High-temperature-resistant PCTG blending material and preparation method thereof

Abstract

The invention belongs to the technical field of polymer materials, and particularly relates to a high-temperature-resistant PCTG blending material and a preparation method thereof.The method comprises the following steps that PTA, EG, CHDM and a catalyst are placed in a reaction kettle, the reaction kettle is filled with shielding gas and then heated for an esterification reaction, when the water yield reaches the standard, pressure is relieved, the temperature is increased, a titanium catalyst is added for a pre-polycondensation reaction, and the high-temperature-resistant PCTG blending material is obtained; after the pre-polycondensation reaction is finished, heating and controlling kettle pressure to enter a final polycondensation reaction, and after the reaction is finished, discharging and pelletizing to obtain PCTG slices; the preparation method comprises the following steps: respectively drying PCTG slices and HDPE particles, adding the dried PCTG slices and HDPE particles into a mixing tank, adding an ethylene acrylic copolymer, a compatilizer and an antioxidant into the mixing tank, mixing, feeding into a twin-screw extruder for extrusion, and then carrying out water-cooling granulation and drying. The HDPE is added into the PCTG material for blending modification, and the ethylene acrylic copolymer is used as the compatilizer, so that the PCTG material and the HDPE material can be combined to form a cross-linked network structure, and the heat resistance and wear resistance of the PCTG material are improved under the condition that the mechanical property of the PCTG material is not lost.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to a high-temperature resistant PCTG blend material and a preparation method thereof. Background Art

[0002] PCTG (polyethylene terephthalate-1,4-cyclohexanedimethanol ester) is an amorphous copolyester. Due to its excellent transparency, toughness, chemical resistance and processing performance, it is widely used in fields such as food packaging, medical devices, cosmetic containers, and transparent daily necessities. Compared with traditional PET, PCTG significantly reduces the crystallinity by introducing cyclohexanedimethanol (CHDM) monomers, thereby improving transparency and impact resistance. However, the PCTG material itself lacks heat resistance, and its heat distortion temperature is only 80-90 °C (under a load of 0.45 MPa), which severely limits its application scenarios.

[0003] In the prior art, for example, Chinese Patent CN117586487A provides a high-temperature resistant and weather-resistant PCTG material and a preparation method thereof. By adding nano-scale temperature-resistant metal elements during the preparation process, it endows the PCTG material with intentional temperature-resistant and weather-resistant properties without reducing its performance, enabling it to have a longer service life in harsh environments such as outdoors. However, the use of nano-metals will increase production costs and reduce the transparency of the material.

[0004] Another example is Chinese Patent CN119286206A in the prior art, which provides a high-impact transparent and chemical-resistant PC / PCTG alloy and a preparation method thereof. By blending PC material with PCTG material and adding a toughening agent, an antioxidant, a lubricant and an ester exchange inhibitor, an alloy material with high transparency, high impact resistance, heat resistance and chemical resistance can be obtained. However, the heat resistance of the above alloy is limited, the heat distortion temperature is lower than 110 °C, and the wear resistance of the alloy material is insufficient.

[0005] Therefore, it is particularly important to provide a PCTG material with excellent heat resistance and wear resistance and low preparation cost. Summary of the Invention

[0006] Aiming at the problems mentioned in the background art, the present invention provides a high-temperature resistant PCTG blend material and a preparation method thereof. By adding HDPE to the PCTG material for blending modification and using ethylene-acrylic copolymer as a compatibilizer, the PCTG material and the HDPE material can be combined to form an interconnected network structure, improving the heat resistance and wear resistance of PCTG without losing its mechanical properties.

