Oil-resistant solvent-resistant high-performance modified polypropylene material and preparation method thereof

Abstract

The invention discloses an oil-resistant and solvent-resistant high-performance modified polypropylene material and a preparation method thereof, and belongs to the technical field of high polymer material modification. The material is prepared from the following raw materials in parts by weight: 50 to 80 percent of polypropylene resin, 5 to 15 percent of modified nano silicon dioxide, 3 to 8 percent of fluororubber powder, 4 to 10 percent of maleic anhydride grafted polypropylene, 0.1 to 0.5 percent of antioxidant, 0.2 to 0.5 percent of light stabilizer and 0.5 to 2 percent of lubricant. The modified polypropylene material prepared by the invention not only keeps the original mechanical properties of polypropylene, but also has excellent oil resistance and solvent resistance, can effectively resist the erosion of various oils and chemical solvents such as gasoline, diesel oil, ethanol, acetone and the like, can still keep good performance stability after aging, has good processability, and can be widely applied to the field of high-performance engineering machinery. The oil-resistant solvent-resistant plastic can be widely applied to the fields with high requirements on oil resistance and solvent resistance, such as automobile parts and the like.

Description

Technical Field

[0001] This invention relates to the field of polymer material modification technology, specifically to a high-performance modified polypropylene material that is resistant to oil and solvents, its preparation method, and its applications. Background Technology

[0002] Polypropylene (PP) is a general-purpose plastic with advantages such as low density, excellent mechanical properties, good processing flowability, and low cost, and is widely used in many fields such as automobiles, chemicals, packaging, and electronics. However, pure polypropylene has poor oil and solvent resistance. Low molecular weight aliphatic hydrocarbons, gasoline, xylene, etc., can soften and swell it. When in contact with oils, organic solvents, and other media, it is prone to swelling and cracking, leading to a decline in mechanical properties. At the same time, it is susceptible to aging due to environmental factors during long-term use, which further accelerates performance degradation. This limits its application in scenarios with high requirements for oil and solvent resistance and durability, such as automotive fuel system components, chemical pipelines, and solvent packaging.

[0003] To improve the oil and solvent resistance of polypropylene, existing technologies often employ methods such as filler modification and blending modification. For example, adding inorganic fillers such as talc and calcium carbonate can increase the rigidity of polypropylene, but its effect on improving oil and solvent resistance is limited, and excessive filling can lead to a decrease in toughness and processing fluidity. Blending with rubbers such as nitrile rubber and EPDM rubber can improve the toughness of polypropylene, but often leads to a decrease in the rigidity of the material, and the oil and solvent resistance still cannot meet the requirements of high-end applications, while the performance stability after aging is insufficient. Therefore, developing a modified polypropylene material that retains the original excellent properties of polypropylene while possessing highly efficient oil and solvent resistance and good aging stability is of significant practical importance. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-performance modified polypropylene material that is resistant to oil and solvents. This material, through reasonable raw material ratio and preparation process, significantly improves the oil and solvent resistance and aging stability of polypropylene while maintaining its good mechanical properties and processing fluidity.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A high-performance modified polypropylene material with oil and solvent resistance is composed of the following raw materials in parts by weight: polypropylene resin: 50-80%, modified nano silica: 5-15%, fluororubber powder: 3-8%, maleic anhydride grafted polypropylene: 4-10%, antioxidant: 0.1-0.5%, light stabilizer: 0.2-0.5%, and lubricant: 0.5-2%.

[0007] In this invention, polypropylene resin is used as the base material to provide the basic mechanical and processing properties of the material. Homopolymer polypropylene is selected, with a melt index of 25-30 g / 10 min (230℃, 2.16 kg), which ensures both processing fluidity and good rigidity and strength.

[0008] The modified nano-silica is nano-silica modified with silane coupling agent KH-550, wherein the amount of silane coupling agent added is 3-8% of the mass of nano-silica. As a reinforcing filler, the modified nano-silica, after modification with silane coupling agent KH-550, forms organic functional groups on its surface, which can chemically react with polypropylene resin and compatibilizers, improving its dispersibility in the substrate. Its high specific surface area and rigidity enhance the mechanical properties of the material, and its inorganic phase structure can block the penetration of oil and solvent molecules. Simultaneously, it forms a synergistic effect with fluororubber powder, further improving oil and solvent resistance and structural stability by improving dispersibility and enhancing interfacial interactions.

[0009] The fluororubber powder has a particle size of 50-100 μm and a Shore hardness of 40-60 A. Fluororubber powder exhibits excellent oil and solvent resistance. When blended with polypropylene, it forms a continuous media-resistant network within the material, enhancing its resistance to oils and solvents. Its elasticity improves the material's toughness, preventing it from becoming brittle due to excessive rigidity. Furthermore, when synergistically combined with modified nano-silica, it can enhance the material's tear resistance and low-temperature stability through a "micro-reinforcement" effect.

