PETG composite material for 3D printing and preparation method thereof

Abstract

This invention provides a PETG composite material for 3D printing and its preparation method. The PETG composite material of this invention comprises the following components: PETG, polyester, compatibilizer, and natural mineral filler. The compatibilizer is prepared by the following steps: mixing PETG, maleic anhydride, and an initiator, then adding the mixture to a screw extruder and extruding via reaction to obtain maleic anhydride-grafted PETG, which serves as the compatibilizer. The PETG composite material for 3D printing of this invention uses natural minerals as the reinforcing phase and maleic anhydride (MAH)-grafted polymer PETG as the compatibilizer, and is prepared by melt blending. Adding the maleic anhydride (MAH)-grafted polymer PETG as the compatibilizer improves the melt flow index and tensile strength of the material. This PETG composite material exhibits high melt flowability, comprehensive mechanical properties, and thermal properties, meeting the high application requirements of 3D printing.

Description

Technical Field

[0001] This invention relates to the field of 3D printing materials technology, and in particular to a PETG composite material for 3D printing and its preparation method. Background Technology

[0002] 3D printing (also known as additive manufacturing) is a technology that creates three-dimensional objects by depositing materials layer by layer. Compared to traditional processing methods, 3D printing can create complex geometries and is especially suitable for small-batch production. Polymer materials are the most popular 3D printing materials, as they are low-cost, easy to process, and suitable for FDM (Fused Deposition Modeling) technology. Traditional 3D printing polymer materials mainly include polylactic acid (PLA) and polyacrylonitrile-butadiene-styrene (ABS). PLA is a biodegradable material with a relatively low processing temperature, but it is brittle, prone to cracking, and has a low heat distortion temperature; ABS has high toughness, but requires higher printing temperatures and produces an irritating odor during the printing process. Polyethylene terephthalate-1,4-cyclohexanediol (PETG) is a newer generation of 3D printing material that combines the printability of PLA with the toughness of ABS, is resistant to chemical corrosion, and is suitable for food containers and mechanical parts.

[0003] PETG is a novel high-molecular-weight polyester material produced by the condensation polymerization of terephthalic acid (PTA), ethylene glycol (EG), and modified diols (such as 1,4-cyclohexanediethanol (CHDM) or neopentyl glycol (NPG)). Compared to other copolyesters, it exhibits higher tensile strength, flexural strength, flexural modulus, and impact strength, and possesses good flowability in the molten state, which is beneficial for the processing and application of the material. However, with the increasing demands of high-end 3D printing applications, the melt flowability, overall mechanical properties, and thermal properties of PETG materials still need further improvement. Summary of the Invention

[0004] To address the aforementioned technical deficiencies, this invention provides a PETG composite material for 3D printing and its preparation method. This invention uses natural mineral fillers as the reinforcing phase and maleic anhydride (MAH) grafted polymers as compatibilizers to prepare the PETG composite material via melt blending. The preparation method provided by this invention is simple, and the use of natural mineral raw materials as additives is inexpensive and environmentally friendly. This PETG composite material exhibits high melt flowability, comprehensive mechanical properties, and thermal properties, meeting the high application requirements of 3D printing.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a PETG composite material for 3D printing, comprising the following components: PETG, polyester, compatibilizer, and natural mineral filler;

[0007] The preparation method of the compatibilizer includes the following steps:

[0008] After mixing PETG, maleic anhydride, and initiator, the mixture is added to a screw extruder and extruded to obtain maleic anhydride-grafted PETG, which is the compatibilizer.

[0009] Preferably, PETG, maleic anhydride, and initiator are mixed and added to a screw extruder. The temperatures of each section are set to 160~165℃, 170~175℃, 180~185℃, 180~185℃, 180~185℃, and 180~185℃. After extrusion, maleic anhydride-grafted PETG is obtained, which is the compatibilizer.

[0010] Preferably, the initiator includes at least one of benzoyl peroxide or dicumyl peroxide.

[0011] Preferably, the mass ratio of PETG, maleic anhydride, and initiator is 100:(1~5):(0.1~0.5).

[0012] Preferably, the polyester includes at least one of PBT, PC, and ABS.

[0013] Preferably, the natural mineral filler includes at least one of montmorillonite, attapulgite, kaolin, talc, and mica.

