Polypropylene composite material and preparation method and application thereof

Abstract

The application discloses a polypropylene composite material and a preparation method and application thereof, and relates to the technical field of polymer materials.The polypropylene composite material 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; wherein, the POE elastomer has a Mooney viscosity of 6-15, and the Mooney viscosity is measured at a temperature of 121 DEG C; and the EMA has an acrylate content of 11-26%. Through the cooperation of the POE elastomer, the EMA and the lubricant, the microstructure is optimized, and the mechanical properties and welding properties of the polypropylene composite material are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, and particularly relates to a polypropylene composite material and a preparation method and application thereof. BACKGROUND

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

[0003] In the production process of polypropylene products, friction welding is a common connection technology. The continuity of the polypropylene body in the existing polypropylene products is poor, and cracks and fractures are easily generated due to stress in the friction welding process. With the mass production and consumption of polypropylene products, the discarded polypropylene products also increase sharply, which causes great pressure on the environment. In order to cope with this challenge, polypropylene recycling (i.e. recycling of waste polypropylene) gradually attracts attention. The use of polypropylene recycling not only helps to reduce environmental pollution, but also saves limited resources such as petroleum, which conforms to the concept of sustainable development. Although polypropylene recycling has significant advantages in environmental protection and resource conservation, in actual application, when polypropylene recycling is mixed into new materials to produce new products, performance degradation often occurs. This is mainly due to the influence of factors such as pollution, aging and degradation of waste polypropylene during the recycling process, which causes changes in the molecular structure of the waste polypropylene, and then affects the physical properties and mechanical properties. For example, the product mixed with polypropylene recycling may exhibit low strength, toughness, heat resistance and other properties, which is difficult to meet the performance requirements of high-end products.

[0004] When polypropylene is mixed with polypropylene recycling, the effect of friction welding is also further affected, resulting in poor welding. This is mainly because the compatibility between polypropylene recycling and new materials is poor, and impurities and defects may exist in the recycling material, so that the material properties of the welding area are inconsistent, and it is difficult to form a stable welding joint. SUMMARY

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

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

[0007] The special chemical structure of EMA can play a bridging role between the molecular chains of polypropylene and form good compatibility with the molecular chains of polypropylene, and on the other hand, the molecular chains of EMA can wrap or isolate impurity particles in the system, and the wrapping or isolation effect helps to maintain the continuity and uniformity of the polypropylene composite system. The POE elastomer can form a reinforced crosslinked network in the microstructure of polypropylene, effectively absorbing and dispersing external impact energy, and improving the mechanical properties of the material. In 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 the lubricant helps to reduce friction resistance and promote the dispersion of impurities during processing, preventing aggregation into groups. The present application realizes the optimization of the microstructure level through the cooperation of POE elastomer, EMA and lubricant, and improves the mechanical properties and welding performance of the polypropylene composite material.

[0008] Preferably, the weight percentage content 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 comprises the following components in parts by weight: polypropylene resin 80-100 parts, POE elastomer 2-3 parts, EMA 5-7 parts, lubricant 0.3-0.4 parts.

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

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

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

[0014] The inventors found in actual experiments that when the Mooney viscosity of the POE elastomer is 7-13, the POE elastomer can better cooperate with the EMA, and the polypropylene composite system has moderate fluidity; when the Mooney viscosity of the POE elastomer is 7-9, the cooperation is further improved.

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

[0016] The inventors found in practical experiments that the content of the acrylate ester of the EMA affects the compatibility and interfacial bonding force between the EMA and the polypropylene system. When the content of the acrylate ester of the EMA is 13-24%, on the one hand, a stable interfacial bonding can be formed, the defects caused by interfacial incompatibility are reduced, the firmness of the welded joint is improved, and the welding performance is improved; on the other hand, the content of the acrylate ester of the EMA is within a reasonable range, the fluidity of the system is moderate, which is helpful to uniformly disperse impurities in the melt and reduce the adverse effects of the impurities on the welding quality.

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

[0018] Preferably, the test method of the content of the acrylate ester of the EMA is FTIR infrared method-GB / T32198-2015: a standard curve is established in infrared using EMA with different content of acrylate ester, then the test product is compared with the standard curve, and the content of the acrylate ester is obtained.

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

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

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

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

[0023] Alternatively, the PP resin comprises at least one of PP virgin resin and PP recycled resin.

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

[0025] Generally, compared with virgin material, recycled material has more impurity molecules. In the prior art, when polypropylene is mixed with polypropylene recycled material, the compatibility between virgin material and recycled material is poorer, and the effect of friction welding is further affected, resulting in poor welding. In the polypropylene composite material described in the present application, EMA can improve the compatibility of virgin material and recycled material, and the molecular chain of EMA can also wrap or isolate the impurity molecules in the system to improve the continuity of the system. And EMA, POE and lubricant cooperate to ensure the mechanical properties and welding properties of the final product even if recycled material is used as a component.

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

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

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

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

[0030] The inventors found in actual experiments that silicone lubricant can significantly reduce the friction resistance during melt flow in the friction welding process due to its molecular structure and excellent lubricating performance, which helps to reduce energy loss and heat accumulation and prevent defects 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 lubricating performance at high temperature, ensuring the smooth progress of the welding process.

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

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

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

[0034] In addition, the present application provides a preparation method of the polypropylene composite material, comprising the following steps:

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

[0036] (2) mixing the above components and then adding them into an extruder for melt dispersion, extruding and granulating to obtain the polypropylene composite material.

