Polypropylene material, method for preparing the same and use thereof

Abstract

This invention belongs to the field of polymer material modification technology, specifically relating to a polypropylene material, its preparation method, and its application. The polypropylene material comprises the following components by weight: 55-70 parts polypropylene resin, 3-10 parts high-density polyethylene, 25-35 parts glass fiber, 1-8 parts compatibilizer, 0.4-2 parts coupling agent, and 0.1-1 parts antioxidant; the coupling agent is a silane coupling agent and a titanate coupling agent; the mass ratio of the silane coupling agent to the titanate coupling agent is (0.2-1):(0.2-1). The polypropylene material obtained by this invention has advantages such as good chemical corrosion resistance, high infrared welding strength, good temperature resistance, and high dimensional stability, and can better meet the performance requirements of integrated water bottle materials for new energy vehicles.

Description

Technical Field

[0001] This invention belongs to the field of polymer material modification technology, specifically relating to a polypropylene material, its preparation method, and its application. Background Technology

[0002] With the rapid development of the automotive industry, the main research directions in automobiles are lightweighting, energy conservation and emission reduction, and improved safety performance. Plastics are playing an increasingly larger role in automobiles, and the trend towards plasticization in automobile manufacturing has become a major development trend. The automotive market demand has shifted towards lighter sports cars, multi-purpose vehicles, and other light vehicles. Automotive components are also moving towards integrated design, especially regarding engine thermal efficiency. In traditional automobiles, much of the heat is wasted instead of used for power. However, the heating and cooling systems of new energy vehicles are highly integrated, efficiently utilizing the waste heat from the motor and significantly improving battery energy efficiency and range. As a core component of thermal management in new energy vehicles, the water manifold allows the ethylene glycol coolant to flow freely between different systems. Therefore, the water chamber material must be resistant to chemical corrosion and have high temperature resistance, while also requiring a high balance between rigidity and toughness to prevent cracking during assembly and use. Polypropylene has excellent solvent extraction resistance, is widely available, and low in cost. Glass fiber reinforced polypropylene also provides high strength and impact resistance, making it the preferred material for lightweight, high-quality, and intelligent development of new energy water manifolds.

[0003] Currently, the manufacturing process for automotive water system manifolds mainly involves injection molding upper and lower main substrates of glass fiber reinforced polypropylene, followed by welding the substrates together using hot plate welding or infrared welding to form a complete and sealed component. Because the substrates are filled with water channels and have a complex structure, extremely high flatness is required for the parts. Otherwise, weak welds, incomplete welds, or cross-welding can easily occur during the welding process. Conventional glass fiber reinforced polypropylene materials are also prone to stringing or weld slag. Even if assembly is successful, during subsequent use, the alternating high and low temperatures and vibrations can cause weld slag to fall into the coolant, affecting the normal operation of the parts and even leading to safety malfunctions.

[0004] Therefore, a glycol-resistant weldable glass fiber reinforced polypropylene composite was prepared, which has an excellent balance of rigidity and toughness and high infrared welding strength, and has excellent prospects for industrial application. Summary of the Invention

[0005] This invention aims to provide a polypropylene material, its preparation method, and its applications. The polypropylene material obtained by this invention has advantages such as good chemical corrosion resistance, high infrared welding strength, good temperature resistance, and high dimensional stability, which can better meet the performance requirements of integrated water bottle materials for new energy vehicles.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a polypropylene material comprising the following components in parts by weight: 55-70 parts of polypropylene resin, 3-10 parts of high-density polyethylene, 25-35 parts of glass fiber, 1-8 parts of compatibilizer, 0.4-2 parts of coupling agent, and 0.1-1 parts of antioxidant; wherein the coupling agent is a silane coupling agent and a titanate coupling agent; and the mass ratio of the silane coupling agent to the titanate coupling agent is (0.2-1):(0.2-1).

