High-heat-resistance and wear-resistance PETG composite wire for 3D printing and preparation method thereof

Abstract

This invention provides a high heat- and wear-resistant PETG composite filament for 3D printing and its preparation method. The composite filament is composed of PETG resin, high heat- and wear-resistant modified PETG, compatibilizer, lubricant, antioxidant, and colorant. The high heat- and wear-resistant modified PETG is prepared through POSS polycondensation, acrylate end-capping, and free radical copolymerization processes. Utilizing the synergistic effect of multiple components, the overall performance of the filament is significantly improved. Specifically, the POSS nanogroups and high-temperature resistant acrylate work together to significantly increase the heat distortion temperature of the filament; synergistically with unsaturated polydimethylsiloxane, it imparts wear resistance, lubrication, and hydrophobic properties to the material; furthermore, by copolymerizing and fixing the ultraviolet absorber monomer, long-term UV aging resistance is achieved. The filament prepared by this invention possesses excellent high heat and wear resistance, anti-aging properties, and low moisture absorption, making it suitable for industrial-grade 3D printing applications such as automotive parts, tooling fixtures, and outdoor equipment.

Description

Technical Field

[0001] This invention belongs to the field of 3D printing materials technology, specifically relating to a heat-resistant and anti-aging PETG filament suitable for industrial applications and its preparation method. Background Technology

[0002] Polyethylene terephthalate-1,4-cyclohexanediol ester (PETG), an amorphous copolyester, combines the printability of polylactic acid (PLA) with the mechanical toughness of acrylonitrile-butadiene-styrene copolymer (ABS). With its excellent melt flowability, low shrinkage, and high molding stability, it has become one of the mainstream materials in fused deposition modeling (FDM) 3D printing. However, conventional PETG filaments still have significant shortcomings in practical applications: their heat distortion temperature is typically below 70℃, indicating insufficient heat resistance; they are prone to photo-oxidative aging under outdoor light, leading to yellowing, embrittlement, and degradation of mechanical properties; their surface hardness is low, resulting in insufficient wear resistance; and they have a certain degree of hygroscopicity, which can easily cause bubbles, stringing, and even nozzle clogging during storage and printing, limiting their further application in industrial scenarios such as automotive parts, tooling fixtures, and outdoor equipment.

[0003] To overcome the aforementioned performance bottlenecks, existing technologies mostly employ physical modification strategies such as alloy blending, micro / nano filler filling, or the addition of small-molecule additives. However, these methods all have corresponding limitations: if the alloy system has poor compatibility, it can easily induce printing warping and interlayer cracking; micro / nano fillers are prone to agglomeration and are difficult to disperse, which may impair the material's uniformity and mechanical properties; and small-molecule additives are prone to migration and volatilization during long-term use or high-temperature processing, making it difficult to achieve long-term performance stability.

[0004] For example, Chinese patent CN121086478A discloses an antistatic material for 3D printing based on a PETG / PC alloy, which improves the material's heat resistance and interlayer bonding to some extent, but fails to improve its wear resistance. Chinese patent CN104861582A improves the material's aging resistance by adding a small-molecule light stabilizer to the PTT / PETG composite system, but still fails to overcome the key drawbacks of small-molecule additives being prone to migration and having a short-lasting effect. Furthermore, Chinese patent CN118879042A enhances the wear resistance of PETG by introducing diol monomers containing amide and pyridine structures into the copolymerization reaction; however, these highly polar groups easily adsorb environmental moisture through hydrogen bonding, potentially increasing the material's hygroscopicity. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high heat-resistant and wear-resistant PETG wire suitable for industrial applications and its preparation method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A high heat-resistant and wear-resistant PETG composite filament for 3D printing, characterized in that it is made from raw materials comprising the following parts by weight: 50-80 parts of PETG resin, 25-40 parts of high heat-resistant and wear-resistant modified PETG, 1-5 parts of compatibilizer, 0.3-1 part of lubricant, 0.2-1 part of antioxidant, and 0.2-3 parts of colorant; Among them, the high heat-resistant and wear-resistant modified PETG is prepared by POSS polycondensation, acrylic acid end-capping and free radical copolymerization. Its free radical copolymer monomers include acrylate-end-capped POSS polycondensation PETG, methyl methacrylate, unsaturated polydimethylsiloxane, high temperature resistant acrylate and active ultraviolet absorber. The acrylate-capped POSS condensation polymer PETG is prepared by reacting diol POSS with terephthalic acid, ethylene glycol, and CHDM to obtain POSS-PETG oligomers, which are then capped with acrylic acid. The number average molecular weight is 4000-8000.

