A high temperature resistant PCTG blend material and preparation method thereof

Abstract

The present invention belongs to the technical field of polymer materials, and specifically relates to a high-temperature resistant PCTG blend material and a preparation method thereof. The method is as follows: PTA, EG, CHDM, and a catalyst are placed in a reactor, filled with protective gas, and heated for esterification reaction. When the water output reaches the standard, the pressure is released and the temperature is increased, and a titanium catalyst is added to perform a pre-polycondensation reaction. After the pre-polycondensation reaction is completed, the temperature is increased and the reactor pressure is controlled to enter the final polycondensation reaction. After the reaction is completed, the material is discharged and pelletized to obtain PCTG slices; the PCTG slices and HDPE particles are dried separately and added to a mixing tank. An ethylene acrylic acid copolymer, a compatibilizer, and an antioxidant are added to the mixing tank, and the mixture is fed into a twin-screw extruder for extrusion, followed by water cooling for pelletization and drying. The present invention adds HDPE to the PCTG material for blending and modification, and uses the ethylene acrylic acid copolymer as a compatibilizer. The PCTG material and the HDPE material are combined to form a mutually cross-linked network structure, thereby improving the heat resistance and wear resistance of the PCTG without losing the mechanical properties of the PCTG material.

Description

Technical Field

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

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

[0003] Existing technology, such as Chinese patent CN117586487A, provides a high-temperature, weather-resistant PCTG material and its preparation method. By adding nanoscale heat-resistant metal elements during the preparation process, the material is given significant heat and weather resistance without degrading its performance, extending its service life in harsh outdoor environments. However, the use of nanometals increases production costs and reduces the material's transparency.

[0004] For example, Chinese patent CN119286206A discloses a highly impact-resistant, transparent, and chemically resistant PC / PCTG alloy and its preparation method. By blending PC and PCTG materials and adding a toughening agent, antioxidant, lubricant, and transesterification inhibitor, an alloy with high transparency, high impact, heat resistance, and chemical resistance is obtained. However, the alloy has limited heat resistance, with a heat deformation temperature below 110°C, and insufficient wear resistance.

[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] In response to the problems mentioned in the background technology, 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 acid copolymer as a compatibilizer, the PCTG material and the HDPE material can be combined to form a mutually cross-linked network structure, thereby improving the heat resistance and wear resistance of the PCTG without losing the mechanical properties of the PCTG material.

[0007] The present invention provides a method for preparing a high-temperature resistant PCTG blend material, the method comprising the following steps:

[0008] S1. Prepare the raw materials according to the molar ratio of (EG+CHDM) to PTA of 1.5-1.7:1 and the molar ratio of EG:CHDM of 1:3-9, and pump them into esterification kettle 1. Then add the mixed catalyst, increase the temperature and pressure to react, and after reacting for 1-5 hours, continuously pump the reactants into esterification kettle 2 to continue the reaction;

[0009] S2. When the water output of S1 reaches 90% of the theoretical water output, the esterification product is continuously pumped into the pre-condensation reactor 1 and a titanium catalyst is added thereto. After reacting for 20 to 25 minutes, the reactant is pumped into the pre-condensation reactor 2 to continue the reaction;

[0010] S3, after the pre-polycondensation reaction is completed, the pre-polycondensation product is pumped into the final polycondensation kettle for final polycondensation reaction. After the reaction is completed, the material is discharged and pelletized to obtain PCTG slices;

[0011] S4, the PCTG slices are transported to a dryer for drying, and after drying, they are transported to a mixing tank, HDPE, ethylene acrylic acid copolymer and antioxidant are added, and after mixing, they are put into a twin-screw extruder for melt blending;

[0012] S5. After melt blending for a period of time, a compatibilizer is added to the extruder to continue melt blending, followed by water cooling and granulation, and drying to obtain a PCTG blended material.

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

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

[0015] Furthermore, the reaction temperature of the final polycondensation reactor in step S3 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: after drying PCTG at 85°C for 2 hours and drying HDPE at 100°C for 1 hour, PCTG and HDPE are placed in a mixing tank, and then ethylene acrylic acid copolymer and antioxidant are added thereto, the mixture is stirred, and then put into an extruder for melt blending, and blending for 10 to 15 minutes; then a compatibilizer is added to the extruder, and melt blending is continued in the extruder for 5 to 10 minutes, followed by water cooling, granulation, and drying.

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

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

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

[0020] Furthermore, the ethylene acrylic acid copolymer includes any one or a combination 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-methacrylic acid ionomer.

