A low-warpage heat-resistant PETG / PBAT composition and its preparation method and application

Abstract

The present invention discloses a low-warpage, heat-resistant PETG / PBAT composition in the field of flooring materials, as well as its preparation method and application. The composition comprises the following components by weight: 50-80 parts PETG resin; 10-40 parts PBAT resin; 30-80 parts calcium carbonate; 10-30 parts modified fly ash; 0.5-3 parts coupling agent; 1-5 parts compatibilizer; and 0.5-3 parts transesterification inhibitor. The present invention provides a simple preparation process and low production cost. The composition exhibits excellent warpage and shrinkage, heat resistance, and a balanced rigidity and toughness, and is applicable in a variety of applications, including wallboards, indoor flooring, outdoor flooring, and home countertops.

Description

Technical Field

[0001] The present invention belongs to the technical field of floor materials, and more specifically, relates to a low-warpage heat-resistant PETG / PBAT composition, a preparation method thereof, and an application thereof. Background Art

[0002] The layered structure of traditional solid wood and composite flooring is susceptible to differential expansion and hygroscopic expansion during humidity fluctuations, leading to three-dimensional warping and deformation. The shrinkage of the wood components and the creep properties of the adhesive in high-temperature environments further exacerbate this deformation. In particular, the difference in thermal expansion coefficients between the aluminum oxide wear layer on the surface of laminate flooring and the base material can easily cause interfacial delamination under continuous heat radiation. While PVC elastic flooring offers moisture-resistant properties, its molecular chain motion intensifies when heated above 60°C, often resulting in irreversible dimensional shrinkage and surface depression. These material defects not only affect the smoothness of the installation but also reduce the safety and service life of the flooring system.

[0003] Existing resin-based composite flooring materials (such as PET, ABS, and polyester boards) still have significant deficiencies in thermal stability and dimensional retention. While PET is lightweight, its glass transition temperature (Tg) is between 70°C and 80°C. Molecular chain segment rearrangement at high temperatures can easily cause local softening and stress relaxation, leading to warping at the floor edges and surface depressions. ABS-based boards are susceptible to creep deformation under sustained heat loads (>55°C), and their lack of rigidity can lead to wavy joints. Some composite flooring, due to a mismatch in the thermal expansion coefficients between the reinforcing fibers and the resin matrix, can develop interfacial microcracks during temperature cycling, accelerating delamination and failure. Furthermore, the anisotropic expansion of polyester materials after absorbing moisture can couple with thermally induced deformation, further reducing the floor's structural reliability in coupled moisture-heat scenarios.

[0004] PETG is a semi-crystalline plastic formed by the copolymerization of two main components, terephthalic acid and ethylene glycol. Compared to traditional PET, PETG offers greater toughness, transparency, and impact resistance. It is a transparent or translucent polymer material. The introduction of 1,4-cyclohexanedimethanol (CHDM) copolymer units into the PETG molecular chain disrupts the crystallinity of PET, forming an amorphous polymer. The disordered arrangement of molecular chains in an amorphous structure leads to weak interchain forces, making chain segments more prone to movement at high temperatures, leading to material softening. The ester groups in the molecular chains react easily with water molecules at high temperatures, causing hydrolysis, further reducing the molecular weight and accelerating performance degradation. Furthermore, the high price of PETG resin further limits its application in many fields.

[0005] For example, when using pure PETG as a flooring substrate, its thermomechanical properties and dimensional stability still present significant shortcomings. When the ambient temperature approaches Tg, molecular chain motion intensifies, leading to a sharp drop in the storage modulus. Under sustained heat loads (such as under floor heating), thermal creep readily occurs, manifesting as a concavity in the center of the board and an upward warping of the edges. Furthermore, while its amorphous structure imparts isotropic shrinkage, improperly controlled cooling gradients during injection molding can lead to the release of internal residual stresses, which can cause non-uniform warping. Furthermore, while PETG has a lower moisture absorption rate than ABS (approximately 0.15%), long-term exposure to high humidity still results in slight expansion, which, coupled with thermally induced shrinkage, leads to dynamic deformation accumulation. At low temperatures (<10°C), PETG's fracture toughness decreases significantly, and localized impacts can easily induce microcrack propagation, further weakening the flooring's structural reliability. While PETG / ABS and PETG / PP alloy systems have improved some mechanical properties through blending and modification, they still face application bottlenecks in coupled heat-humidity environments.

[0006] At the same time, composite flooring also has problems such as interfacial stress concentration caused by compatibility, which induces edge curling; weak interfacial bonding leads to cracking along the weld line under thermal mechanical loads, further reducing the structural durability of the floor; and the problem of expensive materials and high costs. Summary of the Invention

[0007] The purpose of the present invention is to address the above shortcomings and solve the problem that existing floor materials are prone to warping and deformation in hot and humid environments, and to provide a low-warping and heat-resistant PETG / PBAT composition and its preparation method and application. The preparation process is simple and the production cost is low. The composition has good warping and shrinkage, heat resistance and rigidity-toughness balance, and can be used in many fields such as wall panels, indoor flooring, outdoor flooring, and home countertops.

[0008] To achieve the above object, the present invention is implemented through the following technical solutions:

[0009] In a first aspect, the present invention provides a low-warpage heat-resistant PETG / PBAT composition, wherein the raw materials of the composition include a resin, a filler, and a reaction aid, wherein the resin, filler, and reaction aid include the following components in parts by weight:

[0010] 50~80 parts of PETG resin;

[0011] 10~40 parts of PBAT resin;

[0012] 30 to 80 parts of calcium carbonate;

[0013] 10-30 parts of modified fly ash;

[0014] 0.5 to 3 parts of coupling agent;

[0015] 1 to 5 parts of compatibilizer;

[0016] 0.5 to 3 parts of transesterification inhibitor.