[0007] Preferably, the weight ratio of the acrylate-terminated POSS condensation polymer PETG, MMA, unsaturated polydimethylsiloxane, high-temperature resistant acrylate, and active ultraviolet absorber is 40-60:20-30:5-10:10-20:0.5-3.2.

[0008] Preferably, the diol POSS is selected from one or more of (2,3-propanediol)propoxy-heptaisobutyl-substituted POSS and [3-(1,3-propanediol-2-ethyl-2-methoxy)propyldimethylsiloxy]heptacyclopentyl-substituted POSS.

[0009] Preferably, the high-temperature resistant acrylate is one or more of isobornyl methacrylate, isobornyl acrylate, and 1-adamantyl methacrylate.

[0010] Preferably, the unsaturated polydimethylsiloxane is one or more of monoacrylate-terminated polydimethylsiloxane and monomethacrylate-terminated polydimethylsiloxane, with a molecular weight of 1000-5000.

[0011] Preferably, the active ultraviolet absorber is an ultraviolet absorber monomer containing a reactive double bond, selected from one or more of 2-hydroxy-4-(3-methacryloyloxy-2-hydroxypropoxy)benzophenone, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate, and 2-hydroxy-4-(acryloyloxyethoxy)benzophenone.

[0012] Preferably, the compatibilizer is one or more of the following: ethylene-glycidyl acrylate polymer, ethylene-glycidyl methacrylate polymer, epoxy-functionalized acrylate oligomer, and ADR chain extender.

[0013] Preferably, the lubricant is one or more of glyceryl monostearate, pentaerythritol stearate, siloxane-polyester block copolymer, and zinc stearate.

[0014] Preferably, the antioxidant is a compound system of hindered phenol and phosphite antioxidant, wherein the hindered phenol antioxidant is one or more of antioxidant 1010, antioxidant 1076, and antioxidant 1098, and the phosphite antioxidant is one or more of antioxidant 168 and antioxidant 626.

[0015] Preferably, the colorant is one or more of the following: titanium dioxide, carbon black, iron oxide red, iron oxide yellow, phthalocyanine blue, phthalocyanine green, quinacridone red, perylene red, fluorescent pigments, pearlescent pigments, and metallic effect pigments.

[0016] This invention also provides a method for preparing the above-mentioned high heat-resistant and wear-resistant PETG composite filament for 3D printing, characterized by comprising the following steps: (1) Hydroxyl-terminated POSS-PETG oligomers were prepared by copolymerizing diol POSS with terephthalic acid, ethylene glycol and CHDM, and then esterification and end-capping reaction was carried out with acrylic acid to prepare acrylate-terminated POSS condensation PETG. (2) Dissolve the acrylate-terminated POSS polycondensation PETG, methyl methacrylate, unsaturated polydimethylsiloxane, high-temperature resistant acrylate, active ultraviolet absorber and initiator obtained in step (1) in an organic solvent, and carry out solution copolymerization reaction at 60-90℃ under an inert atmosphere for 4-8 hours; cool the reaction solution to room temperature, and slowly add it to an alcohol precipitant under vigorous stirring to precipitate the copolymer, and obtain the high heat resistance and wear resistance modified PETG by filtration, washing and vacuum drying; (3) Add PETG resin, the high heat-resistant and wear-resistant modified PETG obtained in step (2), compatibilizer, lubricant, antioxidant and colorant to a high-speed mixer and mix evenly. Then melt extrusion and granulation are carried out by twin-screw extruder to obtain 3D printing special modified material. (4) After drying the modified material obtained in step (3), it is extruded and formed by a single screw wire drawing machine, cooled and wound up to obtain a high heat-resistant and wear-resistant PETG composite wire for 3D printing.

