Polypropylene composite material as well as preparation method and application thereof

Abstract

The invention discloses a polypropylene composite material as well as a preparation method and application thereof, and relates to the technical field of high polymer materials. The invention provides a polypropylene composite material. The polypropylene composite material comprises the following components in parts by weight: 70-110 parts of polypropylene resin, 1-5 parts of a POE elastomer, 3-8 parts of EMA and 0.2-0.5 part of a lubricant, wherein the Mooney viscosity of the POE elastomer is 6 to 15, and the measurement temperature of the Mooney viscosity is 121 DEG C; the acrylic ester content of the EMA is 11 to 26 percent. Through cooperation of the POE elastomer, the EMA and the lubricant, optimization of a microstructure level is realized, and the mechanical property and the welding property of the polypropylene composite material are improved.

Description

Technical Field

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

[0002] Polypropylene (PP), as a widely used thermoplastic, occupies an important position in many fields such as plastic packaging, household appliance manufacturing, and automotive parts due to its good melting point and strong load-bearing capacity.

[0003] In the production process of polypropylene products, friction welding is a common joining technology. In existing polypropylene products, the continuity of the polypropylene body is poor, and during the friction welding process, cracks and fractures are likely to occur due to stress. Moreover, with the large-scale production and consumption of polypropylene products, the amount of waste polypropylene products has increased sharply, causing great pressure on the environment. To address this challenge, the recycling of polypropylene (i.e., the recycling and reuse of waste polypropylene) has gradually received attention. The use of polypropylene recycled materials not only helps to reduce environmental pollution but also saves limited resources such as petroleum, which is in line with the concept of sustainable development. Although polypropylene recycled materials have significant advantages in environmental protection and resource conservation, in actual applications, when polypropylene recycled materials are incorporated into new materials to produce new products, problems such as performance degradation often occur. This is mainly because waste polypropylene may be affected by factors such as contamination, aging, and degradation during the recycling process, resulting in changes in its molecular structure, which in turn affects its physical and mechanical properties. For example, products incorporating polypropylene recycled materials may exhibit lower strength, toughness, heat resistance, etc., and it is difficult to meet the performance requirements of high-end products.

[0004] When polypropylene recycled materials are incorporated into polypropylene, the effect of friction welding will be further affected, resulting in insecure welding. This is mainly because the compatibility between polypropylene recycled materials and new materials is poor, and the impurities and defects that may exist in the recycled materials make the material properties in the welding area inconsistent, making it difficult to form a stable welded joint. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a polypropylene composite material with good mechanical properties and welding properties, a preparation method thereof, and an application thereof.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: a polypropylene composite material, comprising the following components in parts by weight: 70 - 110 parts of polypropylene resin, 1 - 5 parts of POE elastomer (polyolefin elastomer), 3 - 8 parts of EMA (ethylene-methyl acrylate copolymer), and 0.2 - 0.5 parts of lubricant; wherein, the Mooney viscosity of the POE elastomer is 6 - 15, and the measurement temperature of the Mooney viscosity is 121°C; the acrylate content of the EMA is 11 - 26%.

[0007] The special chemical structure of EMA, on the one hand, can act as a bridge between the polypropylene molecular chains and form good compatibility with the polypropylene molecular chains; on the other hand, the molecular chains of EMA can wrap or isolate the impurity particles in the system, and the wrapping or isolation effect helps to maintain the continuity and uniformity of the polypropylene composite material system. The POE elastomer can form an enhanced cross-linked network in the microstructure of polypropylene, effectively absorb and disperse external impact energy, and improve the mechanical properties of the material. During the friction welding process, the toughening effect of the POE elastomer helps to reduce cracks and fractures caused by stress concentration during welding, thereby enhancing the firmness of the welded joint. The addition of a lubricant helps to reduce the frictional resistance and promote the dispersion of impurities during the processing, preventing aggregation. Through the synergy of the POE elastomer, EMA, and lubricant, the present invention realizes the optimization at the microstructure level and improves the mechanical properties and welding properties of the polypropylene composite material.