[0007] The present invention provides a preparation method of a high-temperature resistant PCTG blend material, and the method includes the following steps:

[0008] S1. Prepare raw materials according to the molar ratio of (EG + CHDM) to PTA being 1.5 - 1.7:1 and the molar ratio of EG to CHDM being 1:3 - 9, then pump them into esterification kettle 1. Then add a mixed catalyst thereto, raise the temperature and pressure for reaction. After reacting for 1 - 5 h, continuously pump the reactants into esterification kettle 2 for continuous reaction;

[0009] S2. When the water output in S1 reaches 90% of the theoretical water output, continuously pump the esterification product into pre - polycondensation kettle 1 and add a titanium - based catalyst thereto. After reacting for 20 - 25 min, pump the reactants into pre - polycondensation kettle 2 for continuous reaction;

[0010] S3. After the pre - polycondensation reaction ends, pump the pre - polycondensation product into the final - polycondensation kettle for final - polycondensation reaction. After the reaction ends, discharge and pelletize to obtain PCTG chips;

[0011] S4. Transport the PCTG chips to a dryer for drying. After drying is completed, transport them to a mixing tank, add HDPE, ethylene - acrylic acid copolymer and antioxidant. After mixing is completed, put them into a twin - screw extruder for melt blending;

[0012] S5. After melt blending for a period of time, add a compatibilizer to the extruder for continued melt blending, then cool and pelletize, and dry to obtain the PCTG blend material.

[0013] Furthermore, in step S1, esterification kettle 1 and esterification kettle 2 are filled with nitrogen for protection. The kettle pressure of esterification kettle 1 is 0.21 - 0.23 MPa, and the reaction temperatures of esterification kettle 1 and esterification kettle 2 are 225 - 240 °C; the mixed catalyst is antimony glycolate and germanium dioxide, the molar ratio of antimony glycolate to germanium dioxide is 1 - 2:1, and the addition concentration of the mixed catalyst is 100 - 150 ppm.

[0014] Furthermore, in step S2, the reaction temperatures of pre - polycondensation kettle 1 and pre - polycondensation kettle 2 are 255 - 263 °C, and the total reaction time is 40 - 45 min; the addition concentration of the titanium - based catalyst is 100 - 300 ppm.

[0015] Furthermore, in step S3, the reaction temperature of the final - polycondensation kettle is 275 - 278 °C, and the vacuum degree is 50 - 100 Pa.

[0016] Furthermore, the specific steps of steps S4 and S5 are as follows: Dry the PCTG at 85 °C for 2 h and dry the HDPE at 100 °C for 1 h. Then put the PCTG and HDPE into a mixing tank, add ethylene - acrylic acid copolymer and antioxidant, mix and stir, and then put them into the extruder for melt blending for 10 - 15 min; then add a compatibilizer to the extruder and continue melt blending in the extruder for 5 - 10 min, then cool and pelletize, and dry.

[0017] Further, in the steps S4 and S5, the extrusion temperature of the extruder is 232-248 °C, and the rotation speed of the extruder is 200-300 r / min.

[0018] The present invention also provides a high-temperature resistant PCTG blend material, which comprises the following components in parts by weight: 100-130 parts of PCTG resin, 50-80 parts of HDPE, 4-9 parts of ethylene acrylic copolymer, 0.1-0.5 part of antioxidant, and 0.5-2 parts of compatibilizer.

[0019] Further, the glass transition temperature of the PCTG resin is 86-91 °C, the cold crystallization temperature is 126-130 °C, the melting point is 222-225 °C, and the melting crystallization temperature is 253-257 °C.

[0020] Further, the ethylene acrylic copolymer includes any one or a combination of several of ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-acrylic acid ionomer, and ethylene-methyl acrylic acid ionomer.

[0021] Further, the antioxidant includes at least one of antioxidant 1010, antioxidant 1098, antioxidant 168, antioxidant 697, and antioxidant 608; the compatibilizer is an acid anhydride-modified high-density polyethylene.

[0022] The beneficial effects of the present invention are as follows:

[0023] 1. In the present invention, HDPE is introduced into the PCTG resin. Blending HDPE with PCTG can significantly improve the high-temperature resistance and rigid strength of PCTG. At the same time, the high toughness and impact resistance of the PCTG resin can improve the low-temperature brittleness of HDPE and improve the overall impact resistance of the blend material. Compared with PCTG, HDPE has better high-temperature resistance. The high-temperature deformation temperature of the HDPE selected in the present invention is above 125-135 °C, and the heat distortion temperature of the blended material can reach up to 125 °C at most, which can meet the use in an environment above 110 °C, greatly broadening the use scenarios of the PCTG material. At the same time, the HDPE material has better wear resistance, which can enhance the wear resistance of the PCTG material.

