PP regenerated material containing bio-based fibers and preparation method thereof

Abstract

The invention relates to the technical field of PP waste plastic recycling and processing, in particular to a PP regenerated material containing bio-based fibers and a preparation method thereof.The PP regenerated material is prepared from, by weight, 40-60 parts of PP waste plastic, 40-50 parts of bio-based fibers, 15-20 parts of modified starch, 2-5 parts of compatilizer, 2-4 parts of flexibilizer, 5-10 parts of lubricant and 4-8 parts of dispersing agent. By adopting the formula, the compatibility of the bio-based fiber and the PP waste plastic can be greatly improved, so that the bio-based fiber and the PP waste plastic are fully mixed, and the formed PP reclaimed material containing the bio-based fiber has good comprehensive properties such as tensile strength, bending modulus, impact resistance and weather resistance, and can be widely applied to the fields of automobiles, household appliances, electronics and the like.

Description

Technical Field

[0001] The present application relates to the technical field of PP waste plastic recycling and processing, and more specifically, to a PP recycled material containing bio-based fibers and a preparation method thereof. Background Art

[0002] PP plastic (polypropylene) is a common plastic material with good mechanical properties, chemical corrosion resistance and thermal stability. However, as PP plastic is used more and more widely, more PP waste plastic is generated, and the pollution to the environment is more serious. Therefore, the recycling of PP plastic is becoming more and more important.

[0003] At present, there are four main ways to recycle PP plastics. The first is to convert discarded PP plastic products into reusable plastic particles through steps such as sorting, cleaning, crushing and smelting. This method is relatively simple, but may lead to a decline in the performance of plastics; the second is to decompose PP waste plastics into monomers or small molecules through chemical methods, and then further synthesize new plastic materials. This method can maintain the original properties of plastics, but the technical difficulty and cost are high; the third is to incinerate discarded PP plastics as fuel to generate energy; although this method can reduce the volume of plastic waste, it may produce harmful gases and requires an efficient emission treatment system; the fourth is to compound PP waste plastics with other materials (such as fibers, polyurethane, polyethylene, polyvinyl chloride, etc.) to prepare composite materials with specific properties. No harmful substances will be produced in this process, nor will the performance of PP plastics be degraded. The technical difficulty will not be as difficult as the chemical method, so the fourth is the best choice.

[0004] Among them, bio-based fiber is an environmentally friendly and high-performance fiber material. Bio-based fiber is made of biomass or polymers containing biomass-derived monomers, and belongs to a large category of green fiber. The composite material obtained by compounding PP plastic with bio-based fiber has good mechanical properties, which can not only solve the recycling problem of PP waste plastics, but also greatly improve environmental protection and can be used in the fields of automobiles, home appliances, electronics, etc.

[0005] However, there are problems of uneven dispersion and poor interface compatibility between bio-based fibers and PP waste plastics, which will affect the comprehensive performance of composite materials. For example, the tensile strength, weather resistance and other properties will decrease, which will limit the application of composite materials. Summary of the invention

[0006] In order to solve the problems of uneven dispersion and poor interface compatibility between bio-based fibers and PP waste plastics, the present application provides a PP recycled material containing bio-based fibers and a preparation method thereof.

[0007] In a first aspect, the present application provides a PP recycled material containing bio-based fibers, using the following technical solution: A PP recycled material containing bio-based fibers is prepared from raw materials including the following parts by weight: 40-60 pieces of PP waste plastic 40-50 parts of bio-based fiber Modified starch 15-20 parts Compatibilizer 2-5 parts Toughener 2-4 parts Lubricant 5-10 parts Dispersant 4-8 parts.

[0008] By adopting the above technical solution, the compatibility of bio-based fibers and PP waste plastics is greatly improved, so that the two are fully mixed with each other. The formed PP recycled material containing bio-based fibers has good mechanical properties, such as good tensile strength, flexural modulus and impact strength. It also has good weather resistance and can be widely used in automobiles, home appliances, electronics and other fields.

