Low-odor reinforced regenerated polypropylene composite material as well as preparation method and application thereof

Abstract

The invention discloses a low-odor reinforced regenerated polypropylene composite material as well as a preparation method and application thereof, and belongs to the technical field of polymer composite materials. The material comprises the following raw materials in parts by weight: 50-80 parts of regenerated PP resin; 10-30 parts of activated carbon fiber; and 5-10 parts of a compatilizer. Wherein the activated carbon fiber is prepared by taking waste paper as a raw material. According to the regenerated polypropylene composite material disclosed by the invention, waste paper-based activated carbon fibers are selected as a deodorant and a reinforcing agent, so that the regenerated polypropylene composite material has high porosity, high specific surface area and rich micro-mesoporous structures, and volatile odor substances generated by melt extrusion of regenerated polypropylene are efficiently adsorbed; the composite material has a typical fibrous structure and a high length-diameter ratio, so that the tensile strength and the impact strength of the composite material are improved, and the rigidity of the product is obviously improved. The low-odor reinforced regenerated polypropylene composite material can be applied to interior and exterior trim parts of automobiles, and recycling of waste paper resources and waste polypropylene is effectively promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer composite materials, and particularly relates to a low-odor reinforced recycled polypropylene composite material, a preparation method thereof, and an application thereof. Background Art

[0002] With the development of industrial technology, the requirements for "low-carbon, circular, and sustainable" in all walks of life are getting higher and higher, which will inevitably bring a series of new challenges to the traditional manufacturing-based automotive industry. How to meet these requirements in automotive manufacturing has become very important. Currently, one of the increasingly prominent trends in the automotive field is "lightweighting", and the proportion of plastic products in the whole vehicle is getting larger and larger, including a series of interior and exterior trim parts such as bumpers, instrument panels, door panels, and storage boxes. Recycled plastics refer to plastic raw materials obtained by processing waste plastics through multiple physical or chemical methods, realizing the recycling of resources and achieving the goals of environmental protection, low-carbon, and sustainable recycling. Therefore, expanding the addition ratio of recycled plastics in automotive parts and improving the utilization rate of recycled plastics are of great significance for the future development of the automotive industry.

[0003] Among recycled plastics, polypropylene is one of the most recycled and widely used recycled plastics, and it is also the plastic variety with the largest consumption in the whole vehicle. However, in actual applications, the mechanical properties of pure recycled polypropylene materials are poor and still need to be improved to meet automotive requirements. At the same time, various unpleasant odors and high volatile matter contents will occur during the processing process and subsequent use, affecting the in-vehicle experience of users. Therefore, it is of great significance to develop a low-odor reinforced recycled polypropylene composite material, a preparation method thereof, and an application thereof. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a low-odor reinforced recycled polypropylene composite material, a preparation method thereof, and an application thereof.

[0005] The object of the present invention can be achieved by the following technical solutions:

[0006] In a first aspect of the present invention, there is provided a reinforced recycled polypropylene composite material, comprising the following raw materials in parts by weight:

[0007] Recycled PP resin 50 - 80 parts;

[0008] Activated carbon fiber 10 - 30 parts;

[0009] Compatibilizer 5 - 10 parts.

[0010] Optionally, it further comprises:

[0011] Toughening agent 4 - 10 parts;

[0012] Antioxidant 0.2 - 0.5 part;

[0013] Lubricant: 0.2 - 0.5 parts;

[0014] Optionally, the preparation method of the activated carbon fiber includes the following steps:

[0015] Soak waste paper fragments in an acidic solution, filter out impurities and wash until neutral, then further crush into pulp, and obtain pulp sheets after drying; place the pulp sheets in a tube furnace, carbonize under the protection of an inert gas, then soak the carbonized pulp sheets in an alkaline solution or an acidic solution, dry and then transfer them to the tube furnace again for activation; finally, wash the sample with ultrapure water until neutral and dry the moisture to obtain activated carbon fibers.

[0016] Optionally, the carbonization temperature is 600 - 800 °C, the heating rate is 5 °C / min - 15 °C / min, and the heat preservation time is 1 h; the activation temperature is 400 - 600 °C, the heating rate is 5 °C / min - 15 °C / min, and the heat preservation time is 2 h; the inert gas is nitrogen or argon; the alkaline solution is at least one of sodium hydroxide, potassium hydroxide, and potassium carbonate, with a concentration of 1 - 5 mol / L; the acidic solution is at least one of concentrated sulfuric acid, phosphoric acid, and nitric acid, with a concentration of 1 - 5 mol / L; the soaking time is 8 - 12 h.

[0017] Optionally, the toughening agent is at least one of ethylene - octene copolymer, ethylene - butene copolymer, and ethylene - propylene - diene monomer / propylene - α - olefin copolymer.