[0017] Preferably, the preparation of acrylate-terminated POSS polycondensation PETG in step (1) includes the following steps: Terephthalic acid, ethylene glycol, and CHDM were added to a reactor and heated to 230–250 °C with stirring to carry out an esterification reaction. When the amount of water produced reached 90%–95% of the theoretical value, the diol POSS and a catalyst were added; the catalyst was selected as tetrabutyl titanate or a tetrabutyl titanate / germanium dioxide composite system, and the amount added was 0.01%–0.05% of the total mass of the reactants. Subsequently, under nitrogen protection, the system temperature was raised to 260–270 °C and a vacuum of 1–10 kPa was applied to carry out a polycondensation reaction for 0.5–1.5 hours to obtain POSS-PETG oligomers with hydroxyl groups at one end and carboxyl groups at the other end. In the above process, the initial total alcohol-acid molar ratio was controlled at 1.05–1.15:1 to compensate for the volatilization loss of ethylene glycol during the reaction, so that the final effective alcohol-acid ratio of the reaction system approached the ideal stoichiometric point of 1:1. The molar ratio of diol POSS, ethylene glycol and CHDM is 0.01–0.02 : 0.65–0.85 : 0.3–0.4. The obtained POSS-PETG oligomer was dissolved in toluene, and acrylic acid (1.05–1.15 moles of the terminal hydroxyl groups of the oligomer), 0.3%–0.5% p-toluenesulfonic acid catalyst (by mass of the total end-capping reactants), and 0.05%–0.2% polymerization inhibitor (selected from hydroquinone, 4-methoxyphenol, or 2,2,6,6-tetramethylpiperidine-1-oxo radical) were added. Under nitrogen protection, the reaction mixture was heated to reflux (approximately 110°C) and stirred for 4–8 hours until no more water was generated in the separator. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was slowly added to deionized water under vigorous stirring to precipitate the product. After filtration, washing, and vacuum drying, acrylate-terminated POSS condensation polyphosphate PETG was obtained.

[0018] Preferably, in step (2), the organic solvent is selected from one or more of toluene, tetrahydrofuran, N,N-dimethylformamide, and ethyl acetate, and the initiator is selected from one or more of azobisisobutyronitrile, azobisisoheptanenitrile, and benzoyl peroxide, and the amount of initiator accounts for 0.5%-2% of the total weight of the comonomer.

[0019] Preferably, in step (3), the temperature of each heating zone of the twin-screw extruder is set to 200-240℃ and the main engine speed is 200-400 r / min; in step (4), the temperature of each heating zone of the single-screw wire drawing machine is set to 210-245℃ and the cooling water temperature is 40-70℃.

[0020] Compared with the prior art, the present invention has the following beneficial effects: (1) In this invention, PETG obtained by acrylate-terminated POSS condensation polymerization is introduced into the modified PETG copolymer system as a macromonomer. Its structure is similar to PETG, which can improve the interfacial compatibility between the high heat-resistant and wear-resistant modified PETG and the PETG matrix resin. POSS stands for cage-like polysilsesquioxane, and its structure contains a polyhedral silicon-oxygen nanostructure framework with a diameter of about 1.5 nm. In this invention, POSS groups are introduced by condensation polymerization, which realizes the uniform dispersion of POSS at the molecular level, thereby giving full play to its nano-reinforcing effect. At the same time, organosiloxane and ultraviolet absorber are also fixed by polymerization, which completely overcomes the disadvantages of small molecule additives that are easy to migrate and volatilize, and eliminates the stringing phenomenon caused by adding a large amount of organosiloxane.

[0021] (2) This invention introduces a rigid cage-like POSS structure into modified PETG via chemical bonding and copolymerizes it with a high-temperature resistant acrylate having a high glass transition temperature, forming a physical cross-linked network in the FDM wire, effectively restricting the movement of PETG molecular chains at high temperatures. The heat distortion temperature of the prepared composite wire is significantly improved, increasing from approximately 70°C for conventional PETG to over 90°C. Furthermore, adding MMA monomer as a copolymer component can effectively reduce the cost of the copolymer system while maintaining a high heat distortion temperature.

[0022] (3) This invention introduces POSS groups and polydimethylsiloxane segments into highly heat-resistant and wear-resistant modified PETG. By utilizing the rigidity-enhancing effect of POSS and the lubrication function of polydimethylsiloxane, a synergistic effect is achieved, constructing a highly efficient wear-resistant system in PETG wire. At the same time, its hydrophobic polysiloxane segments can migrate to the material surface to form a stable low surface energy hydrophobic layer, blocking the adsorption and penetration of water molecules, thereby significantly reducing the water absorption rate of the wire and its printed parts.

