Polypropylene material for logistics turnover and preparation process thereof

Abstract

The present application relates to the technical field of polypropylene material, in particular to a kind of polypropylene material for logistics turnover and preparation process thereof.The polypropylene material for logistics turnover includes the following weight components: polypropylene 80-100 parts, modified nano zinc oxide 10-15 parts, talcum powder 5-10 parts, nucleating agent 3-5 parts, lubricant 0.5-1.5 parts, antioxidant 0.5-1.0 parts, stabilizer 0.5-1.0 parts.The present application obtains mixed material by the following steps: S1: polypropylene, modified nano zinc oxide, talcum powder, nucleating agent, lubricant, antioxidant and stabilizer are stirred uniformly;S2: the mixed material is added into double-screw extruder to melt blend, extrude, foam, and obtain the polypropylene material for logistics turnover, which not only has excellent mechanical properties, but also has excellent antibacterial properties and aging resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polypropylene materials, in particular to a polypropylene material for logistics turnover and a preparation process thereof. BACKGROUND

[0002] With the rapid development of e-commerce, the logistics turnover volume is growing exponentially. Polypropylene (PP) is a widely used thermoplastic plastic, which gradually becomes an important material in the field of logistics turnover due to its good mechanical properties, chemical resistance and lightweight characteristics. Polypropylene not only has excellent forming properties and cost-effectiveness, but also exhibits great flexibility and adaptability in packaging, storage and transportation.

[0003] However, polypropylene itself does not have antibacterial properties and is prone to bacterial and microbial growth in humid or warm environments. In particular, during fruit and vegetable transportation, polypropylene turnover boxes may be affected by fruit spoilage, which affects food safety and hygiene and restricts its reuse in the logistics turnover process. In addition, polypropylene has weak resistance to ultraviolet light, which can cause its physical properties to decline, such as embrittlement, reduced strength, and yellowing of color, which limits its application in outdoor or direct sunlight environments.

[0004] Therefore, we propose a polypropylene material for logistics turnover and a preparation process thereof. SUMMARY

[0005] The present application aims to provide a polypropylene material for logistics turnover and a preparation process thereof to solve the problems in the prior art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] A preparation process of a polypropylene material for logistics turnover, comprising the following steps:

[0008] Step S1: uniformly stirring polypropylene, modified nano zinc oxide, talcum powder, nucleating agent, lubricant, antioxidant and stabilizer to obtain a mixture;

[0009] Step S2: adding the mixture into a twin-screw extruder for melt blending, extruding, and foaming to obtain a polypropylene material for logistics turnover.

[0010] Further, the polypropylene material for logistics turnover comprises the following weight components: polypropylene 80-100 parts, modified nano zinc oxide 10-15 parts, talcum powder 5-10 parts, nucleating agent 3-5 parts, lubricant 0.5-1.5 parts, antioxidant 0.5-1.0 parts, and stabilizer 0.5-1.0 parts.

[0011] Further, the preparation method of the modified nano zinc oxide is as follows:

[0012] Step A: under nitrogen protection, mix nano zinc oxide, anhydrous ethanol and deionized water uniformly, heat to 70-80℃, add γ-(methacryloyloxy) propyl trimethoxysilane, react for 4-6h, after centrifugation, washing, drying, obtain nano zinc oxide containing double bond;

[0013] Step B: mix nano zinc oxide containing double bond and deionized water uniformly, add methyl methacrylate, modified lignin and 4-epoxy isoeugenol, pass nitrogen, add potassium persulfate, react at 70-80℃ for 10-12h, after centrifugation, washing, drying, obtain epoxy compound;

[0014] Step C: mix epoxy compound, p-aminodiphenylamine and ethanol uniformly, react at 60-70℃ for 5-10h, after filtration, washing, drying, obtain modified nano zinc oxide.

[0015] Further, in step A, the mass ratio of nano zinc oxide, anhydrous ethanol, deionized water and γ-(methacryloyloxy) propyl trimethoxysilane is 1: (15-20): (3-5): (2-4).