[0014] Preferably, the mass ratio of PETG to polyester is (6~9.5):(0.5~4);

[0015] Based on a total weight of 100 parts of PETG and polyester, the compatibilizer comprises 1 to 15 parts by weight, and the natural mineral filler comprises 0.1 to 5 parts by weight.

[0016] Secondly, the present invention also provides a method for preparing the PETG composite material, comprising the following steps:

[0017] PETG, polyester, compatibilizer, and natural mineral filler are mixed and then extruded in a screw extruder to obtain PETG composite material.

[0018] Preferably, PETG, polyester, compatibilizer, and natural mineral filler are mixed and added to a screw extruder, and the temperatures of each section are set to 180~250℃, 185~255℃, 195~265℃, 200~270℃, 200~270℃, and 200~270℃.

[0019] Thirdly, the present invention also provides the application of the PETG composite material in 3D printing.

[0020] The PETG composite material for 3D printing and its preparation method of the present invention have the following advantages compared with the prior art:

[0021] The PETG composite material for 3D printing of the present invention uses natural minerals as the reinforcing phase and maleic anhydride (MAH)-grafted polymer PETG as the compatibilizer. The PETG composite material is prepared by melt blending. The preparation method provided by the present invention is simple, and the use of natural minerals as additives is inexpensive and environmentally friendly. With the addition of the maleic anhydride (MAH)-grafted polymer PETG (PETG-g-MAH) of the present invention as the compatibilizer, the melt flow index (MFR) can be increased from 11.7 g / 10min to 15.1~17.6 g / 10min; simultaneously, the tensile strength of the PETG composite material prepared with the addition of the compatibilizer and MMT reaches 61.1~62.2 MPa. Compared with PLA-g-MAH, PP-g-MAH, and POE-g-MAH, the PETG-g-MAH compatibilizer of the present invention has a larger melt flow index, better flow enhancement effect, and optimal compatibility. This PETG composite material has high melt flowability, comprehensive mechanical properties, and thermal properties, meeting the high application requirements of 3D printing. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 The infrared spectra of the compatibilizer maleic anhydride grafted with PETG (PETG-g-MAH) synthesized in Example 1, and the raw materials maleic anhydride (MAH) and PETG used.

[0024] Figure 2 The tensile strength of the PETG composite materials prepared in Examples 1-3 and Comparative Examples 1-5;

[0025] Figure 3 The TG curves of the PETG composite materials prepared in Example 1, Comparative Example 3, Comparative Example 1, and Comparative Example 2 are shown.

[0026] Figure 4 The TG curve of the PETG composite material prepared in Example 1 is obtained by isothermal heating at 260°C for 20 minutes. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single digits within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0029] This application provides a PETG composite material for 3D printing, comprising the following components: PETG, polyester, compatibilizer, and natural mineral filler;

[0030] The preparation method of the compatibilizer includes the following steps:

[0031] After mixing PETG, maleic anhydride, and initiator, the mixture is added to a screw extruder and extruded to obtain maleic anhydride-grafted PETG, which is the compatibilizer.

[0032] In some embodiments, PETG, maleic anhydride, and initiator are mixed and added to a screw extruder. The temperatures of each section are set to 160~165℃, 170~175℃, 180~185℃, 180~185℃, 180~185℃, and 180~185℃. After extrusion, maleic anhydride-grafted PETG is obtained, which is the compatibilizer.

[0033] In some embodiments, the initiator includes at least one of benzoyl peroxide or dicumyl peroxide.

[0034] In some embodiments, the mass ratio of PETG, maleic anhydride, and initiator is 100:(1~5):(0.1~0.5).

[0035] In some embodiments, the polyester includes at least one of PBT (polybutylene terephthalate), PC (polycarbonate), and ABS (acrylonitrile-butadiene-styrene copolymer).

[0036] In some embodiments, the natural mineral filler includes at least one of montmorillonite, attapulgite, kaolin, talc, and mica.

[0037] In some embodiments, the mass ratio of PETG to polyester is (6~9.5):(0.5~4);

[0038] Based on a total weight of 100 parts of PETG and polyester, the compatibilizer is 1 to 15 parts by weight, and the natural mineral filler is 0.1 to 5 parts by weight.

