any specific point value between the above values, or any range of these values. For the sake of simplicity, not all possible point values ​​or range values ​​are listed here.

[0015] Specifically, the low-crystallinity bio-based elastomer can be 10 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, etc., or any specific point value between the above values, or any range of these values. For the sake of simplicity, not all possible point values ​​or range values ​​are listed here.

[0016] Specifically, the high molecular weight multiblock compatibilizer can be 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, etc., or any specific point value between the above values, or any range of these values. For the sake of simplicity, not all possible point values ​​or range values ​​are listed here.

[0017] Specifically, the crystallinity of the low-crystallinity bio-based elastomer can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, etc., or specific point values ​​between any of the above values, or any range of these values. For the sake of simplicity, not all possible point values ​​or range values ​​are listed here.

[0018] Furthermore, the method for determining the crystallinity of the low-crystallinity bio-based elastomer of the present invention is as follows: the measurement is performed using a differential scanning calorimeter (DSC). The temperature is first raised from room temperature of 23°C to 200°C, and then lowered from 200°C to -90°C at a heating / cooling rate of 20°C / min. The crystallinity can be calculated based on the crystallization enthalpy value obtained from the cooling crystallization curve, specifically referring to standard ISO11357-3-2018 (DSC method).

[0019] Preferably, the weight-average molecular weight (Mw) of the high molecular weight multi-block compatibilizer is 45,000 to 60,000. Preferably, the high molecular weight multiblock compatibilizer includes one or more of the conditions in (1) to (3): (1) The molecular weight distribution index Mw / Mn of the high molecular weight multiblock compatibilizer is 5 to 30; (2) The high molecular weight multiblock compatibilizer is a high molecular weight ethylene-propylene multiblock copolymer; (3) The high molecular weight multi-block compatibilizer has a melt flow rate of 0.3~12g / 10min under test conditions of 190℃ and 2.16kg, in accordance with ISO 1133-1-2022 standard.

[0020] Furthermore, the test methods for the above-mentioned weight-average molecular weight Mw and molecular weight distribution index Mw / Mn are in accordance with the standard ISO16014-2019.

[0021] Specifically, the melt flow rate of the high molecular weight multiblock compatibilizer, according to ISO 1133-1-2022 standard, under test conditions of 190℃ and 2.16 kg, can be 0.3 g / 10 min, 0.4 g / 10 min, 0.5 g / 10 min, 0.6 g / 10 min, 1 g / 10 min, 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, 5 g / 10 min, 6 g / 10 min, 7 g / 10 min, 8 g / 10 min, 9 g / 10 min, 10 g / 10 min, etc., or any specific point value between the above values, or any range of these values. For the sake of simplicity, not all possible point values ​​or range values ​​are listed here.

[0022] Preferably, the molecular weight distribution index (Mw / Mn) of the high molecular weight multiblock compatibilizer is 14 to 30.

[0023] Preferably, the high molecular weight multiblock compatibilizer has a melt flow rate of 2~10 g / 10 min under test conditions of 190°C and 2.16 kg, in accordance with ISO 1133-1-2022 standard.

[0024] Furthermore, the silane coupling agent-modified phytic acid piperazine compound can be obtained in any way in the art; such as commercially available or prepared by conventional methods.

[0025] Specifically, silane coupling agents can be used to treat the surface of phytic acid piperazine compounds.

[0026] More specifically, the phytate piperazine compound solution and the silane coupling agent are mixed thoroughly, reacted completely, and then post-treated to obtain the silane coupling agent modified phytate piperazine compound.

[0027] The phytate piperazine compounds used in the modification of phytate piperazine compounds by the silane coupling agent of this invention are phytate piperazine salts or derivatives of phytate piperazine salts. Phytate piperazine compounds are commercially available or can be prepared using methods known in the art.

[0028] Preferably, the phytate piperazine compound solution is prepared by the following steps: adding phytic acid solution and piperazine compound sequentially to water, and stirring to react and obtain the phytate piperazine compound solution.

[0029] Preferably, in the preparation of the phytic acid piperazine compound solution, the molar ratio of phytic acid to piperazine compound is (1~2):1.

