Temperature-resistant 3D printing PETG polyester material and preparation method thereof

Abstract

The invention relates to the technical field of 3D printing materials, in particular to a temperature-resistant 3D printing PETG polyester material and a preparation method thereof.The temperature-resistant 3D printing PETG polyester material is prepared from, by mass, 10-100 parts of polybasic acid, 20-180 parts of polyhydric alcohol, 10-50 parts of functional monomer, 1-20 parts of antioxidant, 2-20 parts of dispersing agent, 0.1-1.5 parts of protective agent and 0.03-0.3 part of germanium dioxide. The PETG polyester material disclosed by the invention is applicable to the 3D printing material, has relatively good temperature resistance and toughness, and can prevent brittle rupture of the 3D printing material in a use process from influencing use.

Description

Technical Field

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

[0002] PETG (polyethylene terephthalate-1,4-cyclohexanediethanol), as a revolutionary 3D printing material, has a development history closely intertwined with breakthroughs in polymer chemistry and the upgrading of manufacturing demands. In the 1940s, the invention of polyethylene terephthalate (PET) laid the foundation for the synthetic fiber and packaging industries, but the high crystallinity of traditional PET limited its processing capabilities. In the 1970s, to address the brittleness and crystallinity issues of PET at high temperatures, scientists introduced macromolecular diol monomers such as cyclohexanediethanol (CHDM) for copolymer modification, significantly suppressing the regular arrangement of molecular chains and thus giving rise to amorphous PETG materials. This modification not only retained the strength and chemical resistance of PET but also endowed it with high transparency, impact toughness, and excellent thermoforming capabilities, enabling its rapid penetration into fields such as food packaging and medical devices.

[0003] In the early 21st century, with the popularization of fused deposition modeling (FDM) 3D printing technology, PETG stood out due to its unique performance balance. Compared to ABS, it has a lower printing temperature, is virtually odorless, and has extremely low shrinkage, effectively avoiding warping and deformation problems. This combination of printability and functionality makes it a bridge between consumer and industrial applications—from drone shells and gardening tools to FDA-approved food containers, PETG surpasses traditional materials in overall performance in terms of weather resistance, biocompatibility, and environmental friendliness. Notably, its transparency reaches up to 90%, simulating the effect of acrylic, further expanding its application to optical components such as lampshades and observation windows for laboratory instruments.

[0004] Although there is a lot of research and development on PETG materials, some problems still exist. For example, patent number CN120865682A discloses "a high-toughness high-layer adhesive polyester for 3D printing and its preparation method", which is made from antioxidants, dispersants and matrix resins. The matrix resin is made from dibasic acid, diol, graft polymer, catalyst and protective agent. This polyester material makes it easier for the layers to bond and prevent cracking during 3D printing, and it has excellent interlayer adhesion.

[0005] For example, patent number CN119823541A discloses "a 3D printing matte high-speed PETG modified material and its preparation method". It is made from PETG resin, toughening agent, matting agent, internal lubricant, external lubricant, anti-hydrolysis agent and antioxidant as the main raw materials, which effectively improves the printing performance of the filament and has good biocompatibility, making it suitable for medical and food packaging fields.

[0006] However, in the field of 3D printing, the current conventional PETG material has poor temperature resistance, and the printed products are prone to brittleness and cracking. Therefore, there is an urgent need to develop a PETG polyester material that is both temperature resistant and tough. Summary of the Invention

[0007] The purpose of this invention is to provide a heat-resistant 3D printing PETG polyester material and its preparation method, so as to solve the problem of poor heat resistance and toughness of the current PETG polyester material when used for 3D printing.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention provides a heat-resistant 3D printing PETG polyester material, comprising the following raw materials by mass parts: 10-100 parts of polyacid, 20-180 parts of polyol, 10-50 parts of functional monomer, 1-20 parts of antioxidant, 2-20 parts of dispersant, 0.1-1.5 parts of protective agent and 0.03-0.3 parts of germanium dioxide.

[0009] The PETG polyester material of this invention uses polyacids, polyols, functional monomers, antioxidants, dispersants, protective agents, and germanium dioxide catalysts as main raw materials, and is obtained through a polycondensation reaction. This PETG polyester material is suitable for the field of 3D printing technology, and can solve the problems of poor temperature resistance and toughness of current 3D printing materials, thus improving the stability of 3D printed products.

[0010] In some embodiments, the polybasic acid is terephthalic acid.

