A full life cycle low-emission polypropylene composite material and a preparation method and application thereof

Abstract

The application discloses a full-life-cycle low-emission polypropylene composite material and a preparation method and application thereof. The full-life-cycle low-emission polypropylene composite material comprises the following components in percentage by mass: polypropylene: 65-75%; polyolefin elastomer: 5-15%; inorganic filler: 15-25%; reactive trapping agent containing an oxazoline functional group: 0.1-0.5%; and other auxiliaries: 0.5-5%. The full-life-cycle low-emission polypropylene composite material can keep ultra-low VOC emission and odor in the full life cycle, has excellent mechanical properties, is simple in preparation process, low in production cost, green and environment-friendly, and is suitable for being used for preparing automobile interior parts, household appliances, medical and health equipment and other products with high requirements on VOC emission and odor.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a low-emission polypropylene composite material with a complete life cycle, its preparation method, and its application. Background Technology

[0002] Polypropylene (PP) is a semi-crystalline plastic with excellent properties such as low density, easy processing, and low cost, and is widely used in the automotive industry. With the increasing popularity of the concept of healthy automotive cabins, people have increasingly stringent requirements regarding the emission and odor performance of volatile organic compounds (VOCs) from automotive interior materials. However, existing PP composite materials continuously release volatile substances such as small-molecule aldehydes, ketones, carboxylic acids, and hydrocarbons throughout their production, use, and even their entire life cycle (mainly from resin synthesis residues, additive decomposition, processing thermo-oxidative degradation, and slow aging decomposition during long-term use). Using PP as an automotive interior material does not conform to the concept of a healthy automotive cabin.

[0003] Currently, the main methods used in the industry to reduce VOCs in PP composite materials to address the above-mentioned problems include the following: 1) Physical adsorption method: VOCs are adsorbed by adding porous adsorbents such as zeolite, activated carbon, and diatomaceous earth to the PP composite material. This method is only effective in the initial use of PP composite materials. However, due to the limited adsorption capacity of porous adsorbents and the reversible adsorption effect, small molecules adsorbed by porous adsorbents will be re-desorbed and released during high-temperature or long-term use of PP composite materials, which will lead to "secondary pollution" and cannot meet the low emission requirements throughout the entire life cycle; 2) Enhanced devolatilization method: The VOC content of PP composite materials is reduced by optimizing the extrusion process (e.g., increasing vacuum degree, extending exhaust stroke, etc.). This method not only has high requirements for production equipment, but also has very limited removal effect on highly polar, high-boiling-point small molecules; 3) Raw material optimization method: Low emission raw materials are used (e.g., hydrogen-modified PP, high-purity additives, etc.). This method can reduce the initial VOC emission of PP composite materials, but it cannot solve the problem of new emissions generated by thermo-oxidative aging of PP composite materials during later processing and use. In summary, existing methods for reducing VOCs in PP composite materials all have significant shortcomings and cannot fully meet the growing practical application demands.

[0004] Therefore, developing a polypropylene composite material that can maintain low emissions throughout its entire life cycle is of great significance. Summary of the Invention

[0005] One of the objectives of this invention is to solve the problem that existing polypropylene composite materials continuously release volatile substances such as small molecule aldehydes, ketones, carboxylic acids and hydrocarbons during production, use and even the entire life cycle, and to provide a polypropylene composite material that can maintain low emissions throughout its entire life cycle.

[0006] The second objective of this invention is to provide a method for preparing polypropylene composite materials that is simple in process, uses readily available equipment, and has low production costs.

[0007] The third objective of this invention is to provide an application of polypropylene composite materials in automotive interior parts, household appliances, or medical and health devices.

[0008] The technical solution adopted in this invention is: A low-emission polypropylene composite material with a complete life cycle comprises the following components by weight percentage: Polypropylene: 65%–75%; Polyolefin elastomers: 5%–15%; Inorganic fillers: 15%–25%; Reactive scavengers containing oxazoline functional groups: 0.1%–0.5%; Other additives: 0.5%–5%.

[0009] Preferably, the polypropylene is at least one of homopolymer polypropylene and ethylene-propylene block copolymer polypropylene.

[0010] Preferably, the melt index of the polypropylene is 1 g / 10 min to 100 g / 10 min, and the melt index test conditions are 230℃ / 2.16 kg.

