238 / 2022-03-14 21:18:53

Preparation and electrothermal mechanical properties of PBO fiber reinforced microspheres / epoxy insulating materials

PBO fiber; Syntactic foam; Epoxy resin; Lightweight insulating material

Hollow polymeric microsphere filled epoxy resin syntactic foam has the advantages of light weight, high insulation and low water absorption. It is widely used in electrical insulation, deep sea buoyancy, aerospace and so on. However, it has some problems, such as brittle, poor toughness and poor bending and tensile resistance, which lead to easy cracking during pouring and affect the comprehensive properties. The above problems restrict the popularization and application of syntactic foam on composite insulation core. The use of PBO (p-phenylene-2, 6- benzobisoxazole) fiber toughened composite foam is one of the solutions to the above problems. In this paper, short PBO fiber was added to the preparation of Hollow polymeric microsphere / epoxy resin syntactic foam, and flexural test, tensile test, breakdown test and leakage current measurement of syntactic foam with different PBO fiber content were carried out. The test results showed that the mechanical properties and electrical properties of the syntactic foam reinforced by PBO fiber were significantly improved, and the breakdown voltage increased from 20.61kV to 23.32kV, which increased by 13.15%. After adding 0.2% PBO fiber, the flexural and tensile properties of the syntactic foams increased the most, and the elastic modulus of the syntactic foams increased from 269.45MPa to 430.76MPa, up by 59.87%. The bending modulus increased from 650MPa to 841.25MPa, an increase of 29.42%. However, due to the problem of chemical inertness and dispersion on the surface of PBO fibers, the fiber / resin interface defects increase as the fiber content continues to rise, and the growth of mechanical and insulating properties of syntactic foam presents a downward trend. This test conclusion is helpful to further develop PBO fiber modified syntactic foam.