[0018] Optionally, the antioxidant is at least one of hindered phenol antioxidants, thioester antioxidants, and phosphite antioxidants; the hindered phenol antioxidant is pentaerythritol tetra[β-(3,5 - di - tert - butyl - 4 - hydroxyphenyl)propionate], the thioester antioxidant is distearyl thiodipropionate, and the phosphite antioxidant is tris(2,4 - di - tert - butylphenyl) phosphite.

[0019] Optionally, the lubricant is at least one of silicone, polyethylene wax, calcium stearate, zinc stearate, and ethylene bisstearamide.

[0020] Optionally, the compatibilizer includes PP - g - MAH.

[0021] The second aspect of the present invention relates to a preparation method of a reinforced recycled polypropylene composite material, including the following steps:

[0022] Mix recycled PP resin, activated carbon fiber, and compatibilizer, stir to obtain a mixture; put the mixture into a parallel twin - screw extruder for melting and extrusion granulation to obtain the reinforced recycled polypropylene composite material;

[0023] Among them, the barrel temperature of the parallel twin-screw extruder is 180 - 220 °C, the screw speed is 300 - 600 r / min, the melt pressure is 1.5 - 2.5 MPa, and the vacuum degree is -0.06 - -0.1 MPa.

[0024] The third aspect of the present invention relates to the application of the above-mentioned enhanced recycled polypropylene composite material in the preparation of automotive interior parts.

[0025] Beneficial effects of the present invention:

[0026] 1. The present invention uses recycled polypropylene as the main material and waste paper-based activated carbon fibers as the filling and reinforcing phase, which can meet the development needs of green, environmental protection and recycled materials for automobiles.

[0027] 2. The low-odor enhanced recycled polypropylene composite material prepared by the present invention, in which activated carbon fibers serve as a bifunctional filling phase, having both odor removal and strengthening effects. Activated carbon fibers not only have a high porosity, high specific surface area and rich micro-mesoporous structure, which can efficiently adsorb volatile odor substances generated during the melt extrusion of polypropylene recycled materials; but also have a typical fibrous structure and a relatively high aspect ratio, enhancing the tensile strength and impact strength of the composite material, and significantly improving the rigidity of the product to meet the requirements of automotive parts.

[0028] 3. The preparation process of the present invention is simple, can be mass-produced, and the odor of the extruded particles or parts is significantly improved.

[0029] 4. The present application obtains activated carbon fiber materials through the recycling and treatment of waste paper, which can play an effective role in polypropylene composite materials, thereby providing a new idea for the secondary utilization of waste paper, reducing production costs and environmental protection capabilities. Specific embodiments

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] Example 1

[0032] This example provides a waste paper-based activated carbon fiber material, which is prepared through the following steps:

[0033] The waste paper is broken into tiny flakes, soaked in a 0.3 mol / L nitric acid solution for 10 h, the impurities are filtered off and washed until neutral, and then further shredded into pulp at a speed of 3000 r / min. After drying at 80 °C, pure pulp flakes are obtained; the pulp flakes are placed in a tube furnace and carbonized in an N2 atmosphere. The carbonization temperature is 600 °C, the heating rate is 5 °C / min, and it is kept warm for 1 h; then the carbonized pulp flakes are taken and soaked in a 1 mol / L potassium hydroxide solution for 12 h. After drying at 80 °C, they are transferred to the tube furnace again and activated in an N2 atmosphere at a temperature of 500 °C, a heating rate of 10 °C / min, and kept warm for 2 h; finally, the sample is washed with ultrapure water until neutral and dried at 100 °C to remove moisture to obtain activated carbon fibers.

[0034] Example 2

[0035] This example provides a waste paper-based activated carbon fiber material, which is prepared by the following steps:

[0036] The waste paper is broken into tiny flakes, soaked in a 0.3 mol / L nitric acid solution for 10 h, the impurities are filtered off and washed until neutral, and then further shredded into pulp at a speed of 4000 r / min. After drying at 80 °C, pure pulp flakes are obtained; the pulp flakes are placed in a tube furnace and carbonized in an N2 atmosphere. The carbonization temperature is 700 °C, the heating rate is 5 °C / min, and it is kept warm for 1 h; then the carbonized pulp flakes are taken and soaked in a 1 mol / L potassium carbonate solution for 10 h. After drying at 80 °C, they are transferred to the tube furnace again and activated in an N2 atmosphere at a temperature of 500 °C, a heating rate of 5 °C / min, and kept warm for 2 h; finally, the sample is washed with ultrapure water until neutral and dried at 100 °C to remove moisture to obtain activated carbon fibers.