[0016] Further, in step B, the mass ratio of nano zinc oxide containing double bond and deionized water is 1: (50-80).

[0017] Further, in step B, the mass ratio of nano zinc oxide containing double bond, methyl methacrylate, modified lignin and 4-epoxy isoeugenol is 1: (1-2): (2-4): (0.5-1.5).

[0018] Further, the amount of potassium persulfate is 1-3% of the total mass of nano zinc oxide containing double bond, methyl methacrylate, modified lignin and 4-epoxy isoeugenol.

[0019] Further, the preparation method of modified lignin is as follows:

[0020] Add alkali lignin and sodium hydroxide to the mixed solution of dimethyl sulfoxide and deionized water, stir until dissolved, heat to 90-100℃, add glycidyl methacrylate, react for 3-5h, after dialysis, drying, obtain double-bond-containing lignin;

[0021] Mix double-bond-containing lignin and sodium hydroxide solution uniformly, heat to 80-90℃, add 3-chloro-2-hydroxypropyl trimethyl ammonium chloride, react for 4-6h, after dialysis, drying, obtain modified lignin.

[0022] Further, the mass ratio of alkali lignin, sodium hydroxide and glycidyl methacrylate is 1: (0.2-0.4): (2-3).

[0023] Further, the mixed solution is composed of dimethyl sulfoxide and deionized water in a mass ratio of 1:1, and the amount is 15-20 times of the alkali lignin.

[0024] Further, the mass ratio of the double-bond-containing lignin, the sodium hydroxide solution and 3-chloro-2-hydroxypropyl trimethyl ammonium chloride is 1:(15-20):(0.3-0.5), and the concentration of the sodium hydroxide solution is 20wt%.

[0025] In the above technical solution, glycidyl methacrylate (GMA) is used as a modifier, and the unsaturated double bond is grafted to the lignin by the reaction between the epoxy group and the hydroxyl group of the lignin to obtain the double-bond-containing lignin; meanwhile, the ether bond is generated by the reaction between the epoxy group and the hydroxyl group, and new hydroxyl groups are generated in the side chain, so that continuous graft modification can be realized, and the 3-chloro-2-hydroxypropyl trimethyl ammonium chloride is used for modification to obtain the double-bond-containing quaternary ammonium lignin, i.e., the modified lignin.

[0026] Further, the mass ratio of the epoxy compound, the p-aminodiphenylamine and the ethanol is 1:(2-4):(15-20).

[0027] Further, the lubricant is polyethylene wax.

[0028] Further, the stabilizer is an organic tin stabilizer.

[0029] Further, the temperature of each zone of the twin-screw extruder is as follows: the first zone is 178-182 DEG C, the second zone is 188-192 DEG C, the third zone is 198-202 DEG C, the fourth zone is 208-212 DEG C, the fifth zone is 220-225 DEG C, and the die head is 215-220 DEG C; and the screw rotation speed is 120-180 r / min.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] 1、The polypropylene material for logistics turnover and the preparation process thereof, lignin, as a natural non-toxic biomass material, not only has antibacterial activity, but also shows antioxidant and ultraviolet shielding ability, however, due to the complex structure of lignin, the content of effective antibacterial components is low, therefore, in the scheme, the lignin is modified by glycidyl methacrylate (GMA) and 3-chloro-2-hydroxypropyl trimethyl ammonium chloride, the double-bond active site and the quaternary ammonium salt group are successfully introduced into the natural lignin molecular structure, and the modified lignin is prepared, wherein the grafting of GMA endows the lignin with radical polymerization activity, and the quaternization treatment enables the lignin to effectively inhibit the growth and reproduction of bacteria when contacting with the bacteria, and significantly improves the antibacterial performance of the lignin.

