Polypropylene composite material for 3D printing and preparation method thereof

Abstract

The invention discloses a polypropylene composite material for 3D printing and a preparation method of the polypropylene composite material. The polypropylene composite material is prepared from the following raw materials in parts by weight: 100 parts of polypropylene, 20 to 40 parts of reinforced fibers, 15 to 25 parts of an elastomer, 10 to 20 parts of talcum powder, 0.1 to 0.5 part of peroxide, 0.5 to 1 part of a coupling agent, 0.1 to 0.5 part of a curing accelerator, 0.1 to 0.5 part of a toughening agent and 0.4 to 0.8 part of a nucleating agent. The polypropylene composite material disclosed by the invention is low in transverse shrinkage rate and longitudinal shrinkage rate, high in melt index, strong in impact resistance and excellent in wear resistance, is particularly suitable for 3D printing, and is strong in flowability and smooth in printing during printing, and a printed model is basically free of edge warping.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and more specifically, the present invention relates to a polypropylene composite material for 3D printing and a preparation method thereof. Background Art

[0002] 3D printing is an advanced technology used to manufacture three-dimensional objects. Compared with traditional industrial manufacturing, it does not require molds or large production lines. Simply put, 3D printing is the process of converting digital models into physical objects. This process can be done with a 3D printer. In a 3D printer, the printing material is heated to the melting point and ejected through a nozzle. The nozzle moves along the path of each layer and piles up the printing material layer by layer until the entire object is manufactured.

[0003] At present, the printing materials on the market include ABS / PLA / PP (rolled materials), bright resin liquid, nylon powder, metal powder, ceramic powder, gypsum powder and other materials. Among them, PP coiled materials are low in price and good in toughness, and the printed products are more delicate and beautiful. However, due to its large shrinkage, it is easy to curl when printing with PP, resulting in poor printing effect. The current solution is to change the printing base plate, for example, use a base plate with many holes to fix the bottom of the printed product on the base plate, but this will cause problems such as difficulty in demoulding and troublesome cleaning of the base plate. Summary of the invention

[0004] Based on this, the object of the present invention is to provide a polypropylene composite material for 3D printing with a small shrinkage rate, which is not easy to curl during 3D printing.

[0005] The specific technical solutions for achieving the above-mentioned invention objectives include the following.

[0006] In a first aspect of the present invention, a polypropylene composite material for 3D printing is provided, which is prepared from the following raw materials in parts by weight: 100 parts of polypropylene, 20 to 40 parts of reinforcing fiber, 15 to 25 parts of elastomer, 10 to 20 parts of talc, 0.1 to 0.5 parts of peroxide, 0.5 to 1 part of coupling agent, 0.1 to 0.5 parts of curing accelerator, 0.1 to 0.5 parts of toughening agent, and 0.4 to 0.8 parts of nucleating agent.

[0007] A second aspect of the present invention provides a method for preparing a polypropylene composite material for 3D printing, comprising the following steps:

[0008] S1: mixing polypropylene, reinforcing fiber, elastomer, talcum powder, peroxide, coupling agent, curing accelerator, toughening agent and nucleating agent to obtain a mixed material;

[0009] S2: The mixed material obtained in S1 is put into a twin-screw extruder, extruded into granules, and then injection molded to obtain the product.

[0010] The present invention optimizes and obtains a polypropylene composite material, which adopts polypropylene, reinforcing fiber, elastomer, talcum powder, peroxide, coupling agent, curing accelerator, toughening agent, nucleating agent, and is made by extrusion granulation and injection molding. On the one hand, the reinforcing fiber can form a strong interaction with polypropylene, effectively improve the linear expansion coefficient of the composite material, reduce the shrinkage rate of the polypropylene composite material, and increase the toughness of the composite material; on the other hand, talcum powder can change the structural state of polypropylene, avoid the appearance of large crystal balls, and further reduce the shrinkage rate of the polypropylene composite; on the other hand, the free radicals generated by peroxide can make auxiliary agents such as coupling agent, curing accelerator, toughening agent, nucleating agent and elastomer form crosslinking, increase the toughness of the polypropylene composite material, and also contribute to the reduction of shrinkage rate; and the β-crystal nucleating agent can induce the crystal form in polypropylene to change from α-crystal form to β-crystal form, improve the cold resistance of the composite material, and also improve its toughness. Through the mutual cooperation of the above components, not only the lateral shrinkage rate and longitudinal shrinkage rate of the composite material are greatly reduced, but also the melt index, impact resistance (especially low-temperature impact resistance) and wear resistance of the composite material are improved. Therefore, the polypropylene composite material prepared by the present invention is particularly suitable for 3D printing, has strong fluidity during printing, prints smoothly, and the printed model has substantially no warping.