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

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

[0023] 1. In this invention, HDPE is introduced into PCTG resin. Blending HDPE with PCTG significantly improves PCTG's high-temperature resistance and rigidity. The high toughness and impact resistance of PCTG resin can also improve HDPE's low-temperature brittleness, improving the overall impact resistance of the blended material. Compared to PCTG, HDPE has better high-temperature resistance. The HDPE used in this invention has a high-temperature deformation temperature of 125-135°C. The blended material can reach a maximum heat deformation temperature of 125°C, suitable for use in environments above 110°C, greatly expanding the application scenarios of PCTG materials. HDPE also exhibits excellent wear resistance, which can enhance the wear resistance of PCTG materials.

[0024] 2. In the present invention, 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. The current general solution is to use a compatibilizer such as maleic anhydride grafted polymer or redox grafted polymer to melt blend together. The inventors of the present invention have tried conventional methods and have not been able to solve the problem of incompatibility between PCTG and HDPE. Therefore, they creatively selected ethylene-acrylic acid copolymer as a compatibilizer during blending, utilizing the carboxylic acid groups in the copolymer to form hydrogen bonds or ion-dipole interactions with the polar groups of PCTG. 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 have found that after melt blending ethylene-acrylic acid copolymer with PCTG and HDPE, adding a small amount of anhydride-modified high-density polyethylene compatibilizer masterbatch as a binder can further tightly combine the two materials, improve the structural stability of the material, and give the blended material better strength and wear resistance.

[0025] 3. The present invention defines the basic properties of the PCTG sheet. By controlling the alkyd ratio and the amount of CHDM added during preparation, the melting point and crystallization temperature of the PCTG sheet are increased compared to the PCTG sheet in the prior art, making the grain structure of the PCTG sheet more complete, thereby improving the thermal properties of the prepared PCTG sheet. In the process of preparing the PCTG blended material, by setting a higher blending temperature, the melting and connection between PCTG and HDPE can be promoted under the action of the ethylene-acrylic acid copolymer and the anhydride-modified high-density polyethylene compatibilizer masterbatch, improving the interfacial bonding effect and reducing phase separation. At the same time, the higher blending temperature during preparation can increase the crystallinity of the material, especially HDPE, thereby increasing the heat deformation temperature of the material and optimizing the heat resistance of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a flow chart of a method for preparing a high-temperature resistant PCTG blend material. DETAILED DESCRIPTION

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

[0028] PTA, polymer grade, Yizheng Chemical Fiber; EG, polymer 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 Petrochemical Research Institute.

[0029] Example 1

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

[0031] As attached Figure 1 As shown, this embodiment provides a method for preparing a high temperature resistant PCTG blend material, comprising the following steps:

[0032] S1. Prepare the raw materials at a molar ratio of (EG + CHDM) to PTA of 1.6:1 and a molar ratio of EG to CHDM of 1:9. Pump them into esterification kettle 1. Simultaneously, weigh ethylene glycol antimony and germanium dioxide as catalysts. The total concentration of ethylene glycol antimony and germanium dioxide is 100 ppm, and the molar ratio of ethylene glycol antimony to germanium dioxide is 1:1. Place the raw materials into esterification kettle 1. Flush the esterification kettle 1 with nitrogen three times to displace the atmosphere. Finally, flush with nitrogen as a protective gas, maintaining the pressure in esterification kettle 1 at 210 kPa. Set the reactor temperature to 235°C for the esterification reaction. After one hour of reaction, continuously pump the reactants into esterification kettle 2 for further reaction. The reaction temperature in esterification kettle 2 is 235°C and atmospheric pressure.

[0033] S2. When the water output of S1 reaches 90% of the theoretical water output, the esterification product is continuously pumped into pre-condensation reactor 1 and a titanium catalyst such as tetrabutyl titanate is added thereto. The concentration of tetrabutyl titanate added is 200 ppm. The reaction temperature of pre-condensation reactor 1 and pre-condensation reactor 2 is set to 255°C. After reacting for 40 minutes, the reaction product is pumped into pre-condensation reactor 2 and the reaction continues for 40 minutes.

[0034] After the pre-polycondensation reaction in step S3 is completed, the pre-polycondensation product is pumped into a final polycondensation kettle for a final polycondensation reaction. The final polycondensation kettle reaction temperature is set to 275°C and the kettle pressure is set to 100 Pa. After 70 minutes of reaction, the product is discharged and pelletized to obtain PCTG chips. The obtained PCTG chips were subjected to performance testing. The intrinsic viscosity of the PCTG chips was 0.57 dL / g, the glass transition temperature of the PCTG chips was 88.5°C, the cold crystallization temperature was 129°C, the melting point was 222°C, and the melt crystallization temperature was 253°C.