[0010] The compatibilizer is maleic anhydride-grafted polypropylene with a grafting rate of 0.8-1.5%, preferably 3%. It can effectively improve the compatibility between polypropylene resin and modified nano-silica and fluororubber powder, reduce interfacial tension, make the components uniformly dispersed, and improve the overall performance stability of the material.

[0011] The antioxidant is a compound of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1 to 2:1. They can work synergistically to prevent the material from aging due to oxidation during processing and use, thus extending the material's service life.

[0012] The lubricant selected is a mixture of magnesium stearate, zinc stearate, and amides in a 1:1:1 ratio. This lubricant can reduce frictional resistance during material processing, improve processing fluidity, and prevent material from sticking to the mold during extrusion and injection molding.

[0013] This invention also provides a method for preparing the above-mentioned oil- and solvent-resistant high-performance modified polypropylene material, comprising the following steps:

[0014] (1) Weigh each raw material according to the weight parts, add polypropylene resin, modified nano silica, maleic anhydride grafted polypropylene, fluororubber powder, antioxidant, light stabilizer and lubricant into a high-speed mixer, mix for 10-20 minutes to obtain the mixture.

[0015] (2) Add the mixture into the twin-screw extruder. The extrusion temperatures in the screw are: Zone 1 0-100℃, Zone 2 200-220℃, Zone 3 200-220℃, Zone 4 190-210℃, Zone 5 180-200℃, and the screw speed is 350-400r / min.

[0016] (3) The material is melt-blended in a twin-screw extruder, then cooled with water after extrusion, dried, and pelletized. After that, it enters a homogenization and drying system for deodorization, and finally the modified polypropylene material is obtained.

[0017] This invention relates to a modified polypropylene material obtained by melt-blending and extruding nano-silica modified with silane coupling agent with raw materials such as polypropylene resin and fluororubber powder in a twin-screw extruder, followed by granulation. The modified polypropylene material prepared by this invention not only retains the original mechanical properties of polypropylene but also possesses excellent oil and solvent resistance, effectively resisting the erosion of various oils and chemical solvents such as gasoline, diesel, ethanol, and acetone. Furthermore, it maintains good performance stability even after aging and exhibits good processability, making it widely applicable in fields such as automotive parts where high oil and solvent resistance is required. Detailed Implementation

[0018] The technical features of the present invention will be further illustrated below with reference to specific embodiments.

[0019] Performance testing

[0020] Test standards and conditions

[0021] 1. Mechanical property testing: Tensile strength and elongation at break were tested according to GB / T 1040.1-2006 "Determination of tensile properties of plastics - Part 1: General rules", with a tensile rate of 50 mm / min; impact strength was tested according to GB / T 1843-2008 "Determination of impact strength of plastic cantilever beam", with notch type A and a test temperature of 23℃.

[0022] 2. Oil and solvent resistance test: According to GB / T 11547-2008 "Determination of resistance of plastics to liquid chemical reagents", the sample was cut into standard pieces of 50mm×50mm×2mm and immersed in 92# gasoline, 0# diesel, 95% ethanol and analytical grade acetone respectively. The immersion temperature was 23℃ and the immersion time was 72h. The volume change rate and mass change rate before and after immersion were tested.

[0023] 3. Processing performance test: According to GB / T 3682-2000 "Determination of melt mass flow rate and melt volume flow rate of thermoplastics", the test conditions are 230℃ and 2.16kg.

[0024] 4. Thermal performance test: According to GB / T 1633-2000 "Determination of Vicat softening temperature (VST) of thermoplastics", the test load is 10N and the heating rate is 50℃ / h.

[0025] 5. Aging performance test: According to GB / T 3512-2014 "Accelerated aging and heat resistance test of vulcanized rubber or thermoplastic rubber in hot air", the mechanical properties retention rate before and after aging was tested after aging for 1000h in hot air at 120℃; at the same time, the volume change rate of the aged sample after immersion in 92# gasoline for 72h was tested.

[0026] Test Results

[0027] 1. Performance comparison of different formulation ratios

[0028] Three groups of materials of this invention with different formulations (numbered A1-A3) were selected and their performance was compared with that of pure polypropylene (B1) and conventional talc-filled modified polypropylene (B2, talc filling amount 15 parts). The test results are shown in the table below:

[0029] Table 3. Material formulations (wt%) for Examples 1-5

[0030]

[0031]

[0032] Table 4. Performance test results of comparative examples 1-5

[0033]

[0034] As shown in the table above, the performance of the materials of this invention with different formulation ratios is superior to that of pure PP and conventional talc-modified PP: with the increase of modified nano silica and fluororubber powder, the tensile strength and impact strength of the materials gradually improve, and the oil and solvent resistance is continuously optimized; among them, the A3 formulation has the best comprehensive performance, maintaining good processing fluidity (MFR=18.2g / 10min) and possessing excellent mechanical properties and oil and solvent resistance.

