Study On New Type Of Composite Polyimide Double-layer Hollow Fiber Damping Materials Which Can Resistant High Temperature

In this paper, The polyimide(P84) had been manufactured to hollow fiber damping materials which can resistant high temperature through experiments, on this basis, nitrile-butadiene rubber(NBR) and acrylic rubber(ACM) and polyvinyl chloride(PVC) had been chose as spinning damping material which used as inner core supper materials, and the polyimide(P84) hollow fiber damping material as outer core supper materials. the combination of those two materials became a new double hollow fiber damping materials which can resistant high temperature. Finally, using rubber materials(NBR or ACM) to blend with polyimide(P84) to get two kinds of new modified hollow fiber damping material(P84/NBR/ PVC hollow fiber damping material and P84/ACM/ PVC hollow fiber damping material), and this damping material not only has great damping capacity but also can resistant high temperature.Through a lot of experiments to get a series of hollow fiber damping materials successfully, after those materials had been tested by using dynamic thermal mechanical analyzer(DMA), then discuss the difference between polyimide hollow fiber membranes and polyimide plate membranes, and discuss the effects of inner core supper materials and outer core supper materials on double-layer hollow fiber materials, and also analyze the influence of different solid content, different blending ratio, the size of the nozzles and different types of rubber on modified hollow fiber damping materials, The results showed that:(1)Comparing the damping capacity of polyimide hollow fiber membranes and polyimide plate membranes can found the former is better than the latter, so it proved that hollow structure is better than plate structure in terms of the damping capacity of materials once again, when the solid content of polyimide hollow fiber membranes is28%, the temperature at 250℃, the damping capacity of material is best and Tan δ is0.2365.(2)Using DMA to test the damping capacity of compound double hollow fiber damping materials and compared with the damping performance of single-layer hollow fiber damping materials, you will find that the former have two loss factor peaks, and temperature range had been broaden obviously, so it means the damping performance of inner core supper materials had been restricted, It is because the outer core supper materials lack of viscoelasticity and it affects the damping performance of composite double hollow fiber damping materials. It means when put two differentmaterials which have different temperature range together can design its damping peak temperature.( 3) Observing cross-sectional area of compound hollow fiber damping materials by scanning electron microscopy, the results show that there are almost no gap between inner core supper materials and outer core supper materials.(4) Using rubber(NBR or ACM) to blend with polyimide, not only greatly improved their toughness and strength, and also damping properties of the materials had very big enhancement. Within the scope of the experimental conditions, different blend ratio of P84/NBR/PVC have a big impact on damping properties of modified hollow fiber damping materials, when the content of NBR and P84 are 10%, the content of PVC is 80%, damping properties of modified hollow fiber damping material is the best, it’s loss factor is close to 0.45 and the glass transition temperature of that is 80℃. And it still has a good damping performance when temperature is at160 ℃.when the ACM/P84 / PVC = 2/1/7, damping properties of modified hollow fiber damping material is the best, it’s loss factor is close to 0.4, the glass transition temperature of that is 60℃.( 5) Observing cross-sectional area of modified hollow fiber membrane by scanning electron microscopy, the results show that: different blending ratio, the size of the nozzles and different types of rubber all can have an influence on internal structure of modified hollow fiber membrane, and the results of infrared spectral show that the three components of blending materials have compatibility, the rubber material is verified with the feasibility of changing the P84’s toughness.(6)Within the scope of the experimental conditions, when other factors are the same, the size of the nozzle also have an great influence on damping properties of modified hollow fiber damping materials, in terms of damping performance of materials, 16-9(mm)>13-7(mm) > 18-9(mm). It means the pore size and pore wall thickness of modified hollow fiber damping materials also has an optimum value.