[0023] (4) The PETG filament provided by the present invention significantly improves heat resistance, wear resistance, aging resistance and reduces water absorption, while still maintaining the good printing flow, interlayer bonding force and mechanical properties inherent in PETG. It can be widely used in the field of industrial-grade FDM 3D printing with high requirements for heat resistance, weather resistance and wear resistance. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. The following embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Example

[0025] A high heat-resistant and wear-resistant PETG composite filament for 3D printing, the filament being obtained from the following formulation and preparation method: (1) Preparation of acrylate-terminated POSS polycondensation of PETG 7.5 kg of terephthalic acid, 2.05 kg of ethylene glycol, and 2.25 kg of CHDM were added to a polymerization reactor. Under nitrogen protection, the mixture was stirred and heated to 240 °C for esterification. The water byproduct was collected to 95% of the theoretical value. Subsequently, 0.92 kg of (2,3-propanediol)propoxy-heptaisobutyl-substituted POSS and 10 g of tetrabutyl titanate catalyst were added. The mixture was heated to 265 °C and subjected to a vacuum of 4-5 kPa for condensation polymerization for 1 hour to obtain POSS-PETG oligomers with hydroxyl groups at one end and carboxyl groups at the other end.

[0026] Take 10.0 kg of the oligomer obtained above and add it to 25 L of toluene, stirring to dissolve at room temperature. Add 0.15 kg of acrylic acid, 50 g of p-toluenesulfonic acid, and 10.1 g of 4-methoxyphenol. Under nitrogen protection, heat the reaction mixture to reflux (approximately 110°C) and stir for 6 hours until no more water is generated in the separator. Cool the reaction solution to room temperature and slowly add it to deionized water under vigorous stirring to precipitate. After filtration, washing, and vacuum drying, acrylate-terminated POSS condensation polyphosphate PETG is obtained with a number average molecular weight of 5200.

[0027] (2) Preparation of high heat-resistant and wear-resistant modified PETG resin Take 2.4 kg of acrylate-terminated POSS condensation PETG prepared in step (1), and dissolve it together with 1.2 kg MMA, 0.40 kg monoacrylate-terminated polydimethylsiloxane (number average molecular weight 2000), 0.80 kg isobornyl methacrylate, 128 g 2-hydroxy-4-(3-methacryloyloxy-2-hydroxypropoxy)benzophenone and 20 g azobisisobutyronitrile in 8 L of ethyl acetate. React at 70 °C under nitrogen protection for 6 hours. Cool the reaction solution, and slowly add it to a large amount of ethanol under vigorous stirring to precipitate. After filtration, washing and vacuum drying, a high heat-resistant and wear-resistant modified PETG resin is obtained.

[0028] (3) Preparation of PETG composite wire 7.8 kg of PETG resin, 2.7 kg of the high heat-resistant and wear-resistant modified PETG resin obtained in step (2), 0.1 kg of ethylene-glycidyl methacrylate copolymer, 42 g of pentaerythritol stearate, 11 g of antioxidant 1010, 11 g of antioxidant 168, and 38 g of phthalocyanine blue colorant were mixed evenly using a mixer. The modified material was then melt-granulated using a twin-screw extruder, with each heating zone at a temperature range of 210-230℃ and the main extruder speed at 300 r / min. After drying the modified material granules at 80℃ for 4 hours, a single-screw wire drawing machine was used to draw the filaments, with each heating zone at a temperature range of 220-240℃ and the cooling water temperature at 55℃, to obtain a high heat-resistant and wear-resistant PETG composite filament with a diameter of 1.75 mm for 3D printing. Example

[0029] A high heat-resistant and wear-resistant PETG composite filament for 3D printing, the filament being obtained from the following formulation and preparation method: (1) Preparation of acrylate-terminated POSS polycondensation of PETG 6.0 kg of terephthalic acid, 1.70 kg of ethylene glycol, and 1.74 kg of CHDM were added to a polymerization reactor. Under nitrogen protection, the mixture was stirred and heated to 240 °C for esterification. The water byproduct was collected to 95% of the theoretical value. Subsequently, 0.64 kg of [3-(1,3-propanediol-2-ethyl-2-methoxy)propyldimethylsiloxy]heptacyclopentyl-substituted POSS and 8 g of tetrabutyl titanate / germanium dioxide composite catalyst (molar ratio 1:1) were added. The mixture was heated to 260 °C and subjected to vacuum at 6-8 kPa for polycondensation reaction for 1.5 hours to obtain POSS-PETG oligomers with hydroxyl groups at one end and carboxyl groups at the other end.