[0035] 2. Performance retention rate test after aging

[0036] The A3 formulation material, which exhibited the best overall performance, was selected for aging performance testing and compared with B1 (pure PP) and B2 (talc-modified). The results are shown in the table below:

[0037] Table 5. Performance test results of Examples A3, B1, and B2 after thermal aging.

[0038]

[0039]

[0040] The test results show that after aging in hot air at 120℃ for 1000h, the tensile strength retention rate of the material of this invention reaches 98.2%, the notched impact strength retention rate reaches 86.0%, and the volume change rate after immersion in 92# gasoline is only 1.2%, and the volume change rate after immersion in acetone for 72h is only 0.9%, which is far superior to pure PP and conventional talc-modified PP, showing excellent aging stability and oil resistance.

[0041] This invention also protects the application of the above-mentioned high-performance modified polypropylene material with oil and solvent resistance, which can be used to prepare automotive fuel system components such as fuel lines, fuel tank liners, exposed interior parts, chemical conveying pipelines, and solvent packaging containers, as well as other products with high requirements for oil and solvent resistance.

[0042] 1. This invention constructs a dual protective structure of "inorganic barrier - organic media resistance" through the synergistic effect of modified nano-silica and fluororubber powder. The volume change rate of the material after immersion in strong corrosive media such as 92# gasoline and acetone for 72 hours is ≤1.8%, and it is still ≤1.6% after aging, which is significantly better than pure PP. The oil and solvent resistance and durability are greatly improved, which broadens the application range of polypropylene materials.

[0043] 2. Using maleic anhydride-grafted polypropylene as a compatibilizer solves the compatibility problem between inorganic fillers and organic substrates and rubber phases. The mechanical properties of materials with different formulation ratios are comprehensively superior to those of pure PP and conventional modified PP, while maintaining good processing fluidity (MFR = 18-23 g / 10 min), which is convenient for industrial production adjustments.

[0044] 3. After being aged in hot air at 120℃ for 1000 hours, the material retains more than 85% of its mechanical properties, demonstrating excellent anti-aging ability and meeting the requirements for long-term use in harsh environments.

[0045] 4. The preparation process is simple, the raw materials are readily available, the cost is low, and all test data are tested in accordance with national standards, so the results are reliable and suitable for large-scale promotion and application.

Claims

1. A high-performance modified polypropylene material resistant to oil and solvents, characterized in that, It is composed of the following raw materials in parts by weight: polypropylene resin: 50-80%, modified nano silica: 5-15%, fluororubber powder: 3-8%, maleic anhydride grafted polypropylene: 4-10%, antioxidant: 0.1-0.5%, light stabilizer: 0.2-0.5%, lubricant: 0.5-2%.

2. The high-performance modified polypropylene material with oil and solvent resistance according to claim 1, characterized in that: The polypropylene resin is homopolymer polypropylene with a melt index of 25-30 g / 10 min. The test conditions are 230℃ and 2.16 kg.

3. The high-performance modified polypropylene material with oil and solvent resistance according to claim 1, characterized in that: The modified nano-silica is nano-silica modified with silane coupling agent KH-550, wherein the amount of silane coupling agent added is 3-8% of the mass of nano-silica.

4. The high-performance modified polypropylene material with oil and solvent resistance according to claim 1, characterized in that: The fluororubber powder has a particle size of 50-100μm and a Shore hardness of 40-60A.

5. The high-performance modified polypropylene material with oil and solvent resistance according to claim 1, characterized in that: The compatibilizer is maleic anhydride-grafted polypropylene with a grafting rate of 0.8-1.5%.

6. The high-performance modified polypropylene material with oil and solvent resistance according to claim 5, characterized in that: The grafting rate is 3%.

7. The high-performance modified polypropylene material with oil and solvent resistance according to claim 1, characterized in that: The antioxidant is a compound of antioxidant 1010 and antioxidant 168, with a mass ratio of 1:1 to 2:

1.

8. The high-performance modified polypropylene material with oil and solvent resistance according to claim 1, characterized in that: The lubricant selected is a mixture of magnesium stearate, zinc stearate, and amides in a 1:1:1 ratio.

9. A method for preparing the oil- and solvent-resistant high-performance modified polypropylene material according to any one of claims 1-8, characterized in that, Includes the following steps: (1) Weigh each raw material according to the weight parts, add polypropylene resin, modified nano silica, maleic anhydride grafted polypropylene, fluororubber powder, antioxidant, light stabilizer and lubricant into a high-speed mixer, mix for 10-20 minutes to obtain the mixture. (2) Add the mixture into the twin-screw extruder. The extrusion temperatures in the screw are: Zone 1 0-100℃, Zone 2 200-220℃, Zone 3 200-220℃, Zone 4 190-210℃, Zone 5 180-200℃, and the screw speed is 350-400r / min. (3) The material is melt-blended in a twin-screw extruder, then cooled with water after extrusion, dried, and pelletized. After that, it enters a homogenization and drying system for deodorization, and finally the modified polypropylene material is obtained.

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