Composite aramid fiber/polyimide material and its prepn

An aramid fiber and polyimide technology, which is applied in the field of new material preparation, can solve the problems of complex molding process, unsuitable production shape, complex molding, etc., and achieves a simple process, excellent tribological properties, and excellent mechanical properties. Effect

Inactive Publication Date: 2004-04-07
SHANGHAI JIAO TONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] CN1080298A discloses a thermoplastic polyimide composite material and its preparation method. The continuous fiber-reinforced polyimide composite material is prepared by in-situ polymerization. The polyimide used is thermoplastic, and its molding is relatively complicated, so it is more suitable for composite The ...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Prepare aramid fiber / polyimide composite material component weight percent as: F-12 chopped aramid fiber (length is about 15mm): 30%, PMR-15 polyimide molding powder: 65%, polytetrafluoroethylene Vinyl fluoride 2.5%, graphite 2.5%.

[0020] First, γ-rays are used to irradiate the aramid fiber under nitrogen environment, and the irradiation dose is 300kGy, and then it is mixed with polyimide molding powder, polytetrafluoroethylene, and graphite in a jet mill for jet milling. The compressed air pressure is 4MPa, and then undergoes hot compression molding at a temperature of 200°C for 1 hour and a pressure of 23MPa.

[0021] According to the GB1446-83 standard, the tensile strength of the composite material is 58.4MPa.

Embodiment 2

[0023] In order to test the tribological properties of the composite material, adjust the raw material ratio of the composite material, increase the polytetrafluoroethylene component and the graphite component, and the weight percentage is as follows: chopped Kevlar fiber (about 3mm in length): 20%, PMR-15 Polyimide molding powder: 70%, polytetrafluoroethylene: 5%, graphite: 5%.

[0024] Firstly, γ-rays are used to irradiate the aramid fibers in a nitrogen environment, and the irradiation dose is 400kGy, and then they are mixed with polyimide molding powder, polytetrafluoroethylene, and graphite in an airflow mill. The compressed air pressure is 5MPa, and then it is molded by hot compression at a temperature of 220°C for 40 minutes and a pressure of 20MPa.

[0025] After forming, it is machined into a bolt sample of Φ5mm×18mm polyimide composite material, and the tribological properties of the material are measured on the Xuanwu No. 1.2×10 -14 m 3 (Nm) -1 .

Embodiment 3

[0027] The weight percent of raw material components is: APMOC chopped aramid fiber (about 10mm in length): 15%, PMR-15 polyimide molding powder: 80%, polytetrafluoroethylene 2.5%, graphite 2.5%.

[0028] Firstly, γ-rays are used to irradiate the aramid fibers in a nitrogen environment, and the irradiation dose is 500kGy, and then they are mixed with polyimide molding powder, polytetrafluoroethylene, and graphite in an airflow mill. The compressed air pressure is 6MPa, and then it is molded by hot compression at a temperature of 240°C for 0.5 hours and a pressure of 16MPa.

[0029] GB1449-83 standard test its bending strength, the result is 70.2Mpa.

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Abstract

During the preparation of composite aramid fiber/polyimide material, aramid fiber is first surface modified via gamma-ray irradiation of dosage 300-500 kGy in nitrogen atmosphere to raise surface activity; the surface modified aramid fiber, additive polyimide powder, PTEF and graphite are then airflow crushed and mixed in an air flow crusher of air pressure 4-6 MPa; the mixture powder is hot pressing molded at 200-240 deg.c and 16-23 MPa for 0.5-1 hr. Thus prepared composite aramid fiber/polymide material has excellent mechanical performance and friction performance and may be used in the structural part and friction part in aeronautic and astronautic fields.

Description

Technical field: [0001] The invention relates to a novel composite material and a preparation method thereof, in particular to an aramid fiber / polyimide composite material and a preparation method thereof, and belongs to the technical field of new material preparation. Background technique: [0002] Polyimide is a kind of organic polymer containing imide groups in the main chain, which has the advantages of excellent thermal stability, high vacuum, radiation resistance and low friction and wear. As a self-lubricating and wear-resistant material, polyimide is used in friction systems in aerospace and other fields, and has increasingly received great attention from national defense, military and cutting-edge technology departments. Among them, the addition type polyimide (API) has excellent processing performance and outstanding thermal oxidation stability, but the wear resistance is poor when used alone, so various fillers are added to the matrix to make polyimide composite ...

Claims

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Application Information

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IPC IPC(8): C08J5/06C08L27/18D06M11/00
Inventor 吴炬程先华
Owner SHANGHAI JIAO TONG UNIV
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