[0009] Among them, modified starch, as a bio-based compatibilizer, can improve the interfacial compatibility between bio-based fibers and PP waste plastics. Modified starch is made from ordinary starch after esterification or etherification treatment, which can enhance its dispersibility and compatibility in non-polar PP waste plastics. At the same time, the compatibilizer can reduce the interfacial tension between bio-based fibers and PP waste plastics and improve the compatibility between the two. The synergistic effect of the compatibilizer and modified starch will greatly improve the dispersibility of PP waste plastics. Bio-based fibers have poor compatibility with PP waste plastics, and the interface bonding is unstable. The common use of the two is prone to cracking and other phenomena. The toughening agent can form a good interface bonding with PP waste plastics and bio-based fibers, reducing stress concentration and cracking caused by poor interface bonding. By adding an appropriate amount of dispersant, the bio-based fibers can be more evenly dispersed in the PP waste plastic matrix. The dispersant can effectively prevent the agglomeration of bio-based fibers and PP waste plastics and improve the overall uniformity of the material. Lubricants can significantly improve the processing fluidity of the blending system of bio-based fibers and PP waste plastics. During the processing, lubricants can reduce the viscosity and cohesion of the melt, making the composite material easier to flow and form.

[0010] Preferably, the compatibilizer is prepared by the following method: A: Add polyethylene glycol ether, initiator, cyclohexyl acrylate and solvent into a reaction vessel, evacuate the reaction system, fill it with nitrogen, heat it to 80-100°C, react for 4-6h, and obtain reactant A; B: Mix polypropylene and dimethylformamide, and heat to 60-80°C until the polypropylene is dissolved to obtain a polypropylene solution; C: Under a nitrogen atmosphere, reactant A is mixed with maleic anhydride and a catalyst, the temperature is raised to 70-80°C, heated for 30-50 minutes, and then a polypropylene solution is added, the temperature is raised to 100-120°C, the reaction is carried out for 4-6 hours, and the solvent and dimethylformamide are recovered to obtain a compatibilizer.

[0011] By adopting the above-mentioned technical scheme, the compatibilizer prepared can greatly improve the compatibility between bio-based fibers and PP waste plastics, so that they can be fully mixed during the processing process to obtain PP recycled materials containing bio-based fibers with good comprehensive performance.

[0012] In step A, functional groups such as carboxyl and hydroxyl groups are introduced into the compatibilizer by reacting polyethylene glycol ether, initiator and cyclohexyl acrylate, providing polar groups similar to those of bio-based fibers, which facilitate the interaction between the compatibilizer and the bio-based fibers, thereby enhancing the bonding force between the bio-based fibers and PP waste plastics.

[0013] In step B, polypropylene is dissolved to facilitate the subsequent reaction of polypropylene with reactant A, maleic anhydride and catalyst. In step C, polypropylene is reacted with reactant A, maleic anhydride and catalyst to introduce anhydride groups, which can react with hydroxyl or carboxyl groups in bio-based fibers to further improve the binding force between bio-based fibers and PP waste plastics. At the same time, the addition of polypropylene solution not only provides a structure similar to PP waste plastics, but also can form a stable composite with reactant A and maleic anhydride. This composite has functional groups and structures that are compatible with both bio-based fibers and PP waste plastics, thereby significantly improving the compatibility between them, thereby improving the comprehensive properties of PP recycled materials containing bio-based fibers, such as tensile strength, flexural modulus, impact strength and weather resistance.

[0014] Preferably, the weight parts of the raw materials used to prepare the compatibilizer are as follows: Polyethylene glycol ether 10-15 parts Initiator 0.5-1 part Cyclohexyl acrylate 5-10 parts 40-50 parts of solvent Polypropylene 5-10 parts 20-40 parts of dimethylformamide 4-6 parts of maleic anhydride 1-2 parts of catalyst.

[0015] By adopting the above technical scheme, the amount of raw materials used in preparing the compatibilizer is optimized, so that the polyethylene glycol ether, the initiator and the cyclohexyl acrylate can fully react to obtain the reactant A, and the reactant A can fully react with maleic anhydride and the catalyst to obtain the compatibilizer, thereby improving the reaction efficiency.

[0016] Preferably, the molecular weight of the polyethylene glycol ether is 500-4000.

[0017] By adopting the above technical solution, the molecular weight of the polyethylene glycol ether is optimized, which is conducive to the reaction with cyclohexyl acrylate. If the high molecular weight polyethylene glycol ether chain segment is long and the activity is poor, the reaction will be delayed.