[0035] S4. Transfer 120 parts of PCTG chips to a dryer and dry at 85°C for 2 hours. After drying, transfer them to a mixing tank, add 60 parts of HDPE, 4.5 parts of ethylene acrylic acid copolymer, and 0.45 parts of antioxidant, and then transfer them to a twin-screw extruder for melt blending. The HDPE needs to be dried at 100°C for 1 hour.

[0036] After melt blending for 10 minutes in step S5, 0.9 parts of a compatibilizer was added to the extruder and melt blending continued for another 10 minutes. The mixture was then water-cooled, pelletized, and dried to obtain a PCTG blend. The screw temperature in steps S4 and S5 was 232-248°C, with the temperatures in each zone being 232, 237, 237, 242, 248, 248, 248, 248, and 248°C. The screw speed was 250 rpm.

[0037] Example 2

[0038] This embodiment differs from Example 1 in that the components of the PCTG material are prepared using different extrusion methods. Specifically, the following components are included by weight: 100 parts PCTG resin, 80 parts HDPE, 9 parts ethylene acrylic acid copolymer, 0.9 parts antioxidant, and 1.8 parts compatibilizer. In this embodiment, the ethylene acrylic acid copolymer is DuPont Surlyn Ionomer, brand 9320W. The antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. The compatibilizer is DuPont Fusabond E100 compatibilizer masterbatch.

[0039] Example 3

[0040] The difference between this embodiment and embodiment 1 is that the preparation method of PCTG and the component ratio are different. Specifically, the following steps are included:

[0041] S1. Prepare the raw materials at a molar ratio of (EG + CHDM) to PTA of 1.6:1 and a molar ratio of EG to CHDM of 1:5.6. Pump them into esterification kettle 1. Simultaneously, weigh ethylene glycol antimony and germanium dioxide as catalysts. The total concentration of ethylene glycol antimony and germanium dioxide is 100 ppm, and the molar ratio of ethylene glycol antimony to germanium dioxide is 1:1. Place the raw materials into esterification kettle 1. Flush the esterification kettle 1 with nitrogen three times to displace the atmosphere. Finally, flush with nitrogen as a protective gas, maintaining the pressure in esterification kettle 1 at 230 kPa. Set the reactor temperature to 240°C for the esterification reaction. After one hour of reaction, continuously pump the reactants into esterification kettle 2 for further reaction. The reaction temperature in esterification kettle 2 is 235°C and atmospheric pressure.

[0042] S2. When the water output of S1 reaches 90% of the theoretical water output, the esterification product is continuously pumped into pre-condensation reactor 1 and a titanium catalyst such as tetrabutyl titanate is added thereto. The concentration of tetrabutyl titanate added is 200 ppm. The reaction temperature of pre-condensation reactor 1 and pre-condensation reactor 2 is set to 260°C. After reacting for 40 minutes, the reaction product is pumped into pre-condensation reactor 2 and the reaction continues for 40 minutes.

[0043] After the pre-polycondensation reaction is completed, the pre-polycondensation product is pumped into a final polycondensation kettle for a final polycondensation reaction. The final polycondensation kettle reaction temperature is set to 278°C and the kettle pressure is set to 100 Pa. After 60 minutes of reaction, the product is discharged and pelletized to obtain PCTG chips. The obtained PCTG chips are subjected to performance testing. 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 melt crystallization temperature is 254°C.

[0044] S4. Transfer 120 parts of PCTG chips to a dryer and dry at 85°C for 2 hours. After drying, transfer them to a mixing tank, add 60 parts of HDPE, 4.5 parts of ethylene acrylic acid copolymer, and 0.45 parts of antioxidant, and then transfer them to a twin-screw extruder for melt blending. The HDPE needs to be dried at 100°C for 1 hour.

[0045] After melt blending for 10 minutes in step S5, 0.9 parts of a compatibilizer was added to the extruder and melt blending continued for another 10 minutes. The mixture was then water-cooled, pelletized, and dried to obtain a PCTG blend. The screw temperature in steps S4 and S5 was 232-248°C, with the temperatures in each zone being 232, 237, 237, 242, 248, 248, 248, 248, and 248°C. The screw speed was 250 rpm.