[0024] 2. In the present invention, the PCTG resin is a polar material, while HDPE is a non-polar material. Therefore, conventional blending of the two will lead to phase separation and affect the performance of the blended material. Currently, the general solution is to use compatibilizers such as maleic anhydride grafted polymers and epoxy group grafted polymers for melt blending together. The inventors of the present invention tried the conventional method but could not solve the problem of incompatibility between PCTG and HDPE during blending. Therefore, creatively, an ethylene-acrylic copolymer was selected as the compatibilizer during blending. The carboxylic acid groups in the copolymer form hydrogen bonds or ion-dipole interactions with the polar groups of PCTG, and at the same time, the ethylene end is compatible with HDPE, which can greatly improve the compatibility of the two materials. At the same time, the inventors of the present invention found that after melt blending the ethylene-acrylic copolymer with PCTG and HDPE, adding a small amount of acid anhydride-modified high-density polyethylene compatibilizing masterbatch as an adhesive can further tightly bond the two materials, improve the structural stability of the material, and endow the blended material with better strength performance and wear resistance.

[0025] 3. In the present invention, the basic properties of the PCTG sheet are defined. During the preparation, by controlling the alcohol-acid ratio and the addition amount of CHDM, the melting point and crystallization temperature of the PCTG sheet are increased compared with the PCTG sheet in the prior art, making the crystal grain structure of the PCTG sheet more complete, and thus improving the thermal performance of the prepared PCTG sheet. During the process of preparing the PCTG blended material, by setting a higher blending temperature, under the action of the ethylene-acrylic copolymer and the acid anhydride-modified high-density polyethylene compatibilizing masterbatch, it can promote the melting and connection between PCTG and HDPE, improve the effect of interfacial adhesion, and reduce phase separation. At the same time, the higher blending temperature during the preparation can increase the crystallinity of the material, especially HDPE, and thus increase the heat distortion temperature of the material and optimize the heat resistance performance of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flowchart of a preparation method of a high-temperature resistant PCTG blended material according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The specific embodiments of the present invention will be described in detail below with reference to the specific drawings. It should be noted that the technical features described in the following embodiments or the combination of technical features should not be considered in isolation, and they can be combined with each other to achieve better technical effects.

[0028] PTA, polymerization grade, Yizheng Chemical Fiber; EG, polymerization grade, Yangzi Petrochemical; CHDM, purity > 99%, SK of South Korea; ethylene glycol antimony, industrial grade, Yihua Dakang Company; high-purity germanium dioxide, Yunnan Lincang Xinyuan Germanium Industry Co., Ltd.; titanium-based catalyst, industrial grade, Shanghai Research Institute of Petrochemical Technology.

[0029] Example 1

[0030] This embodiment provides a high-temperature resistant PCTG blend material, which comprises the following components in parts by weight: 120 parts of PCTG resin, 60 parts of HDPE, 4.5 parts of ethylene acrylic copolymer, 0.45 part of antioxidant, and 0.9 part of compatibilizer. In this embodiment, the ethylene acrylic copolymer is DuPont Surlyn Ionomer, with the brand number 9320W. The antioxidant is pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], purchased from BASF, and the product model is IRGANOX 1010. The compatibilizer is DuPont Fusabond E100 compatibilizing masterbatch.

[0031] As shown in the appendix Figure 1 This embodiment provides a preparation method of a high-temperature resistant PCTG blend material, which comprises the following steps:

[0032] S1. Prepare raw materials according to the molar ratio of (EG + CHDM) to PTA being 1.6:1 and the molar ratio of EG:CHDM being 1:9, and then pump them into esterification kettle 1. At the same time, weigh ethylene glycol antimonate and germanium dioxide as catalysts, with the total concentration of ethylene glycol antimonate and germanium dioxide being 100 ppm and the added molar ratio of ethylene glycol antimonate to germanium dioxide being 1:1. Place the above raw materials in esterification kettle 1, flush nitrogen into esterification kettle 1 three times to displace the gas in the kettle, and finally flush nitrogen as the protective gas and keep the air pressure in esterification kettle 1 at 210 kPa. Set the reaction kettle temperature to 235 °C for the esterification reaction. After reacting for 1 h, continuously pump the reactants into esterification kettle 2 for continuous reaction. The reaction temperature of esterification kettle 2 is 235 °C and the pressure is normal pressure.