[0008] Preferably, the weight percentage of the PP resin in the polypropylene composite material is not less than 80%.

[0009] Preferably, the POE elastomer is a polyolefin elastomer, including but not limited to ethylene-butene copolymer or ethylene-octene copolymer.

[0010] Preferably, the polypropylene composite material includes the following components in parts by weight: 80-100 parts of polypropylene resin, 2-3 parts of POE elastomer, 5-7 parts of EMA, and 0.3-0.4 parts of lubricant.

[0011] Optionally, the acrylate content of the EMA is one of 11%, 13%, 15%, 18%, 20%, 23%, 25%, 26% or the range value of any two of them.

[0012] Optionally, the Mooney viscosity of the POE elastomer is one of 6, 7, 8, 9, 10, 13, 15 or the range value of any two of them.

[0013] Preferably, the Mooney viscosity of the POE elastomer is 7-13; more preferably, the Mooney viscosity of the POE elastomer is 7-9.

[0014] The inventor found during the actual experiment process that when the Mooney viscosity of the POE elastomer is 7-13, it can better cooperate with EMA, and the fluidity of the polypropylene composite material system is moderate; when the Mooney viscosity of the POE elastomer is 7-9, the cooperation is further improved.

[0015] Preferably, the acrylate content of the EMA is 13-24%.

[0016] During the actual experiment, the inventor found that the acrylate content of EMA affects the compatibility and interfacial bonding strength between the EMA and polypropylene systems. When the acrylate content of the EMA is 13-24%, on the one hand, a stable interfacial bond can be formed, reducing defects caused by interfacial incompatibility and improving the firmness of the welded joint and the welding performance; on the other hand, when the acrylate content of EMA is within a reasonable range, the fluidity of the system can be moderate, which helps to evenly disperse impurities into the melt and reduce their adverse effects on the welding quality.

[0017] Further preferably, the acrylate content of the EMA is 16-20%.

[0018] Preferably, the test method for the acrylate content of the EMA is FTIR infrared method - GB / T32198-2015: Establish a standard curve in the infrared spectrum for EMAs with different acrylate contents, and then compare the test sample with the standard curve to obtain the acrylate content.

[0019] Preferably, the test method for the Mooney viscosity of the POE elastomer is ASTM D1646-2015.

[0020] Preferably, the melt flow rate of the PP resin at 230°C / 2.16 kg load according to ISO 1133-2011 is 1-10 g / 10 min, and the density of the PP resin is 0.89-0.93 g / cm 3 .

[0021] Optionally, the melt flow rate of the PP resin at 230°C / 2.16 kg load according to ISO 1133-2011 is one of 1, 1.5, 2, 2.5, 3, 4, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10 g / 10 min or any range value between any two of them; the density of the PP resin is one of 0.89, 0.90, 0.91, 0.92, 0.93 g / cm 3 or any range value between any two of them.

[0022] Optionally, the density of the PP resin is tested according to GB / T 1033.1-2008.

[0023] Optionally, the PP resin includes at least one of PP virgin resin and PP recycled resin.

[0024] Optionally, the density of the PP recycled resin is 0.91-0.93 g / cm 3 .

[0025] Generally speaking, compared with virgin materials, recycled materials have more impurity molecules. In the prior art, when polypropylene is blended with recycled polypropylene, the compatibility between the virgin material and the recycled material is worse, and the effect of friction welding will be further affected, resulting in insecure welding. In the polypropylene composite material of the present invention, EMA can improve the compatibility between the virgin material and the recycled material, and the molecular chains of EMA can also encapsulate or isolate the impurity molecules in the system to improve the system continuity. Moreover, the cooperation of EMA, POE and lubricant enables the mechanical properties and welding properties of the final product to be guaranteed even when recycled materials are used as components.