[0046] Example 4

[0047] This Example differs from Example 1 in the preparation method and component ratios of PCTG. Specifically, the following steps are included: S1. Raw materials are prepared at a molar ratio of (EG + CHDM) to PTA of 1.6:1 and a molar ratio of EG to CHDM of 1:3, and then pumped into esterification kettle 1. Ethylene glycol antimony and germanium dioxide are weighed as catalysts to a total concentration of 100 ppm, with a molar ratio of 1:1. The raw materials are placed in esterification kettle 1. Nitrogen is flushed into esterification kettle 1 three times to displace the atmosphere therein. Finally, nitrogen is flushed in as a protective gas, maintaining the pressure in esterification kettle 1 at 210 kPa. The reactor temperature is set at 235°C for the esterification reaction. After 1.5 hours of reaction, the reactants are continuously pumped into esterification kettle 2 for further reaction. The reaction temperature in esterification kettle 2 is maintained at 235°C and atmospheric pressure.

[0048] S2. When the water output of S1 reaches 90% of the theoretical water output, the esterification product is continuously pumped into pre-condensation reactor 1 and a titanium catalyst such as tetrabutyl titanate is added thereto. The concentration of tetrabutyl titanate added is 200 ppm. The reaction temperature of pre-condensation reactor 1 and pre-condensation reactor 2 is set to 260°C. After reacting for 45 minutes, the reaction product is pumped into pre-condensation reactor 2 and the reaction continues for 40 minutes.

[0049] After the pre-polycondensation reaction is completed, the pre-polycondensation product is pumped into a final polycondensation kettle for a final polycondensation reaction. The final polycondensation kettle reaction temperature is set to 275°C and the kettle pressure is set to 100 Pa. After 60 minutes of reaction, the product is discharged and pelletized to obtain PCTG chips. The obtained PCTG chips were subjected to performance testing. The intrinsic viscosity of the PCTG chips was 0.51 dL / g, the glass transition temperature of the PCTG chips was 86°C, the cold crystallization temperature was 126°C, the melting point was 224°C, and the melt crystallization temperature was 257°C.

[0050] S4. Transfer 120 parts of PCTG chips to a dryer and dry at 85°C for 2 hours. After drying, transfer them to a mixing tank, add 60 parts of HDPE, 4.5 parts of ethylene acrylic acid copolymer, and 0.45 parts of antioxidant, and then transfer them to a twin-screw extruder for melt blending. The HDPE needs to be dried at 100°C for 1 hour.

[0051] After melt blending for 10 minutes in step S5, 0.9 parts of a compatibilizer was added to the extruder and melt blending continued for another 10 minutes. The mixture was then water-cooled, pelletized, and dried to obtain a PCTG blend. The screw temperature in steps S4 and S5 was 232-248°C, with the temperatures in each zone being 232, 237, 237, 242, 248, 248, 248, 248, and 248°C. The screw speed was 250 rpm.

[0052] Comparative Example 1

[0053] The difference between this comparative example and the embodiment is that the component ratio and preparation method of the PCTG sheet are different. Specifically, the following steps are included:

[0054] S1. Prepare the raw materials at a molar ratio of (EG + CHDM) to PTA of 1.3:1 and a molar ratio of EG to CHDM of 1:2.3. Pump them into esterification kettle 1. Simultaneously, weigh ethylene glycol antimony and germanium dioxide as catalysts. The total concentration of ethylene glycol antimony and germanium dioxide is 150 ppm, and the molar ratio of ethylene glycol antimony to germanium dioxide is 1:1. Place the raw materials into esterification kettle 1. Flush the esterification kettle 1 with nitrogen three times to displace the atmosphere. Finally, flush with nitrogen as a protective gas, maintaining the pressure in esterification kettle 1 at 230 kPa. Set the reactor temperature to 240°C for the esterification reaction. After one hour of reaction, continuously pump the reactants into esterification kettle 2 for further reaction. The reaction temperature in esterification kettle 2 is 240°C and atmospheric pressure.

[0055] S2. When the water output of S1 reaches 90% of the theoretical water output, the esterification product is continuously pumped into pre-condensation reactor 1 and a titanium catalyst such as tetrabutyl titanate is added thereto. The concentration of tetrabutyl titanate added is 200 ppm. The reaction temperature of pre-condensation reactor 1 and pre-condensation reactor 2 is set to 255°C. After reacting for 40 minutes, the reaction product is pumped into pre-condensation reactor 2 and the reaction continues for 40 minutes.