[0018] Preferably, the modified starch is at least one of carboxymethyl starch, distarch phosphate, acetylated starch and hydroxypropyl starch.

[0019] By adopting the above technical solution, the type of modified starch is optimized, and the interface compatibility between bio-based fibers and PP waste plastics is further improved, so that the comprehensive performance of PP recycled materials containing bio-based fibers is better.

[0020] Preferably, the PP waste plastic needs to be pre-treated by the following steps: The PP waste plastic is crushed, and then the PP waste plastic is soaked in hydrogen peroxide for 4-6 hours, taken out, and dried to obtain the pretreated PP waste plastic.

[0021] By adopting the above technical solution, grease, dirt, pigments and other organic pollutants on the surface of PP waste plastics can be removed. At the same time, the surface of PP waste plastics can also be given hydroxyl groups. The compatibility of PP waste plastics with hydroxyl groups and bio-based fibers will be further improved, making the comprehensive performance of PP recycled materials containing bio-based fibers better.

[0022] Preferably, the dispersant is obtained by mixing polymethyl acrylate, polyvinyl acetate and polypropylene alcohol in a weight ratio of (4-6): (8-10): 3.

[0023] By adopting the above technical solution and further optimizing the type and amount of dispersant, the dispersion stability of bio-based fibers and PP waste plastics can be greatly improved, and the comprehensive properties of PP recycled materials containing bio-based fibers, such as tensile strength, flexural modulus, impact strength and weather resistance, can be further improved.

[0024] Preferably, the lubricant includes at least one of silicone oil, stearamide, paraffin, pentaerythritol stearate, N,N-ethylene bisstearamide and mineral oil.

[0025] By adopting the above technical solution, the type of lubricant is optimized, the dispersion degree between bio-based fibers and PP waste plastics is further improved, and the two are fully mixed, thereby improving the comprehensive properties of PP recycled materials containing bio-based fibers, such as tensile strength, flexural modulus, impact strength and weather resistance.

[0026] Preferably, the toughening agent includes at least one of trioctyl trimellitate, tributyl citrate, epoxy fatty acid butyl ester, epoxy soybean oil, azelaic acid ester and sebacic acid ester.

[0027] By adopting the above technical solution, the types of toughening agents are optimized, and the toughness and mechanical strength of PP recycled materials containing bio-based fibers are further improved, making it less likely to crack during use.

[0028] In a second aspect, the present application provides a method for preparing a PP recycled material containing bio-based fibers, using the following technical solution: A method for preparing PP recycled material containing bio-based fibers comprises the following preparation steps: S1, mixing PP waste plastic, bio-based fiber and a compatibilizer to obtain a mixture A; S2. Mix the mixture A, modified starch, toughening agent, lubricant and dispersant, and then place the mixture in a twin-screw extruder for extrusion and granulation to obtain a PP recycled material containing bio-based fibers.

[0029] Preferably, the temperature of the feeding section of the twin-screw extruder is 170-190°C, the temperature of the plasticizing section is 190-210°C, the temperature of the homogenizing section is 200-210°C, and the screw speed is 500-800rpm.

[0030] By adopting the above technical scheme, the prepared PP recycled material containing bio-based fibers has comprehensive properties such as good tensile strength, flexural modulus, impact strength and weather resistance, and the preparation process is simple and convenient, and a large amount of PP waste plastics can be used to improve environmental protection.

[0031] In summary, this application has the following beneficial effects: 1. The PP recycled material containing bio-based fibers prepared by this application has excellent tensile strength, bending modulus, impact resistance, weather resistance and environmental protection performance. At the same time, this technology also has the advantages of simple process, low cost and easy industrial production.

[0032] 2. The PP recycled material containing bio-based fibers prepared in this application can be widely used in the fields of automobiles, home appliances, electronics, etc., for the production of high-performance, environmentally friendly parts and products, reducing production costs while improving the environmental performance of products.