[0030] Preferably, in the preparation process of silane coupling agent modified phytate piperazine compound, the molar ratio of phytate piperazine compound to silane coupling agent is (1~2):1.

[0031] Preferably, the silane coupling agent is at least one of vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltri(β-methoxyethoxy)silane, and more preferably vinyltrialkoxysilane.

[0032] Further, the temperature for the complete reaction is 20~80℃. As a preferred embodiment, the complete reaction is carried out by stirring at room temperature for 5~7h, stirring at 35~45℃ for 0.5~1.5h, stirring at 48~55℃ for 0.5~1.5h, stirring at 58~65℃ for 0.5~1.5h, and stirring at 68~80℃ for 3~5h.

[0033] Furthermore, the complete reaction is carried out under stirring conditions.

[0034] Furthermore, the post-processing includes solvent evaporation, washing, and drying.

[0035] In order to better balance flame retardancy and system compatibility, and to achieve a better balance of multiple performance optimizations such as flame retardancy, mechanical properties and light transmittance, in a specific embodiment, the mass of the silane coupling agent modified phytic acid piperazine compound is 10% to 16% of the total mass of the polypropylene composite material.

[0036] Preferably, the low-crystallinity bio-based elastomer is one or more of the following: bio-based ethylene-propylene copolymer, bio-based ethylene-octene copolymer, bio-based ethylene-butene copolymer, or bio-based ethylene-propylene-octene terpolymer, more preferably bio-based ethylene-octene copolymer.

[0037] Furthermore, the carbon value of the low-crystallinity bio-based elastomer is ≤-2000 kg CO2e / t.

[0038] Preferably, the carbon value of the low-crystallinity bio-based elastomer is -2500 to -2000 kg CO2e / t, more preferably -2150 to -2030 kg CO2e / t.

[0039] Furthermore, the carbon value mentioned above is the Global Warming Potential (GWP), which measures the cumulative radiative forcing of 1 kg of greenhouse gas relative to 1 kg of CO2 over a 100-year period.

[0040] The carbon values ​​mentioned above were calculated with reference to ISO 14067:2018(E) standard "Greenhouse gases - Carbon footprint of products - Requirements and guidance for quantification and communication" and PAS 2050:2011 "Specifications for assessment of greenhouse gas emissions of goods and services over their life cycle". The databases were sourced from the GaBi10 / GaBi10.6 database and the Ecoinvent3.8 database. Carbon values ​​mentioned elsewhere were calculated using the same method.

[0041] Specifically, the melt flow rate of the homopolymer polypropylene under test conditions, according to ISO 1133-1-2022 standard, can be 25 g / 10 min, 30 g / 10 min, 40 g / 10 min, 50 g / 10 min, 60 g / 10 min, 65 g / 10 min, 70 g / 10 min, 80 g / 10 min, 90 g / 10 min, 100 g / 10 min, 120 g / 10 min, 150 g / 10 min, etc., or any specific point value between the above values, or any range of these values. For the sake of simplicity, not all possible point values ​​or range values ​​are listed here.

[0042] Preferably, the homopolymer polypropylene has a melt flow rate of 25~150g / 10min under test conditions of 230℃ and 2.16kg, as per ISO 1133-1-2022 standard; more preferably, 30~120g / 10min; and even more preferably, 30~50g / 10min.

[0043] Specifically, the homopolymer polypropylene accounts for no less than 60% of the mass percentage of the polypropylene composite material.

[0044] Specifically, the homopolymer polypropylene can be 60 parts, 63 parts, 65 parts, 70 parts, 72 parts, 74 parts, 76 parts, 78 parts, etc., or any specific point value between the above values, or any range of these values. For the sake of simplicity, not all possible point values ​​or range values ​​are listed here.

[0045] Preferably, by weight, the polypropylene composite material comprises the following components: 63-76 parts of homopolymer polypropylene, 10-15 parts of silane coupling agent modified phytic acid piperazine compound, 10-20 parts of low-crystallinity bio-based elastomer, and 2-5 parts of high molecular weight multi-block compatibilizer.