[0039] More preferably, the mass ratio of PETG to polyester is 8:2, and based on a total weight of 100 parts of PETG and polyester, the weight of compatibilizer is 5 parts and the weight of natural mineral filler is 0.5 parts.

[0040] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned PETG composite material, comprising the following steps:

[0041] PETG, polyester, compatibilizer, and natural mineral filler are mixed and then extruded in a screw extruder to obtain PETG composite material.

[0042] In some embodiments, PETG, polyester, compatibilizer, and natural mineral filler are mixed and added to a screw extruder, and the temperatures of each section are set to 180~250℃, 185~255℃, 195~265℃, 200~270℃, 200~270℃, and 200~270℃.

[0043] In some embodiments, the natural mineral filler is montmorillonite. PETG, PBT, compatibilizer, and montmorillonite are mixed and added to a screw extruder. The temperatures of each section are set to 180~185℃, 185~190℃, 195~200℃, 200~205℃, 200~205℃, and 200~205℃. After extrusion, a PETG composite material is obtained.

[0044] In some embodiments, the natural mineral filler is rapasite. PETG, PC, compatibilizer, and rapasite are mixed and added to a screw extruder. The temperatures of each section are set to 250~255℃, 255~260℃, 265~270℃, 265~270℃, and 265~270℃. After extrusion, a PETG composite material is obtained.

[0045] In some embodiments, the natural mineral filler is kaolin. After mixing PETG, ABS, compatibilizer and kaolin, it is added to a screw extruder. The temperature of each section is set to 230~235℃, 240~245℃, 250~255℃, 260~265℃, 260~265℃, and 260~265℃. After extrusion, PETG composite material is obtained.

[0046] This invention uses natural minerals as the reinforcing phase and maleic anhydride (MAH)-grafted polymer PETG as the compatibilizer to prepare PETG composite materials via melt blending. The preparation method provided by this invention is simple, and the use of natural minerals as additives is inexpensive and environmentally friendly. With the addition of the maleic anhydride (MAH)-grafted polymer PETG (PETG-g-MAH) of this invention as the compatibilizer, the melt flow index (MFR) can be increased from 11.7 g / 10min to 15.1~17.6 g / 10min; simultaneously, the tensile strength of the PETG composite material prepared with the addition of the compatibilizer and MMT reaches 61.1~62.2 MPa. Compared with PLA-g-MAH, PP-g-MAH, and POE-g-MAH, the PETG-g-MAH compatibilizer of this invention has a higher melt flow index, better flow enhancement effect, and optimal compatibility; this PETG composite material has high melt flowability, comprehensive mechanical properties, and thermal properties, meeting the high application requirements of 3D printing.

[0047] Based on the same inventive concept, the present invention also provides the application of the above-mentioned PETG composite material in 3D printing.

[0048] The following detailed embodiments further illustrate the PETG composite material for 3D printing and its preparation method. This section, in conjunction with specific embodiments, further explains the content of the present invention, but should not be construed as limiting the invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0049] In the following examples and comparative examples, PETG is polyethylene terephthalate-1,4-cyclohexanediol ester, and specifically, the product with model number GX-702 provided by Guoxin Polyester New Material Technology Co., Ltd. can be used.

[0050] The PBT resin was purchased from Guangdong Kingfa Science & Technology Co., Ltd., model TH6082.

[0051] The montmorillonite was purchased from Shanghai E-En Chemical Technology Co., Ltd., and its model number was K-10 (calcium-based).

[0052] Example 1

[0053] This embodiment provides a PETG composite material for 3D printing, comprising the following parts by weight of raw materials: 80 parts PETG, 20 parts PBT, 5 parts compatibilizer, and 0.5 parts montmorillonite (MMT);

[0054] The preparation method of the compatibilizer includes the following steps:

[0055] PETG, maleic anhydride (MAH), and initiator (specifically benzoyl peroxide BPO) in a mass ratio of 100:2:0.1 are mixed and then added to a screw extruder for extrusion. The temperatures of each section are set to 160℃, 170℃, 180℃, 180℃, 180℃, and 180℃. After extrusion, maleic anhydride-grafted PETG (PETG-g-MAH) is obtained, which is the compatibilizer.