[0037] Example 3

[0038] This example provides a low-odor enhanced recycled polypropylene composite material, and the preparation method includes the following steps:

[0039] Using POE LC565 as a toughening agent, compounding pentaerythritol tetrakis [B-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and distearyl thiodipropionate with a mass ratio of 1:1 as antioxidants, using calcium stearate as a lubricant, using PP-g-MAH as a compatibilizer, and using the activated carbon fibers prepared in Example 1 as a filler phase;

[0040] According to the ratio in Table 1, the recycled PP resin, activated carbon fibers, toughening agent, antioxidant, lubricant, and compatibilizer are stirred at a speed of 300 r / min for 10 min to obtain a mixture;

[0041] Put the mixture into a parallel twin-screw extruder. The barrel temperature is 180 °C, the screw speed is 400 r / min, the melt pressure is 1.5 MPa, and the vacuum degree is -0.06 MPa. Through melting and extrusion granulation, a low-odor reinforced recycled polypropylene composite material is obtained.

[0042] Example 4

[0043] This example provides a low-odor recycled polypropylene composite material, and the preparation method includes the following steps:

[0044] Use POE875L as the toughening agent, use a compound of pentaerythritol tetrakis [B-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and distearyl thiodipropionate with a mass ratio of 1:1 as the antioxidant, use silicone as the lubricant, use PP-g-MAH as the compatibilizer, and use the activated carbon fiber prepared in Example 2 as the filler phase;

[0045] According to the ratio in Table 1, stir the recycled PP resin, activated carbon fiber, toughening agent, antioxidant, lubricant, and compatibilizer at a speed of 300 r / min for 10 min to obtain a mixture;

[0046] Put the mixture into a parallel twin-screw extruder. The barrel temperature is 220 °C, the screw speed is 600 r / min, the melt pressure is 2.5 MPa, and the vacuum degree is -0.1 MPa. Through melting and extrusion granulation, a low-odor reinforced recycled polypropylene composite material is obtained.

[0047] Example 5

[0048] This example provides a low-odor reinforced recycled polypropylene composite material, and the preparation method includes the following steps:

[0049] Compared with Example 3, add each component according to the ratio in Table 1, where the filler in Example 3 is replaced with barium sulfate and the lubricant is replaced with polyethylene wax. The remaining raw materials and preparation process are the same as those in Example 3.

[0050] Example 6

[0051] This example provides a low-odor reinforced recycled polypropylene composite material, and the preparation method includes the following steps:

[0052] Compared with Example 3, add each component according to the ratio in Table 1, where the toughening agent in Example 3 is replaced with POE875L and the lubricant is replaced with zinc stearate. The remaining raw materials and preparation process are the same as those in Example 3.

[0053] Example 7

[0054] This example provides a low-odor reinforced recycled polypropylene composite material, and the preparation method includes the following steps:

[0055] Compared with Example 3, each component was added according to the ratio in Table 1, where the toughener in Example 3 was replaced by POE875L and the lubricant was replaced by ethylene bisstearamide. The remaining raw materials and the preparation process were the same as those in Example 3.

[0056] Table 1 shows the weight parts of each component added in Examples 3 to 7 and Comparative Examples 1 to 2.

[0057] Table 1

[0058]

[0059] Comparative Example 1

[0060] This example provides a low-odor reinforced recycled polypropylene composite material, and the preparation method includes the following steps:

[0061] Compared with Example 3, each component was added according to the ratio in Table 1, and the remaining raw materials and the preparation process were the same as those in Example 3.

[0062] Comparative Example 2

[0063] This example provides a low-odor reinforced recycled polypropylene composite material, and the preparation method includes the following steps:

[0064] Compared with Example 3, each component was added according to the ratio in Table 1, and the remaining raw materials and the preparation process were the same as those in Example 3.

[0065] Comparative Example 3

[0066] This example provides a low-odor recycled polypropylene composite material, and the preparation method includes the following steps:

[0067] Compared with Example 4, each component was added according to the ratio in Table 1, and the remaining raw materials and the preparation process were the same as those in Example 3.

[0068] The low-odor reinforced recycled polypropylene composite materials prepared in Examples 3 to 7 and Comparative Examples 1 to 2 were respectively tested for the properties of tensile strength, flexural strength, flexural modulus, and cantilever beam notched impact strength according to the GB / T standard. The odor level test method refers to the German Volkswagen PV3900 test method to test the odor level. The specific method for the odor level test is as follows:

[0069] Put 20 g of the above sample into a test vessel, place it in an oven for 2 h, set the oven temperature at (80 ± 2) °C, ensure that the test vessel is tightly sealed. After the test vessel is taken out of the oven and cooled to 60 °C, slightly open the lid, and evaluate according to the above test method. The odor grade of the material is classified according to the standard as follows: Grade 1: odorless; Grade 2: having an odor, but no interfering odor; Grade 3: having an obvious odor, but no interfering odor; Grade 4: having an interfering odor; Grade 5: having a strong interfering odor; Grade 6: having an intolerable odor. The test results are shown in Table 3.