[0046] Furthermore, the homopolymer polypropylene accounts for 60% or more of the total mass of the polypropylene composite material.

[0047] In a specific embodiment, based on the actual processing requirements of polypropylene materials, the polypropylene composite material of the present invention further includes 0.05 to 5 parts by weight of processing aids.

[0048] Specifically, the processing aid can be 0.01 parts, 0.05 parts, 0.08 parts, 0.1 parts, 0.2 parts, 0.5 parts, 0.8 parts, 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, etc., or specific point values ​​between any of the above values, or any range of these values. For the sake of simplicity, not all possible point values ​​or range values ​​are listed here.

[0049] Furthermore, the processing aid is preferably 0.05 to 2 parts, more preferably 0.5 to 1 part.

[0050] In specific embodiments, the processing aids of the present invention include various processing aids that can be used in the art, such as one or more of pigments, antioxidants, weathering agents, and lubricants.

[0051] In specific embodiments, the pigments of the present invention include one or more of titanium dioxide, cyanine blue, and carbon black.

[0052] The antioxidants of the present invention include one or more of amine antioxidants, hindered phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

[0053] Furthermore, the amine antioxidant is selected from one or more of 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, and N-isopropyl-N'-phenyl-p-phenylenediamine.

[0054] Furthermore, the hindered phenolic antioxidant is selected from one or more of antioxidant 1010, antioxidant 2246, and antioxidant 1076.

[0055] Furthermore, the phosphite antioxidant is selected from one or more of antioxidant 168, triphenyl phosphite, and antioxidant 626.

[0056] Furthermore, the thioester antioxidant is selected from one or more of dilauryl thiodipropionate and distearate thiodipropionate.

[0057] The weathering agent of the present invention includes one or more of ultraviolet absorbers, hindered amine light stabilizers, and ultraviolet shielding agents.

[0058] The lubricants of the present invention include one or more of amide lubricants, silicone lubricants, stearic acid or its salts, paraffin wax, and synthetic waxes.

[0059] Preferably, the amide lubricant is selected from one or more of ethylene bis-stearamide, oleamide, and stearamide.

[0060] Preferably, the silicone lubricant is selected from one or more of polydimethylsiloxane and polyether-modified silicone.

[0061] Preferably, the stearic acid or its salt lubricant is selected from one or more of calcium stearate, magnesium stearate, and zinc stearate.

[0062] The present invention also protects a method for preparing the polypropylene composite material, comprising the following steps: mixing the components in proportion, melting and kneading, granulating, cooling, and drying to obtain the polypropylene composite material.

[0063] Furthermore, the melt mixing and granulation are carried out using an extruder. In a specific embodiment, the extruder can be a twin-screw extruder or a reciprocating single-screw extruder, with a screw length-to-diameter ratio of not less than 32:1, for example, a screw length-to-diameter ratio of (32~40):1.

[0064] Preferably, the temperature of the melt mixing is 170~240℃.

[0065] The present invention also protects the use of the polypropylene composite material in the preparation of automotive interior parts.

[0066] The low-carbon, halogen-free, flame-retardant, and high-transmittance polypropylene composite material of this invention has excellent flame-retardant and light-transmitting properties, and the rigidity and toughness of the material have also been greatly improved. It can be widely used in the preparation of automotive interior and exterior trim parts, especially large interior and exterior trim parts for new energy vehicles.

[0067] Compared with the prior art, the present invention has the following beneficial effects: The low-carbon-value halogen-free flame-retardant high-transmittance polypropylene composite material of the present invention comprises, by weight, the following components: 60-78 parts of homopolymer polypropylene, 10-15 parts of silane coupling agent-modified phytic acid piperazine compound, 10-20 parts of low-crystallinity bio-based elastomer, and 2-5 parts of high molecular weight multi-block compatibilizer. The low-carbon-value halogen-free flame-retardant high-transmittance polypropylene composite material of the present invention possesses both excellent flame-retardant properties and high light transmittance, exhibits a good balance of rigidity and toughness, and shows a significantly reduced GWP carbon value, aligning with the industry's development direction of carbon peaking and carbon neutrality, making it highly suitable for the application requirements of interior and exterior components in future new energy vehicles. Detailed Implementation

[0068] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0069] The raw materials for the examples and comparative examples are as follows: Polypropylene resin (PP): Homopolymer PP-1: Homopolymer polypropylene, melt flow rate (ISO 1133-1-2022) of 150 g / 10 min at 230℃ and 2.16 kg, GWP carbon value of 2400 kg CO2e / t; PPH-Y150, SK Chemicals Co., Ltd., South Korea.