[0011] In some embodiments, the polyol is a mixture of ethylene glycol and 1,4-cyclohexanediethanol in a molar ratio of 1:(0.4~0.7).

[0012] Preferably, the polyol is a mixture of ethylene glycol and 1,4-cyclohexanediethanol in a molar ratio of 1:0.6.

[0013] In some embodiments, the structure of the functional unit is shown in Formula I: (I); Wherein, R is a C4~C10 alkyl segment.

[0014] In some embodiments, the method for preparing the functional monomer includes the following steps: A1. Under an inert protective gas atmosphere, the compound shown in Formula II... (II) 4-Ethylaniline, catalyst a, strong base reagent, and ligand were mixed and added to toluene. The mixture was heated and stirred. After the stirring was completed, the mixture was filtered, extracted, and the organic phases were combined and dried under reduced pressure to obtain compound a. A2. Mix allyl succinic anhydride, compound a from step A1 and catalyst b in toluene solution, heat to 75-85℃, then add tetramethyldisiloxane, stir at constant temperature for 4-6 hours, decolorize with activated carbon, filter, concentrate under reduced pressure, and precipitate by column chromatography to obtain functional monomer. Where X is Br or I; R is a C4~C10 alkyl segment.

[0015] Currently, there are still some problems with the use of PETG polyester material in the field of 3D printing technology. For example, the poor temperature resistance of PETG polyester material causes 3D printed products to soften and deform and lose their basic functions when exposed to high temperatures for a long time. This can even pose a life-threatening danger to users, especially in some outdoor vehicles. Another issue is that the poor toughness of PETG material causes internal stress during the production process of 3D printed products, which reduces the interlayer adhesion and leads to cracking of the product, affecting its strength. At the same time, the impact resistance of the product will also be reduced, and even a slight impact from external force may cause cracks, affecting the service life of the product.

[0016] To address the aforementioned problems, this invention provides a self-developed functional monomer. This functional monomer uses the compound shown in Formula II, 4-vinylaniline, allyl succinic anhydride, and tetramethyldisiloxane as the main synthetic raw materials. First, the compound shown in Formula II and 4-vinylaniline are reacted via a substitution reaction to obtain compound a. Then, the unsaturated double bonds in compound a and allyl succinic anhydride are subjected to hydrosilylation reactions with tetramethyldisiloxane, respectively. The resulting functional monomer has a benzene ring and a long alkyl chain structure at one end, and an anhydride group at the other end. The anhydride group can participate in the polycondensation reaction of PETG polyester, ultimately yielding a modified PETG.

[0017] The benzene ring structure of the side chain in modified PETG can undergo π-π stacking to improve the temperature resistance of PETG. At the same time, the long alkyl chain of the side chain has flexible characteristics, which can increase the molecular chain spacing, weaken the intermolecular forces, and improve the chain segment mobility, thereby improving the impact resistance. The -Si-O- structure of the side chain can also appropriately improve the toughness of PETG.

[0018] In some embodiments, in step A1, the heating temperature is 60~80℃ and the stirring time is 2~12h.

[0019] This application enables a more complete substitution reaction by controlling the reaction temperature and time in step A1, while avoiding the byproducts produced by the Heck reaction.

[0020] In some embodiments, in step A1, the molar ratio of the compound represented by Formula II to 4-ethyleneaniline is (2.1~2.3):1.

[0021] Preferably, in step A1, the molar ratio of the compound represented by Formula II to 4-ethyleneaniline is 2.2:1.

[0022] This application enables the complete substitution of -NH2 in the compound represented by Formula II by adjusting the molar ratio of the compound to 4-ethyleneaniline. The resulting functional monomer contains two flexible segments, which improves the toughness of PETG polyester material and can compensate for the brittleness caused by the benzene ring.

[0023] In some embodiments, in step A1, the amount of catalyst a added is 1.8 to 2.2 mol of the total molar amount of the compound represented by Formula II and 4-ethyleneaniline.

[0024] In some embodiments, in step A1, the molar ratio of the strong base reagent to 4-ethyleneaniline is (3.3~3.6):1.

[0025] In some embodiments, in step A1, the amount of ligand added is 3.8 to 4.2 mol of the total molar amount of the compound represented by Formula II and 4-ethyleneaniline.

[0026] In some embodiments, in step A2, the molar ratio of allyl succinic anhydride, compound a, and tetramethyldisiloxane is (0.9~1.1):(0.9~1.1):1.