[0070] Table 3

[0071]

[0072]

[0073] From the test results of Comparative Example 1 and Comparative Example 2, it can be seen that the tensile strength and impact strength of the recycled polypropylene material are not high, and the odor is poor; after introducing activated carbon fibers, the mechanical properties of the composite material are improved and the odor is improved. The test results of Examples 3 to 7 show that with the increase in the addition amount of activated carbon fibers, the mechanical properties are gradually improved, the odor is significantly improved, and the final odor grade can reach 3.5.

[0074] In addition, adding a compatibilizer to the formula can promote the combination of activated carbon fibers and PP resin, greatly improve the interfacial strength, and thus improve the relevant mechanical properties.

[0075] It can be seen from the above examples that activated carbon fibers, as a filler phase, play the roles of both deodorant and reinforcing agent. Not only can the adsorption of volatile odor substances be realized with its rich porous structure, but also the tensile strength and impact strength of the composite material are improved, the rigidity of the product is significantly enhanced, effectively promoting the circular recycling of waste polypropylene and waste paper resources, and can be applied to automotive interior and exterior parts.

[0076] On the other hand, the present application proposes a carbon fiber material obtained from waste paper, which plays an effective role in the polypropylene composite material, promotes the secondary utilization of resources such as waste paper, reduces waste generation while also being able to reduce the production cost of enterprises.

[0077] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0078] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed.

Claims

1. An enhanced recycled polypropylene composite material, characterized in that, It comprises the following raw materials in parts by weight: Recycled PP resin: 50 - 80 parts; Activated carbon fiber: 10 - 30 parts; Compatibilizer: 5 - 10 parts.

2. The reinforced recycled polypropylene composite material according to claim 1, wherein It further comprises: Toughening agent: 4 - 10 parts; Antioxidant: 0.2 - 0.5 parts; Lubricant: 0.2 - 0.5 parts.

3. The reinforced recycled polypropylene composite material according to claim 1, wherein The preparation method of the activated carbon fiber comprises the following steps: Soak waste paper fragments in an acidic solution, filter out impurities and wash until neutral, then further crush into pulp, and obtain pulp sheets after drying; place the pulp sheets in a tube furnace, carbonize under the protection of an inert gas, then soak the carbonized pulp sheets in an alkaline solution or an acidic solution, and transfer them to the tube furnace again for activation after drying; finally, wash the sample with ultrapure water until neutral and dry the moisture to obtain activated carbon fiber.

4. The reinforced recycled polypropylene composite material according to claim 3, wherein The carbonization temperature is 600 - 800 °C, the heating rate is 5 °C / min - 15 °C / min, and the heat preservation time is 1 h; the activation temperature is 400 - 600 °C, the heating rate is 5 °C / min - 15 °C / min, and the heat preservation time is 2 h; the inert gas is nitrogen or argon; the alkaline solution is at least one of sodium hydroxide, potassium hydroxide, and potassium carbonate, with a concentration of 1 - 5 mol / L; the acidic solution is at least one of concentrated sulfuric acid, phosphoric acid, and nitric acid, with a concentration of 1 - 5 mol / L; the soaking time is 8 - 12 h.

5. The reinforced recycled polypropylene composite material according to claim 2, wherein The toughening agent is at least one of ethylene - octene copolymer, ethylene - butene copolymer, and ethylene - propylene - diene monomer / propylene - α - olefin copolymer.

6. The reinforced recycled polypropylene composite material according to claim 2, wherein The antioxidant is at least one of hindered phenol antioxidants, thioester antioxidants, and phosphite antioxidants; the hindered phenol antioxidant is pentaerythritol tetra[β-(3,5 - di - tert - butyl - 4 - hydroxyphenyl)propionate], the thioester antioxidant is distearyl thiodipropionate, and the phosphite antioxidant is tris(2,4 - di - tert - butylphenyl) phosphite.

7. The reinforced recycled polypropylene composite material according to claim 2, wherein The lubricant is at least one of silicone, polyethylene wax, calcium stearate, zinc stearate, and ethylene bisstearamide.

8. The reinforced recycled polypropylene composite material according to claim 1, wherein The compatibilizer includes PP - g - MAH.

9. A preparation method of an enhanced recycled polypropylene composite material, characterized in that, It comprises the following steps: Mix the recycled PP resin, activated carbon fiber, and compatibilizer, stir to obtain a mixture; put the mixture into a parallel twin - screw extruder for melting and extrusion granulation to obtain the reinforced recycled polypropylene composite material. Among them, the barrel temperature of the parallel twin - screw extruder is 180 - 220 °C, the screw speed is 300 - 600 r / min, the melt pressure is 1.5 - 2.5 MPa, and the vacuum degree is - 0.06 - - 0.1 MPa.

10. Use of the reinforced recycled polypropylene composite material according to any one of claims 1 - 8 in the preparation of automotive interior parts.

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