[0007] The silane coupling agent's silane oxygen groups are reactive to glass fibers, while its organic functional groups are compatible with organic polypropylene resins, thus improving the adhesion between glass fibers and polypropylene resins and significantly enhancing the strength, toughness, and solvent resistance of glass fiber reinforced composites. Glass fiber reinforced polypropylene composites pretreated with coupling agents exhibit significantly improved mechanical properties. The main function of titanate coupling agents is to induce transesterification and crosslinking during the welding process. During infrared welding, catalysis by infrared light irradiation, especially in the 600–800 nm wavelength range, causes crosslinking of the welding interface layer material, resulting in tighter molecular bonding and higher weld strength, reaching up to 42 MPa, nearly twice that of conventional materials.

[0008] Preferably, the polypropylene material comprises the following components in parts by weight: 62-64 parts polypropylene resin, 5-8 parts high-density polyethylene, 28-30 parts glass fiber, 3-5 parts compatibilizer, 1-1.5 parts coupling agent, and 0.5-0.6 parts antioxidant.

[0009] Preferably, the polypropylene resin is a mixture of homopolymer polypropylene and copolymer polypropylene.

[0010] Preferably, the mass ratio of homopolymer polypropylene to copolymer polypropylene is (1-6):1.

[0011] More preferably, the mass ratio of the homopolymer polypropylene to the copolymer polypropylene is (3-5):1.

[0012] Preferably, the homopolymer polypropylene has a melt flow rate of 3 to 25 g / 10 min at 230°C and a load of 2.16 kg.

[0013] More preferably, the homopolymer polypropylene has a melt flow rate of 10-16 g / 10 min at 230°C and 2.16 kg load.

[0014] Preferably, the melt mass flow rate of the copolymer polypropylene at 230°C and 2.16 kg load is 3–15 g / 10 min;

[0015] More preferably, the melt flow rate of the copolymerized polypropylene at 230°C and 2.16 kg load is 5–11 g / 10 min.

[0016] Preferably, the melt flow rate of the high-density polyethylene at 230°C and 2.16 kg load is 6–16 g / 10 min.

[0017] More preferably, the melt mass flow rate of the high-density polyethylene at 230°C and 2.16 kg load is 5–11 g / 10 min.

[0018] Preferably, the silane coupling agent includes at least one of γ-aminopropyltriethoxysilane coupling agent, methyltrichlorosilane coupling agent, and vinylsilane coupling agent.

[0019] Preferably, the titanate coupling agent includes at least one of monoalkoxy titanate, monoalkoxy pyrophosphate titanate, and integrated titanate.

[0020] Preferably, the diameter of the glass fiber monofilament is 10-15 μm.

[0021] Preferably, the compatibilizer is a maleic anhydride graft.

[0022] More preferably, the compatibilizer includes at least one of maleic anhydride-grafted PE (PE-g-MAH), maleic anhydride-grafted PP (PP-g-MAH), and maleic anhydride-grafted POE (POE-G-MAH).

[0023] Preferably, the antioxidant is a mixture of hindered phenolic and phosphite antioxidants.

[0024] This invention also claims protection for a method for preparing the polypropylene material, comprising the following steps:

[0025] All components except glass fiber are mixed, and then glass fiber is added for melt extrusion granulation to obtain the polypropylene material.

[0026] Preferably, the mixing conditions are to mix under a nitrogen protective atmosphere for 3 to 5 minutes.

[0027] Preferably, the temperature of the melt extrusion granulation is 100-200℃, the rotation speed is 350-500 rpm, and the vacuum degree is -0.04MPa to -0.08MPa.

[0028] The preparation method of the present invention allows various raw materials to react fully, thereby achieving excellent plasticizing and mixing effects, and maximizing the tensile strength and ethylene glycol resistance of the final polypropylene material.

