A low-odor recycled polypropylene composite material and its preparation method and application

Abstract

The present invention relates to a low-odor recycled polypropylene composite material, its preparation method, and application. The composite material comprises 60-80 parts of polypropylene resin; 5-10 parts of a toughening agent; 20-30 parts of a filler; 0.2-0.5 parts of an antioxidant; 0.2-0.5 parts of a lubricant; 0.2-3 parts of a compatibilizer; and 0.3-1.5 parts of an odor suppressant. The odor suppressant is a compound of a metal oxidizing framework (MOF) material and TiO2 nanoparticles. The MOFs material prepared by the present invention not only has high porosity, high specific surface area, and a micro-mesoporous structure, but is also rich in conjugated benzene ring structures and oxygen-containing functional groups. It can absorb volatile odorous substances generated by recycled polypropylene during melt extrusion. Combined with the photocatalytic effect of TiO2, it further effectively decomposes organic molecules emitted by the material system, achieving a significant improvement in odor through synergistic effects. The MOFs material can be applied to automotive interior and exterior trims, effectively promoting the recycling of waste polypropylene.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer composite materials, and in particular is a low-odor regenerated polypropylene composite material and a preparation method and application thereof. Background Art

[0002] With the development of society, the demand for environmental protection and low carbon emissions is growing across all industries. This undoubtedly presents new challenges for the traditional manufacturing-based automotive industry, requiring the practical implementation of low-carbon, green, and environmentally friendly practices throughout the vehicle manufacturing process. With the rise of concepts such as lightweighting and replacing steel with plastic, the proportion of plastic materials used in vehicles is increasing. Therefore, strengthening policy guidance for the use of recycled plastics in the automotive industry, increasing their utilization rate, and expanding their proportion in finished vehicles are crucial for achieving carbon neutrality in the automotive industry.

[0003] Recycled plastics refer to plastic raw materials obtained by processing waste plastics through physical or chemical methods such as pretreatment, melt granulation, and modification. Through resource recycling, they achieve true environmental protection, carbon reduction, and sustainable circulation. Currently, recycled polypropylene is one of the most recycled and widely used recycled plastics. Although some mechanical properties of recycled polypropylene meet the requirements in practical applications, they often exhibit unpleasant odors and high VOC content. Therefore, the development of a low-odor recycled polypropylene composite material, its preparation method, and its application are of great significance. Summary of the Invention

[0004] The purpose of the present invention is to provide a low-odor recycled polypropylene composite material and its preparation method and application, so as to solve the problems of unbearable odor and high VOC content of recycled polypropylene materials in the background art.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A low-odor recycled polypropylene composite material comprises the following raw materials: PP resin, a toughening agent, a filler, an antioxidant, a lubricant, a compatibilizer, and an odor inhibitor.

[0007] Furthermore, the low-odor recycled polypropylene composite material comprises the following raw materials in parts by weight:

[0008]

[0009] Furthermore, the odor suppressant is compounded by MOFs material and TiO2.

[0010] Furthermore, the odor suppressant is compounded by MOFs material and TiO2 in a mass ratio of 1:0.5 to 2.

[0011] Furthermore, the synthesis steps of the MOFs material are as follows:

[0012] Add a zirconium source and benzoic acid to N,N-dimethylformamide, then add 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, transfer to a sealed container, heat to 110-120°C, maintain for 24-48 hours, centrifuge, wash, soak, centrifuge, and dry to obtain the MOFs material.

[0013] Furthermore, the TiO2 is anatase TiO2 with a particle size of 50 to 100 nm.

[0014] Furthermore, the zirconium source is ZrOCl2·8H2O or ZrCl4.

[0015] Furthermore, the mass ratio of the zirconium source, benzoic acid, N,N-dimethylformamide and 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene is 3:50:180:1.

[0016] Furthermore, the PP resin is a mixture of recycled polypropylene and copolymerized polypropylene.

[0017] Furthermore, the cleaning solvent is N,N-dimethylformamide; and the soaking solvent is acetone.

[0018] Furthermore, the recycled polypropylene is a light grey opaque granule obtained by washing, crushing and extruding recycled polypropylene plastic.

[0019] Furthermore, the toughening agent is at least one of ethylene-octene copolymer, ethylene-butene copolymer, EPDM rubber / propylene-α-olefin copolymer, propylene-α-olefin copolymer, and styrene-ethylene-propylene-styrene block copolymer.