[0032] 2、The polypropylene material for logistics turnover and the preparation process thereof, the nano zinc oxide has good ultraviolet resistance and antibacterial performance, the surface of the nano zinc oxide is coated with acrylic acid, modified lignin and 4-epoxy isoeugenol by a free radical copolymerization method, and the formation of a "core-shell" structure helps to improve the strength and toughness of the polypropylene; wherein the 4-epoxy isoeugenol, as a derivative of eugenol, has certain antibacterial performance, the quaternary ammonium lignin coated on the surface of the nano zinc oxide and the 4-epoxy isoeugenol form a double antibacterial system, and the antibacterial performance of the material is improved.

[0033] Finally, in order to further improve the anti-aging performance of the material, the epoxy group is reacted with the amino group, the p-phenylenediamine (PPDA) is grafted on the surface of the epoxy compound, the anti-aging agent is grafted, and the modified nano zinc oxide is obtained. The polypropylene material for logistics turnover prepared by melt blending the modified nano zinc oxide and the polypropylene not only improves the mechanical properties of the material, but also has excellent antibacterial performance and anti-aging performance. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0035] In the embodiment, the polypropylene is a type of Korea Xiaoxing R701; the nano zinc oxide has a particle size of 30 nm and is from Shanghai Qiantian New Material Technology Co., Ltd.; the alkali lignin is a type of 471003 and is from Merck; the talc powder has a particle size of 5000 mesh and is from Jiangyin Guangyuan Superfine Powder Co., Ltd.; the nucleating agent is a type of Millad NX8000i; the lubricant is polyethylene wax with a type of Honeywell AC-6A; the antioxidant is a type of antioxidant 1010; and the stabilizer is a type of TM-181FS.

[0036] The following parts are mass parts unless otherwise specified.

[0037] Embodiment 1: A preparation process of a polypropylene material for logistics turnover, comprising the following processes:

[0038] Step S1: 80 parts of polypropylene, 10 parts of modified nano zinc oxide, 5 parts of talc powder, 3 parts of nucleating agent, 0.5 parts of lubricant, 0.5 parts of antioxidant and 0.5 parts of stabilizer are uniformly stirred to obtain a mixture;

[0039] Step S2: melt blending, extruding, foaming the mixture in a twin-screw extruder to obtain a polypropylene material for logistics; the temperature of each zone of the twin-screw extruder is: 178℃ for zone 1, 188℃ for zone 2, 198℃ for zone 3, 208℃ for zone 4, 220℃ for zone 5, and 215℃ for the die head; the screw rotation speed is 120r / min;

[0040] The preparation method of the modified nano zinc oxide is as follows:

[0041] Step A: under nitrogen protection, 10 parts of nano zinc oxide, 150 parts of anhydrous ethanol and 30 parts of deionized water are uniformly mixed, heated to 70℃, 20 parts of γ-(methacryloyloxy) propyl trimethoxysilane is added, and the reaction is carried out for 4h, and after centrifugation, washing and drying, the nano zinc oxide containing double bonds is obtained;

[0042] Step B: 10 parts of nano zinc oxide containing double bonds and 500 parts of deionized water are uniformly mixed, 10 parts of methyl methacrylate, 20 parts of modified lignin and 5 parts of 4-epoxy isoeugenol are added, nitrogen is introduced, 0.45 parts of potassium persulfate is added, and the reaction is carried out at 70℃ for 10h, and after centrifugation, washing and drying, the epoxy compound is obtained;

[0043] Step C: 10 parts of the epoxy compound, 20 parts of p-aminodiphenylamine and 150 parts of ethanol solution are uniformly mixed, and the reaction is carried out at 60℃ for 10h, and after filtration, washing and drying, the modified nano zinc oxide is obtained;

[0044] The preparation method of the modified lignin is as follows:

[0045] 20 parts of alkali lignin and 4 parts of sodium hydroxide are added to a mixed solution of 150 parts of dimethyl sulfoxide and 150 parts of deionized water, stirred to dissolve, heated to 90℃, 40 parts of glycidyl methacrylate is added, and the reaction is carried out for 3h, and after dialysis and drying, the lignin containing double bonds is obtained;

[0046] 20 parts of the lignin containing double bonds and 300 parts of 20wt% sodium hydroxide solution are uniformly mixed, heated to 80℃, 6 parts of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride is added, and the reaction is carried out for 4h, and after dialysis and drying, the modified lignin is obtained.