[0033] S2. When the water output in S1 reaches 90% of the theoretical water output, continuously pump the esterification product into prepolymerization kettle 1 and add a titanium-based catalyst such as tetrabutyl titanate to it, with the added concentration of tetrabutyl titanate being 200 ppm. Set the reaction temperatures of prepolymerization kettle 1 and prepolymerization kettle 2 to 255 °C. After reacting for 40 min, pump the reaction product into prepolymerization kettle 2 for continuous reaction for 40 min.

[0034] S3. After the prepolymerization reaction is completed, pump the prepolymerization product into the final polymerization kettle for the final polymerization reaction. Set the reaction temperature of the final polymerization kettle to 275 °C and the kettle pressure to 100 Pa. After reacting for 70 min, discharge the material and pelletize it to obtain PCTG chips. Perform performance testing on the obtained PCTG chips. The intrinsic viscosity of the PCTG chips is 0.57 dL / g, the glass transition temperature of the PCTG chips is 88.5 °C, the cold crystallization temperature is 129 °C, the melting point is 222 °C, and the melting crystallization temperature is 253 °C.

[0035] S4. Convey 120 parts by weight of PCTG slices to a dryer and dry them at 85 °C for 2 h. After drying, convey them to a mixing tank, add 60 parts by weight of HDPE, 4.5 parts by weight of ethylene acrylic copolymer, and 0.45 part by weight of antioxidant. After mixing, put them into a twin-screw extruder for melt blending. Among them, HDPE needs to be dried at 100 °C for 1 h.

[0036] S5. After melt blending for 10 min, add 0.9 part by weight of compatibilizer to the extruder and continue melt blending for 10 min. Then, cool it with water and pelletize, and dry to obtain the PCTG blend material. In steps S4 and S5, the screw temperature is 232 - 248 °C, and the temperature of each zone of the screw is: 232, 237, 237, 242, 248, 248, 248, 248, 248 °C, and the screw speed is 250 r / min.

[0037] Example 2

[0038] The difference between this example and Example 1 lies in the different component weight parts of the PCTG material and the different extrusion preparation methods. Specifically, it includes the following component weight parts: 100 parts by weight of PCTG resin, 80 parts by weight of HDPE, 9 parts by weight of ethylene acrylic copolymer, 0.9 part by weight of antioxidant, and 1.8 parts by weight of compatibilizer. In this example, the ethylene acrylic copolymer is DuPont Surlyn Ionomer, with the grade of 9320W. The antioxidant is pentaerythritol tetrakis [β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate]. The compatibilizer is DuPont Fusabond E100 compatibilizing masterbatch.

[0039] Example 3

[0040] The difference between this example and Example 1 lies in the different PCTG preparation methods and component ratios. Specifically, it includes the following steps:

[0041] S1. Prepare raw materials according to the molar ratio of (EG + CHDM) to PTA of 1.6:1 and the molar ratio of EG:CHDM of 1:5.6, and then pump them into esterification kettle 1. At the same time, weigh ethylene glycol antimony and germanium dioxide as catalysts, and the total concentration of ethylene glycol antimony and germanium dioxide is 100 ppm, and the added molar ratio of ethylene glycol antimony and germanium dioxide is 1:1. Place the above raw materials in esterification kettle 1, flush nitrogen into esterification kettle 1 three times to displace the gas in esterification kettle 1, and finally flush nitrogen as the protective gas and keep the air pressure in esterification kettle 1 at 230 kPa. Set the reaction kettle temperature to 240 °C for esterification reaction. After reacting for 1 h, continuously pump the reactants into esterification kettle 2 for further reaction. The reaction temperature of esterification kettle 2 is 235 °C and the pressure is normal pressure.

[0042] S2. When the water output of S1 reaches 90% of the theoretical water output, continuously pump the esterification product into the prepolymerization kettle 1 and add a titanium-based catalyst such as tetrabutyl titanate thereto. The addition concentration of tetrabutyl titanate is 200 ppm. Set the reaction temperatures of the prepolymerization kettle 1 and the prepolymerization kettle 2 to 260 °C. After reacting for 40 min, pump the reaction product into the prepolymerization kettle 2 and continue to react for 40 min.