[0011] The present invention adopts a twin-screw extruder to extrude and granulate to prepare a polypropylene composite material. The temperature of the screw gradually increases from the conveying section to the mixing section and gradually decreases from the mixing section to the homogenizing section, thereby being able to control the crystallization degree of the polypropylene and achieving the effect of reducing the shrinkage rate of the composite material. DETAILED DESCRIPTION

[0012] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0013] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in the present invention includes any and all combinations of one or more of the related listed items.

[0014] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods, and the materials, reagents, etc. used can be purchased from commercial channels unless otherwise specified.

[0015] In some embodiments of the present invention, a polypropylene composite material for 3D printing is disclosed, which is prepared from the following raw materials in parts by weight: 100 parts of polypropylene, 20 to 40 parts of reinforcing fiber, 15 to 25 parts of elastomer, 10 to 20 parts of talc, 0.1 to 0.5 parts of peroxide, 0.5 to 1 part of coupling agent, 0.1 to 0.5 parts of curing accelerator, 0.1 to 0.5 parts of toughening agent, and 0.4 to 0.8 parts of nucleating agent.

[0016] In some of the embodiments, the polypropylene composite material for 3D printing is prepared from the following raw materials in parts by weight: 100 parts of polypropylene, 30 to 40 parts of reinforcing fiber, 20 to 25 parts of elastomer, 18 to 20 parts of talc, 0.3 to 0.5 parts of peroxide, 0.8 to 1.0 parts of coupling agent, 0.4 to 0.5 parts of curing accelerator, 0.3 to 0.5 parts of toughening agent, and 0.6 to 0.8 parts of nucleating agent.

[0017] In some embodiments, the nucleating agent is an α-crystalline nucleating agent and / or a β-crystalline nucleating agent.

[0018] In some embodiments, the nucleating agent is an α-crystal nucleating agent and a β-crystal nucleating agent, and the weight ratio of the α-crystal nucleating agent to the β-crystal nucleating agent is 1:0.8-1.2.

[0019] In some embodiments, the weight ratio of the α-crystal nucleating agent to the β-crystal nucleating agent is 1:0.9-1.1.

[0020] In some of the embodiments, the weight ratio of the α-crystal nucleating agent to the β-crystal nucleating agent is 1:0.95-1.05.

[0021] In some embodiments, the reinforcing fiber is one or more of nylon fiber, aramid fiber, glass fiber and PBO fiber.

[0022] In some embodiments, the nylon fiber is polyamide, and the polyamide is one or more of polycaprolactam, polyhexamethylene adipamide, polypentamethylene adipamide, and polydecamethylene sebacamide.

[0023] In some embodiments, the elastomer is a polyolefin elastomer, and the Mooney viscosity of the polyolefin elastomer at 120° C. is 15-25.

[0024] In some embodiments, the toughening agent is a metallocene polyethylene or a polyolefin plastomer.

[0025] In some embodiments, the peroxide is dicumyl peroxide and / or diisopropylbenzene peroxide.

[0026] In some embodiments, the peroxide is dicumyl peroxide and diisopropylbenzene peroxide.

[0027] In some of the embodiments, the weight ratio of the benzoyl peroxide to dicumyl peroxide is 1:0.8-1.2.

[0028] In some of the embodiments, the weight ratio of the benzoyl peroxide to dicumyl peroxide is 1:0.9-1.1.

[0029] In some of the embodiments, the weight ratio of the benzoyl peroxide to dicumyl peroxide is 1:0.95-1.05.

[0030] In some embodiments, the coupling agent is a silane coupling agent and an aluminate coupling agent, and the weight ratio of the silane coupling agent to the aluminate coupling agent is 1:0.8-1.2.