[0070] Homopolymer PP-2: Homopolymer polypropylene, melt flow rate (ISO 1133-1-2022) of 120 g / 10 min at 230℃ and 2.16 kg, GWP carbon value of 2320 kg CO2e / t; Moplen HP500V, LyondellBasell Petrochemical.

[0071] Homopolymer PP-3: Homopolymer polypropylene, melt flow rate (ISO 1133-1-2022) of 50 g / 10 min at 230℃ and 2.16 kg, GWP carbon value of 2300 kg CO2e / t; PP H9018, Lanzhou Petrochemical Company of China National Petroleum Corporation.

[0072] Homopolymer PP-4: Homopolymer polypropylene, melt flow rate (ISO 1133-1-2022) of 30 g / 10 min at 230℃ and 2.16 kg, GWP carbon value of 2260 kg CO2e / t; PP 52T30V, Braskem Petrochemical.

[0073] Homopolymer PP-5: Homopolymer polypropylene, melt flow rate (ISO 1133-1-2022) of 25 g / 10 min at 230℃ and 2.16 kg, GWP carbon value of 2240 kg CO2e / t; PP SZ30S, Wuhan Petrochemical Company of China National Petroleum Corporation.

[0074] Copolymer PP: Copolymer polypropylene, 230℃, 2.16kg melt flow rate (ISO 1133-1-2022) is 65g / 10min, GWP carbon value is 2200 kg CO2e / t; PP EP648U, CNOOC Shell Petrochemicals Co., Ltd.

[0075] Flame retardant: Silane coupling agent modified phytic acid piperazine compound-1 (VsPhypi-1), self-made, raw material carbon value GWP is 320kg CO2e / t; Silane coupling agent modified phytic acid piperazine compound-2 (VsPhypi-2), self-made, with raw material carbon value GWP of 340kg CO2e / t; Silane coupling agent modified phytic acid piperazine compound-3 (VsPhypi-3), self-made, with raw material carbon value GWP of 350kg CO2e / t.

[0076] Halogen-free flame retardant-1: piperazine pyrophosphate, FP-2200, Adico, raw material carbon value GWP is 7200kg CO2e / t; Halogen-free flame retardant-2: Bisphenol A bis(diphenyl phosphate) BDP, Shandong Xurui New Material Co., Ltd., raw material carbon value GWP is 7600 kg CO2e / t.

[0077] Elastomers: Bio-based POE-1: Melt flow rate (ISO 1133-1-2022) at 190℃ and 2.16 kg is 5 g / 10 min; crystallinity is 8%; the crystallinity test method refers to standard ISO11357-3-2018 (DSC method); GWP carbon value is -2030 kg CO2e / t; ENGAGE 8200 REN, DOW; Bio-based POE-2: Melt flow rate (ISO 1133-1-2022) at 190℃ and 2.16kg is 3g / 10min, crystallinity (ISO11357-3-2018) is 10%, GWP carbon value is -2100 kg CO2e / t; ENGAGE 8450 REN, DOW; Bio-based POE-3: Melt flow rate (ISO 1133-1-2022) at 190℃ and 2.16 kg is 0.5 g / 10 min, crystallinity (ISO11357-3-2018) is 15%, GWP carbon value is -2150 kg CO2e / t; ENGAGE 8150 REN, DOW; Bio-based POE-4: Melt flow rate (ISO 1133-1-2022) at 190℃ and 2.16 kg is 5 g / 10 min, crystallinity (ISO11357-3-2018) is 21%, GWP carbon value is -2080 kg CO2e / t; ENGAGE 8207 REN, DOW; Petroleum-based POE: at 190℃ and 2.16 kg, the melt flow rate (ISO 1133-1-2022) is 0.5 g / 10 min, the crystallinity (ISO11357-3-2018) is 16%, and the GWP carbon value is 1950 kg CO2e / t; ENAGEG POE 8180, DOW.

