CN117777689A - A magnetic PLA/PBAT composite material for FDM type 3D printing and its preparation method and application - Google Patents

Abstract

The invention discloses a magnetic PLA/PBAT composite material for FDM 3D printing, a preparation method and application thereof, wherein the PLA/PBAT composite material comprises the following components in parts by weight: 150-210 parts of PLA resin, 100-140 parts of PBAT resin, 90-150 parts of magnetic powder, 3.4-5 parts of compatilizer and 1-1.5 parts of coupling agent, wherein the mass ratio of the PLA resin to the PBAT resin is (1.5-2): 1. The PLA/PBAT composite material provided by the invention has better magnetic force performance, and simultaneously can give consideration to the dryness and mechanical performance of the material, is a novel magnetic composite 3D printing material, and expands the technical category of FDM type 3D printing technology.

Description

A magnetic PLA/PBAT composite material for FDM type 3D printing and its preparation method Laws and Applications

Technical field

The present invention relates to the technical field of engineering plastics, and in particular to a magnetic PLA/PBAT composite material for FDM type 3D printing, and a preparation method and application thereof.

Background technique

3D printing technology is a rapid additive manufacturing technology that generates three-dimensional entities by adding and stacking materials layer by layer. Compared with traditional subtractive manufacturing technology, it has the characteristics of low loss, intelligent product manufacturing, precision and high efficiency. When it comes to high-end manufacturing fields with complex shapes, 3D printing technology can show great superiority. However, the development of 3D printing technology is largely limited by the development of 3D printing materials. Therefore, the development of more diverse and multifunctional 3D printing materials has become a hot spot and key to research and application. Polylactic acid (PLA) is a fully biodegradable aliphatic polyester polymer material, which is usually synthesized by multi-step reactions from renewable resources such as biomass materials such as corn starch or sucrose. It has good chemical inertness, good biocompatibility, and is extremely easy to process. After the corresponding products are discarded, they can be completely decomposed into carbon dioxide and water that are non-toxic and harmless to the environment under natural conditions such as microorganisms, acids and alkalis. However, the elongation at break of PLA resin is only 10%, it is brittle, has low impact strength and poor flexibility. These shortcomings greatly limit the application of PLA in the field of 3D printing materials.

Fused Deposition Modeling (FDM) is a commonly used technology for 3D printing. This technology uses thermoplastic polymers in a molten state to extrude from the print head, then solidify into a thin layer of contour, and then stack them layer by layer. Currently, FDM is the most widely used and cheapest molding technology. However, there are very few magnetic composite materials for FDM-type 3D printing on the market. Most of the products are prepared by designing Fe ₃ O ₄ doped PLA materials. The products prepared by this method have poor magnetic effects and only have the characteristics of soft magnetic materials. In certain cases, they will be attracted by strong magnetic fields and cannot be widely used. This cannot meet the needs of real magnetic materials. Therefore, there is an urgent need for a magnetic FDM-type 3D printing material that can take into account both magnetic functions and mechanical properties to fill the gap in the industry and expand the application range of FDM-type 3D printing materials.

Summary of the invention

In view of the defects in the prior art, the present invention proposes a magnetic PLA/PBAT composite material for FDM type 3D printing and its preparation method and application.

The invention provides a magnetic PLA/PBAT composite material for FDM type 3D printing, which includes the following components in parts by weight:

Wherein, the mass ratio of the PLA resin and PBAT resin is (1.5-2):1;

PBAT resin (polybutylene terephthalate-adipate) is a biodegradable thermoplastic copolymer, usually synthesized from raw materials such as butanediol, adipic acid and terephthalic acid. It has Biodegradability, reproducibility, thermoplasticity, elasticity and toughness. Compounding PLA resin with high toughness PBAT resin can increase the overall toughness of the extruded material; and due to the poor compatibility of PBAT resin and PLA resin, Adding a compatibilizer can help the materials mix better; and after adding magnetic powder, in order to overcome the interface energy difference between the magnetic substance and the composite material, a coupling agent needs to be added to solve the problem of interfacial anisotropy between the materials.

Further, the mass ratio of the PLA resin and PBAT resin is 3:2.

Further, the magnetic powder is NdFeB.