[0029] This invention also claims protection for the application of the aforementioned polypropylene material in the preparation of chemically resistant materials. These chemically resistant materials include materials for integrated water bottles in new energy vehicles, etc.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) In this invention, by selecting silane coupling agent and titanate coupling agent to interact with polypropylene resin and high-density polyethylene, the material mechanical properties and infrared welding process comprehensive performance are optimized, the welding tensile strength, chemical corrosion resistance and other properties are significantly improved, and the welding wire drawing and surface smoothness are effectively improved, so that the material is suitable for the working environment with high cleanliness requirements of new energy water manifold.

[0032] (2) The polypropylene material obtained by this invention has the characteristics of high tensile strength, high impact resistance, high welding tensile strength, and resistance to ethylene glycol. It is a type of automotive component that is very suitable for the requirements of low temperature water chamber water manifold of new energy vehicles, and it is also environmentally friendly and recyclable. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] Unless otherwise specified, the experimental methods used in the following examples and comparative examples are conventional methods. Unless otherwise specified, the antioxidants are commercially available, and the same antioxidants are used in parallel experiments.

[0035] The raw materials used in the examples and comparative examples are shown in Table 1.

[0036] Table 1

[0037]

[0038]

[0039]

[0040] Examples 1-19 and Comparative Examples 1-8

[0041] The components and weight parts of the polypropylene materials of Examples 1-19 and Comparative Examples 1-8 are shown in Tables 2-4.

[0042] The preparation methods of the polypropylene materials in Examples 1-19 and Comparative Examples 1-8 include the following steps:

[0043] Polypropylene resin, high-density polyethylene, compatibilizer, coupling agent, and antioxidant are weighed according to their mass proportions and added to a nitrogen-protected high-speed mixer, which is then mixed for 3-5 minutes. The mixture is then added to a twin-screw extruder with a length-to-diameter ratio of 40:1 for melt mixing and dispersion. Glass fiber is added to the heating section of the twin-screw extruder, followed by plasticizing and granulation through the twin-screw extruder. Finally, the extruded pellets are prepared using an injection molding machine to produce standard samples. The processing temperatures of the twin-screw extruder (from the feed port to the die) are: 100℃, 180℃, 180℃, 200℃, 200℃, 200℃, 200℃, 200℃, 200℃, 200℃, 200℃. The main extruder speed is 500 rpm, and the vacuum degree is -0.04 MPa to -0.08 MPa.

[0044] Table 2 shows the component amounts (parts by weight) in the examples.

[0045]

[0046]

[0047] Table 3 shows the component dosages (parts by weight) in the examples.

[0048]

[0049] Table 4. Component dosage (parts by weight) in the comparative examples

[0050]

[0051]

[0052] Performance testing

[0053] The polypropylene materials prepared in the examples and comparative examples were subjected to the following performance tests:

[0054] Tensile strength: Tested according to ISO 527-2-2012, 1A specimen, 10 mm / min;

[0055] Notched impact strength of cantilever beam: according to ISO 180-2000, 4mm, 23℃;

[0056] Welding tensile strength: Tested according to ISO 527-2-2012, with a sample size of 100*40*4mm and a speed of 10mm / min;

[0057] Ethylene glycol tensile strength retention rate: After immersing the polypropylene materials of each group in 100% ethylene glycol at 135°C for 500 hours, the tensile strength test described above was performed, and the tensile strength retention rate was calculated.

[0058] The performance test results are shown in Table 5.

[0059] Table 5. Test results of polypropylene composites in the examples and comparative examples.

[0060]

[0061]

[0062] As can be seen from the data in Table 4, the polypropylene material prepared in the embodiments of the present invention has good chemical corrosion resistance and infrared welding strength. Furthermore, due to the addition of 30% glass fiber reinforcement in the formula, the material exhibits good temperature resistance and high dimensional stability, better meeting the performance requirements of integrated water bottle materials for new energy vehicles. Specifically, the tensile strength can be maintained above 82 MPa, achieving a range of 82-98 MPa, and the cantilever beam notched impact strength can reach 10 J / m. 2 Above, maintain at 10-18 KJ / m 2 The welding tensile strength can be achieved above 33 MPa and maintained within the range of 33-53 MPa, and the ethylene glycol tensile strength retention rate can be achieved above 83% and maintained within the range of 83-105%.