[0030] Take 8.0 kg of the oligomer obtained above and add it to 24 L of toluene, stirring to dissolve at room temperature. Add 0.10 kg of acrylic acid, 31 g of p-toluenesulfonic acid, and 6.5 g of 2,2,6,6-tetramethylpiperidine-1-oxy radicals. Under nitrogen protection, heat the reaction mixture to reflux (approximately 110°C) and stir for 5 hours until no more water is generated in the separator. Cool the reaction solution to room temperature and slowly add it to deionized water under vigorous stirring to precipitate. After filtration, washing, and vacuum drying, acrylate-terminated POSS condensation polyphosphate PETG is obtained with a number average molecular weight of 6500.

[0031] (2) Preparation of high heat-resistant and wear-resistant modified PETG Take 2.0 kg of acrylate-terminated POSS condensation PETG prepared in step (1), and dissolve it together with 1.1 kg MMA, 0.35 kg monomethacrylate-terminated polydimethylsiloxane (number average molecular weight 3000), 0.68 kg isobornyl acrylate, 90 g 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate and 25 g benzoyl peroxide in 10 L of toluene. React at 80 °C under nitrogen protection for 5 hours. Cool the reaction solution, and slowly add it to a large amount of methanol under vigorous stirring to precipitate. After filtration, washing and vacuum drying, a high heat-resistant and wear-resistant modified PETG resin is obtained.

[0032] (3) Preparation of PETG composite wire 6.5 kg of PETG resin, 3.25 kg of the high heat-resistant and wear-resistant modified PETG resin obtained in step (2), 0.3 kg of epoxy-functionalized acrylate oligomer, 35 g of glyceryl monostearate, 20 g of antioxidant 1076, 10 g of antioxidant 626, and 80 g of titanium dioxide colorant were mixed evenly using a mixer. The mixture was then melt-granulated using a twin-screw extruder with a heating zone temperature range of 210-230℃ and a main extruder speed of 300 r / min. After drying the modified material granules, they were drawn into threads using a single-screw wire drawing machine with a heating zone temperature range of 220-240℃ and a cooling water temperature of 55℃ to obtain high heat-resistant and wear-resistant PETG composite filaments for 3D printing. Example

[0033] A high heat-resistant and wear-resistant PETG composite filament for 3D printing, the filament being obtained from the following formulation and preparation method: (1) Preparation of acrylate-terminated POSS polycondensation of PETG 4.5 kg of terephthalic acid, 1.28 kg of ethylene glycol, and 1.32 kg of CHDM were added to a polymerization reactor. Under nitrogen protection, the mixture was stirred and heated to 240 °C for esterification. The water byproduct was collected to 95% of the theoretical value. Subsequently, 0.43 kg of (2,3-propanediol)propoxy-heptaisobutyl-substituted POSS and 6 g of tetrabutyl titanate catalyst were added. The mixture was heated to 270 °C and evacuated to below 4 kPa for polycondensation reaction for 0.5 hours to obtain POSS-PETG oligomers with hydroxyl groups at one end and carboxyl groups at the other end.

[0034] Take 7.0 kg of the oligomer obtained above and add it to 21 L of toluene, stirring to dissolve at room temperature. Add 0.11 kg of acrylic acid, 35 g of p-toluenesulfonic acid, and 8.5 g of hydroquinone. Under nitrogen protection, heat the reaction mixture to reflux (approximately 110°C) and stir for 4.5 hours until no more water is generated in the separator. Cool the reaction solution to room temperature and slowly add it to deionized water under vigorous stirring to precipitate. After filtration, washing, and vacuum drying, acrylate-terminated POSS condensation polyphosphate PETG is obtained with a number average molecular weight of 4800.