Further, the compatibilizer is biodegradable resin chain extender YMX-06, BASF chain extender joncrylADR-4468, maleic anhydride, dicumyl peroxide and ethylene-methyl acrylate-glycidyl methacrylate. One or more of the esters, preferably BASF chain extender joncryl ADR-4468. Using BASF chain extender as a compatibilizer can improve the compatibility between different condensation polymer materials by utilizing its compatibility ability.

Further, the coupling agent is selected from one or more types of phthalate coupling agents and silane coupling agents.

Further, the coupling agent is selected from phthalate ester coupling agents. Phthalate ester coupling agents can improve the interfacial compatibility between different materials, especially the bonding between reinforcing fillers (magnetic powder) and polymer matrix. This coupling agent has two different functional groups, one end can react with polymer materials, and the other end can react with inorganic fillers or other substances, and this type of coupling agent has the function of preventing hydrolysis. The amine salt solution GR-311W of bis(dioctyloxypyrophosphate)ethylene titanate is preferred.

Furthermore, the weight average molecular weight (Mw) of the PLA resin is 180000-220000. If the Mw is too low, it means that the polymer chain is shorter, resulting in a decrease in the strength and toughness of PLA, making it easy to break, and becoming deformed during processing. It is easier to degrade and the heat resistance will decrease. It will also cause the viscosity of the material to change during the material processing. If the viscosity is too high, the nozzle will be blocked and the screw will not be able to extrude the composite material; if the viscosity is too low, the composite material will not be extruded. The material is difficult to form and cannot produce continuous and uniform 3D printing materials; when the Mw of PLA is too high, it will affect the viscosity of PLA, resulting in internal stress within the material and poor formability.

Further, the weight average molecular weight (Mw) of the PBAT resin is 50,000-80,000.

The invention also provides a method for preparing the PLA/PBAT composite material, which includes the following steps:

S1: Dry PLA resin and PBAT resin;

S2: Weigh each component by weight, stir and mix, dry again, and then use a dynamic twin-screw extruder to extrude and shear to prepare the PLA/PBAT composite material;

The drying step is to dry the mixed material on a hot plate at 70°C-90°C for 8-12 hours. When drying again, the mixed material is placed in a moisture-absorbing bag and dried on a hot plate at 70°C-90°C for 8-12 hours to avoid the material being too dry to affect the printing effect. The extrusion temperature is 190-200°C, and the extrusion speed is 75%-85%.

Since the coupling process between magnetic powder and PLA/PBAT is prone to various reasons such as agglomeration and segregation, resulting in poor mechanical properties of the material, the addition of coupling agents and stirring are used to slow down the performance degradation of the material caused by the coupling of heterogeneous materials. question.

The present invention also provides the use of the PLA/PBAT composite material in preparing magnetic FDM type 3D printing filament.

In summary, compared with the prior art, the present invention achieves the following technical effects:

(1) The PLA/PBAT composite material provided by the present invention has high magnetic properties;

(2) The PLA/PBAT composite material provided by the present invention has high mechanical properties;

(3) The PLA/PBAT composite material prepared by the present invention has high dryness.

Description of the drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

Figure 1 shows the specific preparation process of PLA/PBAT composite material in Example 1 of the present invention;

Figure 2 is a physical diagram of the PLA/PBAT composite material prepared in Example 1 of the present invention;

Figure 3 is a diameter measurement diagram of the PLA/PBAT composite material prepared in Example 1 of the present invention;

Figure 4 is a magnetic induction intensity measurement diagram of the PLA/PBAT composite material prepared in Example 1 of the present invention.

Detailed ways

In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only These are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts should fall within the scope of protection of the present invention.

Example

The present invention will be further described below with reference to specific examples and comparative examples. The following specific examples are all preferred embodiments of the present invention, but the implementation of the present invention is not limited to the following examples, and is not limited in particular. The types of raw materials used in each component are used in the following specific examples.