[0056] The preparation method of the above-mentioned PETG composite material for 3D printing includes the following steps:

[0057] After mixing PETG, PBT, compatibilizer, and montmorillonite, the mixture is added to a screw extruder. The temperatures of each section are set to 180℃, 185℃, 195℃, 200℃, 200℃, and 200℃. After extrusion, PETG composite material is obtained.

[0058] Example 2

[0059] The preparation method of PETG composite material for 3D printing provided in this embodiment is the same as that in Embodiment 1, except that the compatibilizer is 10 parts, and the other process parameters are the same as those in Embodiment 1.

[0060] Example 3

[0061] The preparation method of PETG composite material for 3D printing provided in this embodiment is the same as that in Example 1, except that the compatibilizer is 15 parts, and the other process parameters are the same as those in Example 1.

[0062] Comparative Example 1

[0063] The preparation method of the PETG composite material for 3D printing provided in this comparative example is the same as that in Example 1, except that the compatibilizer is 0 parts and the other process parameters are the same as those in Example 1.

[0064] Comparative Example 2

[0065] This comparative example provides a PETG composite material for 3D printing, comprising the following parts by weight of raw materials: 80 parts PETG and 20 parts PBT;

[0066] The preparation method of the above-mentioned PETG composite material for 3D printing includes the following steps:

[0067] After mixing PETG and PBT, the mixture is added to a screw extruder, and the temperature of each section is set to 180℃, 185℃, 195℃, 200℃, 200℃, and 200℃. After extrusion, a PETG composite material is obtained.

[0068] Comparative Example 3

[0069] This comparative example provides a PETG composite material for 3D printing, comprising the following parts by weight of raw materials: 80 parts PETG, 20 parts PBT, and 5 parts compatibilizer;

[0070] The compatibilizer was prepared using the same method as in Example 1.

[0071] The preparation method of the above-mentioned PETG composite material for 3D printing includes the following steps:

[0072] After mixing PETG, PBT, and compatibilizer, the mixture is added to a screw extruder. The temperatures of each section are set to 180℃, 185℃, 195℃, 200℃, 200℃, and 200℃. After extrusion, a PETG composite material is obtained.

[0073] Comparative Example 4

[0074] This comparative example provides a PETG composite material for 3D printing, comprising the following parts by weight of raw materials: 80 parts PETG, 20 parts PBT, and 10 parts compatibilizer;

[0075] The compatibilizer was prepared using the same method as in Example 1.

[0076] The preparation method of the above-mentioned PETG composite material for 3D printing includes the following steps:

[0077] After mixing PETG, PBT, and compatibilizer, the mixture is added to a screw extruder. The temperatures of each section are set to 180℃, 185℃, 195℃, 200℃, 200℃, and 200℃. After extrusion, a PETG composite material is obtained.

[0078] Comparative Example 5

[0079] This comparative example provides a PETG composite material for 3D printing, comprising the following parts by weight of raw materials: 80 parts PETG, 20 parts PBT, and 15 parts compatibilizer;

[0080] The compatibilizer was prepared using the same method as in Example 1.

[0081] The preparation method of the above-mentioned PETG composite material for 3D printing includes the following steps:

[0082] After mixing PETG, PBT, and compatibilizer, the mixture is added to a screw extruder. The temperatures of each section are set to 180℃, 185℃, 195℃, 200℃, 200℃, and 200℃. After extrusion, a PETG composite material is obtained.

[0083] Comparative Example 6

[0084] This comparative example provides a PETG composite material for 3D printing, comprising the following parts by weight of raw materials: 80 parts PETG, 20 parts PBT, 5 parts compatibilizer, and 0.5 parts montmorillonite;

[0085] The preparation method of the compatibilizer includes the following steps:

[0086] A mixture of polylactic acid (specifically, Ingeo™ 4043D, purchased from NatureWorks, USA), maleic anhydride (MAH), and initiator (specifically benzoyl peroxide BPO) in a mass ratio of 100:2:0.1 was added to a screw extruder and extruded. The temperatures of each section were set to 160℃, 170℃, 180℃, 180℃, 180℃, and 180℃. After extrusion, maleic anhydride-grafted polylactic acid was obtained, which is the compatibilizer.