[0033] 3. The compatibilizer obtained by the preparation method in this application can greatly improve the compatibility between bio-based fibers and PP waste plastics, so that they can be fully mixed during the processing process to obtain PP recycled materials containing bio-based fibers with better comprehensive properties such as tensile strength, flexural modulus, impact resistance and weather resistance. DETAILED DESCRIPTION Example

[0034] The bio-based fiber is bamboo powder starch rice husk plant fiber, purchased from Dongguan Huike Polymer Technology Co., Ltd., with a density of 1.1088g / cm 3 .

[0035] Example 1.

[0036] A PP recycled material containing bio-based fibers is prepared by the following method: S1, mixing 400 g of PP waste plastic, 400 g of bio-based fiber and 20 g of compatibilizer to obtain a mixture A; S2. Mix mixture A, 150 g of modified starch, 20 g of toughening agent (trioctyl trimellitate), 50 g of lubricant (silicone oil) and 40 g of dispersant (polymethyl acrylate), and then place them in a twin-screw extruder for extrusion and granulation to obtain PP recycled material containing bio-based fibers.

[0037] The feeding section temperature of the twin-screw extruder was 170°C, the plasticizing section temperature was 190°C, the homogenizing section temperature was 200°C, and the screw speed was 500 rpm.

[0038] The modified starch was carboxymethyl starch, which was purchased from Langfang Changlin Cellulose Co., Ltd.

[0039] Silicone oil was purchased from Suzhou Jusheng Chemical Co., Ltd. with model number JS-00123.

[0040] Polymethyl acrylate was purchased from Wuhan Kanosi Technology Co., Ltd., CAS 9003-21-8.

[0041] The compatibilizer was maleic anhydride grafted PP, purchased from Dongguan Xingyuan Chemical Co., Ltd., model number XYJ1210.

[0042] The difference between Example 2-3 and Example 1 is that the types, amounts and experimental parameters of some raw materials for preparing the PP recycled material containing bio-based fibers are different. The specific differences are shown in Table 1: Table 1 Types, amounts and experimental parameters of PP recycled materials containing bio-based fibers prepared in Examples 1-3 Polyvinyl acetate was purchased from Shandong Xinghai Chemical Co., Ltd. with model number XH-018.

[0043] Polypropylene alcohol was purchased from Taizhou Jiayin Chemical Co., Ltd., CAS 25322-69-4.

[0044] Example 4 A PP recycled material containing bio-based fibers, the difference between this embodiment and embodiment 1 is that the compatibilizer is prepared by the following method: A: 100 g of polyethylene glycol ether, 5 g of initiator (benzoyl peroxide), 50 g of cyclohexyl acrylate and 400 g of solvent (isopropanol) were added to a reaction vessel, the reaction system was evacuated and filled with nitrogen, the temperature was raised to 80° C., and the reaction was carried out for 4 hours to obtain reactant A; B: Mix 50 g of polypropylene and 200 g of dimethylformamide, and heat to 60°C until the polypropylene is dissolved to obtain a polypropylene solution; C: Under a nitrogen atmosphere, reactant A was mixed with 40 g of maleic anhydride and 10 g of catalyst (erbium oxide), the temperature was raised to 70°C, heated for 30 min, polypropylene solution was added, the temperature was raised to 100°C, the reaction was carried out for 4 h, the solvent and dimethylformamide were recovered, and a compatibilizer was obtained.

[0045] The molecular weight of the polyethylene glycol ether is 500.

[0046] Polypropylene was purchased from Dongguan Zhimao Plastic Raw Materials Co., Ltd. The brand is Basell and the grade is 7823.

[0047] Example 5 A PP recycled material containing bio-based fibers, the difference between this embodiment and embodiment 1 is that the compatibilizer is prepared by the following method: A: 150 g of polyethylene glycol ether, 10 g of initiator (azobisisocyanate), 100 g of cyclohexyl acrylate and 500 g of solvent (acetone) were added into a reaction vessel, the reaction system was evacuated and filled with nitrogen, the temperature was raised to 100° C., and the reaction was carried out for 6 h to obtain reactant A; B: Mix 100 g of polypropylene and 400 g of dimethylformamide, and heat to 80° C. until the polypropylene is dissolved to obtain a polypropylene solution; C: Under a nitrogen atmosphere, reactant A was mixed with 60 g of maleic anhydride and 20 g of catalyst (cerium oxide), the temperature was raised to 80°C, heated for 50 min, polypropylene solution was added, the temperature was raised to 120°C, the reaction was carried out for 6 h, the solvent and dimethylformamide were recovered, and a compatibilizer was obtained.