[0056] After the pre-polycondensation reaction is completed, the pre-polycondensation product is pumped into a final polycondensation reactor for a final polycondensation reaction. The final polycondensation reactor reaction temperature is set to 275°C and the reactor pressure is set to 100 Pa. After 70 minutes of reaction, the product is discharged and pelletized to obtain PCTG chips. The obtained PCTG chips are subjected to performance testing. 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 melt crystallization temperature is 239°C.

[0057] S4. Transfer 120 parts of PCTG chips to a dryer and dry at 85°C for 2 hours. After drying, transfer them to a mixing tank, add 60 parts of HDPE, 4.5 parts of ethylene acrylic acid copolymer, and 0.45 parts of antioxidant, and then transfer them to a twin-screw extruder for melt blending. The HDPE needs to be dried at 100°C for 1 hour.

[0058] After melt blending for 10 minutes in step S5, 0.9 parts of a compatibilizer was added to the extruder and melt blending continued for another 10 minutes. The mixture was then water-cooled, pelletized, and dried to obtain a PCTG blend. The screw temperature in steps S4 and S5 was 232-248°C, with the temperatures in each zone being 232, 237, 237, 242, 248, 248, 248, 248, and 248°C. The screw speed was 250 rpm.

[0059] Comparative Example 2

[0060] This comparative example differs from Example 1 in that the PCTG blend material preparation step S2 contains different components. Specifically, the PCTG blend material in this comparative example includes the following components by weight: 120 parts PCTG resin, 60 parts HDPE, 5.4 parts compatibilizer, and 0.45 parts 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 them at 85°C for 2 hours. Weigh 60 parts of HDPE and dry them at 100°C for 1 hour. Place the dried PCTG and HDPE in a mixing tank. Add 5.4 parts of maleic anhydride-grafted polyethylene and 0.45 parts of an antioxidant. Stir for 5 minutes, then place the mixture in a twin-screw extruder for melt blending for 15 minutes. Then, water-cool, pelletize, and dry. The screw temperature is 232-248°C, with the temperatures in each zone being: 232, 237, 237, 242, 248, 248, 248, 248, 248°C. The screw speed is 250 rpm.

[0062] Comparative Example 3

[0063] This comparative example differs from Example 1 in the composition ratio of the PCTG blend. Specifically, the PCTG blend prepared in this comparative example comprises the following components by weight: 100 parts PCTG resin, 100 parts HDPE, 5 parts ethylene acrylic acid copolymer, 0.5 parts antioxidant, and 1 part compatibilizer. The ethylene acrylic acid copolymer is DuPont Surlyn Ionomer, brand 9320W. The antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and the compatibilizer is DuPont Fusabond E100 compatibilizer masterbatch.

[0064] Comparative Example 4

[0065] This comparative example differs from Example 1 in that the blending temperature during the preparation of the PCTG blend is different. Specifically, during the preparation process, the screw temperature was 210-230°C, the temperatures in each screw zone were: 210, 215, 215, 220, 220, 230, 230, 230, 230°C, and the screw speed was 250 r / min.

[0066] The PCTG blends prepared in the above examples and comparative examples were tested for performance, and the test standards were as follows:

[0067] Heat deflection 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 of examples and comparative examples

[0070]

[0071] From the above experimental results, we can know that:

[0072] The PCTG blended material prepared in this application has excellent heat resistance, and the heat deformation temperature is above 110 ° C, and can reach up to 124 ° C, which greatly broadens the heat resistance of the PCTG material itself. At the same time, the PCTG blended material prepared by the present invention combines the advantages of PCTG sheet and HDPE material. Under the action of the compatibilizer of the two, it can be better combined, forming a complete and dense cross-linked network inside and at the interface, without losing the strength performance of the blended material. The prepared PCTG blended material has a higher Rockwell hardness, which makes up for the lack of wear resistance of PCTG sheet and greatly broadens the use scenario of PCTG material.

[0073] Comparative Example 1 changed the preparation parameters of the PCTG sheet used in the embodiment, reduced the amount of CHDM used and the content of alcohol, and the thermal properties of the prepared PCTG sheet decreased to a certain extent. When such a PCTG sheet was used to prepare the PCTG blended material, the heat resistance was significantly reduced. At the same time, due to the decrease in the thermal properties of the PCTG sheet, the higher the blending temperature used in the subsequent preparation process, the PCTG sheet would be thermally decomposed, thereby damaging the heat resistance and strength properties of the material.