[0031] In some embodiments, the silane coupling agent is vinyl triethoxysilane or γ-methacryloxypropyl trimethoxysilane; the aluminate coupling agent is distearoyloxyisopropyl aluminate, DL-411 or DL-411DF.

[0032] In some embodiments, the weight ratio of the silane coupling agent to the aluminate coupling agent is 1:0.9-1.1.

[0033] In some of the embodiments, the weight ratio of the silane coupling agent to the aluminate coupling agent is 1:0.95-1.05.

[0034] In some embodiments, the curing accelerator is phenol and benzyl alcohol, and the weight ratio of phenol to benzyl alcohol is 1:0.8-1.2.

[0035] In some embodiments, the weight ratio of phenol to benzyl alcohol is 1:0.9-1.1.

[0036] In some of the embodiments, the weight ratio of phenol to benzyl alcohol is 1:0.95-1.05.

[0037] In other embodiments of the present invention, a method for preparing a polypropylene composite material for 3D printing is disclosed, comprising the following steps:

[0038] S1: mixing polypropylene, reinforcing fiber, elastomer, talcum powder, peroxide, coupling agent, curing accelerator, toughening agent and nucleating agent to obtain a mixed material;

[0039] S2: The mixed material obtained in S1 is put into a twin-screw extruder, extruded into granules, and then injection molded to obtain the product.

[0040] In some embodiments, the screw of the twin-screw extruder in step S2 includes a conveying section, a melting section, a mixing section, a exhaust end and a homogenizing section. The temperature of the conveying section is 160°C to 180°C, the temperature of the melting section is 185°C to 195°C, the temperature of the mixing section is 210°C to 220°C, the temperature of the exhaust end is 200°C to 210°C, and the temperature of the homogenizing section is 195°C to 205°C.

[0041] In the following examples and comparative examples, the model of polypropylene is M800E, purchased from Shanghai Petrochemical; the reinforcing fiber is purchased from Shandong Oude Chemical Fiber Products Co., Ltd.; the model of polyolefin elastomer is Vistamax-3000; the model of talc is Shuntian-HSF001; benzoyl peroxide is purchased from Guangzhou Senyou Biotechnology Co., Ltd.; diisopropyl peroxide is purchased from Guangzhou Fangruida Chemical Co., Ltd.; vinyl triethoxysilane is purchased from Shandong Shuntai New Materials Co., Ltd.; phenol is purchased from Jiangsu Yuntong New Materials Technology Co., Ltd.; distearyloxyisopropylaluminate is purchased from Shaoguan Fangxin Chemical Co., Ltd.; metallocene polyethylene is purchased from Ningbo Jinchi Plastic Co., Ltd.; β-crystal nucleating agent is purchased from Beijing Jihaichuan Technology Co., Ltd.; α-crystal nucleating agent is purchased from Tianjin Jinheng Blue Ocean Technology Co., Ltd. Other raw materials not specified are commercially available conventional raw materials.

[0042] The present invention is described in detail below with reference to specific embodiments.

[0043] Example 1

[0044] The polypropylene composite material of this embodiment includes the following preparation raw materials (by weight) and steps:

[0045] S1: 100 parts of polypropylene, 20 parts of reinforcing fiber, 15 parts of elastomer (polyolefin elastomer, Mooney viscosity at 120° C. is 15-25), 15 parts of talc (particle size is 5-25 μm), 0.05 parts of benzoyl peroxide, 0.05 parts of dicumyl peroxide, 0.25 parts of vinyl triethoxysilane, 0.25 parts of distearoyloxyisopropylaluminate, 0.05 parts of phenol, 0.05 parts of benzyl alcohol, 0.1 parts of metallocene polyethylene, 0.2 parts of α-crystalline nucleating agent and 0.2 parts of β-crystalline nucleating agent are measured and mixed uniformly to obtain a mixed material for standby use;

[0046] S2: The mixed material obtained in S1 is put into a twin-screw extruder (the screw includes a conveying section, a melting section, a mixing section, a venting end and a homogenizing section, the temperature of the conveying section is 160°C, the temperature of the melting section is 185°C, the temperature of the mixing section is 210°C, the temperature of the venting end is 200°C, and the temperature of the homogenizing section is 195°C), and extruded into granules;

[0047] S3: Then put it into the injection molding machine to make a strip-shaped polypropylene composite material.