[0020] Furthermore, the filler is at least one of talc, calcium carbonate, barium sulfate, wollastonite, and mica.

[0021] Furthermore, the antioxidant is at least one of hindered phenols, thioesters, and phosphites.

[0022] Furthermore, the hindered phenol antioxidant is pentaerythritol tetrakis[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.

[0023] Furthermore, the lubricant is at least one of silicone, polyethylene wax, calcium stearate, zinc stearate, and ethylene bisstearamide.

[0024] A method for preparing a low-odor recycled polypropylene composite material comprises the following steps:

[0025] PP resin, toughening agent, filler, antioxidant, lubricant compatibilizer and odor inhibitor are mixed and stirred at a speed of 300 to 500 r / min for 5 to 10 minutes to obtain a mixture; the mixture is put into a parallel twin-screw extruder for melting and extrusion granulation to obtain a low-odor recycled polypropylene composite material.

[0026] The barrel temperature of the parallel twin-screw extruder is 180-220° C., the screw speed is 400-600 r / min, the melt pressure is 1.5-2.5 MPa, and the vacuum degree is -0.06--0.1 MPa.

[0027] Application of a low-odor recycled polypropylene composite material: The low-odor recycled polypropylene composite material prepared by the present invention is mainly used in the preparation of automotive interior and exterior trims.

[0028] Beneficial effects of the present invention:

[0029] 1. The low-odor recycled polypropylene composite material prepared by the present invention can meet the development needs of green and recycled materials in automobiles.

[0030] 2. The low-odor recycled polypropylene composite material prepared by the present invention, wherein the odor suppressant is compounded by a MOFs material with adsorption function and TiO2 nanoparticles with photocatalytic function. The MOFs material prepared by the present invention not only has high porosity, high specific surface area and micro-mesoporous structure (1-3 nm), but also is rich in conjugated benzene ring structure and oxygen-containing functional groups. It absorbs benzene, aldehydes and other small molecules produced by melt extrusion of recycled polypropylene materials through conjugation, hydrogen bonding and physical action. After the introduction of TiO2, it exerts its catalytic effect under visible light, further effectively decomposes the organic molecules emitted by the material system, achieves synergistic effect to improve the odor, and effectively suppresses the emission of odor.

[0031] 3. The preparation process of the present invention is simple and can be produced in large quantities. The odor of the extruded particles or products is significantly improved. DETAILED DESCRIPTION

[0032] To facilitate understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0034] Example 1

[0035] This embodiment provides a MOFs material, which is synthesized by the following steps:

[0036] 0.3 g ZrOCl2·8H2O and 5 g benzoic acid were fully dissolved in 18 g N,N-dimethylformamide, and then 0.1 g 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene was added. The mixture was transferred to a reactor and heated to 120°C for 24 h. After the reaction, the mixture was centrifuged at 8000 r / min and washed with N,N-dimethylformamide at 8000 r / min. The precipitate was soaked in 50 mL acetone for 12 h, centrifuged at 8000 r / min, and kept in a vacuum drying oven at 120°C for 12 h to obtain MOFs material. The powder was light yellow.

[0037] Example 2

[0038] This embodiment provides a MOFs material, which is synthesized by the following steps:

[0039] 0.6g ZrCl4 and 10g benzoic acid were fully dissolved in 36g N,N-dimethylformamide, and then 0.2g 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene was added. The mixture was transferred to a reactor and heated to 110°C for 48h. After the reaction, the mixture was centrifuged at 8000r / min and washed with N,N-dimethylformamide at 8000r / min. The precipitate was soaked in 50mL acetone for 12h, centrifuged at 8000r / min, and kept in a vacuum drying oven at 120°C for 12h to obtain MOFs material. The powder was light yellow.

[0040] Example 3

[0041] This embodiment provides a low-odor recycled polypropylene composite material, the preparation method of which includes the following steps:

[0042] POE LC565 was used as a toughening agent, talc was used as a filler, pentaerythritol tetrakis[B-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and distearyl thiodipropionate in a mass ratio of 1:1 were compounded as an antioxidant, calcium stearate was used as a lubricant, PP-g-MAH was used as a compatibilizer, and the MOFs material prepared in Example 1 was compounded with nano-TiO2 as an odor suppressant;

[0043] Among them, TiO2 is anatase TiO2 with a particle size of 50 to 100 nm, and recycled polypropylene is light gray opaque particles obtained by washing, crushing and extruding recycled polypropylene plastic;

[0044] According to the ratio in Table 1, the recycled PP resin, copolymerized PP resin, toughening agent, filler, antioxidant, lubricant, compatibilizer and odor suppressant were stirred at a speed of 300 r / min for 10 min to obtain a mixture;

[0045] The mixture was fed into a parallel twin-screw extruder with a barrel temperature of 180°C, a screw speed of 400 r / min, a melt pressure of 1.5 MPa, and a vacuum degree of -0.06 MPa. The low-odor recycled polypropylene composite material was obtained by melting, extruding and granulating.

