Low-VOC (volatile organic compound) polypropylene material as well as preparation method and application thereof

Abstract

The invention discloses a low-VOC (volatile organic compound) polypropylene material as well as a preparation method and application thereof. The low-VOC polypropylene material comprises polypropylene, polyethylene glycol and an adsorbent, wherein the adsorbent is selected from at least one of a whisker material, zeolite, talcum powder, wollastonite and a silicate compound. The polypropylene material disclosed by the invention has the characteristics of high toughness, low shrinkage and low VOC (Volatile Organic Compounds), can be used for 3D printing, and expands the application field of the polypropylene material.

Description

Technical Field

[0001] The invention relates to the technical field of polymer processing, in particular to a low-VOC polypropylene material prepared by a twin-screw extrusion process and a preparation method and application thereof. Background Art

[0002] Polypropylene (PP) material is one of the most widely used materials in general plastics. According to the spatial regularity of PP materials, it can be divided into three types: isotactic, atactic, and syndiotactic. According to the polymerization monomer, it can be divided into three types: homopolymer, random copolymer, and impact copolymer. Polypropylene is a thermoplastic synthetic resin with excellent performance. It is a colorless, translucent, thermoplastic, lightweight general-purpose plastic with chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties, and good high-wear-resistant processing properties. Since its advent, polypropylene has been rapidly developed and applied in many fields such as machinery, automobiles, electronics, construction, textiles, packaging, agriculture, forestry, fishery, and food industries. With the rapid development of my country's packaging, electronics, automobile and other industries, it has greatly promoted the development of my country's industry. And because of its plasticity, polypropylene materials are gradually replacing wooden products, and high strength toughness and high wear resistance have gradually replaced the mechanical functions of metals. In addition, polypropylene has good grafting and composite functions, and has huge application space in concrete, textiles, packaging, and agriculture, forestry, and fishery. In recent years, with the enhancement of people's awareness of environmental protection and higher and higher requirements for people's living environment, the preparation level of blended modified composite materials has been raised to a new height.

[0003] Polypropylene material has low density, high strength, heat resistance, good insulation and low price, and has attracted much attention in the fields of home appliances, automobiles, plastic pipes, etc. However, this material has disadvantages such as poor impact resistance, poor toughness and large molding shrinkage. With the rapid development of the automobile industry today, people are looking for new materials in terms of lightness, comfort, greenness and environmental protection. Polypropylene materials account for an increasing proportion of our automotive parts, especially in automotive interior parts.

[0004] Today, with the development of Industry 4.0, traditional manufacturing has been impacted by new high-tech concepts. Environmental protection and low carbon have become important factors affecting the development of national GDP. The application of 3D printing has brought great help to our traditional manufacturing industry, and its application in the fields of automobiles, building materials, and medical and health care has become the norm. When 3D printing products, they are often restricted by material application due to environmental factors of materials.

[0005] Tertiary carbon atoms in PP materials are prone to aging and degradation under light and heat conditions, and the VOCs produced are mostly small molecular compounds such as alkanes and alkenes. The traditional method of preparing low-VOC materials mainly uses the addition of different types of adsorbents through twin-screw extrusion, cooling, granulation, and secondary deashing during the blast drying process to achieve the purpose of removing low-molecular substances in polypropylene materials.

[0006] Low-VOC polypropylene materials are prepared from composite materials. They not only serve as the main raw materials in automobiles and home appliances, but are also more widely used in the currently popular 3D printing materials. The shrinkage rate of composite polypropylene materials prepared by 3D technology is reduced to less than ten times, and the new extrusion process reduces the VOC content by 20-30%.