[0011] Preferably, the polyolefin elastomer is at least one of ethylene propylene rubber, ethylene-octene copolymer, ethylene-butene copolymer, and ethylene-vinyl acetate copolymer.

[0012] More preferably, the polyolefin elastomer is an ethylene-butene copolymer.

[0013] More preferably, the polyolefin elastomer is a gas-phase POE, the main component of which is an ethylene-butene copolymer, with a melt index of 1g / 10min to 30g / 10min, and the melt index test conditions are 190℃ / 2.16kg.

[0014] Preferably, the inorganic filler is at least one of talc powder, mica powder, kaolin, and montmorillonite.

[0015] More preferably, the inorganic filler is talc.

[0016] More preferably, the inorganic filler is talc powder with low apparent iron content and a particle size of 1μm to 15μm.

[0017] Preferably, the reactive scavenger containing the oxazoline functional group is at least one of bisoxazoline and polyoxazoline.

[0018] More preferably, the reactive scavenger containing the oxazoline functional group is 2,2′-(1,3-phenylene)bis(2-oxazoline).

[0019] Preferably, the other additives are at least one of antioxidants, lubricants, light stabilizers, scratch resistant agents, and colorants.

[0020] Preferably, the antioxidant is at least one of antioxidant 1010, antioxidant 1076, antioxidant 168, and antioxidant 1098.

[0021] Preferably, the lubricant is at least one of calcium stearate, zinc stearate, and vinyl bis-stearamide (EBS).

[0022] Preferably, the light stabilizer is at least one of the light stabilizer T-81 from Beijing Tiangang Additives Co., Ltd. and the light stabilizer LA-402AF from Japan Adico Corporation.

[0023] Preferably, the scratch-resistant agent is at least one of Chengdu Silike Technology Co., Ltd.'s scratch-resistant agent LYSI-906 and Zhejiang Jiahua Fine Chemicals Co., Ltd.'s scratch-resistant agent HG-600.

[0024] Preferably, the colorant is at least one of Cabot's masterbatch XP6622A and Foshan Hongshengde Masterbatch New Material Co., Ltd.'s masterbatch HSD849.

[0025] A method for preparing a low-emission polypropylene composite material with a complete life cycle as described above includes the following steps: 1) Polypropylene, polyolefin elastomer, inorganic filler, reactive scavenger containing oxazoline functional group and other additives are added to a high-speed mixer and mixed to obtain a premix; 2) The premix and surfactant aqueous solution are added to a twin-screw extruder for melt blending. The premix is ​​added from the main feed port, and the surfactant aqueous solution is added from the middle and rear of the melt section. Then, the mixture is extruded, water-cooled and pelletized, and then dried to obtain a low-emission polypropylene composite material with a full life cycle.

[0026] Preferably, the mixing in step 1) is carried out in a high-speed mixer at a speed of 800 r / min to 1500 r / min, and the mixing time is 5 min to 10 min.

[0027] Preferably, the surfactant in the surfactant aqueous solution in step 2) is at least one of a nonionic surfactant and anionic surfactant.

[0028] More preferably, the surfactant in the aqueous surfactant solution in step 2) is at least one of polyoxyethylene ether, alkylphenol polyoxyethylene ether, and alkyl sulfonate.

[0029] Preferably, the mass fraction of the surfactant in the aqueous surfactant solution in step 2) is 1% to 6%.

[0030] Preferably, the injection rate of the surfactant aqueous solution in step 2) is 50 mL / min to 150 mL / min.

[0031] Preferably, the melt blending in step 2) is carried out at a temperature of 170℃~200℃ and a screw speed of 700r / min~900r / min.

[0032] Preferably, the drying in step 2) is carried out at a temperature of 100℃~120℃ for 2h~4h.

[0033] Application of a low-emission polypropylene composite material with a full life cycle as described above in the preparation of automotive interior parts, home appliances or medical and health devices.

[0034] The beneficial effects of the present invention are: the low-emission polypropylene composite material of the present invention can maintain ultra-low VOC release and odor throughout its entire life cycle, and it has excellent mechanical properties, simple preparation process, low production cost, and is green and environmentally friendly. It is suitable for use in the preparation of automotive interior parts, home appliances, medical and health equipment and other products with high requirements for VOC release and odor.

