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CN-121975294-A - Preparation process of composite material for high-strength electronic product shell

CN121975294ACN 121975294 ACN121975294 ACN 121975294ACN-121975294-A

Abstract

The invention relates to the field of modification of high polymer materials, in particular to a preparation process of a composite material for a high-strength electronic product shell, which comprises the following steps of premixing a matrix polymer and a multifunctional auxiliary agent to obtain a mixture, adding the mixture into a double-screw extruder, carrying out reactive extrusion under the conditions of gradient heating and specific screw rotating speed to enable the multifunctional auxiliary agent to be subjected to chemical bonding with the matrix polymer, cooling and granulating an extrudate to obtain the composite material, wherein the multifunctional auxiliary agent preparation method comprises the steps of (a) synthesizing an amino-terminated hyperbranched polyaramid as a rigid core, (b) forming a core-shell structure intermediate, and (c) enabling the terminal hydroxyl of the core-shell structure intermediate to react with epoxy chloropropane to be converted into an epoxy group to obtain the epoxy-terminated core-shell structure hyperbranched polymer. The invention solves the problem that the toughness and the rigidity are difficult to be compatible in the traditional toughening modification.

Inventors

  • LI WENJUN
  • ZHENG XUEJUN
  • LI YINGCHUN
  • PENG JUHONG

Assignees

  • 青岛凯瑞电子有限公司

Dates

Publication Date
20260505
Application Date
20260316

Claims (10)

  1. 1. The preparation process of the composite material for the high-strength electronic product shell is characterized by comprising the following steps of: Premixing a matrix polymer and a multifunctional auxiliary agent to obtain a mixture; adding the mixture into a double-screw extruder, and performing reactive extrusion under the conditions of gradient heating and specific screw rotation speed to enable the multifunctional auxiliary agent to be chemically bonded with the matrix polymer; cooling and granulating the extrudate to obtain the composite material; The multifunctional auxiliary agent is an epoxy-terminated core-shell structure hyperbranched polymer, and the preparation method comprises the following steps: under the protection of inert atmosphere, synthesizing amino-terminated hyperbranched polyaramid serving as a rigid core through low-temperature polycondensation; step (b), grafting a polycaprolactone soft segment on the surface of the rigid core through ring-opening polymerization reaction under the action of a catalyst to form a core-shell structure intermediate; and (c) under the action of a phase transfer catalyst, enabling the terminal hydroxyl of the core-shell structure intermediate to react with epichlorohydrin and be converted into an epoxy group, so as to obtain the epoxy-terminated core-shell structure hyperbranched polymer.
  2. 2. The preparation process according to claim 1, wherein the matrix polymer is polycarbonate, and the mass ratio of the matrix polymer to the multifunctional auxiliary agent is (92-97): 3-8.
  3. 3. The process according to claim 1, wherein the gradient heating mode of the reactive extrusion is such that the temperature of each zone of the extruder is set to 230-270 ℃ and the screw rotation speed is set to 250-350 rpm.
  4. 4. The process of claim 1, wherein the synthesis of the amino-terminated hyperbranched polyaramid in step (a) comprises the steps of: Carrying out polycondensation reaction on tris (4-aminophenyl) amine and terephthaloyl chloride in an N-methylpyrrolidone solvent at a low temperature of 0-5 ℃ under the protection of inert atmosphere; After the reaction is finished, heating to room temperature to perform curing reaction; And (3) precipitating and separating out the reaction liquid in methanol, filtering, washing and drying in vacuum to obtain the amino-terminated hyperbranched polyaramid.
  5. 5. The preparation process according to claim 4, wherein the mass ratio of the tri (4-aminophenyl) amine, terephthaloyl chloride and N-methylpyrrolidone is 3:2.1 (80+20).
  6. 6. The process of claim 1, wherein grafting the soft segment in step (b) comprises the steps of: mixing terminal amino hyperbranched polyaramid, epsilon-caprolactone and stannous octoate catalyst; and heating to 125-135 ℃ under the protection of nitrogen to carry out ring-opening polymerization for 3.5-4.5 hours.
  7. 7. The preparation process according to claim 6, wherein the mass ratio of the amino-terminated hyperbranched polyaramid to the epsilon-caprolactone is 2 (7-9).
  8. 8. The process of claim 1, wherein the step (c) of introducing an epoxy group comprises the steps of: mixing the core-shell structure intermediate, epichlorohydrin and tetrabutylammonium bromide phase transfer catalyst; Dropwise adding sodium hydroxide aqueous solution, and reacting at a constant temperature of not more than 85 ℃; and after the reaction is finished, filtering while the reaction is hot, performing rotary evaporation, extraction washing, precipitation and vacuum drying on the filtrate to obtain the epoxy-terminated core-shell structure hyperbranched polymer.
  9. 9. A composite material for a high-strength electronic product housing prepared by the preparation process according to any one of claims 1 to 8.
  10. 10. Use of the composite material of claim 9 in a notebook computer housing, a drone fuselage or a smartphone center.