[0078] All of the POEs mentioned above are ethylene-octene copolymers.

[0079] Compatibilizer: EP OBCs-1: High molecular weight ethylene-propylene multiblock copolymer, Mw 48000, Mw / Mn 14, melt flow rate (MFR) 2.0 g / 10min, test standard ISO 1133-1-2022, test conditions 190℃, 2.16Kg, GWP carbon value 1900kg CO2e / t; BASELL, Hifax X 1956A; EP OBCs-2: High molecular weight ethylene-propylene multiblock copolymer, Mw = 20000, Mw / Mn = 5, melt flow rate (MFR) = 0.5 g / 10 min, test standard ISO 1133-1-2022, test conditions 190℃, 2.16 kg, GWP carbon value = 1920 kg CO2e / t; BASELL, Hifax X 1979A; EP OBCs-3: High molecular weight ethylene-propylene multiblock copolymer, Mw = 60000, Mw / Mn = 30, melt flow rate (MFR) = 10 g / 10 min, test standard ISO 1133-1-2022, test conditions 190℃, 2.16 kg, GWP carbon value = 1980 kg CO2e / t; BASELL, Hifax X 1986A; EP OBCs-4: Ethylene-propylene multiblock copolymer, Mw = 10000, Mw / Mn = 10, melt flow rate = 6 g / 10 min, test standard ISO 1133-1-2022, test conditions 190℃, 2.16 kg, GWP carbon value = 2140 kg CO2e / t; BASELL, Hifax X 1500.

[0080] Maleic anhydride-grafted polypropylene (PP-g-MAH): Mw = 20000, Mw / Mn = 6, melt flow rate (MFR) = 50 g / 10 min, test standard ISO 1133-1-2022, test conditions 190℃, 2.16 kg, GWP carbon value = 2280 kg CO2e / t; Jia Yi Rong, CMG9801.

[0081] Antioxidant 1010: Commercially available; the examples and comparative examples are the same product. Antioxidant 168: Commercially available; the examples and comparative examples are the same product. Hindered amine light stabilizer and weathering agent: LA-402AF: Adico, commercially available; the examples and comparative examples are the same product. Stearamide lubricant: STRUKTOL® TR 451: Commercially available; the examples and comparative examples are the same product.

[0082] Unless otherwise specified, all components used in the parallel embodiments and comparative examples are the same commercially available products.

[0083] Example 1: A silane coupling agent modified phytic acid piperazine compound A silane coupling agent modified phytic acid piperazine compound is prepared by the following steps: S1. Dissolve a phytic acid solution with a phytic acid content of 0.05 mol in 200 ml of distilled water, then add 0.05 mol of piperazine to the above phytic acid aqueous solution. After the piperazine is completely dissolved, stir the resulting solution for 30 min to obtain a phytic acid-piperazine solution. S2. Add 0.025 mol of silane coupling agent vinyltriethoxysilane (VTES) (soluble in 10 ml of ethanol) to the phytate piperazine solution obtained in step S1, and stir sequentially at room temperature for 6 h, 40 °C for 1 h, 50 °C for 1 h, 60 °C for 1 h, and 70 °C for 4 h. Then transfer the clear solution to a single-necked flask and rotary evaporate at 95 °C for 4 h. After removing the water, wash with ethanol and finally dry in a vacuum oven at 90 °C to constant weight to obtain the product silane coupling agent modified phytate piperazine compound-1 (VsPhypi-1), with a carbon value GWP of 320 kg CO2e / t.

[0084] Example 2: A silane coupling agent modified phytic acid piperazine compound This embodiment provides a silane coupling agent modified phytic acid piperazine compound. The preparation process is basically the same as that in Example 1, except that the molar amount of silane coupling agent added in step S2 is 0.05 mol, and the carbon value GWP of the prepared silane coupling agent modified phytic acid piperazine compound-2 (VsPhypi-2) is 340 kg CO2e / t.