[0017] Preferably, the PETG resin has a melt index of 2 g / 10 min to 5 g / 10 min under the test conditions of 250° C. and 2.16 kg; and the content of 1,4-cyclohexanedimethanol in the PETG resin is 20 wt % to 45 wt %.

[0018] Preferably, the PBAT resin has a melt index of 4 g / 10 min to 6 g / 10 min under the test conditions of 190° C. and 2.16 kg.

[0019] PBAT resin, or polybutylene terephthalate adipate, is a common biodegradable thermoplastic polyester with excellent biodegradability, is environmentally friendly, and can effectively reduce white pollution. PBAT has high tensile strength and elongation at break, and its mechanical properties are similar to, and in some cases even superior to, those of traditional plastics like polyethylene and polypropylene. Products made from PBAT exhibit good toughness and tear resistance. However, PBAT suffers from issues such as low modulus and poor heat resistance, and currently has a limited market share in film bags. The present invention introduces PBAT resin and blends it with PETG, replacing more expensive toughening agents to improve the material's toughness and impact strength while reducing costs.

[0020] Preferably, the particle size of the calcium carbonate is 200-1500 mesh; using low-mesh calcium carbonate as filler can effectively reduce product costs while increasing material dimensional stability.

[0021] Preferably, the modified fly ash is obtained by surface coating and modification of primary ash through chemical excitation.

[0022] Fly ash, a major solid waste product from coal-fired power plants, is formed from fine dust captured from the flue gases after coal combustion. However, due to its smooth surface, it has poor compatibility with the polymer matrix, making the interface between the fly ash and the matrix a potential weak link in composite materials. Fly ash is also dark in color, with a whiteness of only around 30, which does not meet the requirements for light-colored fillers. Furthermore, its Vickers hardness exceeds 1000, exceeding the 38CrMoAl alloy steel used in typical extruder barrels and screws. Filling polymers with fly ash can cause significant wear on contacting metal parts. These inherent flaws restrict its application in polymers. Even using strong bases or acids like sodium hydroxide and hydrochloric acid to increase the specific surface area of ​​fly ash, it is difficult to improve its color.

[0023] This application uses surface-coated modified fly ash as filler to improve its compatibility with polymers, form more stable chemical bonds with resin molecular chains, effectively increase the thermal deformation temperature of the material, and save energy, protect the environment and reduce costs.

[0024] Preferably, the coupling agent is at least one of a titanate coupling agent and an aluminate coupling agent. Adding an appropriate amount of coupling agent can improve the dispersibility of the filler, enhance the interfacial bonding strength, and improve the mechanical properties of the composite material.

[0025] Preferably, the compatibilizer is at least one of PE-g-MAH (maleic anhydride grafted polyethylene), PP-g-MAH (maleic anhydride grafted polypropylene), ethylene-acrylate glycidyl methacrylate, SEBS-g-MAH (maleic anhydride grafted styrene-ethylene-butylene-styrene block copolymer), and POE-g-GMA (glycidyl methacrylate grafted polyolefin elastomer). Adding an appropriate amount of the compatibilizer promotes dispersion, reduces interfacial tension, enhances interfacial bonding, and improves the mechanical and processing properties of the material.

[0026] Preferably, the transesterification inhibitor is at least one of triphenyl phosphite, sodium dihydrogen phosphate, or disodium dihydrogen pyrophosphate. Adding an appropriate amount of transesterification inhibitor can prevent transesterification between PETG and PBAT, thereby preventing the destruction of the molecular chain structure caused by the transesterification reaction, maintaining the stability of the molecular chain structure, and preventing degradation or material performance degradation. Excessive inhibitors may affect the material processing performance or introduce impurities.

[0027] Preferably, the raw materials of the composition also include 0.1 to 2 parts of an antioxidant and / or 0.1 to 2 parts of a lubricant. The antioxidant is a hindered phenol antioxidant or a phosphite antioxidant; the lubricant is a vinyl bisstearamide, polysiloxane, calcium stearate, magnesium stearate, zinc stearate, PE wax, PP wax, ethylene bisstearamide, or a fatty acid ester. An appropriate amount of antioxidant can prevent oxidation-induced molecular chain breakage (degradation) or crosslinking (hardening) by blocking free radical chain reactions or decomposing peroxides, thereby delaying material aging. An appropriate amount of lubricant can improve processing fluidity, reduce processing energy consumption, and increase production efficiency, while preventing extrusion bonding and improving demolding properties and material surface finish.

[0028] In a second aspect, the present invention provides a method for preparing the low-warpage heat-resistant PETG / PBAT composition according to the first aspect, comprising:

[0029] Drying PETG resin, PBAT resin, calcium carbonate and fly ash;

[0030] The dried fly ash is surface-coated and modified by chemical excitation to obtain modified fly ash;

[0031] The dried PETG resin, PBAT resin, calcium carbonate and modified fly ash are mixed with a reaction aid in proportion to obtain a mixture;

[0032] The above mixture is melted, blended and extruded to prepare a PETG / PBAT composition.

[0033] Preferably, the PETG resin and PBAT resin are dried at 60° C. to 80° C. for 6 h to 12 h; and the calcium carbonate and fly ash are dried at 80° C. to 130° C. for 1 h to 2 h using a high-speed mixer.