[0007] Patent CN111533993A (CN202010384201.1) discloses a low-odor, low-VOC long glass fiber reinforced polypropylene composite material and a preparation method. Using low-odor, low-VOC flat glass fibers instead of ordinary cylindrical glass fibers not only reduces the odor and VOC content of the long glass fiber reinforced polypropylene composite material, but also improves the fluidity, mechanical properties and appearance of the long glass fiber reinforced polypropylene composite material, and reduces the warping deformation of long glass fiber reinforced polypropylene composite products. The main purpose of the glass fiber reinforced polypropylene material in this invention is to improve the strength of the material. After reinforcement, the continuity of the glass fiber is broken, and relatively fine fibers are formed after processing, and are easily precipitated on the surface of the material. This material is not very meaningful for low odor and is difficult to use in environments with odor requirements.

[0008] Patent CN111533997A (CN202010442351.3) discloses a low-VOC, antistatic polypropylene material and its preparation method and application. In the invention, carbon aerogel is applied to plastics. The characteristics of carbon aerogel are utilized and reasonably proportioned with epoxy resin and compatibilizer to obtain a polypropylene composite material with excellent mechanical properties, VOC emission properties and antistatic properties. It can be used in automotive interior and exterior parts, with excellent touch and long-term dustproof. The main consideration for adding aerogel to the polypropylene material in this invention is that it has a good barrier effect. After adding polypropylene, due to the inertness of the aerogel itself, it is difficult to react with the material to improve the performance, and the prepared filled polypropylene material has poor performance. Summary of the invention

[0009] In order to solve the above problems existing in the prior art, the present invention develops and utilizes a twin-screw extrusion process to prepare a filled polypropylene composite material for 3D printing with high toughness, low shrinkage, and low VOC, so as to overcome the limitations of 3D printing materials in automobiles, home appliances, etc., and expand the application field of polypropylene materials.

[0010] One of the purposes of the present invention is to provide a low VOC polypropylene material, comprising polypropylene, polyethylene glycol, and an adsorbent, wherein the adsorbent is selected from at least one of whisker materials, zeolite, talc, wollastonite, and silicate compounds.

[0011] In the low VOC polypropylene material, based on 100 parts by weight of polypropylene, the polyethylene glycol is 1 to 30 parts by weight and the adsorbent is 1 to 30 parts by weight; preferably, the polyethylene glycol is 5 to 8 parts by weight and the adsorbent is 1 to 25 parts by weight.

[0012] The polypropylene is preferably prepared by hydrogenation. Different grades of polypropylene materials have different VOCs due to different polymerization processes. Polypropylene materials prepared by hydrogenation are selected as the substrate, so that the VOC of the prepared polypropylene is the lowest, including tetrahydrofuran, ethyl acetate, xylene, ethylbenzene and other impurities.

[0013] The adsorbent may be selected from one, two or more of whisker materials, zeolite, talc, wollastonite and silicate compounds.

[0014] The whisker material is selected from at least one of calcium sulfate whiskers, calcium carbonate whiskers and wollastonite whiskers.

[0015] According to one embodiment of the present invention, the whisker material may be selected from one or a mixture of two or more of wollastonite whiskers, zeolite, talcum powder, wollastonite, and silicate compounds.

[0016] Zeolite is the general term for zeolite family minerals, which are hydrated alkali or alkaline earth metal aluminum silicate minerals. More than 40 kinds of natural zeolites have been discovered in the world, among which the most common ones are clinoptilolite, mordenite, chabazite, erionite, phillipsite, heulandite, lauzenite, stilbite and analcime. Clinoptilolite and mordenite have been used in large quantities. Zeolite family minerals belong to different crystal systems, and the crystals are mostly fibrous, hair-like, columnar, and a few are plate-like or short columnar. Zeolite has ion exchange, adsorption separation, catalysis, stability, chemical reactivity, reversible dehydration, conductivity, etc. Zeolite is mainly produced in the cracks or amygdala of volcanic rocks, and coexists with calcite, chalcedony, and quartz; it is also produced in volcanic clastic sedimentary rocks and hot spring deposits. Preferably, the specific gravity of zeolite is 2 to 3.