[0047] Example 2: a preparation process of a polypropylene material for logistics, comprising the following processes:

[0048] Step S1: 90 parts of polypropylene, 12 parts of modified nano zinc oxide, 8 parts of talc, 4 parts of nucleating agent, 1 part of lubricant, 1 part of antioxidant and 0.8 parts of stabilizer are uniformly stirred to obtain a mixture;

[0049] Step S2: melt blending, extruding, foaming the mixture in a twin-screw extruder to obtain a polypropylene material for logistics; the temperature of each zone of the twin-screw extruder is: 180℃ for zone 1, 190℃ for zone 2, 200℃ for zone 3, 210℃ for zone 4, 222℃ for zone 5, and 218℃ for the die head; the screw rotation speed is 160 r / min;

[0050] The preparation method of the modified nano zinc oxide is as follows:

[0051] Step A: uniformly mix 12 parts of nano zinc oxide, 220 parts of anhydrous ethanol, and 48 parts of deionized water, heat to 75℃, and then add 36 parts of γ-(methacryloyloxy) propyl trimethoxysilane, react for 5h, centrifuge, wash, and dry to obtain nano zinc oxide containing double bonds;

[0052] Step B: uniformly mix 12 parts of nano zinc oxide containing double bonds and 720 parts of deionized water, add 18 parts of methyl methacrylate, 36 parts of modified lignin, and 12 parts of 4-epoxy isoeugenol, pass nitrogen, add 1.56 parts of potassium persulfate, and react at 75℃ for 11h, then centrifuge, wash, and dry to obtain an epoxy compound;

[0053] Step C: uniformly mix 12 parts of the epoxy compound, 36 parts of p-aminodiphenylamine, and 216 parts of an ethanol solution, react at 65℃ for 8h, filter, wash, and dry to obtain modified nano zinc oxide;

[0054] The preparation method of the modified lignin is as follows:

[0055] Add 36 parts of alkali lignin and 10.8 parts of sodium hydroxide to a mixed solution of 320 parts of dimethyl sulfoxide and 320 parts of deionized water, stir until dissolved, heat to 95℃, add 90 parts of glycidyl methacrylate, react for 4h, then dialyze and dry to obtain lignin containing double bonds;

[0056] Uniformly mix 36 parts of lignin containing double bonds and 650 parts of a 20wt% sodium hydroxide solution, heat to 85℃, add 14.4 parts of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride, react for 5h, then dialyze and dry to obtain modified lignin.

[0057] Example 3: a preparation process of a polypropylene material for logistics, including the following processes:

[0058] Step S1: uniformly stir 100 parts of polypropylene, 15 parts of modified nano zinc oxide, 10 parts of talc, 5 parts of a nucleating agent, 1.5 parts of a lubricant, 1.0 part of an antioxidant, and 1.0 part of a stabilizer to obtain a mixture;

[0059] Step S2: melt blending, extruding, foaming the mixture in a twin-screw extruder to obtain the polypropylene material for logistics; the temperature of each zone of the twin-screw extruder is: 182℃ for the first zone, 192℃ for the second zone, 202℃ for the third zone, 212℃ for the fourth zone, 225℃ for the fifth zone, and 220℃ for the die head; the screw rotation speed is 180r / min;

[0060] The preparation method of the modified nano zinc oxide is as follows:

[0061] Step A: under nitrogen protection, 15 parts of nano zinc oxide, 300 parts of anhydrous ethanol and 75 parts of deionized water are uniformly mixed, heated to 80℃, 60 parts of γ-(methacryloyloxy) propyl trimethoxysilane is added, and the reaction is carried out for 6h, and after centrifugation, washing and drying, the nano zinc oxide containing double bonds is obtained;