[0034] Preferably, the dried fly ash is subjected to surface coating modification by chemical excitation to obtain modified fly ash, comprising:

[0035] Place fly ash and calcium hydroxide solution in an open reactor, stir thoroughly to make the slurry evenly mixed, heat to 60℃~95℃, and keep warm for 2h~3h;

[0036] The reaction was terminated by introducing carbon dioxide gas until the pH value was 7, and the reaction slurry was filtered and dried to obtain the modified fly ash.

[0037] Further preferably, the mass ratio of the fly ash to the calcium hydroxide solution is 1:10, the concentration of the calcium hydroxide solution is 7 wt %; and the rate of introducing carbon dioxide gas is 0.15 L / min.

[0038] According to the principle of fly ash activation, the nano-silicate components generated by the reaction will deposit and grow on the surface of the fly ash particles as sub-particles to form a coating layer. The subsequent introduction of air and carbon dioxide mixed gas can neutralize the residual calcium hydroxide in the slurry.

[0039] Preferably, the mixed material is melted, blended and extruded through a twin-screw extruder;

[0040] The blending temperature is 80°C to 120°C, the mixing time is 10 min to 30 min, and the rotation speed is 300 r / min to 400 r / min;

[0041] The twin-screw extruder is equipped with 12 temperature setting zones, namely: Zones 1 to 3 are feeding sections for continuous feeding, with a temperature set at 150°C to 190°C; Zones 4 to 5 are melting sections for heating the entire material to form a molten state, with a temperature set at 180°C to 190°C; Zones 6 to 7 are plasticizing sections for plasticizing the material, with a temperature set at 190°C to 205°C; Zone 8 is a venting section for exhausting excess air holes in the melt, with a temperature set at 190°C to 205°C; Zones 9 to 10 are mixing sections for fully mixing the raw materials, with a temperature set at 190°C to 205°C; Zones 11 to 12 are extrusion sections for extruding the material inside the twin-screw extruder, with a temperature set at 190°C to 200°C.

[0042] In a third aspect, the present invention further provides the use of the low-warpage heat-resistant PETG / PBAT composition described in the first aspect in wall panels, indoor floors, outdoor floors, and home countertops.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The low-warpage heat-resistant PETG / PBAT composition of the present invention reduces the use of toughening agents by introducing PBAT into the PETG filling system. The addition of modified fly ash further reduces the cost of the composite material. Suitable reaction additives are screened and a specific ratio is set. Inorganic powder is filled in the gaps between molecular chains to increase the resistance to chain segment movement and improve the rigidity of the material. The main components of the fly ash, SiO2 (40% to 60%) and Al2O3 (20% to 30%), have a high melting point (>1500°C) and form a thermal insulation barrier to hinder heat transfer to the matrix. Through the synergistic effect of the various components, the heat-resistant temperature of the material is increased, the warpage shrinkage and thermal expansion coefficient of the product are improved, and the application of PETG in building materials and other fields is expanded. In addition, the raw material cost is low, and the material is modified by recycling industrial waste, which is energy-saving and environmentally friendly.

[0045] The preparation method of the present invention has simple process and low production cost. DETAILED DESCRIPTION

[0046] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. Instead, these embodiments are provided to make the present invention more thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0047] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0048] The raw materials used in the following examples and comparative examples are as follows:

[0049] PETG resin: 1,4-cyclohexanedimethanol 30% by mass, melt index 2-5g / 10min, Henan Yinjinda New Materials Co., Ltd.

[0050] PBAT resin: intrinsic viscosity 2.5 dl / g, Zhejiang Huafeng Group Co., Ltd.

[0051] Calcium carbonate: 325 mesh calcium carbonate, Quanzhou Xufeng Powder Raw Material Co., Ltd.;

[0052] Fly ash; first-grade ash, Jining Hengzhi New Building Materials Co., Ltd.;

[0053] Calcium hydroxide solution: 7% mass concentration, homemade;

[0054] Coupling agent: aluminate coupling agent, NXH-821, Nanjing Xuanhao New Material Technology Co., Ltd.

[0055] Compatibilizer: POE-g-GMA, W5D, Coase Chemical Co., Ltd.

[0056] Transesterification inhibitor: disodium dihydrogen pyrophosphate, Hubei Xingfa Chemical Group Co., Ltd.

[0057] Antioxidant: hindered phenol antioxidant, RIANOX 1010;

[0058] Lubricant: EBS (ethylene bisstearamide), WAX 2200, Changzhou Kesai Chenggong Plastic Material Co., Ltd.

[0059] The present invention will be described in detail below with reference to Examples and Comparative Examples.

[0060] Example 1:

[0061] This embodiment provides a low-warpage heat-resistant PETG / PBAT composition, the ingredients of which are shown in Table 1. The preparation method thereof comprises the following steps:

[0062] S1: PETG and PBAT resins were dried at 70°C for 6 h to remove their own moisture. Calcium carbonate and fly ash were dried at 80°C for 1 h in a high-speed mixer and set aside.

[0063] S2: Fly ash is added to a 7wt% calcium hydroxide suspension in an open reactor. The mixture is stirred thoroughly to ensure uniform mixing. The temperature is then raised to 60°C and maintained for 2 hours. The mass ratio of fly ash to calcium hydroxide suspension is 1:10. Based on the principle of fly ash activation, the nanosilicate components generated by the reaction act as sub-particles and deposit and grow on the surface of the fly ash particles, forming a coating. Carbon dioxide is then introduced at a rate of 0.15 L / min to neutralize any residual calcium hydroxide in the slurry. The reaction terminates at a pH of 7. The slurry is filtered and dried to obtain the modified fly ash for later use.

