Study On The Preparations And Performance Analysis Of Composite Double-layer Hollow Fiber Damping Materials

In this paper, nitrile-butadiene rubber (NBR) and acrylic rubber (ACM) andpolyvinyl chloride (PVC) had been chosen as spinning damping material, hope to obtaina controllable damping wide and temperature range through blending modification. Forthe better film-forming and mechanical properties of polyvinylidene fluoride (PVDF),the problem of difficult to mold hollow and easy to fall flat shrinkage during thespinning process of rubber hollow fiber membranes had been solved by use PVDFhollow fiber damping material as inner core supper materials. A preliminary explorationpreparation of hollow fiber use of the properties of the hollow fiber of PVDFpiezoelectric polarization to active control damping for future, studied dampingcharacteristics of multi-layer composite hollow fiber, an extended range of applicationof the hollow fiber damping material.Through lots of experiments, the preparation technology of compounddouble-layer hollow fiber damping material was obtained，the influence of blendingratio and process conditions on damping loss factor curve of the NBR/ACM/PVC blendmodified hollow fiber and PVDF hollow fiber are discussed by dynamic mechanicalanalysis (DMA), and discussed the effects of damping properties on stratificationphenomenon of double-layer hollow fiber material, it also analyzed the dampingproperties of the core support layer material of type and concentration and outer layersolution of blending ratio and concentration on the double hollow fiber compositematerial. The results showed that:The NBR/ACM/PVC blend modified hollow fiber was compatible for the reasonof the only one loss factor peak，its damping performance effected by the combinedfactors of these three components, The mass radio of NBR/ACM/PVC leads to thehighest peak of the damping loss factor is1/5/4, the widest temperature range of thematerial NBR/ACM/PVC is3/1/5, the highest glass transition temperature of thematerial NBR/ACM/PVC is1/1/8. These results confirm that different compositematerials were optional and adjusting the damping properties of materials were possibleaccording to the different need.Compared the loss factor of temperature curve of two different types of PVDFhollow fiber damping materials, discovered that there were two different loss factorpeaks which in glass transition temperature and crystallization temperature respectively,and the peak in crystallization temperature was higher. This result shows that the PVDF hollow fiber damping material which had good application prospect in piezoelectricfield had a wide temperature range.There were two complete separate peaks in double-layer hollow fiber dampingmaterials, this shows that choosing appropriate inner and outer layers of compositematerials to expand the damping temperature range is necessary.The water content of the core material and the blending radio of the externalmaterial had a great influence on forming the double-layer hollow fiber dampingmaterials. If the water content of the core materials or the blending radio of the contentof PVC in the casting solution of the outer layer increases, the stratification will becomemore and more obvious. This shows that adjusting curing shrinkage of the inner andouter layer material is the key to control stratification structure.The damping properties of the inside layer materials of double-layer hollow fiberdamping materials plays a major role, and the damping properties of the outside layermaterials was weakened at the same time. Therefore, choosing materials which have agood damping performance as the inside layer materials is more advantageous topreparing the double-layer hollow fiber damping materials.The stratification structure of double-layer fiber materials was helpful for outsidematerials to show its damping performance. The interactions between the inner andouter materials are weakened.When PVDF material act as inside-layer material, different model of raw PVDFhave different effect on the damping properties of double-layer hollow fiber materials asthe blending radio of the outside materials changed. Increase solid content of PVDFFR904will inhibit the damping properties of double-layer fiber materials, lowered thedamping loss factor.The blending radio of NBR/ACM/PVC has direct influence on viscosity ofmaterial and rate of phase transition. The damping properties of double-layer fibermaterials will be raised through change the blending radio of NBR/ACM/PVC.Improving solid content of NBR/ACM/PVC blending materials will enhance thedamping properties of double-layer hollow fiber materials.