[0062] Step B: 15 parts of nano zinc oxide containing double bonds and 1200 parts of deionized water are uniformly mixed, 30 parts of methyl methacrylate, 60 parts of modified lignin and 22.5 parts of 4-epoxy isoeugenol are added, nitrogen is introduced, 3.8 parts of potassium persulfate is added, and the reaction is carried out at 80℃ for 12h, and after centrifugation, washing and drying, the epoxy compound is obtained;

[0063] Step C: 15 parts of epoxy compound, 60 parts of p-aminodiphenylamine and 300 parts of ethanol are uniformly mixed, and the reaction is carried out at 70℃ for 5h, and after filtration, washing and drying, the modified nano zinc oxide is obtained;

[0064] The preparation method of the modified lignin is as follows:

[0065] 60 parts of alkali lignin and 24 parts of sodium hydroxide are added to a mixed solution of 600 parts of dimethyl sulfoxide and 600 parts of deionized water, stirred to dissolve, heated to 100℃, 180 parts of glycidyl methacrylate is added, and the reaction is carried out for 5h, and after dialysis and drying, the lignin containing double bonds is obtained;

[0066] 60 parts of lignin containing double bonds and 1200 parts of 20wt% sodium hydroxide solution are uniformly mixed, heated to 90℃, 30 parts of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride is added, and the reaction is carried out for 6h, and after dialysis and drying, the modified lignin is obtained.

[0067] Comparative Example 1: a preparation process of a polypropylene material for logistics, comprising the following processes:

[0068] Step S1: 90 parts of polypropylene, 12 parts of nano zinc oxide, 8 parts of talc, 4 parts of nucleating agent, 1 part of lubricant, 1 part of antioxidant and 0.8 parts of stabilizer are uniformly stirred to obtain a mixture;

[0069] Step S2: melt blending, extruding, foaming the mixture in a twin-screw extruder to obtain the polypropylene material for logistics; the temperature of each zone of the twin-screw extruder is: 180℃ for zone 1, 190℃ for zone 2, 200℃ for zone 3, 210℃ for zone 4, 222℃ for zone 5, and 218℃ for the die head; the screw rotation speed is 160 r / min;

[0070] Compared with Example 2, Comparative Example 1 replaces the modified nano zinc oxide with nano zinc oxide of the same mass.

[0071] Comparative Example 2: a preparation process of a polypropylene material for logistics, comprising the following steps:

[0072] The preparation method of the modified nano zinc oxide is as follows:

[0073] Step A: under nitrogen protection, 12 parts of nano zinc oxide, 220 parts of anhydrous ethanol, and 48 parts of deionized water are uniformly mixed, heated to 75℃, 36 parts of γ-(methacryloyloxy) propyl trimethoxysilane is added, and the reaction is carried out for 5h, and after centrifugation, washing, and drying, the double-bond-containing nano zinc oxide is obtained;

[0074] Step B: 12 parts of the double-bond-containing nano zinc oxide and 720 parts of deionized water are uniformly mixed, 18 parts of methyl methacrylate, 36 parts of lignin, and 12 parts of 4-epoxy isoeugenol are added, nitrogen is introduced, 1.56 parts of potassium persulfate is added, and the reaction is carried out at 75℃ for 11h, and after centrifugation, washing, and drying, the epoxy compound is obtained;

[0075] Step C: 12 parts of the epoxy compound, 36 parts of p-aminodiphenylamine, and 216 parts of ethanol solution are uniformly mixed, and the reaction is carried out at 65℃ for 8h, and after filtration, washing, and drying, the modified nano zinc oxide is obtained;

[0076] Compared with Example 2, Comparative Example 2 replaces the modified lignin with lignin of the same mass, and the other steps are the same as those of Example 2.