[0035] Specifically: 1) The low-emission polypropylene composite material of the present invention contains a reactive scavenger with an oxazoline functional group. The highly active oxazoline ring can undergo irreversible ring-opening addition reactions with small molecules such as carboxylic acids and aldehydes (which can be oxidized to acids) generated inside the material and during subsequent degradation throughout the production, use and even the entire life cycle of the polypropylene composite material to generate a stable macromolecular structure. This can permanently chemically fix the volatiles, fundamentally prevent the release of volatiles, and ultimately enable the polypropylene composite material to maintain ultra-low VOC release and odor throughout its entire life cycle. 2) The low-emission polypropylene composite material of the present invention incorporates an aqueous surfactant solution during the preparation process. This solution significantly reduces the surface tension of water during melt extrusion, making it easier for water to disperse into micro- and nano-sized droplets under high pressure and uniformly distributed in the high-viscosity PP melt. These micro-droplets provide a large gas-liquid interface, serving as a "highway" and "collection station" for the migration of small molecule volatiles (especially polar small molecules) from the melt to the gas phase. Subsequently, during the vacuum degassing stage, water vapor carrying a large amount of small molecule volatiles is rapidly removed, thereby achieving a highly efficient and enhanced devolatilization effect, ultimately further reducing the VOC content of the polypropylene composite material. 3) This invention innovatively combines the dual mechanisms of "reactive chemical fixation" and "process-enhanced physical removal". The reactive trap containing the oxazoline functional group acts like a "molecular sponge" and can permanently neutralize the existing and future acidic / aldehyde small molecules in the PP composite material (compared to the temporary adsorption of physical adsorbents, the chemical capture of this invention is a permanent reaction with irreversible effect, eliminating the risk of secondary release). Meanwhile, the surfactant aqueous solution-enhanced devolatilization can efficiently remove various volatile substances during processing (enhanced devolatilization greatly improves the removal efficiency, especially for high-boiling-point polar substances that are difficult to remove by traditional vacuum devolatilization). The synergistic effect of these two aspects achieves ultra-low emissions throughout the entire life cycle from PP composite material manufacturing and part molding to end use. 4) The low emission polypropylene composite material of the present invention is suitable for the preparation of automotive interior parts, home appliances, medical and health equipment and other products with high requirements for VOC release and odor. Moreover, its preparation process is simple, the equipment is readily available, the production cost is low, and it is easy to realize large-scale industrial production. Detailed Implementation

[0036] The present invention will be further explained and described below with reference to specific embodiments.

[0037] The sources and main parameters of some components in Examples 1-4 and Comparative Examples 1-7 are as follows: Polypropylene EP548R-Z: CNOOC Shell, melt index is 28g / 10min, melt index test conditions are 230℃ / 2.16kg.

[0038] Polyolefin elastomer POE VL8805: Daelim Corporation, South Korea, gas-phase POE, the main component is ethylene-butene copolymer, melt index is 5g / 10min, melt index test conditions are 190℃ / 2.16kg.

[0039] Polyolefin elastomer POE LC565: LG Corporation of South Korea, liquid phase POE, the main component is ethylene-butene copolymer, melt index is 5g / 10min, melt index test conditions are 190℃ / 2.16kg.

[0040] Talc KCM-6300: Liaoning Beihai Industry (Group) Co., Ltd., low phenanthrene iron content talc powder, particle size 1μm~15μm.

[0041] Talc XS-912F: Liaoning Runhai New Materials Co., Ltd., high iron content talc powder, particle size 1μm~15μm.

[0042] Reactive scavenger Epocros ® RPS-1000: Nippon Shokubai Co., Ltd., the main ingredient is 2,2′-(1,3-phenylene)bis(2-oxazoline).

[0043] Antioxidant 1010: BASF.

[0044] Antioxidant 168: BASF.

[0045] Calcium stearate (lubricant): Zhongshan Huamingtai Chemical Co., Ltd.

[0046] Light stabilizer T-81: Beijing Tiangang Additives Co., Ltd., its main components are PP carrier and hindered amine light stabilizer.

[0047] Scratch-resistant agent LYSI-906: Chengdu Silike Technology Co., Ltd., its main components are PP carrier and siloxane.

[0048] Masterbatch XP6622A: Cabot.

[0049] Surfactant NEODOL 23-6.5: Sasol (China) Chemical Co., Ltd., the main component is polyoxyethylene ether.