1. The raw material sources of the examples and comparative examples are as follows:

PLA resin: The grade is 4032D, Mw is 1.5×10 ⁵ , Nature Works;

PBAT resin: The brand name is TH801T, Mw is 50000-80000, China Xinjiang Tunhe Company;

Magnetic powder: NdFeB, 100 mesh powder, element weight percentage: Ne 17.7%, PR 5.7%, B 1%, Fe75.4%, Hebei Chaoyue Metal Alloy Materials Co., Ltd.;

Compatibilizer: BASF chain extender, brand name joncryl ADR-4468, BASF;

Coupling agent: phthalate coupling agent, brand name is GR-311W, Nanjing Herun coupling agent;

The method for preparing the PLA/PBAT composite material of Example 1 of the present invention comprises the following steps:

S1: Dry PLA resin and PBAT resin;

S2: Weigh each component by weight. The mass ratio of PLA resin to PBAT is 3:2. Stir and mix each component and dry it again. Then use a dynamic twin-screw extruder to extrude and shear. Prepare the PLA/PBAT composite material;

Among them, the drying step is to dry on a hot plate at 70°C for 10 hours. When drying again, put the mixed material into a moisture-absorbent bag and dry on a hot plate at 70°C for 10 hours. The extrusion temperature is 190-200°C. Extrusion speed is 75%-85%.

The difference between Comparative Example 1 and Example 1 is that the mass ratio of PLA resin to PBAT is 4:1.

The difference between Comparative Example 2 and Example 1 is that the mass ratio of PLA resin to PBAT is 0.5:1

2. Performance Test Method

Induced magnetic field intensity: Use a Gaussmeter to measure the magnetic induction intensity of the magnet. Place the measuring component of the Gaussmeter close to the magnetic sample to obtain the corresponding magnetic field measurement value.

Example 1

The composite material prepared in Example 1 is shown in Figure 2. The composite material has a good appearance, the diameter is maintained at 1.75mm, the tolerance is ±0.03mm, and has a certain toughness; at the same time, the magnetism of the composite material meets the basic requirements, Gaussian The measurement results of the meter are shown in Figure 1. The measured value of the induced magnetic field intensity of the magnetic composite filament is 118Gs, which has good magnetic properties and has expanded the application of magnetic materials that can be used for FDM-type 3D printing.

The composite material produced by the invention has an induced magnetic field intensity of 100-150Gs (10-15mT) and high mechanical properties. It has obvious advantages compared with the comparative example and can effectively meet the high-standard demands of customers and the market.

Comparative example 1

The mass ratio of PLA to PBAT in Comparative Example 1 is 4:1, and the extrusion viscosity of the composite material is too low, making it difficult to mold.

Comparative Example 2

In Comparative Example 2, the mass ratio of PLA to PBAT was 0.5:1, making it difficult to extrude the composite material and easily burning out the twin-screw extruder.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The magnetic PLA/PBAT composite material for FDM type 3D printing is characterized by comprising the following components in parts by weight:

150-210 parts of PLA resin;

100-140 parts of PBAT resin;

90-150 parts of magnetic powder;

3.4-5 parts of compatilizer;

1-1.5 parts of a coupling agent;

wherein the mass ratio of the PLA resin to the PBAT resin is (1.5-2): 1.

2. The PLA/PBAT composite of claim 1, wherein the mass ratio of PLA resin to PBAT resin is 3:2.

3. The PLA/PBAT composite of claim 1, wherein the magnetic powder is NdFeB.

4. The PLA/PBAT composite of claim 1, wherein the compatibilizer is one or more of a biodegradable resin chain extender, a basf chain extender, maleic anhydride, dicumyl peroxide, and ethylene-methyl acrylate-glycidyl methacrylate.

5. The PLA/PBAT composite of claim 1, wherein the coupling agent is selected from one or more of a phthalate coupling agent and a silane coupling agent.

6. The PLA/PBAT composite of claim 4, wherein the coupling agent is selected from phthalate coupling agents.

7. The PLA/PBAT composite of claim 1, wherein the PLA resin has a weight average molecular weight of 180000 to 220000.

8. The PLA/PBAT composite of claim 1, wherein the PBAT resin has a weight average molecular weight of 50000-80000.

9. A method of preparing a PLA/PBAT composite material according to any one of claims 1 to 8, comprising the steps of:

s1, drying PLA resin and PBAT resin;

and S2, weighing the components according to the weight parts, stirring and mixing, then drying again, and extruding and shearing by using a dynamic double-screw extruder to obtain the PLA/PBAT composite material.

10. Use of the PLA/PBAT composite of any of claims 1-8 in the preparation of a magnetic FDM type 3D printed filament.