[0064] S3: PETG resin, PBAT resin, calcium carbonate, modified fly ash, coupling agent, lubricant, antioxidant and transesterification inhibitor are weighed in proportion and uniformly mixed to obtain a mixture.

[0065] S4: The mixed material in step S3 is added to a twin-screw extruder through a feed port, and after melting, blending, and extrusion, the PETG / PBAT composition is obtained.

[0066] In step S4, the blending temperature is 80° C., the mixing time is 10 min, and the speed is 300 r / min;

[0067] The twin-screw extruder is provided with 12 temperature setting zones, namely: Zones 1 to 3 are feeding sections for continuous feeding, with temperatures set to 150°C, 160°C, and 170°C respectively; Zones 4 to 5 are melting sections for heating the entire material to form a molten state, with temperatures set to 180°C and 185°C respectively; Zones 6 to 7 are plasticizing sections for plasticizing the material, thereby reducing the hardness of the material, improving the toughness of the material, and increasing the ductility and plasticity of the material, with temperatures set to 190°C and 195°C respectively; Zone 8 is a venting section for discharging excess pores in the melt, with a temperature set to 195°C; Zones 9 to 10 are mixing sections for fully mixing the raw materials, with temperatures set to 195°C and 200°C respectively; Zones 11 to 12 are extrusion sections for extruding the material inside the twin-screw extruder equipment to form a floor base shape, with temperatures set to 195°C and 200°C respectively.

[0068] Example 2:

[0069] This embodiment provides a low-warpage heat-resistant PETG / PBAT composition, the ingredients of which are shown in Table 1. The preparation method thereof comprises the following steps:

[0070] S1: PETG and PBAT resins were dried at 80°C for 12 h to remove their own moisture. Calcium carbonate and fly ash were dried at 130°C for 2 h in a high-speed mixer and set aside.

[0071] S2: Fly ash is added to a 7wt% calcium hydroxide suspension in an open reactor. The mixture is stirred thoroughly to ensure uniform mixing. The temperature is then raised to 95°C and maintained for 3 hours. The mass ratio of fly ash to calcium hydroxide suspension is 1:10. Based on the principle of fly ash activation, the nanosilicate components generated by the reaction act as sub-particles and deposit and grow on the surface of the fly ash particles, forming a coating. Carbon dioxide is then introduced at a rate of 0.15 L / min to neutralize any residual calcium hydroxide in the slurry. The reaction terminates at a pH of 7. The slurry is filtered and dried to obtain the modified fly ash for later use.

[0072] S3: PETG resin, PBAT resin, calcium carbonate, modified fly ash, coupling agent, lubricant, antioxidant and transesterification inhibitor are weighed in proportion and uniformly mixed to obtain a mixture.

[0073] S4: The mixed material in step S3 is added to a twin-screw extruder through a feed port, and after melting, blending, and extrusion, the PETG / PBAT composition is obtained.

[0074] In step S4, the blending temperature is 120° C., the mixing time is 30 min, and the speed is 400 r / min;

[0075] The twin-screw extruder is provided with 12 temperature setting zones, namely: Zones 1 to 3 are feeding sections for continuous feeding, with temperatures set to 150°C, 160°C, and 170°C respectively; Zones 4 to 5 are melting sections for heating the entire material to form a molten state, with temperatures set to 180°C and 185°C respectively; Zones 6 to 7 are plasticizing sections for plasticizing the material, thereby reducing the hardness of the material, improving the toughness of the material, and increasing the ductility and plasticity of the material, with temperatures set to 190°C and 195°C respectively; Zone 8 is a venting section for discharging excess pores in the melt, with a temperature set to 195°C; Zones 9 to 10 are mixing sections for fully mixing the raw materials, with temperatures set to 195°C and 200°C respectively; Zones 11 to 12 are extrusion sections for extruding the material inside the twin-screw extruder equipment to form a floor base shape, with temperatures set to 195°C and 200°C respectively.

[0076] Example 3:

[0077] This embodiment provides a low-warpage heat-resistant PETG / PBAT composition, the ingredients of which are shown in Table 1. The preparation method thereof comprises the following steps:

[0078] S1: PETG and PBAT resins were dried at 70°C for 10 hours to remove their own moisture. Calcium carbonate and fly ash were dried at 120°C for 1.5 hours in a high-speed mixer and set aside.

[0079] S2: Fly ash is added to a 7wt% calcium hydroxide suspension in an open reactor. The slurry is stirred thoroughly to ensure uniform mixing. The temperature is then raised to 80°C and maintained for 2.5 hours. The mass ratio of fly ash to calcium hydroxide suspension is 1:10. Based on the principle of fly ash activation, the resulting nanosilicate components, acting as sub-particles, deposit and grow on the fly ash particles, forming a coating. Carbon dioxide is then introduced at a rate of 0.15 L / min to neutralize any residual calcium hydroxide in the slurry. The reaction terminates at a pH of 7. The slurry is filtered and dried to obtain the modified fly ash for later use.

[0080] S3: PETG resin, PBAT resin, calcium carbonate, modified fly ash, coupling agent, lubricant, antioxidant and transesterification inhibitor are weighed in proportion and uniformly mixed to obtain a mixture.

[0081] S4: The mixed material in step S3 is added to a twin-screw extruder through a feed port, and after melting, blending, and extrusion, the PETG / PBAT composition is obtained.