[0027] Preferably, in step A2, the molar ratio of allyl succinic anhydride, compound a, and tetramethyldisiloxane is 1:1:1.

[0028] This application achieves functional monomers with different end groups by adjusting the molar ratio of allyl succinic anhydride, compound a, and tetramethyldisiloxane, enabling both ends of tetramethyldisiloxane to undergo hydrosilylation reactions.

[0029] In some embodiments, in step A2, the molar ratio of catalyst b to allyl succinic anhydride is (0.15~0.25):1.

[0030] In some embodiments, catalyst a is a tris(dibenzylacetone)dipalladium catalyst; catalyst b is 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum.

[0031] In some embodiments, the strong base reagent is sodium tert-butoxide.

[0032] In some embodiments, the ligand is t-Bu3P.

[0033] In some embodiments, the antioxidant is one or more of antioxidant 1010, antioxidant 1076, antioxidant 1098 and antioxidant 168.

[0034] In some embodiments, the dispersant is polyethylene oxide and / or cationic polyacrylamide.

[0035] In some embodiments, the protective agent is one or more of p-methoxyphenol, triphenyl phosphite, ammonium dihydrogen phosphate, and bisphenol A phosphite.

[0036] Another aspect of the present invention provides a method for preparing a heat-resistant 3D printing PETG polyester material, comprising the following steps: (1) Add polyacid, polyol, functional monomer, some germanium dioxide and protective agent into the reactor. Under nitrogen protection, adjust the pressure to 0.03~0.3MPa, raise the temperature to 220~250℃, and react for 2~5h. Then add the remaining germanium dioxide, raise the temperature to 260~290℃, reduce the pressure to 50~100Pa, and react for 2~5h. After completion, modified PETG is obtained. (2) Add the modified PETG from step (1) to an antioxidant and dispersant in a high-speed mixer and mix at high speed for 5-10 minutes. Then, melt-extrude the mixture through a twin-screw extruder, granulate it, and dry it to obtain a heat-resistant 3D printing PETG polyester material.

[0037] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses polyacids, polyols, functional monomers, antioxidants, dispersants, protective agents and germanium dioxide catalysts as main raw materials, and obtains them through polyesterification reaction. The PETG polyester material is suitable for the field of 3D printing technology, and can solve the problems of poor temperature resistance and poor toughness of current 3D printing materials, and improve the stability of 3D printed products.

[0038] (2) The functional monomer of the present invention uses the compound shown in Formula II, 4-ethyleneaniline, allyl succinic anhydride and tetramethyldisiloxane as the main raw materials for synthesis. One end of the functional monomer has a benzene ring and a long alkyl chain structure, and the other end has an anhydride group. The anhydride group can participate in the polycondensation reaction of PETG polyester. The benzene ring structure can undergo π-π stacking to improve the temperature resistance of PETG. At the same time, the long alkyl chain of the side chain has a flexible feature, which can increase the molecular chain spacing, weaken the intermolecular forces, and improve the chain segment mobility, thereby improving the impact resistance. The -Si-O- structure of the side chain can also appropriately improve the toughness of PETG. Detailed Implementation

[0039] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0040] Unless otherwise specified, those skilled in the art may select from the following post-processing operations, such as "stirring," "filtration," "drying," "heating," and "depressurized concentration," based on actual conditions, without further limitation.

[0041] In the following examples and comparative examples, the polyethylene oxide was purchased from Shandong Hongquan Chemical Technology Co., Ltd.

[0042] Preparation Example 1 The preparation method of the functional monomer includes the following steps: A1. Under a nitrogen atmosphere, 0.22 mol of 1-(4-bromophenyl)hexane, 0.1 mol of 4-vinylaniline, 6.4 mmol of tris(dibenzylacetone)dipalladium, 0.35 mol of sodium tert-butoxide, and 12.8 mmol of t-Bu3P were mixed and added to 300 mL of toluene. The mixture was heated to 70 °C and stirred for 6 h. After the reaction was completed, the mixture was filtered, concentrated under reduced pressure, and extracted (with dichloromethane / deionized water). The organic phases were combined and dried under reduced pressure to obtain compound a. A2. Mix 0.1 mol allyl succinic anhydride, 0.1 mol of compound a from step A1, and 400 ml of a toluene solution containing 0.02 mol 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum. Heat to 80 °C, then add 0.1 mol tetramethyldisiloxane. Stir at this temperature for 5 h, decolorize with activated carbon, filter, concentrate under reduced pressure, and perform column chromatography to obtain the functional monomer, as shown in Formula I. (I).