[0035] (2) Preparation of high heat-resistant and wear-resistant modified PETG Take 1.6 kg of acrylate-terminated POSS condensation PETG prepared in step (1), and dissolve it together with 1.1 kg MMA, 0.20 kg monomethacrylate-terminated polydimethylsiloxane (number average molecular weight 1500), 0.75 kg 1-adamantyl methacrylate, 100 g 2-hydroxy-4-(acryloyloxyethoxy)benzophenone, and 15 g azobisisobutyronitrile in 6 L of toluene. React at 60 °C under nitrogen protection for 5 hours. Cool the reaction solution, and slowly add it to a large amount of ethanol under vigorous stirring to precipitate. After filtration, washing, and vacuum drying, obtain highly heat-resistant and wear-resistant modified PETG resin.

[0036] (3) Preparation of PETG composite wire 5.1 kg of PETG resin, 3.7 kg of the high heat-resistant and wear-resistant modified PETG resin obtained in step (2), 0.4 kg of ADR chain extender, 32 g of siloxane-polyester block copolymer, 20 g of antioxidant 1098, 10 g of antioxidant 168, and 60 g of carbon black colorant were mixed evenly using a mixer. The mixture was then melt-granulated using a twin-screw extruder with a heating zone temperature range of 210-230℃ and a main extruder speed of 300 r / min. After drying the modified material granules, they were drawn into threads using a single-screw wire drawing machine with a heating zone temperature range of 220-240℃ and a cooling water temperature of 55℃ to obtain high heat-resistant and wear-resistant PETG composite filaments for 3D printing.

[0037] Compare with Example 1 The wire was prepared according to the method of Example 1, except that in step (1), the diol POSS was not added, and 140g CHDM was used instead of POSS diol, while keeping the total number of moles of diol unchanged and other conditions unchanged.

[0038] Compare with Example 2 The wire was prepared according to the method of Example 1, except that in step (2) the copolymerization reaction, monoacrylate-terminated polydimethylsiloxane was not added, but instead an equal weight of MMA (0.40 kg) was used. The resulting high heat-resistant and wear-resistant modified PETG was a quaternary copolymer composed of acrylate-terminated POSS condensation PETG, MMA, isobornyl acrylate, and active ultraviolet absorber.

[0039] Compare with Example 3 The wire was prepared according to the method of Example 1, except that isobornyl acrylate and active ultraviolet absorber were not added in step (2), and instead, 2-hydroxy-4-(3-methacryloyloxy-2-hydroxypropoxy)benzophenone was added in the wire extrusion step (3) by physical blending with the same weight as in Example 1.

[0040] Compare with Example 4 The wire was prepared according to the method of Example 1, except that in step (3), high heat-resistant and wear-resistant modified PETG resin was not added during blending and granulation. Instead, pure PETG resin (10.5 kg) was directly used to blend and granulate with compatibilizer, lubricant, antioxidant, and colorant, and the amount of each additive was the same as in Example 1. At the same time, in the granulation step, an equal weight of monoacrylate-terminated polydimethylsiloxane (0.40 kg) as in Example 1 was added by physical blending, and no form of ultraviolet absorber was added.

[0041] Testing and Performance Analysis Test samples were obtained by FDM printing of the filaments prepared in Examples 1-3 and Comparative Examples 1-4 using an FDM printer. The nozzle temperature was 230°C, the substrate temperature was 70°C, and the printing speed was 150 mm / s. The test results of the relevant performance are shown in Table 1.

[0042] Table 1. Comparison of performance and printing quality

[0043] Table 1 shows that the heat-resistant, wear-resistant, and anti-aging PETG 3D printing composite filament provided by this invention has high heat and wear resistance, excellent printing applicability, long-lasting anti-aging properties, and good low moisture absorption. Comparing Examples 1-3 with Control Examples 1-4, it can be seen that: (1) The introduction of the rigid structure of POSS and the high-temperature resistant acrylate significantly improves the heat distortion temperature and heat resistance stability of the printed parts; (2) The synergistic modification of POSS and unsaturated polydimethylsiloxane can significantly reduce the wear of the test parts, thereby effectively improving the wear resistance; at the same time, the hydrophobicity of unsaturated polydimethylsiloxane can give the material low moisture absorption; (3) The introduction of active ultraviolet absorbers through copolymerization enables the filament to maintain a high tensile strength retention rate (>90%) and a low color yellowing index (ΔYI<5) after long-term photoaging, showing a long-lasting and stable anti-aging effect; while the introduction of organosilicon through polymerization can eliminate the printing stringing phenomenon caused by organosilicon oligomers.