[0043] S3. After the prepolymerization reaction is completed, pump the prepolymerization product into the final polymerization kettle for the final polymerization reaction. Set the reaction temperature of the final polymerization kettle to 278 °C and the kettle pressure to 100 Pa. After reacting for 60 min, discharge and pelletize to obtain PCTG chips. Perform performance testing on the obtained PCTG chips. The intrinsic viscosity of the PCTG chips is 0.58 dL / g, the glass transition temperature of the PCTG chips is 90 °C, the cold crystallization temperature is 129 °C, the melting point is 224 °C, and the melting crystallization temperature is 254 °C.

[0044] S4. Transport 120 parts of PCTG chips to a dryer and dry them at 85 °C for 2 h. After drying is completed, transport them to a mixing tank, add 60 parts of HDPE, 4.5 parts of ethylene acrylic acid copolymer, and 0.45 part of antioxidant. After mixing is completed, put them into a twin-screw extruder for melt blending. Among them, HDPE needs to be dried at 100 °C for 1 h.

[0045] S5. After melt blending for 10 min, add 0.9 part of compatibilizer to the extruder and continue melt blending for 10 min, and then water-cool and pelletize to obtain the PCTG blend material. In steps S4 and S5, the screw temperature is 232 - 248 °C, and the temperature of each zone of the screw is: 232, 237, 237, 242, 248, 248, 248, 248, 248 °C, and the screw speed is 250 r / min.

[0046] Example 4

[0047] The difference between this example and Example 1 lies in the PCTG preparation method and component ratio. Specifically, it includes the following steps: S1. Prepare raw materials according to the molar ratio of (EG + CHDM) to PTA being 1.6:1 and the molar ratio of EG:CHDM being 1:3, and then pump them into the esterification kettle 1. At the same time, weigh ethylene glycol antimonate and germanium dioxide as catalysts. The total concentration of ethylene glycol antimonate and germanium dioxide is 100 ppm, and the addition molar ratio of ethylene glycol antimonate and germanium dioxide is 1:1. Place the above raw materials in the esterification kettle 1, flush nitrogen into the esterification kettle 1 three times to displace the gas in the esterification kettle 1, and finally flush nitrogen as a protective gas and keep the air pressure in the esterification kettle 1 at 210 kPa. Set the reaction kettle temperature to 235 °C for the esterification reaction. After reacting for 1.5 h, continuously pump the reactants into the esterification kettle 2 and continue to react. The reaction temperature of the esterification kettle 2 is 235 °C and the pressure is normal pressure.

[0048] S2. When the water output of S1 reaches 90% of the theoretical water output, continuously pump the esterification product into the prepolymerization kettle 1 and add a titanium-based catalyst such as tetrabutyl titanate to it. The addition concentration of tetrabutyl titanate is 200 ppm. Set the reaction temperatures of the prepolymerization kettle 1 and the prepolymerization kettle 2 to 260 °C. After reacting for 45 min, pump the reaction product into the prepolymerization kettle 2 and continue to react for 40 min.

[0049] S3. After the prepolymerization reaction is completed, pump the prepolymerization product into the final polymerization kettle for the final polymerization reaction. Set the reaction temperature of the final polymerization kettle to 275 °C and the kettle pressure to 100 Pa. After reacting for 60 min, discharge and pelletize to obtain PCTG chips. Perform performance testing on the obtained PCTG chips. The intrinsic viscosity of the PCTG chips is 0.51 dL / g, the glass transition temperature of the PCTG chips is 86 °C, the cold crystallization temperature is 126 °C, the melting point is 224 °C, and the melting crystallization temperature is 257 °C.

[0050] S4. Transport 120 parts of PCTG chips to a dryer and dry them at 85 °C for 2 h. After drying is completed, transport them to a mixing tank, add 60 parts of HDPE, 4.5 parts of ethylene acrylic copolymer, and 0.45 parts of antioxidant. After mixing is completed, put them into a twin-screw extruder for melt blending. Among them, HDPE needs to be dried at 100 °C for 1 h.