[0082] In step S4, the blending temperature is 100° C., the mixing time is 20 min, and the speed is 350 r / min;

[0083] The twin-screw extruder is provided with 12 temperature setting zones, namely: Zones 1 to 3 are feeding sections for continuous feeding, with temperatures set to 150°C, 160°C, and 170°C respectively; Zones 4 to 5 are melting sections for heating the entire material to form a molten state, with temperatures set to 180°C and 185°C respectively; Zones 6 to 7 are plasticizing sections for plasticizing the material, thereby reducing the hardness of the material, improving the toughness of the material, and increasing the ductility and plasticity of the material, with temperatures set to 190°C and 195°C respectively; Zone 8 is a venting section for discharging excess pores in the melt, with a temperature set to 195°C; Zones 9 to 10 are mixing sections for fully mixing the raw materials, with temperatures set to 195°C and 200°C respectively; Zones 11 to 12 are extrusion sections for extruding the material inside the twin-screw extruder equipment to form a floor base shape, with temperatures set to 195°C and 200°C respectively.

[0084] Example 4:

[0085] This embodiment provides a low-warpage heat-resistant PETG / PBAT composition, the ingredients of which are shown in Table 1. The preparation method thereof comprises the following steps:

[0086] S1: PETG and PBAT resins were dried at 65°C for 11 hours to remove their own moisture. Calcium carbonate and fly ash were dried at 125°C for 1.5 hours in a high-speed mixer and set aside.

[0087] S2: Fly ash is added to a 7wt% calcium hydroxide suspension in an open reactor. The mixture is stirred thoroughly to ensure uniform mixing. The temperature is then raised to 75°C and maintained for 3 hours. The mass ratio of fly ash to calcium hydroxide suspension is 1:10. Based on the principle of fly ash activation, the nanosilicate components generated by the reaction act as sub-particles and deposit and grow on the surface of the fly ash particles, forming a coating. Carbon dioxide is then introduced at a rate of 0.15 L / min to neutralize any residual calcium hydroxide in the slurry. The reaction terminates at a pH of 7. The slurry is filtered and dried to obtain the modified fly ash for later use.

[0088] S3: PETG resin, PBAT resin, calcium carbonate, modified fly ash, coupling agent, lubricant, antioxidant and transesterification inhibitor are weighed in proportion and uniformly mixed to obtain a mixture.

[0089] S4: The mixed material in step S3 is added to a twin-screw extruder through a feed port, and after melting, blending, and extrusion, the PETG / PBAT composition is obtained.

[0090] In step S4, the blending temperature is 90° C., the mixing time is 15 min, and the rotation speed is 320 r / min;

[0091] The twin-screw extruder is provided with 12 temperature setting zones, namely: Zones 1 to 3 are feeding sections for continuous feeding, with temperatures set to 150°C, 160°C, and 170°C respectively; Zones 4 to 5 are melting sections for heating the entire material to form a molten state, with temperatures set to 180°C and 185°C respectively; Zones 6 to 7 are plasticizing sections for plasticizing the material, thereby reducing the hardness of the material, improving the toughness of the material, and increasing the ductility and plasticity of the material, with temperatures set to 190°C and 195°C respectively; Zone 8 is a venting section for discharging excess pores in the melt, with a temperature set to 195°C; Zones 9 to 10 are mixing sections for fully mixing the raw materials, with temperatures set to 195°C and 200°C respectively; Zones 11 to 12 are extrusion sections for extruding the material inside the twin-screw extruder equipment to form a floor base shape, with temperatures set to 195°C and 200°C respectively.

[0092] Example 5:

[0093] This embodiment provides a low-warpage heat-resistant PETG / PBAT composition, the ingredients of which are shown in Table 1. The preparation method thereof comprises the following steps:

[0094] S1: PETG and PBAT resins were dried at 75°C for 10.5 h to remove their own moisture. Calcium carbonate and fly ash were dried at 85°C for 2 h in a high-speed mixer and set aside.

[0095] S2: Fly ash is added to a 7wt% calcium hydroxide suspension in an open reactor. The mixture is stirred thoroughly to ensure uniform mixing. The temperature is then raised to 70°C and maintained for 2.5 hours. The mass ratio of fly ash to calcium hydroxide suspension is 1:10. Based on the principle of fly ash activation, the resulting nanosilicate components, acting as sub-particles, deposit and grow on the fly ash particles, forming a coating. Carbon dioxide is then introduced at a rate of 0.15 L / min to neutralize any residual calcium hydroxide in the slurry. The reaction terminates at a pH of 7. The slurry is filtered and dried to obtain the modified fly ash for later use.

[0096] S3: PETG resin, PBAT resin, calcium carbonate, modified fly ash, coupling agent, lubricant, antioxidant and transesterification inhibitor are weighed in proportion and uniformly mixed to obtain a mixture.

[0097] S4: The mixed material in step S3 is added to a twin-screw extruder through a feed port, and after melting, blending, and extrusion, the PETG / PBAT composition is obtained.

[0098] In step S4, the blending temperature is 95° C., the mixing time is 20 min, and the speed is 350 r / min;

[0099] The twin-screw extruder is provided with 12 temperature setting zones, namely: Zones 1 to 3 are feeding sections for continuous feeding, with temperatures set to 150°C, 160°C, and 170°C respectively; Zones 4 to 5 are melting sections for heating the entire material to form a molten state, with temperatures set to 180°C and 185°C respectively; Zones 6 to 7 are plasticizing sections for plasticizing the material, thereby reducing the hardness of the material, improving the toughness of the material, and increasing the ductility and plasticity of the material, with temperatures set to 190°C and 195°C respectively; Zone 8 is a venting section for discharging excess pores in the melt, with a temperature set to 195°C; Zones 9 to 10 are mixing sections for fully mixing the raw materials, with temperatures set to 195°C and 200°C respectively; Zones 11 to 12 are extrusion sections for extruding the material inside the twin-screw extruder equipment to form a floor base shape, with temperatures set to 195°C and 200°C respectively.