[0087] The preparation method of the above-mentioned PETG composite material for 3D printing includes the following steps:

[0088] After mixing PETG, PBT, compatibilizer, and montmorillonite, the mixture is added to a screw extruder. The temperatures of each section are set to 180℃, 185℃, 195℃, 200℃, 200℃, and 200℃. After extrusion, PETG composite material is obtained.

[0089] Comparative Example 7

[0090] This comparative example provides a PETG composite material for 3D printing, comprising the following parts by weight of raw materials: 80 parts PETG, 20 parts PBT, 5 parts compatibilizer, and 0.5 parts montmorillonite;

[0091] The preparation method of the compatibilizer includes the following steps:

[0092] Polypropylene (specifically P757624 polypropylene, purchased from Maclean's reagents) in a mass ratio of 100:2:0.1, maleic anhydride (MAH), and initiator (specifically benzoyl peroxide BPO) were mixed and then added to a screw extruder for extrusion. The temperatures of each section were set to 160℃, 170℃, 180℃, 180℃, 180℃, and 180℃. After extrusion, maleic anhydride-grafted polypropylene was obtained, which is the compatibilizer.

[0093] The preparation method of the above-mentioned PETG composite material for 3D printing includes the following steps:

[0094] After mixing PETG, PBT, compatibilizer, and montmorillonite, the mixture is added to a screw extruder. The temperatures of each section are set to 180℃, 185℃, 195℃, 200℃, 200℃, and 200℃. After extrusion, PETG composite material is obtained.

[0095] Comparative Example 8

[0096] This comparative example provides a PETG composite material for 3D printing, comprising the following parts by weight of raw materials: 80 parts PETG, 20 parts PBT, 5 parts compatibilizer, and 0.5 parts montmorillonite;

[0097] The preparation method of the compatibilizer includes the following steps:

[0098] A mixture of POE resin (specifically ENGAGE™ 8200, purchased from Dow Chemical Company, USA) in a mass ratio of 100:2:0.1, maleic anhydride (MAH), and initiator (specifically benzoyl peroxide BPO) was added to a screw extruder for extrusion. The temperatures of each section were set to 160°C, 170°C, 180°C, 180°C, 180°C, and 180°C. After extrusion, maleic anhydride-grafted POE resin was obtained, which is the compatibilizer.

[0099] The preparation method of the above-mentioned PETG composite material for 3D printing includes the following steps:

[0100] After mixing PETG, PBT, compatibilizer, and montmorillonite, the mixture is added to a screw extruder. The temperatures of each section are set to 180℃, 185℃, 195℃, 200℃, 200℃, and 200℃. After extrusion, PETG composite material is obtained.

[0101] Performance testing

[0102] Figure 1 The compatibilizer synthesized in Example 1: maleic anhydride grafted PETG (PETG-g-MAH) Figure 1 (c) and the raw material used, maleic anhydride (MAH) Figure 1 (a) ), PETG ( Figure 1 The infrared spectrum of (b) in the middle.

[0103] from Figure 1 As can be seen, PETG-g-MAH retains the CO characteristic peaks of PETG (1250~1000 cm⁻¹). -1 This proves that the PETG main chain structure has not degraded. The product PETG-g-MAH has a molecular weight of 1890~1700 cm⁻¹. -1The presence of distinct absorption peaks at 1650~1600 cm⁻¹ (C=O) and 1650~1600 cm⁻¹ (C=C), with peak shapes consistent with MAH, indicates the introduction of the carbonyl group and carbon-carbon double bond structure of MAH into the product; PETG-g-MAH exhibits the unique C=O absorption peaks (1890~1700 cm⁻¹) characteristic of MAH. -1 C=C (1650~1600 cm) -1 ) and 910~665 cm -1 The characteristic peaks of the benzene ring confirm that MAH was successfully grafted onto the PETG molecular chain. The absence of obvious impurity peaks in the MAH homopolymer indicates that the purity of the grafted product meets the requirements, further confirming the successful synthesis of the PETG-g-MAH grafted product.

[0104] The melt flow rate (MFR) of the PETG composite materials prepared in Examples 1-3, Comparative Examples 1, and Comparative Examples 6-8 was tested, and the results are shown in Table 1 below. The melt flow rate (MFR) was tested according to GB / T 3682.1-2018. The specific test method was as follows: 5 g of sample was weighed, the preheating temperature was set to 230℃, the weight mass was 1200 g, the polymer was placed in the feed hole and preheated to melt for 4 minutes, the air was removed, and the weight was added for measurement; the number of shearing cycles was set to 11, the shearing time interval was 10 seconds, the head was removed, the total mass of 10 sample segments was weighed, and the MFR was calculated.