[0017] The calcium sulfate whisker, calcium carbonate whisker, and wollastonite whisker are needle-shaped. Preferably, the aspect ratio of the calcium sulfate whisker, calcium carbonate whisker, or wollastonite whisker is 10-150, more preferably 100-150.

[0018] The calcium sulfate whiskers, calcium carbonate whiskers, wollastonite whiskers and other materials are preferably dehydrated whisker materials, which are evenly dispersed into the polypropylene material after shearing in the screw. The aspect ratio of the whiskers changes, and the microstructure presents a wood block state. They react chemically with small molecules such as aldehydes and benzene in the matrix resin, and the adsorption effect is more significant.

[0019] The low VOC polypropylene material may further include common additives in the art, such as antioxidants, toughening additives, reinforcing additives, etc., as required.

[0020] Based on 100 parts by weight of polypropylene, the antioxidant is 0.1 to 0.5 parts by weight.

[0021] The toughening aid may be selected from at least one of maleic anhydride grafts, JMA (glycidyl methacrylate) grafts, SEBS, SEBS grafted with maleic anhydride, and the like.

[0022] Based on 100 parts by weight of polypropylene, the toughening aid is preferably 1 to 8 parts by weight, more preferably 2 to 8 parts by weight.

[0023] The reinforcing aid may be selected from at least one of zeolite, calcium carbonate, talc, wollastonite, barium sulfate, kaolin, sodium sulfate, glass beads and the like.

[0024] Based on 100 parts by weight of polypropylene, the reinforcing auxiliary agent is preferably 10 to 30 parts by weight, more preferably 10 to 20 parts by weight.

[0025] The second object of the present invention is to provide a method for preparing a low-VOC polypropylene material, which is prepared from raw materials including polypropylene, polyethylene glycol, an adsorbent, and pure water, wherein the pure water is added in a mist form.

[0026] According to a preferred embodiment of the present invention, the preparation method comprises the following steps:

[0027] (1) melt-blending polypropylene, polyethylene glycol, and an adsorbent;

[0028] (2) spraying pure water in a mist form into the molten material obtained in step (1);

[0029] (3) Vacuum extraction and extrusion granulation.

[0030] In the step (1):

[0031] Based on 100 parts by weight of polypropylene, the amount of polyethylene glycol is 1 to 30 parts by weight, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18, 20, 22, 25, 28, 30 parts by weight, or any value between the above values, or a numerical range between any two of the above values; the amount of adsorbent is 1 to 30 parts by weight, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18, 20, 22, 25, 28, 30 parts by weight, or any value between the above values, or a numerical range between any two of the above values.

[0032] Antioxidants, reinforcing agents and other additives may also be added in step (1).

[0033] Preferably, a twin-screw extruder is used for extrusion; more preferably, the screw block combination is open in the homogenization stage.

[0034] Preferably, the extruder temperature is 180-225°C.

[0035] The adsorbent is selected from at least one of calcium sulfate whiskers, calcium carbonate whiskers, wollastonite whiskers, zeolite, talc, wollastonite, silicate compounds and the like.

[0036] The whisker material can be purchased commercially or prepared by conventional methods in the art, such as preparing mine brine, crystallizing high-salt wastewater, and performing whisker reaction. The whisker properties are controlled by the above steps to obtain a whisker material with a whisker aspect ratio of 10 to 150.

[0037] In the step (2):

[0038] The pure water is tertiary deionized water, and preferably the total ion content in the pure water is below 200 ppb.

[0039] The feeding speed of the pure water is 0.1 to 2 liters / hour, preferably 0.5 to 1 liter / hour.

[0040] The pure water can be added through a liquid feeder and sprayed through a feed gun nozzle in the form of water mist. The temperature of the pure water can be 1-250°C.

[0041] The pure water is preferably added in the melting section of the extruder.

[0042] The pure water can be prepared by common methods in the art, such as electrolytic separation, osmosis, filtration, and sterilization.