[0100] Example 6:

[0101] This embodiment provides a low-warpage heat-resistant PETG / PBAT composition, the ingredients of which are shown in Table 1. The preparation method thereof comprises the following steps:

[0102] S1: PETG and PBAT resins were dried at 75°C for 10 hours to remove their own moisture. Calcium carbonate and fly ash were dried at 120°C for 1.5 hours in a high-speed mixer and set aside.

[0103] S2: Fly ash is added to a 7wt% calcium hydroxide suspension in an open reactor. The mixture is stirred thoroughly to ensure uniform mixing. The temperature is then raised to 80°C and maintained for 2 hours. The mass ratio of fly ash to calcium hydroxide suspension is 1:10. Based on the principle of fly ash activation, the nanosilicate components generated by the reaction act as sub-particles and deposit and grow on the surface of the fly ash particles, forming a coating. Carbon dioxide is then introduced at a rate of 0.15 L / min to neutralize any residual calcium hydroxide in the slurry. The reaction terminates at a pH of 7. The slurry is filtered and dried to obtain the modified fly ash for later use.

[0104] S3: PETG resin, PBAT resin, calcium carbonate, modified fly ash, coupling agent, lubricant, antioxidant and transesterification inhibitor are weighed in proportion and uniformly mixed to obtain a mixture.

[0105] S4: The mixed material in step S3 is added to a twin-screw extruder through a feed port, and after melting, blending, and extrusion, the PETG / PBAT composition is obtained.

[0106] In step S3, the blending temperature is 110° C., the mixing time is 20 min, and the speed is 300 r / min;

[0107] The twin-screw extruder is provided with 12 temperature setting zones, namely: Zones 1 to 3 are feeding sections for continuous feeding, with temperatures set to 150°C, 160°C, and 170°C respectively; Zones 4 to 5 are melting sections for heating the entire material to form a molten state, with temperatures set to 180°C and 185°C respectively; Zones 6 to 7 are plasticizing sections for plasticizing the material, thereby reducing the hardness of the material, improving the toughness of the material, and increasing the ductility and plasticity of the material, with temperatures set to 190°C and 195°C respectively; Zone 8 is a venting section for discharging excess pores in the melt, with a temperature set to 195°C; Zones 9 to 10 are mixing sections for fully mixing the raw materials, with temperatures set to 195°C and 200°C respectively; Zones 11 to 12 are extrusion sections for extruding the material inside the twin-screw extruder equipment to form a floor base shape, with temperatures set to 195°C and 200°C respectively.

[0108] Example 7:

[0109] This embodiment provides a low-warpage heat-resistant PETG / PBAT composition, the ingredients of which are shown in Table 1. The preparation method thereof comprises the following steps:

[0110] S1: PETG and PBAT resins were dried at 75°C for 10 h to remove their own moisture. Calcium carbonate and fly ash were dried at 120°C for 2 h in a high-speed mixer and set aside.

[0111] S2: Fly ash is added to a 7wt% calcium hydroxide suspension in an open reactor. The mixture is stirred thoroughly to ensure uniform mixing. The temperature is then raised to 90°C and maintained for 2 hours. The mass ratio of fly ash to calcium hydroxide suspension is 1:10. Based on the principle of fly ash activation, the nanosilicate components generated by the reaction act as sub-particles and deposit and grow on the surface of the fly ash particles, forming a coating. Carbon dioxide is then introduced at a rate of 0.15 L / min to neutralize any residual calcium hydroxide in the slurry. The reaction terminates at a pH of 7. The slurry is filtered and dried to obtain the modified fly ash for later use.

[0112] S3: PETG resin, PBAT resin, calcium carbonate, modified fly ash, coupling agent, lubricant, antioxidant and transesterification inhibitor are weighed in proportion and uniformly mixed to obtain a mixture.

[0113] S4: The mixed material in step S3 is added to a twin-screw extruder through a feed port, and after melting, blending, and extrusion, the PETG / PBAT composition is obtained.

[0114] In step S3, the blending temperature is 100° C., the mixing time is 20 min, and the rotation speed is 350 r / min;

[0115] The twin-screw extruder is provided with 12 temperature setting zones, namely: Zones 1 to 3 are feeding sections for continuous feeding, with temperatures set to 150°C, 160°C, and 170°C respectively; Zones 4 to 5 are melting sections for heating the entire material to form a molten state, with temperatures set to 180°C and 185°C respectively; Zones 6 to 7 are plasticizing sections for plasticizing the material, thereby reducing the hardness of the material, improving the toughness of the material, and increasing the ductility and plasticity of the material, with temperatures set to 190°C and 195°C respectively; Zone 8 is a venting section for discharging excess pores in the melt, with a temperature set to 195°C; Zones 9 to 10 are mixing sections for fully mixing the raw materials, with temperatures set to 195°C and 200°C respectively; Zones 11 to 12 are extrusion sections for extruding the material inside the twin-screw extruder equipment to form a floor base shape, with temperatures set to 195°C and 200°C respectively.

