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CN-122011702-A - Polyester resin composition and preparation method thereof

CN122011702ACN 122011702 ACN122011702 ACN 122011702ACN-122011702-A

Abstract

The invention relates to the technical field of polyester resin compositions, in particular to a polyester resin composition and a preparation method thereof. The invention solves the technical problems of poor ageing resistance and poor mechanical property of the existing polyester material. The polyester resin composition is prepared from polybutylene terephthalate, 1, 4-cyclohexanedimethanol polyterephthalate, polybutylene succinate, a reactive toughening agent, modified titanium dioxide, modified nanotubes and a chain extender by carrying out supercritical carbon dioxide-assisted double-screw extrusion treatment and gradient vacuum devolatilization and granulating on the mixed components. The invention utilizes the steric effect of alicyclic structure to compensate the rigidity loss caused by toughening, builds a topological cross-linked network through multiple interface reactions, greatly improves the impact strength, combines titanium dioxide loaded with a dual antioxidant system and a polydopamine coated nanotube to form a physical shielding and chemical quenching cooperative defense mechanism, and finally improves the comprehensive mechanical property and ageing resistance.

Inventors

  • She Guizhang
  • NI XIAOQUAN
  • ZHOU CHAO
  • Yao Jiubiao
  • XU FUXING

Assignees

  • 江苏欣宝科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260319

Claims (7)

  1. 1.A method for preparing a polyester resin composition, comprising the steps of: The preparation method comprises the steps of (1) preprocessing polybutylene terephthalate, poly-1, 4-cyclohexanedimethanol terephthalate and polybutylene succinate to obtain a polyester material, mixing and stirring the polyester material, a reactive toughening agent, modified titanium dioxide, a modified nanotube and a chain extender, and carrying out supercritical fluid assisted extrusion treatment, gradient vacuum devolatilization and granulating treatment to obtain a polyester resin composition; The modified titanium dioxide is prepared from nano titanium dioxide, a silane coupling agent, an antioxidant and a light stabilizer, and the modified nanotube is prepared from halloysite nanotubes and dopamine hydrochloride.
  2. 2. The preparation method of the polyester resin composition is characterized in that the preparation method of the modified titanium dioxide comprises the steps of dispersing the nano titanium dioxide in an ethanol water solution, dropwise adding a silane coupling agent, stirring and carrying out ultrasonic reaction to obtain a dispersion liquid, adding an antioxidant 168, a hindered amine light stabilizer and absolute ethanol into the dispersion liquid, dispersing in a water bath under ultrasonic conditions, controlling the temperature to be 50-60 ℃, carrying out vacuum drying, scattering by a jet mill, and obtaining the modified titanium dioxide.
  3. 3. The method for preparing the polyester resin composition according to claim 1, wherein the pretreatment is carried out by putting polybutylene terephthalate, 1, 4-cyclohexanedimethanol terephthalate and polybutylene succinate into a blast drying oven, and drying at 110-120 ℃ to obtain the polyester material.
  4. 4. The preparation method of the polyester resin composition according to claim 1, wherein the specific process of mixing and stirring is that the polyester material, the reactive toughening agent, the modified titanium dioxide, the modified nano tube and the chain extender polycarbodiimide are added into a high-speed mixer to be mixed for 3-5min, so as to obtain a blending material.
  5. 5. The method for preparing the polyester resin composition according to claim 1, wherein the supercritical fluid assisted extrusion treatment comprises the specific process of feeding the blending materials into a co-rotating twin screw extruder, wherein the temperature range is set to be one zone of 170-180 ℃, two to three zones of 230-240 ℃, four zones of 245 ℃ and five to six zones of 210-220 ℃.
  6. 6. The preparation method of the polyester resin composition according to claim 1, wherein the specific process of the gradient vacuum devolatilization and the granulating treatment is that a two-stage exhaust port is arranged at the tail part of an extruder, the first-stage exhaust is normal pressure exhaust, the second-stage exhaust is vacuum exhaust, finally, underwater granulating is adopted, and the polyester resin composition is obtained after centrifugal dehydration and drying.
  7. 7. A polyester resin composition is prepared by the preparation method of any one of claims 1-6, wherein the raw materials for preparing the polyester resin composition comprise polybutylene terephthalate, 1, 4-cyclohexanedimethanol polyterephthalate, polybutylene succinate, a reactive toughening agent, modified titanium dioxide, modified nanotubes and a chain extender.