[0105] Table 1 - Melt Flow Index of PETG Composites Prepared in Examples 1-3, Comparative Examples 1, and Comparative Examples 6-8

[0106] Example MFR (g / 10 min) Example 1 17.6 Example 2 17.3 Example 3 15.1 Comparative Example 1 11.7 Comparative Example 6 16.1 Comparative Example 7 15.2 Comparative Example 8 15.6

[0107] As shown in Table 1, the MFR significantly improved after adding PETG-g-MAH compatibilizer, indicating improved interfacial compatibility, freer molecular chain movement, and decreased melt viscosity. The flowability was similar at 5% and 10% compatibilizer additions, while it decreased slightly at 15%, indicating that excessive compatibilizer may lead to compatibility reversal or increased chain entanglement. Furthermore, as can be seen from Examples 1 and Comparative Examples 6-8, the PETG-g-MAH compatibilizer has a larger melt index, better flow enhancement effect, and optimal matching compared to PLA-g-MAH (Comparative Example 6), PP-g-MAH (Comparative Example 7), and POE-g-MAH (Comparative Example 8).

[0108] Figure 2 The tensile strength of the PETG composite materials prepared in Examples 1-3 and Comparative Examples 1-5 is given. Figure 2PBT / PETG represents the tensile strength of PETG composite materials prepared by adding only compatibilizers without montmorillonite (MMT) in Comparative Examples 2-5. The mass fraction of compatibilizer added in Comparative Example 2 (the mass of compatibilizer divided by the sum of the masses of PBT and PETG) is 0%, the mass fraction of compatibilizer added in Comparative Example 3 is 5%, the mass fraction of compatibilizer added in Comparative Example 4 is 10%, and the mass fraction of compatibilizer added in Comparative Example 5 is 15%. Figure 2 The term MMT / PBT-PETG represents the tensile strength of the PETG composite materials prepared in Examples 1-3 and Comparative Example 1, which contain montmorillonite (MMT) and a compatibilizer. The compatibilizer mass fraction added in Example 1 was 5%, in Example 2 it was 10%, in Example 3 it was 15%, and in Comparative Example 1 it was 0%. Table 2 shows the tensile strength of the PETG composite materials prepared in Examples 1-3 and Comparative Examples 1-5.

[0109] Table 2 - Tensile strength of PETG composite materials prepared in Examples 1-3 and Comparative Examples 1-5

[0110] Example Tensile strength (MPa) Example 1 62.2 Example 2 61.1 Example 3 62.0 Comparative Example 1 62.0 Comparative Example 2 61.7 Comparative Example 3 53.6 Comparative Example 4 56.0 Comparative Example 5 56.5

[0111] As shown in Table 2, the tensile strength of the PETG composite material prepared from pure PETG / PBT (Comparative Example 2) is 61.7 MPa; the tensile strength of the PETG composite material prepared with only compatibilizer (Comparative Examples 3, 4, and 5) is 53.6~56.5 MPa, significantly lower than that of the pure blend system; the tensile strength of the PETG composite material prepared with both compatibilizer and 0.5% MMT (Examples 1, 2, and 3) is 61.1~62.2 MPa, recovering to the level of the pure system with a slight improvement; adding PETG-g-MAH compatibilizer alone improves interfacial compatibility but reduces the crystallinity of the system, leading to a decrease in tensile strength; MMT can act as a nucleating agent and reinforcing phase, significantly improving the crystallinity and load-bearing capacity of the material, offsetting the strength loss caused by the compatibilizer; the synergistic effect of compatibilizer + MMT ensures interfacial bonding and achieves efficient reinforcement, keeping the tensile strength stable at a high level. At the same time, the addition of compatibilizer can make MMT uniformly dispersed in the PBT / PETG composite material, so the tensile strength remains stable.