[0116] The amounts of components used in the above examples are shown in Table 1.

[0117] Table 1: Amount of each component in Examples 1 to 7 (parts by weight)

[0118] .

[0119] Comparative Example 1:

[0120] A PETG / PBAT composition, the ingredients of which are shown in Table 2, and the preparation method thereof is the same as that in Example 1.

[0121] Comparative Example 2:

[0122] A PETG / PBAT composition, the ingredients of which are shown in Table 2. The preparation method thereof does not include the preparation of modified fly ash, and the rest is the same as in Example 1.

[0123] Comparative Example 3:

[0124] A PETG / PBAT composition, the ingredients of which are shown in Table 2, and the preparation method thereof is the same as that in Example 1.

[0125] Comparative Example 4:

[0126] A PETG / PBAT composition, the ingredients of which are shown in Table 2, and the preparation method thereof is the same as that in Example 1.

[0127] Comparative Example 5:

[0128] A PETG / PBAT composition, the ingredients of which are shown in Table 2, and the preparation method thereof is the same as that in Example 1.

[0129] Table 2: Amount of each component in Comparative Examples 1 to 5 (parts by weight)

[0130] .

[0131] The PETG / PBAT compositions prepared in the above examples and comparative examples were subjected to the following performance tests, and the test standards and methods were as follows:

[0132] Melt flow rate: According to the GB / T 3682-2018 standard, the PETG / PBAT composite particles were tested using a melt flow tester that complies with the standard. The test temperature was 190°C, the pressure load was 2.16 kg, and the cut-off time was 30 s.

[0133] Flexural strength and flexural modulus: According to the GB / T 3341-2008 standard test, 80 mm × 10 mm × 4 mm test specimens of the PETG / PBAT composition were prepared and placed in a testing machine that complies with the GB / T 17200-1997 standard for flexural strength and flexural modulus testing.

[0134] Tensile strength and elongation at break: According to the GB / T 1040-2018 standard, the PETG / PBAT composition was prepared into type 1A dumbbell test specimens in the standard and tested using a testing machine that complies with the requirements of GB / T 16825.1-2008 and GB / T 12160-2002.

[0135] Izod notched impact: According to the GB / T 1843-2008 standard test, the PETG / PBAT composition was prepared into 80 mm × 10 mm × 4 mm test specimens with a notch depth of 2 mm. The Izod notched impact strength test was performed using a testing machine that complies with the GB / T 21189-2007 standard.

[0136] Heat Deformation Temperature: According to GB / T 1634.2-2019, 80 mm × 10 mm × 4 mm test specimens of the PETG / PBAT composition were prepared and the heat deformation temperature test was performed using a heating device and weights that meet the standard.

[0137] Warpage: Tested according to ISO 24342. Prepare a 250 mm x 250 mm square test sample of the PETG / PBAT composition, place it on a flat table, and use a feeler gauge to test each of the four corners of the sample. The maximum value among the four corners is used as the test result.

[0138] Shrinkage: Tested according to ISO 24342. A 250 mm × 250 mm square test specimen of the PETG / PBAT composition was prepared. The length and width of the specimen were measured (all four sides were measured and recorded; length was recorded as L10 and L20, and width was recorded as W10 and W20). The specimen was placed in an 80°C oven for 6 hours and then removed from the oven and allowed to rest in the laboratory for 3 hours. The length and width of the specimen were then measured (length was recorded as L11 and L21, and width was recorded as W11 and W21). The length was calculated as [(L11 + L21) / 2 - (L10 + L20) / 2] / [(L10 + L20) / 2]; the width was calculated as [(W11 + W21) / 2 - (W10 + W20) / 2] / [(W10 + W20) / 2]. The maximum value was used.

[0139] Thermal Expansion Coefficient: According to GB / T36800.2-2018 standard test, PETG / PBAT composite rectangular test samples with a length of 5-10 mm and a width of 5 mm were prepared. The thermal expansion coefficient test was performed using the instrument calibrated according to the requirements of ISO 11359-1.

[0140] The PETG / PBAT compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 5 were tested. The test results are shown in Tables 3 and 4.

[0141] Table 3: Performance test results of PETG / PBAT compositions prepared in Examples 1 to 7

[0142] .

[0143] Table 4: Performance test results of PETG / PBAT compositions prepared in Comparative Examples 1 to 5

[0144] .

[0145] According to the comparison of the above test data:

[0146] According to the test results of Examples 1 to 3 and Comparative Example 1, blending PBAT with PBAT can effectively increase the toughness of the material and improve the impact strength of the material, but too high a PBAT ratio will lead to a decrease in flexural strength, flexural modulus and tensile strength.

[0147] From the test results of Examples 4-5 and Comparative Example 2, it can be seen that the addition of fly ash forms a more stable chemical bond with the resin molecular chain, effectively increasing the heat deformation temperature of the material.

[0148] From the test results of Comparative Example 3, it can be seen that the absence of a coupling agent will cause the powder to agglomerate, and at the same time, the interfacial bonding force between the powder and the resin will be reduced, causing the physical properties of the material to deteriorate; from the test results of Example 6 and Comparative Example 4, the absence of a compatibilizer or too little compatibilizer will cause phase separation in the composite system, resulting in a decrease in the physical properties of the material and easy cracking.

[0149] From the test results of Example 7 and Comparative Example 5, it can be seen that the absence of an ester exchange inhibitor or a small amount of an ester exchange inhibitor will cause PETG and PBAT to undergo ester exchange, resulting in deterioration of material properties.