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

[0038] Further, the present application provides an application of the polypropylene composite material in the fields of automobile parts, household appliances, and daily products.

[0039] Still further, the present application provides an application of the polypropylene composite material in friction welding.

[0040] The present application also provides an automobile trim part comprising the polypropylene composite material; specifically, the automobile trim part comprises a seat guard, a door sill of an automobile interior, and a bottom guard, a wheel arch, and a side skirt of an automobile exterior.

[0041] Compared with the prior art, the present application has the following beneficial effects: the present application realizes the optimization of the microstructure level through the cooperation of the POE elastomer, the EMA, and the lubricant, and improves the mechanical properties and welding properties of the polypropylene composite material. DETAILED DESCRIPTION

[0042] For better illustrating the purpose, technical scheme and advantages of the present application, the present application will be further described in combination with specific examples. The purpose is to understand the content of the present application in detail, rather than limiting the present application. All other examples obtained by the ordinary skilled in the art without making creative efforts fall within the protection scope of the present application. The experimental reagents and instruments designed in the examples and comparative examples are common reagents and instruments, which can be obtained from commercial channels, unless otherwise specified. In the examples and comparative examples, the experimental methods used are conventional methods, unless otherwise specified; and the raw materials used in parallel experiments are the same batch of raw materials, unless otherwise specified.

[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, Sinopec;

[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, Letian 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%, grade 1913, manufacturer 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 24%, grade ELVALOY TM AC 12024S, manufacturer Dow;

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

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

[0059] Lubricant-1: Silicone lubricant, B. GREASE-69(FX), manufacturer Bixiu Lubricating Technology Co., Ltd;

[0060] Lubricant-2: Ester lubricant, Pentaerythritol Stearate (PETS), manufacturer Jiaxing Zhongcheng Environmental Protection;

[0061] Lubricant-3: Fatty acid lubricant, Zinc Stearate, manufacturer Hongyuan Chemical Industry;

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

[0063] Nucleating agent: β crystal nucleating agent TMB-5 ， manufacturer Shanxi Chemical Research Institute.

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

[0065] The components and weight parts of the polypropylene composite material described in the present application are shown in Tables 1-2, and the preparation method of the polypropylene composite material described in the present application comprises the following steps:

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

[0067] (2) After mixing the above components, melt and disperse in an extruder, extrude and granulate to obtain the polypropylene composite material; the extrusion temperature of the twin-screw extruder is 180-210°C, wherein the first segment is 180°C, the second-fourth segments are 210°C, the fifth-eighth segments are 200°C, and the ninth segment of the die head is 190°C.

[0068] Performance test

[0069] Tensile strength: tested according to ISO 527-1-2012 standard, with a tensile speed of 70 mm / min;

[0070] Charpy notched impact strength: tested according to ISO 180-2019 standard;

[0071] Tensile breaking force: the polypropylene composition material prepared was respectively injection molded into a sample strip, the sample surface to be welded was carefully cleaned with a cleaning agent and non-woven fabric to remove oil stains, dust and other impurities, and the sample was completely dried before welding. The sample was correctly installed on the vibration friction welding machine, ensuring that they were on the same axis and well centered, and the welding cross section of the sample was 10mm*4mm. The welding parameters were adjusted as follows: amplitude: 1.65mm, mold closing pressure: 30bar, welding pressure: 30bar, holding time: 3s, depth: 1.35mm. The tensile breaking force of the welded sample was tested according to the ISO527-2-2016 standard, and the tensile speed was 10mm / min.

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

[0073] Table 1

[0074]

[0075]

[0076] Table 2

[0077]

[0078] From the above table, it can be seen that the tensile strength of the polypropylene composite material prepared in the embodiment is ≥30MPa, the notched Izod impact strength is ≥5kJ / m 2 , and the tensile breaking force is ≥780N.

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

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

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

[0082] From the comparison of Example 1, Example 8-9, and Comparative Example 5, it can be seen 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 is added in Comparative Example 5, the tensile strength, impact strength, and tensile breaking force all decrease significantly.

[0083] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the essence and scope of the technical solutions of the present application.

Claims

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

2. The polypropylene composite material as described in claim 1, characterized in that, It includes the following components in parts by weight: 80-100 parts polypropylene resin, 2-3 parts POE elastomer, 5-7 parts EMA, and 0.3-0.4 parts lubricant.

3. The polypropylene composite material as described in claim 1, characterized in that, The acrylate content of the EMA is 16-20%.

4. The polypropylene composite material as described in claim 1, characterized in that, The lubricant is at least one of hydrocarbon lubricants, ester lubricants, alcohol lubricants, fatty acid lubricants, and silicone lubricants.

5. The polypropylene composite material as described in claim 1, characterized in that, The lubricant is a silicone-based lubricant.

6. The polypropylene composite material as described in claim 1, characterized in that, It also includes 0.1-10 parts of additives, wherein the additives are at least one of fillers and nucleating agents.

7. A method for preparing a polypropylene composite material according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Weigh each component according to its weight parts; (2) The above components are mixed and added to an extruder for melt dispersion, then extruded and granulated to obtain the polypropylene composite material.

8. The application of a polypropylene composite material as described in any one of claims 1-6 in the fields of automotive parts, home appliances, and daily necessities.

9. The application of a polypropylene composite material as described in any one of claims 1-6 in friction welding.

10. A car trim component, characterized in that, Includes the polypropylene composite material as described in any one of claims 1-6.

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