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A kind of high temperature resistant fluorine-containing polyimide heat-shrinkable tube and its preparation method

A fluorine-containing polyimide heat-shrinkable tube and a technology of fluorine-containing polyimide, which are applied in the field of heat-shrinkable tubes, can solve the problems of consuming a large amount of heat-shrinkable tubes, high water absorption, and application limitations, and achieve energy reduction and low heat Excellent shrinkage temperature and hydrophobic performance

Active Publication Date: 2021-01-08
CHANGCHUN INST OF APPLIED CHEMISTRY - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At present, the maximum operating temperature of heat-shrinkable tubing made of PVC, polyolefin, PVDF, FEP, etc. does not exceed 200°C. Although the heat-shrinkable tubing made of PTFE can work continuously in the temperature range of -270-260°C, its heat-shrinking temperature is lower than 200°C. Up to about 340°C, it takes a lot of heat to make the heat shrinkable tube produce shape memory
[0005] At present, the heat-shrinkable tube material that can be used continuously above 200°C and has a low heat shrinkage temperature is a shape memory polyimide material, but this type of material has a high water absorption rate (above 3%). Applications in the field of shrinkable materials are limited

Method used

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  • A kind of high temperature resistant fluorine-containing polyimide heat-shrinkable tube and its preparation method
  • A kind of high temperature resistant fluorine-containing polyimide heat-shrinkable tube and its preparation method
  • A kind of high temperature resistant fluorine-containing polyimide heat-shrinkable tube and its preparation method

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preparation example Construction

[0040] The present invention also provides a method for preparing a high-temperature-resistant fluorine-containing polyimide heat-shrinkable tube, comprising the following steps:

[0041] a) the structural monomer of formula (i), the structural monomer of formula (ii) and the structural monomer of formula (iii) are mixed and reacted in a solvent to obtain a prepolymer solution;

[0042]

[0043] b) mixing and reacting the prepolymer solution and the end-capping agent to obtain a sol solution;

[0044] c) heating and drying the sol solution in a mold to imidize and shape it to obtain a tube;

[0045] d) heating and expanding the tube, and then cooling and shaping it to obtain a heat-shrinkable tube of high-temperature-resistant fluorine-containing polyimide.

[0046]In the preparation method provided by the present invention, first, the structural monomer of formula (i), the structural monomer of formula (ii) and the structural monomer of formula (iii) are mixed and reacted...

Embodiment 1

[0065] 1) Add the mixture of structural monomers of formula (i) and structural monomers of formula (ii) into N,N-dimethylacetamide, stir at room temperature and nitrogen atmosphere until completely dissolved to obtain a diamine mixed solution, Wherein the mol ratio of formula (i) structural monomer and formula (ii) structural monomer is 1:5, and the volume ratio of the total substance amount of two kinds of diamines and N,N-dimethylacetamide is 0.3mmol: 1mL;

[0066] 2) Dissolve the structural monomer of formula (iii) in N,N-dimethylacetamide, stir at room temperature and nitrogen atmosphere until completely dissolved to obtain a dianhydride solution, the amount of the structural monomer of formula (iii) The volume ratio to N,N-dimethylacetamide is 0.25mmol:1mL;

[0067] 3) According to the volume ratio of 1:1, add the diamine mixed solution into the three-necked flask containing the dianhydride solution, and react for 8 hours at a stirring speed of 250-500rpm in a dry nitrog...

Embodiment 2

[0075] 1) Add the mixture of structural monomers of formula (i) and structural monomers of formula (ii) into N,N-dimethylacetamide, stir at room temperature and nitrogen atmosphere until completely dissolved to obtain a diamine mixed solution, Wherein the mol ratio of formula (i) structural monomer and formula (ii) structural monomer is 1:1, and the volume ratio of the total substance amount of two kinds of diamines and N,N-dimethylacetamide is 0.3mmol: 1mL;

[0076] 2) Dissolve the structural monomer of formula (iii) in N,N-dimethylacetamide, stir at room temperature and nitrogen atmosphere until completely dissolved to obtain a dianhydride solution, the amount of the structural monomer of formula (iii) The volume ratio to N,N-dimethylacetamide is 0.25mmol:1mL;

[0077] 3) According to the volume ratio of 1:1, add the diamine mixed solution into the three-necked flask containing the dianhydride solution, and react for 8 hours at a stirring speed of 250-500rpm in a dry nitrog...

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Abstract

The invention belongs to the technical field of heat-shrinkable tubes, and in particular relates to a high-temperature-resistant fluorine-containing polyimide heat-shrinkable tube and a preparation method thereof. The heat-shrinkable tube provided by the present invention is made of fluorine-containing polyimide with shape memory function, and the fluorine-containing polyimide is composed of formula (i) structural monomer, formula (ii) structural monomer and formula (iii) ) The prepolymer formed by the polymerization of structural monomers is reacted with an end-capping agent. The heat-shrinkable tube provided by the present invention is made of fluorine-containing polyimide material with a specific structure, which can not only meet the protection requirements of cables in a high-temperature environment, but also has a lower heat-shrinkage temperature, which can effectively reduce the heat shrinkage of the heat-shrinkable tube during use. required energy; moreover, the heat-shrinkable tube has a lighter color and excellent hydrophobicity, so it has broad application prospects in the field of heat-shrinkable materials. Experimental results show that: the thermal shock temperature of the heat-shrinkable tube provided by the invention is ≥320°C, the heat-shrinkage temperature is 245-255°C, and the water absorption rate is less than 0.5%.

Description

technical field [0001] The invention belongs to the technical field of heat-shrinkable tubes, and in particular relates to a high-temperature-resistant fluorine-containing polyimide heat-shrinkable tube and a preparation method thereof. Background technique [0002] Heat-shrinkable tubes are made of shape-memory polymer materials. They are mainly used in the junctions, connectors, and ends of wires and cables to protect them from insulation, moisture, corrosion, and wear. It has the characteristics of simplicity, stable performance, and wide application occasions, and has been widely used in the fields of electronics, nuclear power, communications, petroleum, automobiles, and military industries. [0003] Most of the materials of heat shrinkable tubes are blended with several kinds of polymer materials. The main materials include PVC, polyolefin, silicone rubber, PVDF, FEP, PTFE, etc. The main materials determine the use temperature grade and use environment of heat shrinkab...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G73/10
CPCC08G73/1014C08G73/1039C08G73/1042C08G73/1071C08G2101/00C08G2280/00
Inventor 冉祥海付超聂伟钱景
Owner CHANGCHUN INST OF APPLIED CHEMISTRY - CHINESE ACAD OF SCI