[0150] In summary, the present invention proposes a low-warpage heat-resistant PETG / PBAT composition, a preparation method thereof, and an application thereof. The preparation process is simple and the production cost is low. The PETG / PBAT composition has good warpage shrinkage, heat resistance, and rigidity-toughness balance, and can be used in many fields such as wall panels, indoor floors, outdoor floors, and home countertops.

[0151] While various embodiments of the present invention have been described above, the foregoing description is intended to be illustrative and non-exhaustive, and is not intended to be limiting of the disclosed embodiments. Numerous modifications and variations will be apparent to those skilled in the art without departing from the scope and technical principles of the described embodiments, and such modifications and variations should be considered within the scope of the present invention.

Claims

1. A low-warpage heat-resistant PETG / PBAT composition, characterized in that: The raw materials of the composition include resin, filler and reaction aid, and the resin, filler and reaction aid include the following components in parts by weight: 50~80 parts of PETG resin; 10~40 parts of PBAT resin; 30 to 80 parts of calcium carbonate; 10-30 parts of modified fly ash; 0.5 to 3 parts of coupling agent; 1 to 5 parts of compatibilizer; 0.5 to 3 parts of transesterification inhibitor; The modified fly ash is prepared by the following method: Place fly ash and calcium hydroxide solution in an open reactor, stir thoroughly to evenly mix the slurry, heat to 60°C to 95°C, and keep warm for 2 to 3 hours; the mass ratio of fly ash to calcium hydroxide solution is 1:10, and the concentration of calcium hydroxide solution is 7wt%; The reaction was terminated by introducing carbon dioxide gas until the pH value was 7, and the reaction slurry was filtered and dried to obtain the modified fly ash.

2. The low-warpage heat-resistant PETG / PBAT composition according to claim 1, characterized in that The PETG resin has a melt index of 2 g / 10 min to 5 g / 10 min under the test conditions of 250° C. and 2.16 kg; and the content of 1,4-cyclohexanedimethanol in the PETG resin is 20 wt % to 45 wt %.

3. The low-warpage heat-resistant PETG / PBAT composition according to claim 1, characterized in that The PBAT resin has a melt index of 4 g / 10 min to 6 g / 10 min under the test conditions of 190° C. and 2.16 kg.

4. The low-warpage heat-resistant PETG / PBAT composition according to claim 1, characterized in that The particle size of the calcium carbonate is 200-1500 meshes.

5. The low-warpage heat-resistant PETG / PBAT composition according to claim 1, characterized in that The coupling agent is at least one of a titanate coupling agent and an aluminate coupling agent.

6. The low-warpage heat-resistant PETG / PBAT composition according to claim 1, characterized in that The compatibilizer is at least one of PE-g-MAH, PP-g-MAH, ethylene-acrylate glycidyl methacrylate, SEBS-g-MAH, and POE-g-GMA.

7. The low-warpage heat-resistant PETG / PBAT composition according to claim 1, characterized in that: The transesterification inhibitor is at least one of triphenyl phosphite, sodium dihydrogen phosphate or disodium dihydrogen pyrophosphate.

8. The low-warpage heat-resistant PETG / PBAT composition according to claim 1, characterized in that: The raw materials of the composition further include 0.1 to 2 parts of antioxidant and / or 0.1 to 2 parts of lubricant.

9. A method for preparing the low-warpage heat-resistant PETG / PBAT composition according to any one of claims 1 to 8, characterized in that: include: Drying PETG resin, PBAT resin, calcium carbonate and fly ash; The dried fly ash is surface-coated and modified by chemical excitation to obtain modified fly ash; The dried PETG resin, PBAT resin, calcium carbonate and modified fly ash are mixed with a reaction aid in proportion to obtain a mixture; The above mixture is melted, blended and extruded to prepare a PETG / PBAT composition.

10. The method for preparing the low-warpage heat-resistant PETG / PBAT composition according to claim 9, characterized in that: The PETG resin and PBAT resin are dried at a temperature of 60° C. to 80° C. for 6 h to 12 h; And / or, the calcium carbonate and fly ash are dried at 80° C. to 130° C. for 1 h to 2 h in a high-speed mixer.

11. The method for preparing the low-warpage heat-resistant PETG / PBAT composition according to claim 9, wherein: During the preparation of modified fly ash, the rate of introducing carbon dioxide gas was 0.15 L / min.

12. The method for preparing the low-warpage heat-resistant PETG / PBAT composition according to claim 9, wherein: The mixed material is melted, blended and extruded through a twin-screw extruder; The blending temperature is 80°C to 120°C, the mixing time is 10 min to 30 min, and the rotation speed is 300 r / min to 400 r / min; The twin-screw extruder is equipped with 12 temperature setting zones, namely: Zones 1 to 3 are feeding sections for continuous feeding, with a temperature set at 150°C to 190°C; Zones 4 to 5 are melting sections for heating the entire material to form a molten state, with a temperature set at 180°C to 190°C; Zones 6 to 7 are plasticizing sections for plasticizing the material, with a temperature set at 190°C to 205°C; Zone 8 is a venting section for exhausting excess air holes in the melt, with a temperature set at 190°C to 205°C; Zones 9 to 10 are mixing sections for fully mixing the raw materials, with a temperature set at 190°C to 205°C; Zones 11 to 12 are extrusion sections for extruding the material inside the twin-screw extruder, with a temperature set at 190°C to 200°C.

13. Use of the low-warpage heat-resistant PETG / PBAT composition according to any one of claims 1 to 8 in wall panels, indoor floors, outdoor floors, and home countertops.