[0043] The pure water is gasified at high temperature inside the barrel and discharged from the vacuum port of the twin screws of the screw. The vacuum port can be set to two stages.

[0044] In the step (3):

[0045] The extrusion speed is preferably 200 to 350 rpm / min, more preferably 260 to 300 rpm / min.

[0046] In the preparation method of the present invention, according to a preferred embodiment,

[0047] Polypropylene, polyethylene glycol, adsorbent and antioxidant are mixed evenly and added to the extruder. After the above polypropylene materials pass through the melting section of the screw, they form a molten state inside the screw groove of the barrel. Pure water is added through a liquid metering pump, and the heating container heats the pure water. It is injected into the barrel of the twin screw through a liquid gun to achieve stable and uniform mist injection, and is evenly distributed in the molten material, and finally discharged from the two vacuum ports of the twin screws of the screw. The screw combination plays a key role in the transportation of materials. When the molten polypropylene material is transported to the homogenization section by the screw, the screw block combination in the twin screw combination is usually open, which is convenient to further reduce the pressure of the molten material. While the huge extrusion pressure is released, the low molecular weight and residual reaction impurities in the melt material are extracted under the action of the negative pressure vacuum pump, and finally the required low-VOC polypropylene material is obtained.

[0048] The third object of the present invention is to provide application of the above-mentioned polypropylene material or the polypropylene material obtained by the preparation method in 3D rapid prototyping materials.

[0049] The low-VOC polypropylene material of the present invention can be applied to the selective laser sintering technology, has a high sintering success rate, has a small size error between the obtained sintered product and the predetermined product, has few cross-sectional voids, and has excellent comprehensive performance.

[0050] The low-VOC polypropylene material can not only be used as the main raw material in automobiles and home appliances, but is also more widely used in the currently popular 3D printing materials. The low-VOC polypropylene material is prepared by 3D technology, and the shrinkage rate of the composite polypropylene material is reduced by less than ten times, and the VOC content is reduced by 20-30%.

[0051] The advantages of the present invention are:

[0052] 1. Using the traditional twin-screw extrusion process, by adding atomized pure water into the twin-screw barrel and evenly distributing it in the molten material, the water is gasified at high temperature inside the barrel and discharged from the two vacuum ports of the twin-screw screws, which improves the cleanliness of the polypropylene material and is suitable for the preparation of materials with high use requirements such as low VOC and transparent polypropylene.

[0053] 2. By adding material adsorbents, such as whisker materials, zeolite and other fillers, and evenly adding them into the polypropylene material, it has a significant adsorption effect on impurities in the material, such as aldehydes, ketones, xylene and other small molecular substances and C6-C16 long-chain alkanes. Such an experimental formula is entrained by this atomized water mist to remove these low molecular impurities. This extrusion process is simple to operate and has obvious practical effects.

[0054] 3. Polyethylene glycol is a low molecular weight lubricating agent, often used in medicines and foods, with good water solubility and good compatibility with many organic components. It has excellent lubricity, moisture retention, dispersibility, and adhesion, and can be used as an antistatic lubricant. It can melt water vapor in plastic materials and reduce the VOC content in plastic materials.

[0055] 4. Polypropylene composite materials make up for the shortcomings of polypropylene materials such as easy degradation and high shrinkage. In the application of laser sintering, material defects seriously restrict the application field. Filling polypropylene composite materials with whisker materials not only solves the above problems, but also greatly reduces the cost of materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 For zeolite.

[0057] Figure 2 The microstructure of zeolite.

[0058] Figure 3 It is calcium sulfate whisker.

[0059] Figure 4 The microstructure of calcium sulfate whiskers. DETAILED DESCRIPTION

[0060] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the content of the present invention still fall within the scope of protection of the present invention.