[0043] The NMR data are as follows: 1H NMR (400 MHz, DMSO-d6): δ -0.02-0.08 (12H, 0.03 (s),0.03 (s)), 0.64-0.78 (2H, 0.71 (dd, J = 6.8, 6.8 Hz), 0.71 (dd, J = 6.8, 6.8Hz)), 0.80-0.94 (8H, 0.87 (dd, J = 7.0, 7.0 Hz), 0.88 (dd, J = 7.5, 7.5 Hz),0.88 (dd, J = 7.5, 7.5 Hz)), 1.15-1.37 (12H, 1.24 (dddd, J = 6.6, 6.6, 6.5,6.5 Hz), 1.24 (dddd, J = 6.6, 6.6, 6.5, 6.5 Hz), 1.25 (dddd, J = 6.9, 6.9,6.5, 6.5 Hz), 1.25 (dddd, J = 6.9, 6.9, 6.5, 6.5 Hz), 1.28 (qdd, J = 7.0,6.9, 6.9 Hz), 1.28 (qdd, J = 7.0, 6.9, 6.9 Hz)), 1.43-1.60 (4H, 1.52 (dddd, J= 7.6, 7.6, 6.6, 6.6 Hz), 1.52 (dddd, J = 7.6, 7.6, 6.6, 6.6 Hz)), 1.69-1.84(2H, 1.77 (ddd, J = 6.8, 6.8, 5.1 Hz), 1.77 (ddd, J = 6.8, 6.8, 5.1 Hz)),2.47-2.83 (8H, 2.54 (dd, J = 7.6, 7.6 Hz), 2.54 (dd, J = 7.6, 7.6 Hz), 2.65(dd, J = 18.1, 8.1 Hz), 2.67 (dd, J = 7.5, 7.5 Hz), 2.67 (dd, J = 7.5, 7.5Hz), 2.75 (dd, J = 18.1, 4.3 Hz)), 3.02 (1H, dddd, J = 8.1, 5.1, 5.1, 4.3Hz), 6.33-6.46 (6H, 6.39 (ddd, J = 8.2, 1.2, 0.5 Hz), 6.39 (ddd, J = 8.2,1.2, 0.5 Hz)), 7.02-7.18 (6H, 7.09 (ddd, J = 8.2, 1.3, 0.5 Hz), 7.11 (ddd, J= 8.2, 1.3, 0.5 Hz)). .

[0044] Preparation Example 2 The preparation method of the functional monomer is the same as that in Preparation Example 1, except that equimolar amounts of p-bromotoluene are used instead of 1-(4-bromophenyl)hexane.

[0045] Preparation Example 3 The preparation method of the functional monomer is the same as that in Preparation Example 1, except that equimolar amounts of hexane bromide are used instead of 1-(4-bromophenyl)hexane.

[0046] Preparation Example 4 The preparation method of the functional monomer is the same as that in Preparation Example 1, except that 0.1 mol of 1-(4-bromophenyl)hexane is used.

[0047] Preparation Example 5 The preparation method of the functional monomer is the same as that in Preparation Example 1, except that the temperature in step A1 is 110°C.

[0048] Example 1 A heat-resistant 3D printing PETG polyester material comprises the following raw materials by mass parts: 60 parts terephthalic acid, 100 parts polyol, 30 parts functional monomer, 10 parts antioxidant 1010, 15 parts polyethylene oxide, 1 part triphenyl phosphite and 0.2 parts germanium dioxide.

[0049] The polyol is a mixture of ethylene glycol and 1,4-cyclohexanediethanol, with a molar ratio of 1:0.5.

[0050] The functional monomer was prepared by Preparation Example 1.

[0051] A method for preparing heat-resistant 3D printing PETG polyester material includes the following steps: (1) Terephthalic acid, polyol, functional monomer, 1 / 2 germanium dioxide and triphenyl phosphite were added to the reactor. Under nitrogen protection, the pressure was adjusted to 0.2 MPa, the temperature was raised to 230°C, and the reaction was carried out for 3 hours. Then the remaining germanium dioxide was added, the temperature was raised to 280°C, the pressure was reduced to 70 Pa, and the reaction was carried out for 3 hours. After completion, modified PETG was obtained. (2) Add the modified PETG from step (1) to antioxidant 1010 and polyethylene oxide into a high-speed mixer and mix at 3000 r / min for 7 min. Then, melt-extrude the mixture through a twin-screw extruder at 220℃, granulate and dry to obtain a heat-resistant 3D printing PETG polyester material.