[0050] Example 1: A low-emission polypropylene composite material with a complete life cycle has the following composition as shown in the table below: Table 1. Composition of a low-emission polypropylene composite material throughout its entire life cycle.

[0051] The preparation method of the above-mentioned low-emission polypropylene composite material throughout its entire life cycle is as follows: 1) Polypropylene EP548R-Z, polyolefin elastomer POE VL8805, talc KCM-6300, and reactive scavenger Epocros are added. ®RPS-1000, antioxidant 1010, antioxidant 168, calcium stearate, light stabilizer T-81, scratch resistant agent LYSI-906 and color masterbatch XP6622A are added to a high-speed mixer, and the speed of the high-speed mixer is adjusted to 1000 r / min. The mixture is stirred for 5 min to obtain a premix. 2) Dissolve the surfactant NEODOL 23-6.5 in water to prepare a 3% (w / w) surfactant aqueous solution. Then, add the premix and surfactant aqueous solution to a twin-screw extruder for melt blending. The premix is ​​injected from the main feed port, and the surfactant aqueous solution is injected from the middle and rear part of the melt section (where the material is completely plasticized) through the side-line liquid injection system at a rate of 80 mL / min. Melt blending is carried out at a temperature of 180℃ and a screw speed of 800 r / min, with two high-vacuum exhaust sections (vacuum degree ≥ -0.08 MPa; used to quickly remove water vapor and small volatile molecules carried in the melt). The mixture is then extruded through a die head, water-cooled, pelletized, and then dried in a forced-air drying oven at 110℃ for 3 hours (to remove residual surface moisture) to obtain a low-emission polypropylene composite material with a full life cycle.

[0052] Example 2: A low-emission polypropylene composite material with an end-life cycle has the same formulation as the low-emission polypropylene composite material with an end-life cycle in Example 1.

[0053] The preparation method of the above-mentioned low-emission polypropylene composite material throughout its entire life cycle is exactly the same as the preparation method of the low-emission polypropylene composite material throughout its entire life cycle in Example 1, except that the injection rate of the surfactant aqueous solution in step 2) is adjusted from "80mL / min" to "100mL / min".

[0054] Example 3: A low-emission polypropylene composite material with an end-life cycle has the same formulation as the low-emission polypropylene composite material with an end-life cycle in Example 1.

[0055] The preparation method of the above-mentioned low-emission polypropylene composite material throughout its entire life cycle is exactly the same as the preparation method of the low-emission polypropylene composite material throughout its entire life cycle in Example 1, except that the injection rate of the surfactant aqueous solution in step 2) is adjusted from "80mL / min" to "120mL / min".

[0056] Example 4: A low-emission polypropylene composite material with a complete life cycle is identical to the low-emission polypropylene composite material of Example 1, except that the mass percentage of polypropylene EP548R-Z is adjusted from "66.15%" to "65.95%", the mass percentage of antioxidant 1010 is adjusted from "0.1%" to "0.2%", and the mass percentage of antioxidant 168 is adjusted from "0.1%" to "0.2%".

[0057] The preparation method of the above-mentioned low-emission polypropylene composite material throughout its entire life cycle is exactly the same as the preparation method of the low-emission polypropylene composite material throughout its entire life cycle in Example 1, except that the injection rate of the surfactant aqueous solution in step 2) is adjusted from "80mL / min" to "100mL / min".

[0058] Comparative Example 1: A polypropylene composite material, the composition of which is shown in the table below: Table 2 Composition of a polypropylene composite material

[0059] The preparation method of the above polypropylene composite material is as follows: 1) Add polypropylene EP548R-Z, polyolefin elastomer POE LC565, talc XS-912F, antioxidant 1010, antioxidant 168, calcium stearate, light stabilizer T-81, scratch resistant agent LYSI-906, and color masterbatch XP6622A to a high-speed mixer, then adjust the speed of the high-speed mixer to 1000 r / min and stir for 5 min to obtain a premix. 2) The premixed material is added to a twin-screw extruder for melt blending. The premixed material is injected from the main feed port. Melt blending is carried out at a temperature of 180℃ and a screw speed of 800r / min. Then, the material is extruded through the die head, water-cooled, and pelletized to obtain a polypropylene composite material.

[0060] Comparative Example 2: A polypropylene composite material with the same formulation as the polypropylene composite material of Comparative Example 1.