[0061] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0062] According to a preferred embodiment of the present invention, the preparation method of the polypropylene composite material can be as follows: polypropylene, polyethylene glycol, adsorbent, antioxidant, auxiliary agent, etc. are stirred at low speed in a high-speed mixer according to a certain ratio, and the mixed materials are added to the feeder of a reaction type 40 twin-screw extruder. Pure water is added to a container with a heat insulator, and the liquid is injected into a liquid gun in a mist state according to the addition amount of 0.1 to 2 liters of liquid per hour, and is evenly distributed in the molten material, and is evenly extruded, cooled, and granulated at an extrusion speed of 200 to 350rpm / min. The pure water of the present invention passes through the liquid feeder, and the feed gun nozzle is sprayed in the form of water mist, which strengthens the dispersion of water vapor. The water is gasified at high temperature inside the barrel and discharged from the two vacuum ports of the twin screw by vacuum extraction. Polyethylene glycol reduces the friction performance in the material, and can retain the aspect ratio of the whisker, so as to obtain a better whisker material, and the low molecular weight substances are discharged by extraction after reaction extrusion.

[0063] The present invention will be further described below through specific examples.

[0064] raw material:

[0065] PP: Brand K8003, Sinopec Yanshan Petrochemical;

[0066] Calcium sulfate whiskers: industrial grade, produced by Jiangsu Xinyuan Mining, whisker aspect ratio 80-150;

[0067] Polyethylene glycol; industrial grade; Beijing Xinkeao Company;

[0068] Talc: nanometer grade, Beijing Xinkeao Company,

[0069] Deionized water: produced by Beijing Research Institute of Chemical Industry;

[0070] Antioxidant: 1010, produced by BASF, Germany;

[0071] Antioxidant: 168, produced by BASF, Germany;

[0072] Zeolite: experimental grade, Beijing Xinkeao Company, the specific gravity of zeolite is 2.0-2.3.

[0073] The comparative examples and embodiments of the present invention use a reactive twin-screw extruder, the extrusion temperature range is 180-225° C., the twin-screw extruder speed is 300 rpm, and the vacuum pressure of the two-stage vacuum pump is 0.8 MPa.

[0074] The specific embodiments are as follows: wherein the total weight of polypropylene is 100 parts by weight.

[0075] Comparative Example 1: Polypropylene was directly mixed and extruded into pellets for testing. The main purpose was to observe the performance of polypropylene pellets and the VOC changes of the materials after screw extrusion and pelletization.

[0076] Comparative Example 2, the weight of polypropylene is 100 parts by weight, the amount of zeolite added is 5 parts by weight, and the polypropylene material is prepared according to a fixed extrusion process. The main observations are the performance of the pellets after adding the VOC material absorbent to the polypropylene, and the VOC changes of the material after screw extrusion granulation.

[0077] Comparative Example 3, during the direct mixing extrusion granulation of polypropylene, pure water was added directly into the barrel at an amount of 0.5 liters / hour, and extrusion granulation was performed according to a fixed extrusion process. Example 3 was obtained and tested. The main observations were the performance of the polypropylene pellets and the VOC changes of the materials after screw extrusion granulation.

[0078] Comparative Example 4, the weight of polypropylene is 100 parts by weight, the amount of calcium sulfate whisker added is 5 parts by weight, and the polypropylene material is prepared according to a fixed extrusion process. The main observations are the performance of the pellets after adding the VOC material absorbent to the polypropylene, and the VOC changes of the material after screw extrusion granulation.

[0079] Example 1, polypropylene is added in an amount of 100 parts by weight, nano-talc is added in an amount of 20 parts by weight, zeolite is added in an amount of 5 parts by weight, polyethylene glycol is added in an amount of 5 parts by weight, and pure water is added in an amount of 0.5 liters / hour by injecting a liquid gun into the barrel in a mist form, and extrusion granulation is performed according to a fixed extrusion process. The main purpose is to observe the performance changes of the material after adding the nano-talc material as a reinforcing auxiliary agent and the VOC changes of the material after adding the liquid substance for extraction.