Description

Preparation process of composite material for high-strength electronic product shell Technical Field The invention relates to the field of modification of high polymer materials, in particular to a preparation process of a composite material for a high-strength electronic product shell. Background Along with the development of the electronic products towards the light weight and portability, the outer materials of the electronic products need to have excellent impact resistance to cope with accidents such as dropping, collision and the like and have enough rigidity to ensure structural stability and protect internal precise components, the traditional toughening modification method, such as adding a rubber toughening agent, can effectively improve the impact strength of the materials, but usually has the cost of greatly sacrificing the rigidity and strength of the materials, on the other hand, if the interface binding force between the added auxiliary agent and the matrix materials is weaker, the stress cannot be effectively transmitted, the toughening efficiency is low, the rigidity loss is larger, and certain rigid particles even become stress concentration points if the compatibility with the matrix is poor, but the toughness of the materials is reduced, so that the materials become brittle. Therefore, how to overcome the contradiction between toughness and rigidity in the traditional modification method, develop a composite material which can not only remarkably improve the mechanical toughness of a polymer matrix, but also keep the original high strength and high modulus to the maximum extent, and is a key technical problem facing the field. Disclosure of Invention In order to achieve the above object, the present invention provides a process for preparing a composite material for a high-strength electronic product housing, comprising the steps of: Premixing a matrix polymer and a multifunctional auxiliary agent to obtain a mixture; adding the mixture into a double-screw extruder, and performing reactive extrusion under the conditions of gradient heating and specific screw rotation speed to enable the multifunctional auxiliary agent to be chemically bonded with the matrix polymer; cooling and granulating the extrudate to obtain the composite material; The multifunctional auxiliary agent is an epoxy-terminated core-shell structure hyperbranched polymer, and the preparation method comprises the following steps: under the protection of inert atmosphere, synthesizing amino-terminated hyperbranched polyaramid serving as a rigid core through low-temperature polycondensation; step (b), grafting a polycaprolactone soft segment on the surface of the rigid core through ring-opening polymerization reaction under the action of a catalyst to form a core-shell structure intermediate; and (c) under the action of a phase transfer catalyst, enabling the terminal hydroxyl of the core-shell structure intermediate to react with epichlorohydrin and be converted into an epoxy group, so as to obtain the epoxy-terminated core-shell structure hyperbranched polymer. Further, the matrix polymer is polycarbonate, and the mass part ratio of the matrix polymer to the multifunctional auxiliary agent is (92-97) to (3-8). Further, the gradient heating mode of the reactive extrusion is that the temperature of each zone of the extruder is set to be 230-270 ℃ and the screw rotating speed is set to be 250-350 revolutions per minute. Further, the synthesis of the amino-terminated hyperbranched polyaramid in step (a) comprises the following steps: Carrying out polycondensation reaction on tris (4-aminophenyl) amine and terephthaloyl chloride in an N-methylpyrrolidone solvent at a low temperature of 0-5 ℃ under the protection of inert atmosphere; After the reaction is finished, heating to room temperature to perform curing reaction; And (3) precipitating and separating out the reaction liquid in methanol, filtering, washing and drying in vacuum to obtain the amino-terminated hyperbranched polyaramid. Further, the mass ratio of the tri (4-aminophenyl) amine, the terephthaloyl chloride and the N-methylpyrrolidone is 3:2.1 (80+20). Further, the grafting of the soft segment in step (b) comprises the steps of: mixing terminal amino hyperbranched polyaramid, epsilon-caprolactone and stannous octoate catalyst; and heating to 125-135 ℃ under the protection of nitrogen to carry out ring-opening polymerization for 3.5-4.5 hours. Further, the mass part ratio of the amino-terminated hyperbranched polyaramid to the epsilon-caprolactone is 2 (7-9). Further, the step (c) of introducing an epoxy group includes the steps of: mixing the core-shell structure intermediate, epichlorohydrin and tetrabutylammonium bromide phase transfer catalyst; Dropwise adding sodium hydroxide aqueous solution, and reacting at a constant temperature of not more than 85 ℃; and after the reaction is finished, filtering while the reaction is hot, performing rotary evaporation, extr