[0061] The preparation method of the above polypropylene composite material is exactly the same as that of the polypropylene composite material of Comparative Example 1, except that step 2) includes "drying the pelletized product in a forced-air drying oven at 110°C for 3 hours".

[0062] Comparative Example 3: A polypropylene composite material is identical to the polypropylene composite material of Comparative Example 1, except that "polyolefin elastomer POE LC565" is replaced by "polyolefin elastomer POE VL8805" by weight.

[0063] The preparation method of the above polypropylene composite material is exactly the same as that of the polypropylene composite material of Comparative Example 1, except that step 2) includes "drying the pelletized product in a forced-air drying oven at 110°C for 3 hours".

[0064] Comparative Example 4: A polypropylene composite material is identical to the polypropylene composite material of Comparative Example 1, except that "talc XS-912F" is replaced by "talc KCM-6300" by weight.

[0065] The preparation method of the above polypropylene composite material is exactly the same as that of the polypropylene composite material of Comparative Example 1, except that step 2) includes "drying the pelletized product in a forced-air drying oven at 110°C for 3 hours".

[0066] Comparative Example 5: A polypropylene composite material, except that the mass percentage of polypropylene EP548R-Z is adjusted from "66.4%" to "66.3%", "polyolefin elastomer POE LC565" is replaced by "polyolefin elastomer POE VL8805" by weight, "talc XS-912F" is replaced by "talc KCM-6300" by weight, and 0.1% of the reactive scavenger Epocros is added. ® Except for RPS-1000, it is completely identical to the polypropylene composite material of Comparative Example 1.

[0067] The preparation method of the above polypropylene composite material is exactly the same as that of the polypropylene composite material of Comparative Example 1, except that step 2) includes "drying the pelletized product in a forced-air drying oven at 110°C for 3 hours".

[0068] Comparative Example 6: A polypropylene composite material, except that the mass percentage of polypropylene EP548R-Z is adjusted from "66.4%" to "66.15%", "polyolefin elastomer POE LC565" is replaced by "polyolefin elastomer POE VL8805" by weight, "talc XS-912F" is replaced by "talc KCM-6300" by weight, and 0.25% of the reactive scavenger Epocros is added. ® Except for RPS-1000, it is completely identical to the polypropylene composite material of Comparative Example 1.

[0069] The preparation method of the above polypropylene composite material is exactly the same as that of the polypropylene composite material of Comparative Example 1, except that step 2) includes "drying the pelletized product in a forced-air drying oven at 110°C for 3 hours".

[0070] Comparative Example 7: A polypropylene composite material, except that the mass percentage of polypropylene EP548R-Z is adjusted from "66.4%" to "65.9%", "polyolefin elastomer POE LC565" is replaced by "polyolefin elastomer POE VL8805" by weight, "talc XS-912F" is replaced by "talc KCM-6300" by weight, and 0.5% of the reactive scavenger Epocros is added. ® Except for RPS-1000, it is completely identical to the polypropylene composite material of Comparative Example 1.

[0071] The preparation method of the above polypropylene composite material is exactly the same as that of the polypropylene composite material of Comparative Example 1, except that step 2) includes "drying the pelletized product in a forced-air drying oven at 110°C for 3 hours".

[0072] Note: The following table summarizes the components and some process parameters of Examples 1-4 and Comparative Examples 1-7: Table 3 Summary of Components and Some Process Parameters

[0073] Performance testing: The odor level and TVOC content test data of the low-emission polypropylene composites of Examples 1-4 and Comparative Examples 1-7 are shown in the table below: Table 4 Odor rating and TVOC content test data

[0074] Note: Odor rating: Tested in accordance with the “VS-01.00-T-14004-A6-2017 Odor Test Specification for Non-metallic Materials in Vehicle Interiors” published by Changan Automobile.

[0075] TVOC content: Tested in accordance with the "VS-01.00-T-14012-A3-2017 Interior Components / Materials, VOC Sampling Test Specification" issued by Changan Automobile.