[0080] Example 2, polypropylene is added in 100 parts by weight, calcium sulfate whisker material is added in 20 parts by weight, zeolite is added in 5 parts by weight, polyethylene glycol is added in 5 parts by weight, pure water is added in 0.5 liters / hour injection liquid gun to add it into the barrel in a mist form, and extrusion granulation is carried out according to a fixed extrusion process. The main purpose is to observe the performance changes of the material after adding nano-scale calcium sulfate whisker material and the VOC changes of the material after adding liquid material extraction.

[0081] Example 3, polypropylene is added in an amount of 100 parts by weight, calcium sulfate whisker material is added in an amount of 20 parts by weight, polyethylene glycol is added in an amount of 5 parts by weight, the extrusion process remains unchanged, pure water is added in an amount of 1 liter / hour by injecting a liquid gun into the barrel in a mist form, and extrusion granulation is performed according to a fixed extrusion process. The main purpose is to observe the performance changes of the material after adding the calcium sulfate whisker material and the VOC changes of the material after increasing the liquid substance and extracting the added liquid substance.

[0082] Example 4: 100 parts by weight of polypropylene, 20 parts by weight of calcium sulfate whisker material, 5 parts by weight of zeolite, and 5 parts by weight of polyethylene glycol are added, and pure water is added to the barrel in a mist form by injecting a liquid gun at 1 liter / hour, and extrusion granulation is performed according to a fixed extrusion process. The main purpose is to observe the performance changes of the zeolite material after adding the calcium sulfate whisker material, and the VOC changes of the material after increasing the liquid substance and extracting the liquid substance.

[0083] Example 5, polypropylene is added in 100 parts by weight, calcium sulfate whisker material is added in 20 parts by weight, zeolite is added in 5 parts by weight, talcum powder is added in 5 parts by weight, polyethylene glycol is added in 5 parts by weight, the extrusion process remains unchanged, pure water is added in 1 liter / hour by injection liquid gun and added to the barrel in a mist form, and extrusion granulation is performed according to a fixed extrusion process. The main purpose is to observe the performance changes after adding calcium sulfate whisker material, adding talcum powder, adding zeolite material, and the VOC changes of the material after increasing the liquid substance and extracting after adding the liquid substance.

[0084] Example 6, polypropylene is added in 100 parts by weight, calcium sulfate whisker material is added in 10 parts by weight, zeolite is added in 3 parts by weight, talcum powder is added in 3 parts by weight, polyethylene glycol is added in 3 parts by weight, the extrusion process remains unchanged, pure water is added in 1 liter / hour by injection liquid gun and added to the barrel in a mist form, and extrusion granulation is performed according to a fixed extrusion process. The main purpose is to observe the performance changes after adding calcium sulfate whisker material, adding talcum powder, adding zeolite material, and the VOC changes of the material after increasing the liquid substance and extracting after adding the liquid substance.

[0085] The basic formula of the polypropylene composite material provided by the present invention is as follows in Table 1:

[0086] Table 1 Polypropylene composite material formula

[0087]

[0088] The physical properties of the polypropylene composite material provided by the present invention are shown in Table 2 below:

[0089] In the embodiments and comparative examples, the test method for tensile strength is: GB / T1040-2006;

[0090] Test method for flexural strength: GB / T 9341-2008;

[0091] Impact performance (simply supported beam) test method: ISO / R179.