[0046] Example 4

[0047] This embodiment provides a low-odor recycled polypropylene composite material, the preparation method of which includes the following steps:

[0048] POE875L was used as a toughening agent, calcium carbonate was used as a filler, pentaerythritol tetrakis[B-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and distearyl thiodipropionate were compounded in a mass ratio of 1:1 as an antioxidant, silicone was used as a lubricant, PP-g-MAH was used as a compatibilizer, and the MOFs material prepared in Example 1 was compounded with nano-TiO2 as an odor suppressant;

[0049] According to the ratio in Table 1, the recycled PP resin, copolymerized PP resin, toughening agent, filler, antioxidant, lubricant, compatibilizer and odor suppressant were stirred at a speed of 300 r / min for 10 min to obtain a mixture;

[0050] The mixture was fed into a parallel twin-screw extruder with a barrel temperature of 220°C, a screw speed of 600 r / min, a melt pressure of 2.5 MPa, and a vacuum degree of -0.1 MPa. The low-odor recycled polypropylene composite material was obtained by melting, extruding and granulating.

[0051] Example 5

[0052] This embodiment provides a low-odor recycled polypropylene composite material, the preparation method of which includes the following steps:

[0053] Compared with Example 3, the components were added according to the ratios in Table 1, except that the filler in Example 3 was replaced with barium sulfate and the lubricant was replaced with polyethylene wax. The remaining raw materials and preparation process were the same as in Example 3.

[0054] Example 6

[0055] This embodiment provides a low-odor recycled polypropylene composite material, the preparation method of which includes the following steps:

[0056] Compared with Example 3, the components were added according to the ratios in Table 1, with the toughening agent in Example 3 being replaced by POE875L, the filler being replaced by wollastonite, and the lubricant being replaced by zinc stearate. The remaining raw materials and preparation process were the same as in Example 3.

[0057] Example 7

[0058] This embodiment provides a low-odor recycled polypropylene composite material, the preparation method of which includes the following steps:

[0059] Compared with Example 3, the components were added according to the ratios in Table 1, except that the toughening agent in Example 3 was replaced with POE875L, the filler was replaced with mica, and the lubricant was replaced with ethylene bisstearamide. The remaining raw materials and preparation process were the same as in Example 3.

[0060] Example 8

[0061] This embodiment provides a low-odor recycled polypropylene composite material, the preparation method of which includes the following steps:

[0062] Compared with Example 3, the components were added according to the ratios in Table 1. The remaining raw materials and preparation process were the same as in Example 3.

[0063] Table 1 shows the added weight parts of each component in Examples 3 to 8.

[0064] Table 1

[0065]

[0066]

[0067] Comparative Example 1

[0068] This embodiment provides a low-odor recycled polypropylene composite material, the preparation method of which includes the following steps:

[0069] Compared with Example 3, the components were added according to the ratio in Table 2, and the remaining raw materials and preparation process were the same as in Example 3.

[0070] Comparative Example 2

[0071] This embodiment provides a low-odor recycled polypropylene composite material, the preparation method of which includes the following steps:

[0072] Compared with Example 3, the components were added according to the ratio in Table 2, and the remaining raw materials and preparation process were the same as in Example 3.

[0073] Comparative Example 3

[0074] This embodiment provides a low-odor recycled polypropylene composite material, the preparation method of which includes the following steps:

[0075] Compared with Example 3, the components were added according to the ratio in Table 2, and the remaining raw materials and preparation process were the same as in Example 3.

[0076] Comparative Example 4

[0077] This embodiment provides a low-odor recycled polypropylene composite material, the preparation method of which includes the following steps:

[0078] Compared with Example 3, the components were added according to the ratio in Table 2, and the remaining raw materials and preparation process were the same as in Example 3.

[0079] The components of Comparative Examples 1 to 4 in Table 2 were added in parts by weight.