[0048] Example 2

[0049] The polypropylene composite material of this embodiment includes the following preparation raw materials (by weight) and steps:

[0050] S1: 100 parts of polypropylene, 30 parts of reinforcing fiber, 20 parts of elastomer (polyolefin elastomer, Mooney viscosity at 120° C. is 15-25), 18 parts of talc (particle size is 5-25 μm), 0.15 parts of benzoyl peroxide, 0.15 parts of dicumyl peroxide, 0.4 parts of vinyl triethoxysilane, 0.4 parts of distearoyloxyisopropylaluminate, 0.15 parts of phenol, 0.15 parts of benzyl alcohol, 0.3 parts of metallocene polyethylene, 0.3 parts of α-crystalline nucleating agent and 0.3 parts of β-crystalline nucleating agent are measured and mixed uniformly to obtain a mixed material for standby use;

[0051] S2: The mixed material obtained in S1 is put into a twin-screw extruder (the screw includes a conveying section, a melting section, a mixing section, a venting end and a homogenizing section, the temperature of the conveying section is 170°C, the temperature of the melting section is 190°C, the temperature of the mixing section is 215°C, the temperature of the venting end is 205°C, and the temperature of the homogenizing section is 198°C), and extruded into granules;

[0052] S3: Then put it into the injection molding machine to make a strip-shaped polypropylene composite material.

[0053] Example 3

[0054] The polypropylene composite material of this embodiment includes the following preparation raw materials (by weight) and steps:

[0055] S1: 100 parts of polypropylene, 40 parts of reinforcing fiber, 25 parts of elastomer (polyolefin elastomer, Mooney viscosity at 120° C. is 15-25), 20 parts of talc (particle size is 5-25 μm), 0.25 parts of benzoyl peroxide, 0.25 parts of dicumyl peroxide, 0.5 parts of vinyl triethoxysilane, 0.5 parts of distearoyloxyisopropylaluminate, 0.25 parts of phenol, 0.25 parts of benzyl alcohol, 0.5 parts of metallocene polyethylene, 0.4 parts of α-crystalline nucleating agent and 0.4 parts of β-crystalline nucleating agent are measured and mixed to obtain a mixed material for standby use;

[0056] S2: The mixed material obtained in S1 is put into a twin-screw extruder (the screw includes a conveying section, a melting section, a mixing section, a venting end and a homogenizing section, the temperature of the conveying section is 180°C, the temperature of the melting section is 195°C, the temperature of the mixing section is 220°C, the temperature of the venting end is 200°C, and the temperature of the homogenizing section is 195°C), and extruded into granules;

[0057] S3: Then put it into the injection molding machine to make a strip-shaped polypropylene composite material.

[0058] Comparative Example 1

[0059] The polypropylene composite material of this comparative example comprises the following preparation raw materials (by weight) and steps:

[0060] S1: 110 parts of polypropylene, 40 parts of elastomer (polyolefin elastomer, Mooney viscosity at 120° C. is 15-25), 18 parts of talc (particle size is 5-25 μm), 0.15 parts of benzoyl peroxide, 0.15 parts of dicumyl peroxide, 0.4 parts of vinyl triethoxysilane, 0.4 parts of distearoyloxyisopropylaluminate, 0.15 parts of phenol, 0.15 parts of benzyl alcohol, 0.3 parts of metallocene polyethylene, 0.3 parts of α-crystalline nucleating agent and 0.3 parts of β-crystalline nucleating agent are weighed and mixed to obtain a mixed material for standby use;

[0061] S2: Same as Example 2;

[0062] S3: Same as Example 2.

[0063] Comparative Example 2

[0064] The polypropylene composite material of this comparative example comprises the following preparation raw materials (by weight) and steps:

[0065] S1: 100 parts of polypropylene, 48 parts of reinforcing fiber, 20 parts of elastomer (polyolefin elastomer, Mooney viscosity at 120° C. is 15-25), 0.15 parts of benzoyl peroxide, 0.15 parts of dicumyl peroxide, 0.4 parts of vinyl triethoxysilane, 0.4 parts of distearoyloxyisopropylaluminate, 0.15 parts of phenol, 0.15 parts of benzyl alcohol, 0.3 parts of metallocene polyethylene, 0.3 parts of α-crystalline nucleating agent and 0.3 parts of β-crystalline nucleating agent are measured and mixed to obtain a mixed material for standby use;

[0066] S2: Same as Example 2;

[0067] S3: Same as Example 2.