[0092] Table 2 Physical properties of polypropylene composites

[0093]

[0094] The shrinkage rate of the polypropylene composite material provided by the present invention is shown in Table 3 below:

[0095] Shrinkage test standard: GB / T 39818-2021

[0096] Table 3 Shrinkage of polypropylene composite materials

[0097] Material No. Shrinkage rate (%) Comparative Example 1 3.5 Comparative Example 2 3 Comparative Example 3 3.8 Comparative Example 4 0.98 Example 1 1.01 Example 2 0.87 Example 3 0.88 Example 4 0.67 Example 5 0.56

[0098] The VOC test values ​​of the polypropylene composite material provided by the present invention are shown in Table 4 below:

[0099] Table 4 VOC test values ​​of polypropylene composites

[0100] Material No. <![CDATA[VOC / (μgC.10min) -1 ]]> Comparative Example 1 81 Comparative Example 2 68 Comparative Example 3 72 Comparative Example 4 38 Example 1 46 Example 2 29 Example 3 24 Example 4 18 Example 5 13 Example 6 15

[0101] Test method: Thermal desorption / capillary gas chromatography: GB / T27630-2011.

[0102] Based on the above experimental results, the VOCs produced in polypropylene materials contain compounds such as olefins and alkanes, acetone is the main product after polypropylene degradation, and phenol products are mostly produced by the degradation of added antioxidants. The main methods for removing polypropylene materials are: resin polymerization, additives, and physical methods. The present invention adopts a liquid addition and extraction VOC processing technology, and the selection of the processing technology is simple and effective. First, by comparing talcum powder with calcium sulfate whiskers, the VOC results show that the whisker material still has a significant adsorption effect on odor. After adjusting the process, pure water is added and then extracted. The VOC of the material is greatly reduced, and the reduction is greater than 50%. Therefore, it can be concluded that the process of liquid filling pure water to reduce the polypropylene material is simple and effective, and has a certain auxiliary effect on the physical properties of the composite polypropylene material. By adding the whisker material to the polypropylene material, the VOC of the material is significantly reduced, and the physical properties of the material are also greatly improved.

Claims

1. A low VOC polypropylene material, comprising polypropylene, polyethylene glycol, and an adsorbent, wherein the adsorbent is selected from at least one of whisker materials, zeolite, talc, wollastonite, and silicate compounds.

2. The low VOC polypropylene material according to claim 1, characterized in that: Based on 100 parts by weight of polypropylene, the polyethylene glycol is 1 to 30 parts by weight and the adsorbent is 1 to 30 parts by weight; preferably, the polyethylene glycol is 5 to 8 parts by weight and the adsorbent is 1 to 25 parts by weight.

3. The low VOC polypropylene material according to claim 1, characterized in that: The polypropylene is prepared by a hydrogenation process.

4. The low VOC polypropylene material according to claim 1, characterized in that: The whisker material is selected from at least one of calcium sulfate whiskers, calcium carbonate whiskers and wollastonite whiskers; and / or, The whisker material has a whisker aspect ratio of 10 to 150, preferably 100 to 150; and / or, The specific gravity of zeolite is 2 to 3.

5. A method for preparing a low-VOC polypropylene material, which is prepared from raw materials including polypropylene, polyethylene glycol, an adsorbent and pure water, wherein the pure water is added in the form of mist.

6. The preparation method according to claim 5, characterized in that The following steps are involved: (1) melt blending components including polypropylene, polyethylene glycol, and an adsorbent; (2) spraying pure water in a mist form into the molten material obtained in step (1); (3) Extrusion granulation.

7. The preparation method according to claim 6, characterized in that In step (1): Using twin screw extruder; Preferably, the screw block combination is open in the homogenization stage; and the extruder temperature is 180-225°C.

8. The preparation method according to claim 6, characterized in that In step (2): The pure water is grade tertiary deionized water, preferably the total ion content of the pure water is below 200 ppb; and / or, The feeding rate of pure water is 0.1 to 2 liters / hour, preferably 0.5 to 1 liter / hour.

9. The preparation method according to claim 6, characterized in that In step (3): The extrusion speed is 200 to 350 rpm / min, preferably 260 to 300 rpm / min.

10. Use of the polypropylene material according to any one of claims 1 to 4 or the polypropylene material obtained by the preparation method according to any one of claims 5 to 9 in 3D rapid prototyping materials.

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