[0044] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A high heat-resistant and wear-resistant PETG composite filament for 3D printing, characterized in that, It is made from the following raw materials in parts by weight: 50-80 parts PETG resin, 25-40 parts high heat-resistant and wear-resistant modified PETG, 1-5 parts compatibilizer, 0.3-1 part lubricant, 0.2-1 part antioxidant, and 0.2-3 parts colorant; The high heat-resistant and wear-resistant modified PETG is prepared by POSS polycondensation reaction, acrylate end-capping and free radical copolymerization. Its free radical comonomer includes acrylate-terminated POSS polycondensation PETG, methyl methacrylate, unsaturated polydimethylsiloxane, high temperature resistant acrylate and active ultraviolet absorber. The acrylate-capped POSS condensation polymerization of PETG is carried out by reacting diol POSS with terephthalic acid, ethylene glycol, and 1,4-cyclohexanediethanol (CHDM) to obtain POSS-PETG oligomers, which are then prepared by acrylate capping. The number average molecular weight is 4000-8000.

2. The high heat-resistant and wear-resistant PETG composite filament for 3D printing according to claim 1, characterized in that, The weight ratio of the acrylate-terminated POSS condensation polymer PETG, methyl methacrylate, unsaturated polydimethylsiloxane, high-temperature resistant acrylate, and active ultraviolet absorber is 40-60:20-30:5-10:10-20:0.5-3.

2.

3. The high heat-resistant and wear-resistant PETG composite filament for 3D printing according to claim 1, characterized in that, The diol POSS is selected from one or more of (2,3-propanediol)propoxy-heptaisobutyl-substituted POSS and [3-(1,3-propanediol-2-ethyl-2-methoxy)propyldimethylsiloxy]heptacyclopentyl-substituted POSS.

4. The high heat-resistant and wear-resistant PETG composite filament for 3D printing according to claim 1, characterized in that, The high-temperature resistant acrylate is one or more of isoborneol methacrylate, isoborneol acrylate, and 1-adamantyl methacrylate.

5. The high heat-resistant and wear-resistant PETG composite filament for 3D printing according to claim 1, characterized in that, The unsaturated polydimethylsiloxane is one or more of monoacrylate-terminated polydimethylsiloxane and monomethacrylate-terminated polydimethylsiloxane, with a number average molecular weight of 1000-5000.

6. The high heat-resistant and wear-resistant PETG composite filament for 3D printing according to claim 1, characterized in that, The active ultraviolet absorber is an ultraviolet absorber monomer containing a reactive double bond, selected from one or more of 2-hydroxy-4-(3-methacryloyloxy-2-hydroxypropoxy)benzophenone, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate, and 2-hydroxy-4-(acryloyloxyethoxy)benzophenone.

7. The high heat-resistant and wear-resistant PETG composite filament for 3D printing according to claim 1, characterized in that, The compatibilizer is one or more of the following: ethylene-glycidyl acrylate polymer, ethylene-glycidyl methacrylate polymer, epoxy-functionalized acrylate oligomer, and ADR chain extender.

8. The high heat-resistant and wear-resistant PETG composite filament for 3D printing according to claim 1, characterized in that, The lubricant is one or more of glyceryl monostearate, pentaerythritol stearate, siloxane-polyester block copolymer, and zinc stearate.

9. The high heat-resistant and wear-resistant PETG composite filament for 3D printing according to claim 1, characterized in that, The antioxidant is a combination system of hindered phenol and phosphite antioxidants, wherein the hindered phenol antioxidant is one or more of antioxidant 1010, antioxidant 1076, and antioxidant 1098, and the phosphite antioxidant is one or more of antioxidant 168 and antioxidant 626.

10. The high heat-resistant and wear-resistant PETG composite filament for 3D printing according to claim 1, characterized in that, The colorant is one or more of the following: titanium dioxide, carbon black, iron oxide red, iron oxide yellow, phthalocyanine blue, phthalocyanine green, quinacridone red, perylene red, fluorescent pigments, pearlescent pigments, and metallic effect pigments.