[0112] Figure 3The TG curves are for the PETG composite materials prepared in Example 1, Comparative Example 3, Comparative Example 1, and Comparative Example 2. Among them, PETG+20% PBT+5% compatibilizer+0.5% MMT corresponds to Example 1, PETG+20% PBT+5% compatibilizer corresponds to Comparative Example 3, PETG+20% PBT+0.5% MMT corresponds to Comparative Example 1, and PETG+20% PBT corresponds to Comparative Example 2.

[0113] from Figure 3 As can be seen, all PETG composite materials exhibit no significant thermal weight loss below 350℃, fully meeting the 3D printing processing temperature requirements (230~260℃), and no thermal degradation occurs during processing. Adding compatibilizers or MMT alone, or in combination, did not reduce the initial decomposition temperature or the maximum decomposition rate temperature of the materials, nor did it impair the heat resistance of the matrix. The PETG composite material prepared in Example 1 has thermal stability comparable to the pure matrix, while possessing a higher char residue, balancing processing flowability, mechanical properties, and heat resistance, thus meeting practical application requirements.

[0114] Figure 4 The TG curve of the PETG composite material prepared in Example 1 is obtained by isothermal heating at 260°C for 20 minutes.

[0115] from Figure 4 As can be seen, the PETG composite material maintained almost 100% mass retention within 20 minutes, with no significant thermal weight loss. This indicates that the polymer backbone did not degrade or small molecules decomposed under the 3D printing processing temperature. With time, the PETG-g-MAH / MMT / PBT-PETG composite material only experienced small molecule mass loss, without showing a polymer degradation trend. This suggests that the PETG-g-MAH / MMT / PBT-PETG composite material exhibits good thermal stability within the screw extruder and does not show significant degradation during screw extrusion. Furthermore, this indicates that the increase in the melt index of the PETG-g-MAH / MMT / PBT-PETG composite material with increasing compatibilizer and MMT content is due to their interaction, rather than degradation.

[0116] It is understood that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0117] The above are merely preferred embodiments of this application, and only specifically describe the technical principles of this application. These descriptions are only for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, as well as other specific embodiments of this application that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of this application.

Claims

1. A PETG composite material for 3D printing, characterized in that, It includes the following components: PETG, polyester, compatibilizer, and natural mineral filler; The preparation method of the compatibilizer includes the following steps: After mixing PETG, maleic anhydride, and initiator, the mixture is added to a screw extruder and extruded to obtain maleic anhydride-grafted PETG, which is the compatibilizer.

2. The PETG composite material as described in claim 1, characterized in that, After mixing PETG, maleic anhydride, and initiator, the mixture is added to a screw extruder. The temperatures of each section are set to 160~165℃, 170~175℃, 180~185℃, 180~185℃, 180~185℃, and 180~185℃. After extrusion, maleic anhydride-grafted PETG is obtained, which is the compatibilizer.

3. The PETG composite material as described in claim 1, characterized in that, The initiator includes at least one of benzoyl peroxide or dicumyl peroxide.

4. The PETG composite material as described in claim 1, characterized in that, The mass ratio of PETG, maleic anhydride, and initiator is 100:(1~5):(0.1~0.5).

5. The PETG composite material as described in claim 1, characterized in that, The polyester includes at least one of PBT, PC, and ABS.

6. The PETG composite material as described in claim 1, characterized in that, The natural mineral filler includes at least one of montmorillonite, attapulgite, kaolin, talc, and mica.

7. The PETG composite material as described in claim 1, characterized in that, The mass ratio of PETG to polyester is (6~9.5): (0.5~4); Based on a total weight of 100 parts of PETG and polyester, the compatibilizer comprises 1 to 15 parts by weight, and the natural mineral filler comprises 0.1 to 5 parts by weight.

8. A method for preparing a PETG composite material as described in any one of claims 1 to 7, characterized in that, Includes the following steps: PETG, polyester, compatibilizer, and natural mineral filler are mixed and then extruded in a screw extruder to obtain PETG composite material.

9. The method for preparing the PETG composite material as described in claim 8, characterized in that, PETG, polyester, compatibilizer, and natural mineral filler are mixed and added to a screw extruder, with the temperature of each section set to 180~250℃, 185~255℃, 195~265℃, 200~270℃, 200~270℃, and 200~270℃.

10. An application of the PETG composite material as described in any one of claims 1 to 7 in 3D printing.

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