[0048] The molecular weight of polyethylene glycol ether is 4000.

[0049] Polypropylene was purchased from Dongguan Zhimao Plastic Raw Materials Co., Ltd. The brand is Basel and the grade is 7823 Example 6 A PP recycled material containing bio-based fibers. The difference between this embodiment and embodiment 4 is that an equal amount of solvent is used instead of polyethylene glycol ether, and the types, amounts and experimental parameters of other raw materials are consistent with those of embodiment 4.

[0050] Example 7 A PP recycled material containing bio-based fibers. The difference between this embodiment and embodiment 4 is that an equal amount of solvent is used instead of cyclohexyl acrylate, and the types, amounts and experimental parameters of other raw materials are consistent with those of embodiment 4.

[0051] Example 8 A PP recycled material containing bio-based fibers. The difference between this embodiment and embodiment 4 is that an equal amount of dimethylformamide is used instead of polypropylene, and the types, amounts and experimental parameters of other raw materials are consistent with those of embodiment 4.

[0052] Example 9 A PP recycled material containing bio-based fibers. The difference between this embodiment and embodiment 4 is that maleic anhydride is omitted, and the types, amounts and experimental parameters of other raw materials are consistent with those of embodiment 4.

[0053] Example 10 A PP recycled material containing bio-based fibers. The difference between this embodiment and embodiment 1 is that the compatibilizer is ethylene-methyl acrylate copolymer, and the types, amounts and experimental parameters of other raw materials are consistent with those in embodiment 1.

[0054] Ethylene-methyl acrylate copolymer was purchased from Dongguan Kaiwan Engineering Plastic Raw Materials Co., Ltd. with the brand number 2116AC.

[0055] Embodiment 11 A PP recycled material containing bio-based fibers. The difference between this embodiment and embodiment 1 is that the compatibilizer is POE-g-GMA, and the types, amounts and experimental parameters of other raw materials are consistent with those in embodiment 1.

[0056] POE-g-GMA was purchased from Jiangsu Rayne Environmental Protection Technology Co., Ltd. and has a melting point of 62°C (143.6°F).

[0057] Example 12 A PP recycled material containing bio-based fibers, the difference between this embodiment and embodiment 1 is that the PP waste plastic needs to be pre-treated by the following steps: The PP waste plastic is crushed, and then the PP waste plastic is soaked in hydrogen peroxide for 4 hours, taken out, and dried to obtain the pretreated PP waste plastic.

[0058] The mass concentration of hydrogen peroxide is 10%.

[0059] Embodiment 13 A PP recycled material containing bio-based fibers, the difference between this embodiment and embodiment 4 is that the PP waste plastic needs to be pre-treated by the following steps: The PP waste plastic is crushed, and then the PP waste plastic is soaked in hydrogen peroxide for 4-6 hours, taken out, and dried to obtain the pretreated PP waste plastic.

[0060] The mass concentration of hydrogen peroxide is 15%.

[0061] Embodiment 14 A PP recycled material containing bio-based fibers. The difference between this embodiment and embodiment 1 is that the dispersant is obtained by mixing 10.7 g of polymethyl acrylate, 21.3 g of polyvinyl acetate, and 8 g of polypropylene alcohol in a weight ratio of 4:8:3.

[0062] Embodiment 15 A PP recycled material containing bio-based fibers. The difference between this embodiment and Embodiment 13 is that the dispersant is obtained by mixing 12.6 g of polymethyl acrylate, 21.1 g of polyvinyl acetate, and 6.3 g of polypropylene alcohol in a weight ratio of 6:10:3.

[0063] Comparative Example Comparative Example 1 A PP recycled material containing bio-based fibers. The difference between this comparative example and Example 1 is that ordinary starch is used instead of modified starch of equal mass, and the types, amounts and experimental parameters of other raw materials are consistent with those in Example 1.

[0064] Starch was purchased from Suzhou Jubaiyi Chemical Technology Co., Ltd. and the model was corn starch.

[0065] Comparative Example 2 A PP recycled material containing bio-based fibers. The difference between this comparative example and Example 1 is that the dispersant is omitted, and the types, amounts and experimental parameters of other raw materials are consistent with those in Example 1.