11. The method for preparing high heat-resistant and wear-resistant PETG composite filament for 3D printing as described in any one of claims 1-10, characterized in that, Includes the following steps: (1) POSS-PETG oligomers were prepared by polycondensation of diol POSS with terephthalic acid, ethylene glycol and CHDM, and then esterification end-capping reaction was carried out with acrylic acid to prepare acrylate-capped POSS polycondensation PETG. (2) Dissolve the acrylate-terminated POSS polycondensation PETG, methyl methacrylate, unsaturated polydimethylsiloxane, high-temperature resistant acrylate, active ultraviolet absorber and initiator obtained in step (1) in an organic solvent, and carry out solution copolymerization reaction at 60-90℃ under an inert atmosphere for 4-8 hours; cool the reaction solution to room temperature, and slowly add it to an alcohol precipitant under vigorous stirring to precipitate the copolymer, and obtain the high heat resistance and wear resistance modified PETG by filtration, washing and vacuum drying; (3) Add PETG resin, the high heat-resistant and wear-resistant modified PETG obtained in step (2), compatibilizer, lubricant, antioxidant and colorant to a high-speed mixer and mix evenly. Then melt extrusion and granulation are carried out by twin-screw extruder to obtain 3D printing special modified material. (4) After drying the modified material obtained in step (3), it is extruded and formed by a single screw wire drawing machine, cooled and wound up to obtain a high heat-resistant and wear-resistant PETG composite wire for 3D printing.

12. The method for preparing the high heat-resistant and wear-resistant PETG composite filament for 3D printing according to claim 11, characterized in that, The preparation of acrylate-terminated POSS polycondensation PETG in step (1) includes the following steps: Terephthalic acid, ethylene glycol, and CHDM were added to a reactor and heated to 230–250 °C with stirring to carry out an esterification reaction. When the amount of water produced reached 90%–95% of the theoretical value, the diol POSS and a catalyst were added; the catalyst was selected as tetrabutyl titanate or a tetrabutyl titanate / germanium dioxide composite system, and the amount added was 0.01%–0.05% of the total mass of the reactants. Subsequently, under nitrogen protection, the system temperature was raised to 260–270 °C and a vacuum of 1–10 kPa was applied to carry out a polycondensation reaction for 0.5–1.5 hours to obtain POSS-PETG oligomers with hydroxyl groups at one end and carboxyl groups at the other end. In the above process, the initial total alcohol-acid molar ratio was controlled at 1.05–1.15:1 to compensate for the volatilization loss of ethylene glycol during the reaction, so that the final effective alcohol-acid ratio of the reaction system approached the ideal stoichiometric point of 1:

1. The molar ratio of diol POSS, ethylene glycol and CHDM is 0.01–0.02 : 0.65–0.85 : 0.3–0.

4. The obtained POSS-PETG oligomer was dissolved in toluene, and acrylic acid (1.05–1.15 moles of the terminal hydroxyl groups of the oligomer), 0.3%–0.5% p-toluenesulfonic acid catalyst (by mass of the total end-capping reactants), and 0.05%–0.2% polymerization inhibitor (selected from hydroquinone, 4-methoxyphenol, or 2,2,6,6-tetramethylpiperidine-1-oxo radical) were added. Under nitrogen protection, the reaction mixture was heated to reflux (approximately 110°C) and stirred for 4–8 hours until no more water was generated in the separator. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was slowly added to deionized water under vigorous stirring to precipitate the product. After filtration, washing, and vacuum drying, acrylate-terminated POSS condensation polyphosphate PETG was obtained.

13. The method for preparing the high heat-resistant and wear-resistant PETG composite filament for 3D printing according to claim 11, characterized in that, In step (2), the organic solvent is selected from one or more of toluene, tetrahydrofuran, N,N-dimethylformamide, and ethyl acetate, and the initiator is selected from one or more of azobisisobutyronitrile, azobisisoheptanenitrile, and benzoyl peroxide. The amount of initiator accounts for 0.5%-2% of the total weight of the comonomer.

14. The method for preparing the high heat-resistant and wear-resistant PETG composite filament for 3D printing according to claim 11, characterized in that, In step (3), the temperature of each heating zone of the twin-screw extruder is set to 200-240℃ and the main machine speed is 200-400 r / min; in step (4), the temperature of each heating zone of the single-screw wire drawing machine is set to 210-245℃ and the cooling water temperature is 40-70℃.

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