[0051] S5. After melt blending for 10 min, add 0.9 part of compatibilizer to the extruder and continue melt blending for 10 min, and then water-cool and pelletize to obtain the PCTG blend material. In steps S4 and S5, the screw temperature is 232 - 248 °C, and the temperature of each zone of the screw is: 232, 237, 237, 242, 248, 248, 248, 248, 248 °C, and the screw speed is 250 r / min.

[0052] Comparative Example 1

[0053] The difference between this comparative example and the example lies in the component ratio and preparation method of the PCTG sheet. Specifically, it includes the following steps:

[0054] S1. Prepare raw materials according to the molar ratio of (EG + CHDM) to PTA being 1.3:1 and the molar ratio of EG to CHDM being 1:2.3, and then pump them into esterification kettle 1. At the same time, weigh antimony glycolate and germanium dioxide as catalysts, with the total concentration of antimony glycolate and germanium dioxide being 150 ppm and the added molar ratio of antimony glycolate to germanium dioxide being 1:1. Place the above raw materials in esterification kettle 1, flush nitrogen into esterification kettle 1 three times to displace the gas in it, and finally flush nitrogen as the protective gas and keep the air pressure in esterification kettle 1 at 230 kPa. Set the reaction kettle temperature to 240 °C for the esterification reaction. After reacting for 1 h, continuously pump the reactants into esterification kettle 2 to continue the reaction. The reaction temperature of esterification kettle 2 is 240 °C and the pressure is normal pressure.

[0055] S2. When the water output in S1 reaches 90% of the theoretical water output, continuously pump the esterification product into prepolymerization kettle 1 and add a titanium-based catalyst such as tetrabutyl titanate to it, with the added concentration of tetrabutyl titanate being 200 ppm. Set the reaction temperatures of prepolymerization kettle 1 and prepolymerization kettle 2 to 255 °C. After reacting for 40 min, pump the reaction product into prepolymerization kettle 2 to continue the reaction for 40 min.

[0056] S3. After the prepolymerization reaction ends, pump the prepolymerization product into the final polymerization kettle for the final polymerization reaction. Set the reaction temperature of the final polymerization kettle to 275 °C and the kettle pressure to 100 Pa. After reacting for 70 min, discharge the material and pelletize to obtain PCTG chips. Perform performance testing on the obtained PCTG chips. The intrinsic viscosity of the PCTG chips is 0.50 dL / g, the glass transition temperature of the PCTG chips is 81 °C, the cold crystallization temperature is 128 °C, the melting point is 211 °C, and the melting crystallization temperature is 239 °C.

[0057] S4. Transport 120 parts of PCTG chips to a dryer for drying, and dry them at 85 °C for 2 h. After drying is completed, transport them to a mixing tank, add 60 parts of HDPE, 4.5 parts of ethylene acrylic copolymer, and 0.45 part of antioxidant. After mixing is completed, put them into a twin-screw extruder for melt blending. Among them, HDPE needs to be dried at 100 °C for 1 h.

[0058] S5. After melt blending for 10 min, add 0.9 part of compatibilizer to the extruder and continue melt blending for 10 min, and then cool and pelletize and dry to obtain the PCTG blend material. In steps S4 and S5, the screw temperature is 232 - 248 °C, the temperature of each zone of the screw is: 232, 237, 237, 242, 248, 248, 248, 248, 248 °C, and the screw speed is 250 r / min.

[0059] Comparative Example 2

[0060] The difference between this comparative example and Example 1 lies in the blending in Step S2 of the preparation of the PCTG blend material and the different components in the PCTG blend material. Specifically, the PCTG blend material in this comparative example includes the following components by weight: 120 parts of PCTG resin, 60 parts of HDPE, 5.4 parts of compatibilizer, and 0.45 part of antioxidant. The compatibilizer is maleic anhydride grafted polyethylene, purchased from Macklin Reagent. During preparation, Steps S4 and S5 specifically include the following steps:

[0061] Weigh 120 parts of the PCTG obtained in Example 1 and dry it at 85 °C for 2 h. Then weigh 60 parts of HDPE and dry it at 100 °C for 1 h. After that, put the dried PCTG and HDPE into a mixing tank, and then add 5.4 parts of maleic anhydride grafted polyethylene and 0.45 part of antioxidant. Mix and stir for 5 min and then put it into a twin-screw extruder for melt blending for 15 min, followed by water cooling and pelletizing, and drying. The screw temperature is 232~248 °C, and the temperature of each zone of the screw is: 232, 237, 237, 242, 248, 248, 248, 248, 248 °C, and the screw speed is 250 r / min.