[0080] Table 2

[0081]

[0082]

[0083] The low-odor recycled polypropylene composite materials prepared in Examples 3 to 8 and Comparative Examples 1 to 4 were tested for tensile strength, flexural strength, flexural modulus, and Izod notched impact strength according to the standards. The odor level test method was based on the Volkswagen PV3900 test method. The specific odor level test method is as follows:

[0084] Place 20g of the above sample into a test vessel and place it in an oven for 2 hours. The oven temperature is set at (80±2)℃. The test vessel must be tightly sealed. After the test vessel is taken out of the oven, wait for it to cool to 60℃, slightly remove the lid, and have its odor evaluated by a professional odor assessor. The odor level of the material is divided into the following standards: Level 1: No odor, Level 2: Odor, but no disturbing odor, Level 3: Obvious odor, but no disturbing odor, Level 4: Disturbing odor, Level 5: Strongly disturbing odor, Level 6: Unbearable odor.

[0085] The test results are shown in Tables 3 and 4.

[0086] Table 3

[0087]

[0088]

[0089] Table 4

[0090] Physical properties Test standards Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Tensile strength MPa GB / T1040 17.4 18.3 16.7 16.5 Bending strength MPa GB / T9341 26.0 25.7 24.8 25.0 Flexural modulus MPa GB / T9341 1883 1903 1859 1842 <![CDATA[Izod impact strength KJ / m 2 > GB / T1843 14.1 14.7 12.8 13.2 Odor level Popular Standards 4.5 4.5 4 5.5

[0091] The test results of Comparative Examples 3 and 4 show that the introduction of recycled polypropylene into the formulation slightly reduces the basic mechanical properties of the prepared composite material, but significantly worsens the odor. The test results of Comparative Examples 1-2 show that the addition of single-component MOFs and TiO2 nanoparticles can also reduce the odor level, but the effect is limited. The test results of Examples 3-8 show that increasing the total amount of odor suppressant added can significantly improve the odor situation, with the final odor level reaching 3.5, which is better than the odor level of new material, and has little effect on the basic mechanical properties of the product. The optimal ratio of MOFs to TiO2 nanoparticles is 2:1. From the above examples, it can be seen that MOFs and nano-TiO2 can remove volatile small molecules generated during extrusion and injection molding through the synergistic effects of adsorption and catalysis, which helps to prepare low-odor polypropylene composite materials, effectively promotes the recycling of waste polypropylene, and can be used in automotive interior and exterior trim.

[0092] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0093] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A low-odor recycled polypropylene composite material, characterized in that: The low-odor recycled polypropylene composite material comprises the following raw materials in parts by weight: 60-80 parts of PP resin; 5-10 parts of toughening agent; 20-30 parts of filler; 0.2-0.5 parts of antioxidant; 0.2-0.5 parts of lubricant; Compatibilizer 0.2-3 parts; 0.3-1.5 parts of odor suppressant; The odor suppressant is compounded by MOFs material and TiO2; The odor suppressant is prepared by compounding MOFs material and TiO2 in a mass ratio of 1:0.5 to 2; The synthesis steps of the MOFs material are as follows: The zirconium source and benzoic acid are added to N,N-dimethylformamide, followed by the addition of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, and the mixture is transferred to a sealed container, heated to 110-120°C, maintained for 24-48 hours, and then centrifuged, washed, soaked, centrifuged, and dried to obtain a MOFs material. The PP resin is a mixture of recycled polypropylene and copolymerized polypropylene.

2. The low-odor recycled polypropylene composite material according to claim 1, characterized in that: The TiO2 is anatase TiO2 with a particle size of 50 to 100 nm.

3. The low-odor recycled polypropylene composite material according to claim 1, characterized in that: The zirconium source is ZrOCl2·8H2O or ZrCl4; the mass ratio of the zirconium source, benzoic acid, N,N-dimethylformamide and 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene is 3:50:180:

1.

4. A method for preparing the low-odor recycled polypropylene composite material according to any one of claims 1 to 3, characterized in that: The following steps are involved: PP resin, toughening agent, filler, antioxidant, lubricant compatibilizer and odor inhibitor are mixed and stirred to obtain a mixture; the mixture is put into a parallel twin-screw extruder for melting and extrusion granulation to obtain a low-odor recycled polypropylene composite material.

5. An application of the low-odor recycled polypropylene composite material according to any one of claims 1 to 3, characterized in that: Used in the preparation of automotive interior and exterior trims.

Images