[0026] Preferably, the melt flow rate of the POE elastomer at 190 °C / 2.16 kg load according to ISO 1133-2011 is 0.5-10 g / 10 min.

[0027] Optionally, the melt flow rate of the POE elastomer at 190 °C / 2.16 kg load according to ISO 1133-2011 is one of 0.5, 0.8, 1.0, 1.5, 1.6, 2, 3, 4, 5, 6, 7, 8, 9, 10 g / 10 min or the range value of any two of them.

[0028] Optionally, the weight parts of the PP resin are one of 70 parts, 72 parts, 75 parts, 80 parts, 82 parts, 85 parts, 90 parts, 92 parts, 95 parts, 100 parts, 105 parts, 110 or the range value of any two of them; the weight parts of the POE elastomer are one of 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts or the range value of any two of them; the weight parts of the EMA are one of 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts or the range value of any two of them; the weight parts of the lubricant are one of 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts or the range value of any two of them.

[0029] Preferably, the lubricant is at least one of hydrocarbon lubricants, ester lubricants, alcohol lubricants, fatty acid lubricants, silicone lubricants. Further preferably, the lubricant is a silicone lubricant.

[0030] The inventor found in the actual experiment process that, due to its molecular structure and excellent lubrication performance, the silicone lubricant can significantly reduce the frictional resistance during the melt flow in the friction welding process, which helps to reduce energy loss and heat accumulation and prevent defects from occurring in the welded joint due to overheating. During the friction welding process, the welding area is often in a high-temperature state, and the silicone lubricant has good high-temperature stability and can maintain its lubrication performance at high temperature to ensure the smooth progress of the welding process.

[0031] Preferably, the polypropylene composite further comprises 0.1 - 10 parts of an auxiliary agent, and the auxiliary agent is at least one of a filler and a nucleating agent.

[0032] Optionally, the polypropylene composite comprises 0.1 - 5 parts of a filler; the filler is at least one of calcium carbonate, barium sulfate, talcum powder, and fumed silica.

[0033] Optionally, the polypropylene composite comprises 0.1 - 5 parts of a nucleating agent; the nucleating agent is a β-crystalline nucleating agent.

[0034] In addition, the present invention provides a method for preparing the polypropylene composite, comprising the following steps:

[0035] (1) Weigh each component by weight parts;

[0036] (2) Mix the above components and then add them to an extruder for melt dispersion, and extrude and pelletize to obtain the polypropylene composite.

[0037] Preferably, the extrusion temperature of the twin-screw extruder is 180°C - 210°C.

[0038] Furthermore, the present invention provides the application of the polypropylene composite in the fields of automotive parts, household appliances, and daily products.

[0039] Even further, the present invention provides the application of the polypropylene composite in friction welding.

[0040] The present invention also provides an automotive trim part, comprising the polypropylene composite; specifically, the automotive trim part includes seat guards, door sills of automotive interiors, and bottom guards, wheel arches, side skirts, etc. of automotive exteriors.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows: Through the synergy of POE elastomer, EMA, and lubricant, the present invention realizes the optimization at the microscopic structure level, and improves the mechanical properties and welding properties of the polypropylene composite. Specific Embodiments

[0042] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. The purpose is to understand the content of the present invention in detail, rather than to limit the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention. The experimental reagents and instruments designed in the embodiments and comparative examples of the present invention are all common ordinary reagents and instruments, unless otherwise specified, and can be obtained from commercial channels. In the embodiments and comparative examples, the experimental methods used are all conventional methods unless otherwise specified; and unless otherwise specified, the raw materials used in parallel experiments are of the same batch.