[0066] Comparative Example 3 A PP recycled material containing bio-based fibers. The difference between this comparative example and Example 1 is that the lubricant is omitted, and the types, amounts and experimental parameters of other raw materials are consistent with those in Example 1.

[0067] Performance testing The PP recycled materials containing bio-based fibers prepared in Examples 1-15 and Comparative Examples 1-3 were prepared into test specimens, and then subjected to tensile property tests, flexural modulus tests, flexural modulus tests, and aging resistance tests.

[0068] Detection method / test method Tensile properties test: refer to the national standard GB / T1040.2-2006 "Determination of tensile properties of plastics Part 2: Test conditions for molded and extruded plastics" method for testing; the test specimen is 1A type dumbbell type, thickness 4mm, test speed 1mm / min, before the test, the sample is regulated at a constant temperature of 23°C and relative humidity of 50% for 24 hours, 6 parallel groups, and the average value is taken.

[0069] Bending modulus test: refer to the national standard GB / T 9341-008 "Test of plastic bending properties" method for testing. Before testing the sample, place the sample at a temperature of 23°C and a relative humidity of 50% for debugging for 90 hours. The sample size is 8cm*1cm*0.4cm in length, width and thickness. Six parallel groups are used to take the average value.

[0070] Flexural modulus test: refer to the national standard GB / T 1843-2008 "Determination of cantilever beam impact strength of plastics" method for testing. Before the test, the sample is placed at a temperature of 23°C and a relative humidity of 50% for debugging for 20 hours. Notch type: Type A, 6 parallel groups, take the average value.

[0071] Aging resistance test: Refer to GB / T16422.2-2014 (Plastic laboratory light source exposure test method). In order to simulate sunlight, a filter is used to filter the xenon arc lamp. According to method A cycle number 1, the exposure cycle is carried out. After 500 hours of irradiation, the impact strength is tested, and then the tensile properties, bending modulus and impact resistance are tested. The experimental data are shown in Table 2: Table 2 Experimental data of Examples 1-15 and Comparative Examples 1-3 It can be seen from Examples 1-15 and Comparative Examples 1-3 in combination with Table 2 that in the present application, by using PP waste plastic, bio-based fiber, modified starch, compatibilizer, toughening agent, lubricant and dispersant together, the compatibility of PP waste plastic and bio-based fiber can be greatly promoted, and the tensile strength, flexural modulus, impact resistance and aging resistance of PP recycled material containing bio-based fiber can be effectively improved.

[0072] By comparing Example 1 with Comparative Examples 1-3, the tensile strength, flexural modulus and impact resistance of Comparative Examples 1-3 are not as good as those of Example 1; and after aging tests, the changes in tensile strength, flexural modulus and impact resistance of Comparative Examples 1-3 are significantly higher than those of Example 1. It can be seen that the addition of an appropriate amount of modified starch, lubricant and dispersant in the present application is beneficial to improving the tensile strength, flexural modulus, impact resistance and aging resistance of the PP recycled material containing bio-based fibers.

[0073] By comparing Example 1 with Example 4-5, the tensile strength, bending modulus and impact resistance of Example 4-5 are significantly better than those of Example 1; and after the aging test, the change in tensile strength, bending modulus and impact resistance of Example 4-5 is basically unchanged; By comparing Example 4 with Examples 6-9, the tensile strength, bending modulus and impact resistance of Examples 4-5 are significantly better than those of Examples 6-9; and after the aging test, the changes in tensile strength, bending modulus and impact resistance of Examples 6-9 increase; Comparing Example 1 with Examples 10-11, the tensile strength, flexural modulus and impact resistance of Examples 1 and 10-11 are substantially the same, and the changes in tensile strength, flexural modulus and impact resistance are substantially the same.

[0074] It can be seen from Examples 1, 4-9, 10-11 that the compatibilizer obtained by the formula and preparation method in this application can greatly improve the compatibility between PP waste plastics and bio-based fibers, thereby improving the tensile strength, flexural modulus, impact resistance and aging resistance of PP recycled materials containing bio-based fibers.