[0077] Comparative Example 3: a preparation process of a polypropylene material for logistics, comprising the following steps:

[0078] The preparation method of the modified nano zinc oxide is as follows:

[0079] Step A: under nitrogen protection, 12 parts of nano zinc oxide, 220 parts of anhydrous ethanol, and 48 parts of deionized water are uniformly mixed, heated to 75℃, 36 parts of γ-(methacryloyloxy) propyl trimethoxysilane is added, and the reaction is carried out for 5h, and after centrifugation, washing, and drying, the double-bond-containing nano zinc oxide is obtained;

[0080] Step B: 12 parts of double-bond-containing nano zinc oxide and 720 parts of deionized water were uniformly mixed, 18 parts of methyl methacrylate, 36 parts of modified lignin, nitrogen was introduced, 1.56 parts of potassium persulfate was added, and the reaction was carried out at 75°C for 11h. After centrifugation, washing and drying, modified nano zinc oxide was obtained.

[0081] Compared with Example 2, no 4-epoxy isoeugenol was added in Step B of Comparative Example 3, Step C was deleted, and the other steps were the same as Example 2.

[0082] Comparative Example 4: A preparation process of a polypropylene material for logistics turnover, comprising the following processes:

[0083] The preparation method of the modified nano zinc oxide is as follows:

[0084] Step A: Under nitrogen protection, 12 parts of nano zinc oxide, 220 parts of anhydrous ethanol and 48 parts of deionized water were uniformly mixed, heated to 75°C, 36 parts of γ-(methacryloyloxy) propyl trimethoxysilane was added, and the reaction was carried out for 5h. After centrifugation, washing and drying, double-bond-containing nano zinc oxide was obtained.

[0085] Step B: 12 parts of double-bond-containing nano zinc oxide and 720 parts of deionized water were uniformly mixed, 18 parts of methyl methacrylate, 12 parts of modified lignin and 12 parts of 4-epoxy isoeugenol were added, nitrogen was introduced, 1.56 parts of potassium persulfate was added, and the reaction was carried out at 75°C for 11h. After centrifugation, washing and drying, an epoxy compound was obtained.

[0086] Step C: 12 parts of the epoxy compound, 36 parts of p-aminodiphenylamine and 216 parts of ethanol solution were uniformly mixed and reacted at 65°C for 8h. After filtration, washing and drying, modified nano zinc oxide was obtained.

[0087] Compared with Example 2, in Step B of Comparative Example 4, the mass ratio of double-bond-containing nano zinc oxide, methyl methacrylate, modified lignin and 4-epoxy isoeugenol was 1:1.5:1:1; the other steps were the same as Example 2.

[0088] Experiment: The logistics turnover polypropylene materials obtained in Examples 1-3 and Comparative Examples 1-4 were taken to prepare samples, and the performance of the samples was detected and the detection results were recorded.

[0089] The tensile properties were determined according to GB / T1040.2-2022, the sample size was 150mm×10mm×4mm, the determination temperature was 25°C, and the tensile rate was 50mm / min; the xenon lamp aging test was carried out according to GB / T 16422.2-2014: a xenon lamp was used as a light source, the radiation intensity was 550W / m 2, blackboard temperature 45℃, box temperature 30℃, relative humidity 80%, test time 360h, measure the tensile strength before and after aging, calculate the performance decline rate = 1- tensile strength after aging / initial tensile strength; according to the film method in GB / T 31402-2023, measure the antibacterial performance, test bacteria is staphylococcus aureus (bacterial concentration is 3.0x10 5 cfu / mL).

[0090] The test results are as follows:

[0091]

[0092] According to the data in the above table, the following conclusions can be clearly obtained:

[0093] Compared with examples 1-3, the tensile strength and antibacterial rate of the products obtained in comparative examples 1 and 2 are decreased, and the performance decline rate is increased, which shows that the modified nano zinc oxide prepared by the present application can improve the mechanical properties, anti-aging properties and antibacterial properties of the material; the modified lignin prepared by the present application is modified by glycidyl methacrylate and 3-chloro-2-hydroxypropyl trimethyl ammonium chloride, and has better modification effect than lignin, which can effectively improve the antibacterial properties of the material.

[0094] Compared with examples 1-3, the anti-aging properties and antibacterial rate of the product obtained in comparative example 3 are decreased, which shows that by introducing 4-epoxy isoeugenol, the present application improves the antibacterial properties and increases the epoxy reaction site, which is beneficial to the grafting of the anti-aging agent.