[0068] Comparative Example 3

[0069] The polypropylene composite material of this comparative example comprises the following preparation raw materials (by weight) and steps:

[0070] S1: 100 parts of polypropylene, 30 parts of reinforcing fiber, 20 parts of elastomer (polyolefin elastomer, Mooney viscosity at 120° C. is 15-25), 18 parts of talc (particle size is 5-25 μm), 0.55 parts of vinyl triethoxysilane, 0.55 parts of distearoyloxyisopropylaluminate, 0.15 parts of phenol, 0.15 parts of benzyl alcohol, 0.3 parts of metallocene polyethylene, 0.3 parts of α-crystalline nucleating agent and 0.3 parts of β-crystalline nucleating agent are measured and mixed uniformly to obtain a mixed material for standby use;

[0071] S2: Same as Example 2;

[0072] S3: Same as Example 2.

[0073] Comparative Example 4

[0074] The polypropylene composite material of this comparative example comprises the following preparation raw materials (by weight) and steps:

[0075] S1: 100 parts of polypropylene, 30 parts of reinforcing fiber, 20 parts of elastomer (polyolefin elastomer, Mooney viscosity at 120° C. is 15-25), 18 parts of talc, 0.15 parts of benzoyl peroxide, 0.15 parts of dicumyl peroxide, 0.4 parts of vinyl triethoxysilane, 0.4 parts of distearoyloxyisopropylaluminate, 0.15 parts of phenol, 0.15 parts of benzyl alcohol, 0.3 parts of metallocene polyethylene, and 0.6 parts of α-crystalline nucleating agent are weighed and mixed to obtain a mixed material for standby use;

[0076] S2: Same as Example 2;

[0077] S3: Same as Example 2.

[0078] The following performance tests were performed on the polypropylene composite materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4:

[0079] 1. Shrinkage rate: According to "GB / T17037.1.2019 Plastics Thermoplastic Materials Injection Molding Specimens Preparation Part 1: General Principles and Preparation of Multi-purpose Specimens and Long Strip Specimens".

[0080] 2. Melt index: in accordance with "GB / T 3682.1-2018 Plastics Thermoplastics Melt Mass Flow Rate (MFR) and Melt Volume Flow Rate (MVR) Determination Part 1: Standard Method".

[0081] 3. Impact strength: According to the standard "GB / T 1843-2008 Determination of impact strength of plastic cantilever beam", the sample is made by injection molding, the incision depth is 1mm, the pendulum is 5.5J, the sample width is 9mm, the sample thickness is 4mm, and 5 standard samples are tested for each group of samples, and the average value is finally calculated.

[0082] 4. Wear resistance: According to GMW14688 (general standard: scratch resistance test method).

[0083] 5. Warping degree: Use the sample to perform 3D printing test, use the same printer and the same stainless steel bottom plate without holes to print the same model, and observe the degree of warping at the bottom.

[0084] The test results are shown in Table 1.

[0085] Table 1

[0086]

[0087] As can be seen from Table 1, compared with Comparative Examples 1 to 4, the transverse shrinkage and longitudinal shrinkage of the polypropylene composite materials prepared in Examples 1 to 3, especially Examples 2 and 3, are significantly lower, and there is basically no warping when the polypropylene composite materials prepared in Examples 2 and 3 of the present invention are used for 3D printing, while the models obtained by 3D printing using the materials prepared in Comparative Examples 1 and 2 have serious warping, and the models obtained by 3D printing using the materials prepared in Comparative Examples 3 and 4 have slight warping.

[0088] At the same time, the polypropylene composite materials prepared in Examples 1 to 3 of the present invention have excellent impact resistance, especially excellent impact resistance in a low temperature environment; excellent wear resistance; and a high melt index, which makes them smoother for 3D printing.

[0089] In summary, the polypropylene composite material prepared by the present invention is very suitable for 3D printing.