[0075] Comparing Example 1 with Example 12, the tensile strength, flexural modulus and impact resistance of Example 12 are significantly better than those of Example 1; and after the aging test, the changes in tensile strength, flexural modulus and impact resistance of Example 12 are reduced, indicating that the tensile strength, flexural modulus, impact resistance and aging resistance of the PP recycled material containing bio-based fibers can be further improved by pretreating the PP waste plastic.

[0076] Comparing Example 1 with Example 14, the tensile strength, flexural modulus and impact resistance of Example 14 are significantly better than those of Example 1; and after the aging test, the changes in tensile strength, flexural modulus and impact resistance of Example 12 are reduced, indicating that the tensile strength, flexural modulus, impact resistance and aging resistance of the PP recycled material containing bio-based fibers can be further improved by optimizing the type and amount of the dispersant.

[0077] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A PP recycled material containing bio-based fibers, characterized in that: Prepared from the following raw materials in parts by weight: 40-60 pieces of PP waste plastic 40-50 parts of bio-based fiber Modified starch 15-20 parts Compatibilizer 2-5 parts Toughener 2-4 parts Lubricant 5-10 parts Dispersant 4-8 parts.

2. The PP recycled material containing bio-based fibers according to claim 1, characterized in that: The compatibilizer is prepared by the following method: A: Add polyethylene glycol ether, initiator, cyclohexyl acrylate and solvent into a reaction vessel, evacuate the reaction system, fill it with nitrogen, heat it to 80-100°C, react for 4-6h, and obtain reactant A; B: Mix polypropylene and dimethylformamide, and heat to 60-80°C until the polypropylene is dissolved to obtain a polypropylene solution; C: Under a nitrogen atmosphere, reactant A is mixed with maleic anhydride and a catalyst, the temperature is raised to 70-80°C, heated for 30-50 minutes, and then a polypropylene solution is added, the temperature is raised to 100-120°C, the reaction is carried out for 4-6 hours, and the solvent and dimethylformamide are recovered to obtain a compatibilizer.

3. The PP recycled material containing bio-based fibers according to claim 2, characterized in that: The weight parts of the raw materials used to prepare the compatibilizer are as follows: Polyethylene glycol ether 10-15 parts Initiator 0.5-1 part Cyclohexyl acrylate 5-10 parts 40-50 parts of solvent Polypropylene 5-10 parts 20-40 parts of dimethylformamide 4-6 parts of maleic anhydride 1-2 parts of catalyst.

4. The PP recycled material containing bio-based fibers according to claim 3, characterized in that: The molecular weight of the polyethylene glycol ether is 500-4000.

5. The PP recycled material containing bio-based fibers according to claim 1, characterized in that: The modified starch is at least one of carboxymethyl starch, distarch phosphate, acetylated starch and hydroxypropyl starch.

6. The PP recycled material containing bio-based fibers according to claim 4, characterized in that: The PP waste plastic needs to be pre-treated by the following steps: The PP waste plastic is crushed, and then the PP waste plastic is soaked in hydrogen peroxide for 4-6 hours, taken out, and dried to obtain the pretreated PP waste plastic.

7. The PP recycled material containing bio-based fibers according to claim 1, characterized in that: The dispersant is obtained by mixing polymethyl acrylate, polyvinyl acetate and polypropylene alcohol in a weight ratio of (4-6): (8-10):

3.

8. The PP recycled material containing bio-based fibers according to claim 1, characterized in that: The lubricant includes at least one of silicone oil, stearic acid amide, paraffin, pentaerythritol stearate, N,N-ethylene bisstearamide and mineral oil.

9. The PP recycled material containing bio-based fibers according to claim 1, characterized in that: The toughening agent includes at least one of trioctyl trimellitate, tributyl citrate, epoxy fatty acid butyl ester, epoxy soybean oil, azelaic acid ester and sebacate.

10. A method for preparing a PP recycled material containing bio-based fibers as claimed in any one of claims 1 to 9, characterized in that: The method comprises the following preparation steps: S1, mixing PP waste plastic, bio-based fiber and a compatibilizer to obtain a mixture A; S2. Mix the mixture A, modified starch, toughening agent, lubricant and dispersant, and then place the mixture in a twin-screw extruder for extrusion and granulation to obtain a PP recycled material containing bio-based fibers.

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