[0063] In Comparative Example 1, no polyethylene resin was added; in Comparative Example 2, no compatibilizer was added. The polypropylene materials obtained exhibited lower cantilever beam notched impact strength, weld tensile strength, and ethylene glycol tensile strength retention rates compared to the examples. In Comparative Example 3, only a single silane coupling agent was added; in Comparative Example 4, only a single titanate coupling agent was added. The cantilever beam notched impact strength, weld tensile strength, and ethylene glycol tensile strength retention rates of the polypropylene materials were significantly worse. Comparative Example 5 used a mixture of silane and aluminate coupling agents as the coupling agent component; Comparative Example 6 used a mixture of titanate and aluminate coupling agents as the coupling agent component; and the mass ratio of silane and titanate coupling agents used in Comparative Examples 7-8 was inappropriate, resulting in decreased tensile strength, cantilever beam notched impact strength, weld tensile strength, and ethylene glycol resistance of the polypropylene materials. Therefore, it can be concluded that simultaneously adding specific mass ratios of silane and titanate coupling agents to the formulation system is beneficial to improving the mechanical and chemical corrosion resistance properties of polypropylene materials.

[0064] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A polypropylene material, characterized in that, It includes the following components in parts by weight: 57-70 parts polypropylene resin, 3-10 parts high-density polyethylene, 25-35 parts glass fiber, 1-8 parts compatibilizer, 0.4-2 parts coupling agent, and 0.1-1 parts antioxidant; The coupling agent is a silane coupling agent and a titanate coupling agent; the mass ratio of the silane coupling agent to the titanate coupling agent is (0.2~1):(0.2~1).

2. The polypropylene material as described in claim 1, characterized in that, It includes the following components by weight: 62-64 parts polypropylene resin, 5-8 parts high-density polyethylene, 28-30 parts glass fiber, 3-5 parts compatibilizer, 1-1.5 parts coupling agent, and 0.5-0.6 parts antioxidant.

3. The polypropylene material as described in claim 1, characterized in that, The polypropylene resin is a mixture of homopolymer polypropylene and copolymer polypropylene.

4. The polypropylene material as described in claim 3, characterized in that, It must include at least one of the following (1) to (4): (1) The mass ratio of homopolymer polypropylene to copolymer polypropylene is (1~6):1; (2) The melt flow rate of the homopolymer polypropylene at 230°C and 2.16 kg load is 3~25 g / 10 min; (3) The melt flow rate of the copolymer polypropylene at 230°C and 2.16 kg load is 3~15 g / 10 min; (4) The melt flow rate of the high-density polyethylene at 230°C and 2.16 kg load is 6~16 g / 10 min.

5. The polypropylene material as described in claim 1, characterized in that, It must include at least one of the following (1) to (2): (1) The silane coupling agent includes at least one of γ-aminopropyltriethoxysilane, methyltrichlorosilane coupling agent, and vinylsilane coupling agent; (2) The titanate coupling agent includes at least one of monoalkoxy titanate and monoalkoxy pyrophosphate titanate.

6. The polypropylene material as described in claim 1, characterized in that, It must include at least one of the following (1) to (3): (1) The diameter of the single filament of the glass fiber is 10~15µm; (2) The compatibilizer is a maleic anhydride graft; (3) The antioxidant is a mixture of hindered phenolic and phosphite antioxidants.

7. A method for preparing the polypropylene material according to any one of claims 1 to 6, characterized in that, Includes the following steps: All components except glass fiber are mixed, and then glass fiber is added for melt extrusion granulation to obtain the polypropylene material.

8. The preparation method according to claim 7, characterized in that, The melt extrusion granulation temperature is 100-200℃, the rotation speed is 350-500 rpm, and the vacuum degree is -0.04MPa to -0.08MPa.

9. The use of the polypropylene material as described in any one of claims 1 to 6 in the preparation of chemically resistant materials.

Images