[0095] Compared with examples 1-3, the tensile strength, anti-aging properties and antibacterial rate of the product obtained in comparative example 4 are decreased, which shows that when the amount of modified lignin is reduced, the performance of the modified nano zinc oxide will be decreased.

[0096] It is apparent to those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, and the scope of the present application is defined by the appended claims rather than the foregoing description, and it is intended to encompass all changes falling within the meaning and range of equivalents of the claims.

Claims

1. A process for the preparation of a polypropylene material for logistic turnover, characterized by: It comprises the following steps: Step S1: stirring polypropylene, modified nano zinc oxide, talcum powder, nucleating agent, lubricant, antioxidant and stabilizer uniformly to obtain a mixture; Step S2: adding the mixture into a double screw extruder to melt blend, extrude and foam to obtain a polypropylene material for material circulation; The preparation method of the modified nano zinc oxide is as follows: Step A: mixing nano zinc oxide, anhydrous ethanol and deionized water uniformly under nitrogen protection, heating to 70-80℃, adding γ-(methacryloyloxy) propyl trimethoxysilane, reacting for 4-6h, centrifuging, washing and drying to obtain nano zinc oxide containing double bonds; Step B: mixing nano zinc oxide containing double bonds and deionized water uniformly, adding methyl methacrylate, modified lignin and 4-epoxy isoeugenol, passing nitrogen, adding potassium persulfate, reacting at 70-80℃ for 10-12h, centrifuging, washing and drying to obtain an epoxy compound; Step C: mixing the epoxy compound, p-aminodiphenylamine and ethanol uniformly, reacting at 60-70℃ for 5-10h, filtering, washing and drying to obtain modified nano zinc oxide; In step B, the mass ratio of nano zinc oxide containing double bonds, methyl methacrylate, modified lignin and 4-epoxy isoeugenol is 1:(1-2):(2-4):(0.5-1.5); The preparation method of the modified lignin is as follows: Adding alkali lignin and sodium hydroxide into a mixed solution of dimethyl sulfoxide and deionized water, stirring to dissolve, heating to 90-100℃, adding glycidyl methacrylate, reacting for 3-5h, dialyzing and drying to obtain lignin containing double bonds; Mixing lignin containing double bonds and sodium hydroxide solution uniformly, heating to 80-90℃, adding 3-chloro-2-hydroxypropyl trimethyl ammonium chloride, reacting for 4-6h, dialyzing and drying to obtain modified lignin.

2. The process for the preparation of polypropylene material for logistic turnover according to claim 1, characterized in that: The polypropylene material for material circulation comprises the following components by weight: polypropylene 80-100 parts, modified nano zinc oxide 10-15 parts, talcum powder 5-10 parts, nucleating agent 3-5 parts, lubricant 0.5-1.5 parts, antioxidant 0.5-1.0 parts and stabilizer 0.5-1.0 parts.

3. The process for the preparation of polypropylene material for logistic turnover according to claim 1, characterized in that: In step A, the mass ratio of nano zinc oxide, anhydrous ethanol, deionized water and γ-(methacryloyloxy) propyl trimethoxysilane is 1:(15-20):(3-5):(2-4).

4. The process for preparing polypropylene material for logistic turnover as claimed in claim 1, wherein: The mass ratio of alkali lignin, sodium hydroxide and glycidyl methacrylate is 1:(0.2-0.4):(2-3).

5. The process for preparing polypropylene material for logistic turnover as claimed in claim 1, wherein: The mass ratio of lignin containing double bonds, sodium hydroxide solution and 3-chloro-2-hydroxypropyl trimethyl ammonium chloride is 1:(15-20):(0.3-0.5).

6. The process for preparing polypropylene material for logistic turnover as claimed in claim 1, wherein: In step C, the mass ratio of epoxy compound and p-aminodiphenylamine is 1:(2-4).

7. A polypropylene material for material circulation prepared by the preparation process according to any one of claims 1-6.

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