[0052] Example 2 A heat-resistant 3D printing PETG polyester material comprises the following raw materials by mass parts: 10 parts terephthalic acid, 20 parts polyol, 10 parts functional monomer, 1 part antioxidant 1010, 2 parts polyethylene oxide, 0.1 parts triphenyl phosphite and 0.03 parts germanium dioxide.

[0053] The polyol is a mixture of ethylene glycol and 1,4-cyclohexanediethanol, with a molar ratio of 1:0.4.

[0054] The functional monomer was prepared by Preparation Example 1.

[0055] A method for preparing heat-resistant 3D printing PETG polyester material includes the following steps: (1) Terephthalic acid, polyol, functional monomer, 1 / 2 germanium dioxide and triphenyl phosphite were added to the reactor. Under nitrogen protection, the pressure was adjusted to 0.1 MPa, the temperature was raised to 250°C, and the reaction was carried out for 2 hours. Then the remaining germanium dioxide was added, the temperature was raised to 290°C, the pressure was reduced to 50 Pa, and the reaction was carried out for 2 hours. After completion, modified PETG was obtained. (2) Add the modified PETG from step (1) to antioxidant 1010 and polyethylene oxide into a high-speed mixer and mix at 3000 r / min for 5 min. Then, melt-extrude the mixture through a twin-screw extruder at 220℃, granulate and dry to obtain a heat-resistant 3D printing PETG polyester material.

[0056] Example 3 A heat-resistant 3D printing PETG polyester material comprises the following raw materials by mass parts: 100 parts terephthalic acid, 180 parts polyol, 50 parts functional monomer, 20 parts antioxidant 1010, 20 parts polyethylene oxide, 1.5 parts triphenyl phosphite and 0.3 parts germanium dioxide.

[0057] The polyol is a mixture of ethylene glycol and 1,4-cyclohexanediethanol, with a molar ratio of 1:0.7.

[0058] The functional monomer was prepared by Preparation Example 1.

[0059] A method for preparing heat-resistant 3D printing PETG polyester material includes the following steps: (1) Terephthalic acid, polyol, functional monomer, 1 / 2 germanium dioxide and triphenyl phosphite were added to the reactor. Under nitrogen protection, the pressure was adjusted to 0.3 MPa, the temperature was raised to 220°C, and the reaction was carried out for 5 h. Then the remaining germanium dioxide was added, the temperature was raised to 260°C, the pressure was reduced to 100 Pa, and the reaction was carried out for 5 h. After completion, modified PETG was obtained. (2) Add the modified PETG from step (1) to an antioxidant 1010 and polyethylene oxide into a high-speed mixer and mix at 3000 r / min for 10 min. Then, melt-extrude the mixture through a twin-screw extruder at 220℃, granulate it, and dry it to obtain a heat-resistant 3D printing PETG polyester material.

[0060] Example 4 A heat-resistant 3D printing PETG polyester material and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the functional monomer is prepared by Example 2.

[0061] Example 5 A heat-resistant 3D printing PETG polyester material and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the functional monomer is prepared by Example 3.

[0062] Example 6 A heat-resistant 3D printing PETG polyester material and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the functional monomer is prepared by Example 4.

[0063] Example 7 A heat-resistant 3D printing PETG polyester material and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the functional monomer is prepared by Example 5.

[0064] Example 8 A heat-resistant 3D printing PETG polyester material and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the molar ratio of ethylene glycol and 1,4-cyclohexanediethanol is 1:1.

[0065] Comparative Example 1 A heat-resistant 3D printing PETG polyester material and its preparation method are described. The specific implementation method is the same as in Example 1, except that no functional monomers are added.