[0074] Compared with the embodiment, in Comparative Example 2, the conventional maleic anhydride grafted polyethylene was selected as the compatibilizer. From the experimental results, it can be seen that the conventional anhydride grafted polyethylene compatibilizer cannot make the PCTG sheet and HDPE material compatible, which leads to phase separation of the two materials, resulting in a significant decrease in the performance of the blended material.

[0075] Comparative Example 3 increases the proportion of HDPE material compared to the embodiment. Although the heat resistance and wear resistance of the blended material are improved, the impact resistance and strength properties of the material are reduced.

[0076] Comparative Example 4 lowers the blending temperature compared to the embodiment. Obviously, due to the low blending temperature, the two materials will be unevenly dispersed and the crystallinity of the two materials will be affected after the blending is completed, thereby affecting the heat resistance of the PCTG blended material.

[0077] Although several embodiments of the present invention have been described herein, those skilled in the art will appreciate that modifications may be made to the embodiments herein without departing from the spirit of the present invention. The above embodiments are merely exemplary and should not be used as limitations on the scope of the present invention.

Claims

1. A method for preparing a high temperature resistant PCTG blend material, characterized in that: The method comprises the following steps: S1. Prepare the raw materials according to the molar ratio of (EG+CHDM) to PTA of 1.5-1.7:1 and the molar ratio of EG:CHDM of 1:3-9, and pump them into esterification kettle 1. Then add the mixed catalyst, increase the temperature and pressure to react, and after reacting for 1-5 hours, continuously pump the reactants into esterification kettle 2 to continue the reaction; S2. When the water output of S1 reaches 90% of the theoretical water output, the esterification product is continuously pumped into the pre-condensation reactor 1 and a titanium catalyst is added thereto. After reacting for 20 to 25 minutes, the reactant is pumped into the pre-condensation reactor 2 to continue the reaction; S3, after the pre-polycondensation reaction is completed, the pre-polycondensation product is pumped into the final polycondensation kettle for final polycondensation reaction. After the reaction is completed, the material is discharged and pelletized to obtain PCTG slices; S4, the PCTG slices are transported to a dryer for drying, and after drying, they are transported to a mixing tank, HDPE, ethylene acrylic acid copolymer and antioxidant are added, and after mixing, they are put into a twin-screw extruder for melt blending; S5. After melt blending for a period of time, a compatibilizer is added to the extruder to continue melt blending, followed by water cooling and granulation, and drying to obtain a PCTG blended material.

2. The preparation method of a high temperature resistant PCTG blend material according to claim 1, wherein In step S1, the esterification kettle 1 and the esterification kettle 2 are filled with nitrogen for protection, the pressure of the esterification kettle 1 is 0.21-0.23 MPa, and the reaction temperature of the esterification kettle 1 and the esterification kettle 2 is 225-240° C.; the mixed catalyst is ethylene glycol antimony and germanium dioxide, the molar ratio of ethylene glycol antimony to germanium dioxide is 1-2:1, and the added concentration of the mixed catalyst is 100-150 ppm.

3. The preparation method of a high temperature resistant PCTG blend material according to claim 1, wherein In step S2, the reaction temperature of the pre-polycondensation reactor 1 and the pre-polycondensation reactor 2 is 255-263° C., the total reaction time is 40-45 minutes, and the added concentration of the titanium-based catalyst is 100-300 ppm.

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

5. The preparation method of a high temperature resistant PCTG blend material according to claim 1, wherein The specific steps of steps S4 and S5 are as follows: after drying PCTG at 85° C. for 2 hours and drying HDPE at 100° C. for 1 hour, PCTG and HDPE are placed in a mixing tank, ethylene acrylic acid copolymer and antioxidant are added thereto, the mixture is stirred, and then put into an extruder for melt blending for 10 to 15 minutes; then a compatibilizer is added to the extruder, and melt blending is continued in the extruder for 5 to 10 minutes, followed by water cooling, granulation, and drying.

6. The method for preparing a high temperature resistant PCTG blend material according to claim 5, wherein: In the steps S4 and S5, the extrusion temperature of the extruder is 232-248° C., and the extruder speed is 200-300 r / min.

7. A high temperature resistant PCTG blend material prepared by the method according to any one of claims 1 to 6, characterized in that: The invention 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 acid copolymer, 0.1-0.5 parts of antioxidant and 0.5-2 parts of compatibilizer.

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

9. A high temperature resistant PCTG blend material according to claim 7, characterized in that, The ethylene acrylic acid copolymer includes any one or a combination 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-methacrylic acid ionomer.

10. A high temperature 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; and the compatibilizer is anhydride-modified high-density polyethylene.

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