[0062] Comparative Example 3

[0063] The difference between this comparative example and Example 1 lies in the different component ratios of the PCTG blend material. Specifically, the PCTG blend material prepared in this comparative example includes the following components by weight: 100 parts of PCTG resin, 100 parts of HDPE, 5 parts of ethylene acrylic copolymer, 0.5 part of antioxidant, and 1 part of compatibilizer. The ethylene acrylic copolymer is DuPont Surlyn Ionomer, with the grade of 9320W. The antioxidant is pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and the compatibilizer is DuPont Fusabond E100 compatibilizing masterbatch.

[0064] Comparative Example 4

[0065] The difference between this comparative example and Example 1 lies in the different blending temperatures during the preparation of the PCTG blend material. Specifically, during the preparation process, the screw temperature is 210~230 °C, and the temperature of each zone of the screw is: 210, 215, 215, 220, 220, 230, 230, 230, 230 °C, and the screw speed is 250 r / min.

[0066] Perform performance tests on the PCTG blend materials prepared in the above examples and comparative examples. The test standards are as follows:

[0067] Heat distortion temperature: ISO 75-1-2020; Rockwell hardness: ISO 2039-2-2008 (2023); Izod notched impact strength: ISO 180-2019; Tensile strength: ISO 527-1-2019; Flexural strength: ISO 178-2019; Flexural modulus: ISO 178-2019.

[0068] The test results are shown in Table 1 below:

[0069] Table 1: Performance test results table of examples and comparative examples

[0070]

[0071] From the above experimental results, it can be seen that:

[0072] The PCTG blend material prepared in this application has excellent heat resistance. The heat distortion temperature is above 110°C, and the highest can reach 124°C, greatly broadening the heat resistance of the PCTG material itself. At the same time, the PCTG blend material prepared in this invention combines the advantages of PCTG sheets and HDPE materials. Under the action of the compatibilizer between the two, they can be better combined to form a complete and dense cross-linked network inside and at the interface, without losing the strength performance of the blend material. The prepared PCTG blend material has a relatively high Rockwell hardness, making up for the lack of wear resistance of PCTG sheets and greatly broadening the application scenarios of PCTG materials.

[0073] Comparative Example 1 changed the preparation parameters of the PCTG sheet used compared with the example, reducing the usage amount of CHDM and the content of alcohol. The thermal properties of the prepared PCTG sheet decreased to a certain extent. When the PCTG blend material prepared with such a PCTG sheet was used, the heat resistance performance decreased significantly. At the same time, due to the decrease in the thermal properties of the PCTG sheet, during the subsequent preparation process, because this invention uses a relatively high blending temperature, the PCTG sheet will undergo thermal decomposition, thus damaging the heat resistance and strength performance of the material.

[0074] Comparative Example 2 selected maleic anhydride grafted polyethylene, which is commonly used, as the compatibilizer compared with the example. It can be seen from the experimental results that the conventional anhydride grafted polyethylene compatibilizer cannot make the PCTG sheet and HDPE material compatible, which in turn leads to phase separation of the two materials, resulting in a significant decrease in the performance of the blend material.

[0075] Comparative Example 3 increased the proportion of HDPE material compared with the example. Although the heat resistance and wear resistance of the blend material were improved, the impact performance and strength performance of the material decreased.

[0076] Comparative Example 4 reduced the blending temperature compared to the Example. Obviously, due to the relatively low blending temperature, the dispersion of the two materials is uneven, which will affect the crystallinity of the two materials after blending, and further affect the heat resistance of the PCTG blend material.

[0077] Although several embodiments of the present invention have been given in this article, those skilled in the art should understand that the embodiments in this article can be changed without departing from the spirit of the present invention. The above embodiments are only exemplary and should not be used to limit the scope of the present invention.