[0043] The raw materials used in the examples and comparative examples are described as follows, but are not limited to these materials:

[0044] PP resin - 1: homopolymer PP, density 0.9 g / cm 3 , melt flow rate 3 g / 10 min (230 °C / 2.16 kg), PPH - T03, Zhongke Refining & Chemical Co., Ltd.;

[0045] PP resin - 2: random copolymer PP, density 0.9 g / cm 3 , melt flow rate 1.6 g / 10 min (230 °C / 2.16 kg), SM 198, Lotte Chemical;

[0046] PP resin - 3: density 0.912 g / cm 3 , paint bucket polypropylene recycled resin, melt flow rate 3.5 g / 10 min (230 °C / 2.16 kg);

[0047] PP resin - 4: density 0.925 g / cm 3 , paint bucket polypropylene recycled resin, melt flow rate 3.3 g / 10 min (230 °C / 2.16 kg);

[0048] POE elastomer - 1: ethylene - octene copolymer, Mooney viscosity 8, grade 8200, manufacturer Dow;

[0049] POE elastomer - 2: ethylene - octene copolymer, Mooney viscosity 13, grade 8440, manufacturer Dow;

[0050] POE elastomer - 3: ethylene - octene copolymer, Mooney viscosity 10, grade 8450, manufacturer Dow;

[0051] POE elastomer - 4: ethylene - octene copolymer, Mooney viscosity 20, grade 8480, manufacturer Dow;

[0052] POE elastomer - 5: ethylene - octene copolymer, Mooney viscosity 4, grade 8137, manufacturer Dow;

[0053] EMA - 1: acrylate content 13%, 1913, DuPont;

[0054] EMA - 2: acrylate content 18%, grade ELVALOY TM AC 1218, manufacturer Dow;

[0055] EMA - 3: acrylate content 20%, grade ELVALOY TM AC 1820, manufacturer Dow;

[0056] EMA-4: Acrylate content is 24%, grade ELVALOY TM AC 12024S, manufacturer is Dow;

[0057] EMA-5: Acrylate content is 9%, ELVALOY TM AC 1209, DuPont;

[0058] EMA-6: Acrylate content is 30%, ELVALOY TM AC 1330, DuPont;

[0059] Lubricant-1: Silicone lubricant, B.GREASE-69(FX), manufacturer is Besnus (Xiamen) Lubrication Technology;

[0060] Lubricant-2: Ester lubricant, pentaerythritol stearate (PETS), manufacturer is Jiaxing Zhongcheng Environmental Protection;

[0061] Lubricant-3: Fatty acid lubricant, zinc stearate, manufacturer is Hongyuan Chemical Industry;

[0062] Filler: Fumed silica, REOLOSIL DM30, manufacturer is Tokuyama, Japan;

[0063] Nucleating agent: β-crystalline nucleating agent TMB-5 ， Manufacturer is Shanxi Research Institute of Chemical Industry.

[0064] Examples 1-14 and Comparative Examples 1-7

[0065] The components and weight parts of the polypropylene composite material described in the present invention are selected as shown in Table 1 - Table 2. The preparation method of the polypropylene composite material described in the present invention includes the following steps:

[0066] (1) Weigh each component according to the weight parts;

[0067] (2) After mixing the above components, add them to an extruder for melting and dispersion, and then extrude and pelletize to obtain the polypropylene composite material; the extrusion temperature of the twin-screw extruder is 180°C - 210°C, where the first section is 180°C, the 2nd - 4th sections are 210°C, the 5th - 8th sections are 200°C, and the ninth section of the die head is 190°C.

[0068] Performance test

[0069] Tensile strength: Test according to the ISO 527-1-2012 standard, and the tensile speed is 70 mm / min;

[0070] Izod notched impact strength: Test according to the ISO 180-2019 standard;

[0071] Tensile fracture force: For vibration friction welding, injection-molded specimens were prepared using the prepared polypropylene composition material. The welding surfaces of the specimens were carefully cleaned with a cleaner and non-woven fabric to remove impurities such as oil stains and dust. After ensuring that the specimens were completely dry, welding was carried out. The specimens were correctly installed on the vibration friction welding machine to ensure that they were on the same axis and had good centering. The welding cross-sectional area of the welded specimens was 10 mm * 4 mm. The welding parameters were adjusted as follows: amplitude: 1.65 mm, clamping pressure: 30 bar, welding pressure: 30 bar, holding pressure time: 3 s, depth: 1.35 mm. The tensile fracture force of the welded parts was tested in accordance with the ISO527-2-2016 standard, and the tensile speed was 10 mm / min.

