Study On Forming And Characterization Of PAN/PSA Nanocomposite Fiber

As an important component of novel fibers,functional nanofibers are widely concerned with their preparation methods,performance characterization and applications.Polysulfone amide(PSA)is a representative polymer of domestic new high temperature resistant fiber,and polyacrylonitrile(PAN)is an important material for conventional chemical fiber and carbon fiber precursor.It is a new idea to combine these two materials to prepare new type of functional composite fiber.This article focuses on the composite electrospinning of polysulfone amide(PSA)and polyacrylonitrile(PAN)polymers.Designing and developing a self-made electrospinning device that can realize single-needle,multi-needle and parallel needle spinning.The nanocomposite fibers and their aggregates with distinct two-component,multi-product morphology,and different performance were prepared,and the application fields of polyacrylonitrile and polysulfone amide are also extended.The research content of this paper mainly includes: 1)Design and develop a new device to prepare nanoyarns via dynamic rotating electrospinning.The PSA nanoyarns with certain twist are prepared by using multi-needle spinning and dynamic twisting system,and the of concentration of spinning solution and receiver rotating speed on the properties of the nanoyarn are investigated respectively,the more suitable spinning process is also confirmed;2)Establish a geometrical physical model of the spinneret and receiver device,simulate the electric field distribution of the electrospinning process by means of physical simulation,and through a series of characterization methods to test the properties of PSA nanoyarns,furtherly,study the influence of electric field distribution on yarn formation and properties systematically;3)PAN/PSA binary blended nanoyarns were prepared by single needle electrospinning and the properties of nanoyarns were tested by infrared spectrometer(FTIR),scanning electron microscope(SEM),thermogravimetric analyzer(TG),and tensile strength tester respectively;4)The PAN/PSA nanocomposite fiber membrane was prepared by side by side spinneret.After stabilization and high-temperature carbonization,the composite conductive fiber membrane with certain conductive properties was prepared,and its conductivity before and after carbonization was characterized and analyzed.In addition,in order to explore the influence of graphene powder dispersion finishing agent on the electrical conductivity of polyacrylonitrile polymer,different quality fractions of graphene finishing agent were prepared,and polyacrylonitrile/graphene functional composite film was prepared by dip coating.Based on its performance characterization,the influence of dip coating process on its conductive properties was studied.The results show that: 1)Under these experimental conditions,the optimal spinning concentration was 12 wt%,the best receiver speed was 40 r/min,the obtained PSA nanoyarns have good morphology,mechanical properties,wicking properties and heat resistance.2)The distribution of multi-needle electrospinning was simulated by electric field simulation.Combined with the spinning experiment and characterization test,the optimal theoretical spinning voltage of electrospinning of multi-needle sprayer under the experimental conditions was 25 k V,and the best spinning distance between needles is 200 mm.3)During the preparation of PAN/PSA nanoyarns,the morphology and diameter of nanofibers and yarns are obviously influenced by the change of receiver speed and spinning voltage,further affecting the mechanical properties of yarns,under the experimental conditions,the optimal spinning voltage was 25 k V,and the best receiver speed was 40 r/min.The influence of receiver speed and spinning voltage on the thermal properties of fiber is not obviously.4)In the experiments of PAN/PSA side-by-side electrospinning and nanofiber membrane carbonization,when the spinning voltage was set to 20 k V and the receiving distance was 200 mm,the performance of the composite membrane is optimized.5)The addition of graphene by dip coating enhanced the conductivity of the PAN nanofiber membrane and the experimental results showed that: when the mass fraction of graphene in the impregnated slurry was 1.5 wt%,the PAN/G membrane has a better flexibility and conductivity.Through the research and experimental analysis of this dissertation,the basic properties of polysulfone amide/polyacrylonitrile composite nanofibers were initially explored.The influence of the preparation process on its properties were attempted to optimize the process parameters and broad the application fields of polysulfone amide materials.