Claims

1. A preparation method of a high-temperature resistant PCTG blend material, characterized in that, The method includes the following steps: S1. Prepare raw materials according to the molar ratio of (EG + CHDM) to PTA being 1.5 - 1.7:1 and the molar ratio of EG to CHDM being 1:3 - 9, then pump them into esterification kettle 1, add a mixed catalyst thereto, raise the temperature and pressure for reaction. After reacting for 1 - 5 h, continuously pump the reactants into esterification kettle 2 for continuous reaction; S2. When the water output in S1 reaches 90% of the theoretical water output, continuously pump the esterification product into prepolycondensation kettle 1 and add a titanium-based catalyst thereto. After reacting for 20 - 25 min, pump the reactants into prepolycondensation kettle 2 for continuous reaction; S3. After the prepolycondensation reaction ends, pump the prepolycondensation product into the final polycondensation kettle for final polycondensation reaction. After the reaction ends, discharge and pelletize to obtain PCTG chips; S4. Transport the PCTG chips to a dryer for drying. After drying is completed, transport them to a mixing tank, add HDPE, ethylene acrylic copolymer and antioxidant. After mixing is completed, put them into a twin-screw extruder for melt blending; S5. After melt blending for a period of time, add a compatibilizer to the extruder for continuous melt blending, then cool and pelletize, and dry to obtain the PCTG blend material.

2. The preparation method of a high-temperature resistant PCTG blend material according to claim 1, characterized in that, In step S1, esterification kettle 1 and esterification kettle 2 are filled with nitrogen for protection. The kettle pressure of esterification kettle 1 is 0.21 - 0.23 MPa, and the reaction temperatures of esterification kettle 1 and esterification kettle 2 are 225 - 240 °C; the mixed catalyst is antimony glycolate and germanium dioxide, and the molar ratio of antimony glycolate to germanium dioxide is 1 - 2:

1. The addition concentration of the mixed catalyst is 100 - 150 ppm.

3. The preparation method of a high-temperature resistant PCTG blend material as described in claim 1, characterized in that, In step S2, the reaction temperatures of prepolycondensation kettle 1 and prepolycondensation kettle 2 are 255 - 263 °C, and the total reaction time is 40 - 45 min; the addition concentration of the titanium-based catalyst is 100 - 300 ppm.

4. The preparation method of a high-temperature resistant PCTG blend material as described in claim 1, wherein In step S3, the reaction temperature of the final polycondensation kettle is 275 - 278 °C, and the vacuum degree is 50 - 100 Pa.

5. The preparation method of a high-temperature resistant PCTG blend material as described in claim 1, characterized in that, The specific steps of steps S4 and S5 are as follows: Dry PCTG at 85 °C for 2 h and dry HDPE at 100 °C for 1 h. Then put PCTG and HDPE into a mixing tank, add ethylene acrylic copolymer and antioxidant thereto, mix and stir, and then put them into an extruder for melt blending for 10 - 15 min; add a compatibilizer to the extruder and continue melt blending in the extruder for 5 - 10 min, then cool and pelletize, and dry.

6. The preparation method of a high-temperature resistant PCTG blend material as described in claim 5, characterized in that, In steps S4 and S5, the extrusion temperature of the extruder is 232 - 248 °C, and the rotation speed of the extruder is 200 - 300 r / min.

7. A high-temperature resistant PCTG blend material prepared by the method according to any one of claims 1-6, characterized in that, It includes the following components in parts by weight: 100 - 130 parts of PCTG resin, 50 - 80 parts of HDPE, 4 - 9 parts of ethylene acrylic copolymer, 0.1 - 0.5 part of antioxidant, 0.5 - 2 parts of compatibilizer.

8. A heat-resistant PCTG blend material according to claim 7, characterized in that, The glass transition temperature of the PCTG resin is 86 - 91 °C, the cold crystallization temperature is 126 - 130 °C, the melting point is 292 - 295 °C, and the melting crystallization temperature is 253 - 257 °C.

9. The heat-resistant PCTG blend material according to claim 7, wherein The ethylene acrylic copolymer includes any one or a combination of several of ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-acrylic acid ionomer, and ethylene-methyl methacrylic acid ionomer.

10. A heat-resistant PCTG blend material according to claim 7, characterized in that, The antioxidant includes at least one of antioxidant 1010, antioxidant 1098, antioxidant 168, antioxidant 697, and antioxidant 608; the compatibilizer is an acid anhydride-modified high-density polyethylene.

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