[0076] As shown in Table 4: 1) Comparative Example 1 used liquid-phase POE and talc with high apparent iron content, without adding reactive scavenging agents and surfactant aqueous solutions, and without drying treatment after pelleting. The resulting polypropylene composite material had a strong odor, and the original TVOC content and the TVOC content after aging were both very high. 2) Compared with Comparative Example 1, Comparative Example 2 added drying treatment after pelleting, and the odor and TVOC content of the resulting polypropylene composite material decreased to a certain extent. 3) Comparative Example 3 uses the gas phase POE method. The odor of the obtained polypropylene composite material is reduced, but the TVOC content is still very high, especially the TVOC content after aging is very high. This indicates that the high iron content talc will catalyze the degradation of polypropylene to a certain extent, causing it to produce more small molecules. 4) Comparative Example 4 used liquid-phase POE and did not add reactive scavenging agents and surfactant aqueous solutions. The resulting polypropylene composite material had high odor and TVOC content. 5) As the proportion of reactive scavengers in Comparative Examples 5 to 7 increases, the odor and TVOC content of the resulting polypropylene composite materials will decrease significantly. However, the decrease is not significant after the proportion of reactive scavengers reaches 0.5%. 6) In Examples 1-3, a surfactant aqueous solution was added along with the reactive scavenger. As the amount of surfactant aqueous solution increased, the odor and VOC content of the obtained polypropylene composite material were further reduced. 7) In Example 4, the proportion of antioxidant was increased, and the TVOC content of the resulting polypropylene composite material decreased after aging, indicating that the increase of antioxidant can inhibit the degradation of the material to a certain extent. In summary, this invention innovatively combines the dual mechanisms of "reactive chemical fixation" and "process-enhanced physical removal," and employs gas-phase POE and low-iron-content talc powder, achieving a multi-faceted synergistic effect, ultimately enabling polypropylene composite materials to maintain ultra-low VOC release and odor throughout their entire life cycle.

[0077] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A low-emission polypropylene composite material throughout its entire life cycle, characterized in that, Includes the following components by mass percentage: Polypropylene: 65%–75%; Polyolefin elastomers: 5%–15%; Inorganic fillers: 15%–25%; Reactive scavengers containing oxazoline functional groups: 0.1%–0.5%; Other additives: 0.5%–5%.

2. The low-emission polypropylene composite material throughout its entire life cycle according to claim 1, characterized in that: The polypropylene is at least one of homopolymer polypropylene and ethylene-propylene block copolymer polypropylene.

3. The low-emission polypropylene composite material throughout its entire life cycle according to claim 1, characterized in that: The melt index of the polypropylene is 1 g / 10 min to 100 g / 10 min, and the melt index test conditions are 230℃ / 2.16 kg.

4. The low-emission polypropylene composite material throughout its entire life cycle according to claim 1, characterized in that: The polyolefin elastomer is at least one of ethylene propylene rubber, ethylene-octene copolymer, ethylene-butene copolymer, and ethylene-vinyl acetate copolymer.

5. The low-emission polypropylene composite material throughout its entire life cycle according to any one of claims 1 to 4, characterized in that: The inorganic filler is at least one of talc powder, mica powder, kaolin, and montmorillonite.

6. The low-emission polypropylene composite material throughout its entire life cycle according to any one of claims 1 to 4, characterized in that: The reactive scavenger containing the oxazoline functional group is at least one of bisoxazoline and polyoxazoline.

7. The low-emission polypropylene composite material with a full life cycle according to any one of claims 1 to 4, characterized in that: The other additives are at least one of antioxidants, lubricants, light stabilizers, scratch resistant agents, and colorants.

8. A method for preparing a low-emission polypropylene composite material with a full life cycle as described in any one of claims 1 to 7, characterized in that, Includes the following steps: 1) Mix polypropylene, polyolefin elastomer, inorganic filler, reactive scavenger containing oxazoline functional group and other additives evenly to obtain a premix; 2) The premix and surfactant aqueous solution are added to a twin-screw extruder for melt blending. The premix is ​​added from the main feed port, and the surfactant aqueous solution is added from the middle and rear of the melt section. Then, the mixture is extruded, water-cooled and pelletized, and then dried to obtain a low-emission polypropylene composite material with a full life cycle.

9. The preparation method according to claim 8, characterized in that: Step 2) The surfactant in the aqueous solution is at least one of a nonionic surfactant and anionic surfactant.

10. The application of a low-emission polypropylene composite material with a full life cycle as described in any one of claims 1 to 7 in the preparation of automotive interior parts, home appliances or medical and health devices.

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