[0072] The performance test results are shown in Table 1 - Table 2.

[0073] Table 1

[0074]

[0075]

[0076] Table 2

[0077]

[0078] As can be seen from the above table, the tensile strength of the polypropylene composite prepared in the embodiment of the present invention is ≥ 30 MPa, and the Izod notched impact strength is ≥ 5 kJ / m 2 , and the tensile fracture force is ≥ 780 N.

[0079] From the comparison of Examples 1-2, Examples 10-14, and Comparative Examples 6-7, when there are 80-100 parts of polypropylene resin, 2-3 parts of POE elastomer, 5-7 parts of EMA, and 0.3 - 0.4 parts of lubricant, the mechanical properties and welding properties of the polypropylene composite are better.

[0080] From the comparison of Example 1, Examples 3-4, and Comparative Examples 1-2, when the Mooney viscosity of the POE elastomer is 8-13, the mechanical properties and welding properties of the polypropylene composite are better.

[0081] From the comparison of Example 1, Examples 5-7, and Comparative Examples 3-4, when the acrylate content of the EMA is 13-25%, the mechanical properties and welding properties of the polypropylene composite are good; when the acrylate content of the EMA is 16-20%, the mechanical properties and welding properties of the polypropylene composite are better.

[0082] It can be seen from the comparison of Example 1, Examples 8-9 and Comparative Example 5 that the lubricant is indispensable, and when the lubricant is a silicone lubricant, the mechanical properties and welding properties of the polypropylene composite material are better. When no lubricant was added in Comparative Example 5, the tensile strength, impact strength and tensile breaking force all decreased significantly.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polypropylene composite material, characterized in that: The invention comprises the following components in parts by weight: 70-110 parts of polypropylene resin, 1-5 parts of POE elastomer, 3-8 parts of EMA, and 0.2-0.5 parts of lubricant; The Mooney viscosity of the POE elastomer is 6-15, and the measuring temperature of the Mooney viscosity is 121° C.; the acrylate content of the EMA is 11-26%.

2. The polypropylene composite material according to claim 1, characterized in that The invention comprises the following components in parts by weight: 80-100 parts of polypropylene resin, 2-3 parts of POE elastomer, 5-7 parts of EMA and 0.3-0.4 parts of lubricant.

3. The polypropylene composite material according to claim 1, characterized in that: The EMA has an acrylate content of 16-20%.

4. The polypropylene composite material according to claim 1, characterized in that: The lubricant is at least one of a hydrocarbon lubricant, an ester lubricant, an alcohol lubricant, a fatty acid lubricant, and a silicone lubricant.

5. The polypropylene composite material according to claim 1, characterized in that: The lubricant is a silicone lubricant.

6. The polypropylene composite material according to claim 1, characterized in that: The invention also comprises 0.1-10 parts of an auxiliary agent, wherein the auxiliary agent is at least one of a filler and a nucleating agent.

7. A method for preparing a polypropylene composite material according to any one of claims 1 to 6, characterized in that: The steps include: (1) Weigh each component by weight; (2) After mixing the above components, add them into an extruder for melt dispersion, and extrude and granulate to obtain the polypropylene composite material.

8. Use of the polypropylene composite material according to any one of claims 1 to 6 in the fields of automotive parts, home appliances and daily products.

9. Use of the polypropylene composite material according to any one of claims 1 to 6 in friction welding.

10. An automobile accessory, characterized in that: The invention comprises the polypropylene composite material as described in any one of claims 1 to 6.

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