[0085] Example 3: A silane coupling agent modified phytic acid piperazine compound This embodiment provides a silane coupling agent modified phytate piperazine compound, the preparation process of which is basically the same as that in Example 1, except that the silane coupling agent in step S2 is replaced with vinyltris(β-methoxyethoxy)silane, and the carbon value (GWP) of the prepared silane coupling agent modified phytate piperazine compound-3 (VsPhypi-3) is 350 kg CO2e / t.

[0086] Example 4: A low-carbon, halogen-free, flame-retardant, high-transmittance polypropylene composite material A low-carbon, halogen-free, flame-retardant, high-transmittance polypropylene composite material, the weight parts of the raw materials used are shown in Table 1.

[0087] The preparation method of the above-mentioned low-carbon value halogen-free flame-retardant high-transmittance polypropylene composite material includes the following steps: According to the weight parts in Table 1, homopolymer polypropylene, silane coupling agent modified phytic acid piperazine compound, low crystallinity bio-based elastomer, high molecular weight multi-block compatibilizer, antioxidant, weathering agent and lubricant are mixed evenly in a high-speed mixer, and then added to a twin-screw extruder with an aspect ratio of 40:1. The mixture is melt-blended at 200°C, and then granulated, cooled and dried to obtain polypropylene composite material.

[0088] Examples 5-17: A low-carbon, halogen-free, flame-retardant, high-transmittance polypropylene composite material The weight proportions of the raw materials used in Examples 5 to 17 are shown in Table 1.

[0089] The preparation steps of Examples 5 to 17 are the same as those of Example 4.

[0090] Table 1 Formulation components of Examples 4 to 17

[0091] Comparative Examples 1 to 8: A polypropylene composite material A polypropylene composite material, by weight, comprises the components shown in Table 2 below: The preparation steps of Comparative Examples 1 to 8 were the same as those of Example 4.

[0092] Table 2. Formulation components of Comparative Examples 1 to 8

[0093] Experimental Example Performance Determination The polypropylene composite materials prepared in the above embodiments and comparative examples were tested using the following test methods.

[0094] During testing, the polypropylene composite materials of each embodiment and comparative example were subjected to injection molding at an injection temperature of 200℃, an injection pressure of 45MPa, an injection speed of 45s, a holding pressure of 30MPa, and a holding time of 5s. The relevant properties were measured by injection molding ISO mechanical specimens, combustion specimens, and 100mm*100mm*2.5mm evaluation square plates.

[0095] 1. Mechanical property testing: The prepared polypropylene composition was injection molded into ISO standard flexural modulus and cantilever beam notched impact specimens, and the flexural modulus (ISO 178-2019) and cantilever beam notched impact strength (ISO 180-2019) were tested using a universal testing machine and an impact testing machine, respectively.

[0096] 2. Flame retardant performance test: The prepared polypropylene composition injection-molded sample strips with dimensions of 130 mm × 13 mm × 3.2 mm were subjected to vertical burning tests using a CZF-4 vertical burner. The test standard was in accordance with GB / T 2408-2008, and the judgment criteria are shown in Table 3. Table 3 Flame Retardant Rating

[0097] 3. Light transmittance test: The prepared material composition is injection molded into a 100mm*100mm*2.5mm sample, and the light transmittance performance is tested. Light transmittance: The test is carried out in accordance with GBT2410-2008 Test method for haze and light transmittance of transparent plastics.

[0098] 4. Carbon Value (GWP): Carbon value calculation references ISO 14067:2018(E) "Greenhouse gases - Carbon footprint of products - Requirements and guidance for quantification and communication" and PAS 2050:2011 "Specifications for assessment of greenhouse gas emissions of goods and services over their life cycle"; Unit: kg CO2e / t.

[0099] The specific test results are shown in Table 4 below: Table 4 Performance Test Results

[0100] The results from the embodiments in Table 4 above show that the flexural modulus of the polypropylene composite material of the present invention is above 1250 MPa, and the notched impact strength of the cantilever beam is ≥23 KJ / m. 2 Light transmittance ≥60%, vertical combustion performance reaches V0 level, and carbon value GWP≤2000 kg CO2e / t.