[0090] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0091] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A polypropylene composite material for 3D printing, characterized in that: The invention is prepared from the following raw materials in parts by weight: 100 parts of polypropylene, 20 to 40 parts of reinforcing fiber, 15 to 25 parts of elastomer, 10 to 20 parts of talc, 0.1 to 0.5 parts of peroxide, 0.5 to 1 parts of coupling agent, 0.1 to 0.5 parts of curing accelerator, 0.1 to 0.5 parts of toughening agent and 0.4 to 0.8 parts of nucleating agent.

2. The polypropylene composite material for 3D printing according to claim 1, characterized in that: The invention is prepared from the following raw materials in parts by weight: 100 parts of polypropylene, 30 to 40 parts of reinforcing fibers, 20 to 25 parts of elastomers, 18 to 20 parts of talc, 0.3 to 0.5 parts of peroxides, 0.8 to 1.0 parts of coupling agents, 0.4 to 0.5 parts of curing accelerators, 0.3 to 0.5 parts of toughening agents, and 0.6 to 0.8 parts of nucleating agents.

3. The polypropylene composite material for 3D printing according to claim 1 or 2, characterized in that: The nucleating agent is an α-crystal nucleating agent and / or a β-crystal nucleating agent; Preferably, the nucleating agent is an α-crystal nucleating agent and a β-crystal nucleating agent, and the weight ratio of the α-crystal nucleating agent to the β-crystal nucleating agent is 1:0.8-1.2, preferably 1:0.9-1.1, and more preferably 1:0.95-1.

05.

4. The polypropylene composite material for 3D printing according to claim 1 or 2, characterized in that: The reinforcing fiber is one or more of nylon fiber, aramid fiber, glass fiber and PBO fiber; Preferably, the nylon fiber is polyamide, and the polyamide is one or more of polycaprolactam, polyhexamethylene adipamide, polypentamethylene adipamide, and polydecamethylene sebacamide.

5. The polypropylene composite material for 3D printing according to claim 1 or 2, characterized in that: The peroxide is dicumyl peroxide and / or diisopropylbenzene peroxide; Preferably, the peroxide is dicumyl peroxide and diisopropylbenzene peroxide, and the weight ratio of the benzoyl peroxide to diisopropylbenzene peroxide is 1:0.8-1.2, preferably 1:0.9-1.1, and more preferably 1:0.95-1.

05.

6. The polypropylene composite material for 3D printing according to claim 1 or 2, characterized in that: The elastomer is a polyolefin elastomer, and the Mooney viscosity of the polyolefin elastomer at 120° C. is 15-25; and / or the toughening agent is a metallocene polyethylene or a polyolefin plastomer.

7. The polypropylene composite material for 3D printing according to claim 1 or 2, characterized in that: The coupling agent is a silane coupling agent and an aluminate coupling agent, and the weight ratio of the silane coupling agent to the aluminate coupling agent is 1:0.8-1.2, preferably 1:0.9-1.1, and more preferably 1:0.95-1.05; Preferably, the silane coupling agent is vinyl triethoxysilane or γ-methacryloxypropyl trimethoxysilane; and the aluminate coupling agent is distearoyloxyisopropyl aluminate, DL-411 or DL-411DF.

8. The polypropylene composite material for 3D printing according to claim 1 or 2, characterized in that: The curing accelerator is phenol and benzyl alcohol, and the weight ratio of phenol to benzyl alcohol is 1:0.8-1.2, preferably 1:0.9-1.1, and more preferably 1:0.95-1.

05.

9. A method for preparing a polypropylene composite material for 3D printing according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: mixing polypropylene, reinforcing fiber, elastomer, talcum powder, peroxide, coupling agent, curing accelerator, toughening agent and nucleating agent to obtain a mixed material; S2: The mixed material obtained in S1 is put into a twin-screw extruder, extruded into granules, and then injection molded to obtain the product.

10. The method for preparing a polypropylene composite material for 3D printing according to claim 9, characterized in that: The screw of the twin-screw extruder in step S2 includes a conveying section, a melting section, a mixing section, a venting end and a homogenizing section. The temperature of the conveying section is 160°C to 180°C, the temperature of the melting section is 185°C to 195°C, the temperature of the mixing section is 210°C to 220°C, the temperature of the venting end is 200°C to 210°C, and the temperature of the homogenizing section is 195°C to 205°C.

Images