Description

Polyester resin composition and preparation method thereof Technical Field The invention relates to the technical field of polyester resin compositions, in particular to a polyester resin composition and a preparation method thereof. Background Polyester resins have been indispensable in the high-definition fields such as lightweight parts for automobiles, housings for electronic and electric appliances, 5G communication base stations, aerospace, and the like, because of their excellent processability, electrical insulation properties, and chemical resistance. With the continuous extension of application scenes to extreme environments such as outdoor, high temperature, high humidity and the like, the terminal market puts extremely severe demands on the comprehensive service life of the polyester resin composition, and the traditional single polyester material is difficult to compete. The technical problems at present are mainly concentrated on the poor ageing resistance and mechanical properties (especially the cliff-type reduction of the ageing mechanical properties). On one hand, ester bonds on a macromolecular chain of the polyester are extremely easy to generate photooxidative degradation and thermooxidative degradation under the action of long-term light and heat (ultraviolet rays) and oxygen, so that molecular chains are broken and molecular weight is reduced, and on the other hand, the conventional physical blending modification (such as adding an elastomer or an antioxidant) often has the problems of poor compatibility and easy migration and precipitation of small-molecule auxiliary agents. The aging-resistant effect cannot be maintained for a long time, the materials are subjected to serious phase separation, the embrittlement of the materials is macroscopically shown, the notch impact strength is greatly reduced, and the high-end application of the polyester materials is severely restricted. For this purpose, a polyester resin composition and a method for preparing the same are proposed. Disclosure of Invention The invention aims at designing a polyester resin composition and a preparation method thereof. The polyester resin composition is prepared from polybutylene terephthalate, 1, 4-cyclohexanedimethanol polyterephthalate, polybutylene succinate, a reactive toughening agent, modified titanium dioxide, modified nanotubes and a chain extender by carrying out supercritical carbon dioxide-assisted double-screw extrusion treatment and gradient vacuum devolatilization and granulating on the mixed components. The invention utilizes the steric effect of alicyclic structure to compensate the rigidity loss caused by toughening, builds a topological cross-linked network through multiple interface reactions, greatly improves the impact strength, combines titanium dioxide loaded with a dual antioxidant system and a polydopamine coated nanotube to form a physical shielding and chemical quenching cooperative defense mechanism, and finally improves the comprehensive mechanical property and ageing resistance. The invention provides the following technical scheme, wherein the following parts are weight parts unless specified otherwise. In one aspect, the present invention provides a method for preparing a polyester resin composition, comprising the steps of: The preparation method comprises the steps of preprocessing polybutylene terephthalate, 1, 4-cyclohexanedimethanol polyterephthalate and polybutylene succinate to obtain a polyester material, mixing and stirring the polyester material, a reactive toughening agent, modified titanium dioxide, a modified nanotube and a chain extender, and carrying out supercritical fluid assisted extrusion treatment, gradient vacuum devolatilization and granulating treatment to obtain the polyester resin composition. Preferably, the preparation method of the modified titanium dioxide comprises the steps of dispersing 15-25 parts of nano titanium dioxide (rutile type, average particle size of 20-50 nm) in 150 parts of ethanol aqueous solution (ethanol mass concentration of 95%), dropwise adding 1 part of silane coupling agent KH-550, mechanically stirring at 55 ℃ and carrying out ultrasonic reaction for 1.5 hours to obtain a dispersion liquid, adding 5-10 parts of antioxidant 168, 5-7 parts of HALS 944 and 50 parts of absolute ethyl alcohol into the dispersion liquid, carrying out water bath ultrasonic dispersion for 45 minutes at an ultrasonic frequency of 40kHz, controlling the temperature to be 50-60 ℃, then transferring into a vacuum drying box, drying and desolventizing for 12 hours at a vacuum degree of-0.09 MPa and a vacuum degree of 80 ℃, and scattering by a jet mill to obtain the modified titanium dioxide. Preferably, the specific pretreatment process comprises the steps of putting 65-75 parts of polybutylene terephthalate (with the intrinsic viscosity of 0.8-1.0 dL/g), 15-20 parts of poly-1, 4-cyclohexanedimethanol terephthalate (with the intrinsic viscosity of 0.6-0.8