[0101] Compared to Example 6, Comparative Example 1 used copolymer PP as the matrix resin, resulting in a material transmittance of only 51% and a rigidity of only 1120 MPa. Comparative Examples 2 and 3 used common halogen-free flame retardants, leading to a significant decrease in transmittance, low impact resistance, flame retardancy of only V1, and a marked increase in carbon number. Comparative Example 4 used a non-high molecular weight (Mn < 20000) ethylene-propylene multiblock copolymer, resulting in low mechanical properties, decreased transmittance, and flame retardancy only reaching V1 level. Comparative Example 5 used maleic anhydride-grafted polypropylene copolymer, resulting in very low mechanical properties, transmittance of only 39%, and flame retardancy only reaching V2 level. Comparative Example 6 did not add a compatibilizer, resulting in low mechanical properties throughout the blend system, transmittance of only 32%, and flame retardancy only reaching V2 level. Comparative Example 7 used highly crystalline (>15%) bio-based POE, resulting in a material transmittance of only 50% and a toughness of less than 20 KJ / m. 2 In Comparative Example 8, petroleum-based POE was used. The material had a very high carbon value, low light transmittance, and flame retardant performance that could only reach the V1 level.

[0102] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A polypropylene composite, characterized in that, By weight, comprising the following components: homopolymer polypropylene 60~78 parts, silane coupling agent modified phytic acid piperazine compound 10~15 parts, low crystallinity bio-based elastomer 10~20 parts, high molecular weight multi-block type compatibilizer 2~5 parts; The low crystallinity bio-based elastomer has a crystallinity of 5%~16%; The high molecular weight multi-block type compatibilizer has a weight average molecular weight Mw of 20000~60000.

2. The polypropylene composite of claim 1, wherein, The high molecular weight multi-block type compatibilizer comprises one or more of the following conditions (1)~(3): (1) The molecular weight distribution index Mw / Mn of the high molecular weight multi-block type compatibilizer is 5~30; (2) The high molecular weight multi-block type compatibilizer is a high molecular weight ethylene-propylene multi-block copolymer; (3) The high molecular weight multi-block type compatibilizer has a melt flow rate of 0.3~12 g / 10 min under test conditions of 190℃, 2.16 kg.

3. The polypropylene composite of claim 1, wherein, The silane coupling agent modified phytic acid piperazine compound is prepared by the following steps: mixing and uniformly mixing a phytic acid piperazine compound solution and a silane coupling agent, fully reacting, and post-treatment to obtain the silane coupling agent modified phytic acid piperazine compound.

4. The polypropylene composite of claim 1, wherein, The mass of the silane coupling agent modified phytic acid piperazine compound is 10%~16% of the total mass of the polypropylene composite material.

5. The polypropylene composite of claim 1, wherein, The low crystallinity bio-based elastomer is one or more of a bio-based ethylene-propylene copolymer, a bio-based ethylene-octene copolymer, a bio-based ethylene-butene copolymer, or a bio-based ethylene-propylene-octene terpolymer.

6. The polypropylene composite of claim 1, wherein, The low crystallinity bio-based elastomer has a melt flow rate of 0.5~5 g / 10 min under test conditions of 190℃, 2.16 kg.

7. The polypropylene composite of claim 1, wherein The homopolymer polypropylene has a melt flow rate of 25~150 g / 10 min under test conditions of 230℃, 2.16 kg.

8. The polypropylene composite of claims 1-7, wherein, By weight, it also comprises 0.05~5 parts of a processing aid, which comprises one or more of pigments, antioxidants, weather-resistant agents, and lubricants.

9. A process for the production of the polypropylene composite material according to any one of claims 1 to 8, characterized in that The method comprises the following steps: uniformly mixing the components in proportion, melt mixing, granulating, cooling, and drying to obtain the polypropylene composite material.

10. Use of the polypropylene composite material of any one of claims 1~8 in the preparation of a car interior part.

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