[0066] Performance testing: (1) Impact strength: According to the standard test GB / T 1843-2008 "Determination of impact strength of plastic cantilever beam", the better the impact strength, the better the toughness; (2) Temperature resistance test: The heat distortion temperature of the product was tested according to ASTM D1525-2017 "Standard Test Method for Vicat Softening Temperature of Plastics"; Table 1 Analysis of the data in Table 1 shows that the PETG polyester materials prepared in Examples 1-3 have good toughness and temperature resistance. In Example 4, the use of equimolar p-bromotoluene instead of 1-(4-bromophenyl)hexane shortened the flexible alkyl segments, resulting in a decrease in the impact resistance of the PETG polyester material. In Example 5, the use of equimolar bromohexane instead of 1-(4-bromophenyl)hexane resulted in a decrease in the temperature resistance of the PETG polyester material, but a slight improvement in its impact resistance. In Example 6, the change in the molar ratio of the compound shown in Formula II to 4-ethyleneaniline reduced the content of flexible segments, leading to a decrease in the PETG polyester material's impact resistance. The impact resistance of the material decreased; in Example 7, due to the change in the reaction temperature in step A1, the Heck reaction occurred, and the benzene ring content increased, resulting in a decrease in the impact resistance of the PETG polyester material, but a slight improvement in the temperature resistance; in Example 8, due to the change in the molar ratio of ethylene glycol and 1,4-cyclohexanediethanol, a large amount of cyclohexane structure would disrupt the regularity of the molecular chain, resulting in a decrease in the toughness of the PETG polyester material, but an increase in the glass transition temperature and a slight improvement in the temperature resistance; in Comparative Example 1, due to the absence of functional monomers, the toughness and temperature resistance of the PETG polyester material decreased simultaneously.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A heat-resistant 3D printing PETG polyester material, characterized in that, The raw materials include the following by weight: 10-100 parts of polyacid, 20-180 parts of polyol, 10-50 parts of functional monomer, 1-20 parts of antioxidant, 2-20 parts of dispersant, 0.1-1.5 parts of protective agent and 0.03-0.3 parts of germanium dioxide.

2. The heat-resistant 3D printing PETG polyester material according to claim 1, characterized in that, The polyacid is terephthalic acid.

3. The heat-resistant 3D printing PETG polyester material according to claim 1, characterized in that, The polyol is a mixture of ethylene glycol and 1,4-cyclohexanediethanol, with a molar ratio of 1:(0.4~0.7).

4. The heat-resistant 3D printing PETG polyester material according to claim 1, characterized in that, The structure of the functional unit is shown in Formula I: （Ⅰ）； Wherein, R is a C4~C10 alkyl segment.

5. The heat-resistant 3D printing PETG polyester material according to claim 4, characterized in that, The method for preparing the functional monomer includes the following steps: A1. Under an inert protective gas atmosphere, the compound shown in Formula II... （Ⅱ）、 4-Ethylaniline, catalyst a, strong base reagent, and ligand were mixed and added to toluene. The mixture was heated and stirred. After the stirring was completed, the mixture was filtered, extracted, and the organic phases were combined and dried under reduced pressure to obtain compound a. A2. Mix allyl succinic anhydride, compound a from step A1 and catalyst b in toluene solution, heat to 75-85℃, then add tetramethyldisiloxane, stir at constant temperature for 4-6 hours, decolorize with activated carbon, filter, concentrate under reduced pressure, and precipitate by column chromatography to obtain functional monomer. Where X is Br or I; R is a C4~C10 alkyl segment.

6. The heat-resistant 3D printing PETG polyester material according to claim 5, characterized in that, In step A1, the heating temperature is 60~80℃, and the stirring time is 2~12h.

7. The heat-resistant 3D printing PETG polyester material according to claim 5, characterized in that, In step A1, the molar ratio of the compound represented by formula II to 4-ethyleneaniline is (2.1~2.3):

1.

8. The heat-resistant 3D printing PETG polyester material according to claim 5, characterized in that, In step A2, the molar ratio of allyl succinic anhydride, compound a, and tetramethyldisiloxane is (0.9~1.1):(0.9~1.1):

1.

9. The heat-resistant 3D printing PETG polyester material according to claim 1, characterized in that, The dispersant is polyethylene oxide and / or cationic polyacrylamide.

10. A method for preparing a heat-resistant 3D printing PETG polyester material according to any one of claims 1 to 9, characterized in that, Includes the following steps: (1) Add polyacid, polyol, functional monomer, some germanium dioxide and protective agent into the reactor. Under nitrogen protection, adjust the pressure to 0.03~0.3MPa, raise the temperature to 220~250℃, and react for 2~5h. Then add the remaining germanium dioxide, raise the temperature to 260~290℃, reduce the pressure to 50~100Pa, and react for 2~5h. After completion, modified PETG is obtained. (2) Add the modified PETG from step (1) to an antioxidant and dispersant in a high-speed mixer and mix at high speed for 5-10 minutes. Then, melt-extrude the mixture through a twin-screw extruder, granulate it, and dry it to obtain a heat-resistant 3D printing PETG polyester material.

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