Preparation And Mechanical Properties Of Polyacrylonitrile Nanofiber Reinforced Thermoplastic Polyurethane Film

As one of the preparation methods of nanofibers,the electrostatic spinning has been widely used due to its simple preparation technology.However,the nanofibers produced by using electrostatic spinning have poor performance in mechanical properties.Polyacrylonitrile(PAN)was widely used in the preparation of carbon fiber due to its high melting point and molecular orientation.But PAN fiber is not wear-resistant.Thermoplastic Polyurethane(TPU)can improve the shortcomings of PAN because of its good flexibility and fatigue resistance.Using TPU and PAN electrostatic spinning can also improve the surface morphology of nanofibers.In this paper,thermoplastic polyurethane(TPU)and polyacrylonitrile(PAN)polymers of different proportions were soluble in N,N-dimethylformamide(DMF),polyacrylonitrile/ thermoplastic polyurethane(PAN/TPU)composite nanofiber film was prepared by electrospinning.By heating PAN/TPU nanofibrous film,the TPU with low melting point was melt-coated on the PAN nanofiber surface,and polyacrylonitrile nanofiber reinforced thermoplastic polyurethane(PANNFs/TPU)film was prepared to improve mechanical property.Scanning electron microscope(SEM)was applied to analyze the morphological structure of PAN/TPU and PANNFs/TPU film.The mechanical properties of films were tested by multi-function stretcher.The heat treatment range of composite film was determined by TG thermal analysis.The results showed that the best heat treatment conditions is 200 degrees?60mins.The mechanical properties of films were tested by multi-function stretcher.When the quality ratio of PAN and TPU in the electrospun solution was 4:6,the broken strength of prepared PANNFs/TPU film reached 147.1MPa and the broken elongation reached 169.8%.When the quality ratio was 4:6 and the concentration of electrospun solution increased to 18wt%,the viscosity of the solution was 6Pa.S.At this time,the PANNFs/TPU film showed desirable mechanical properties with broken strength 197.8Mpa and broken elongation 307.6%.Compared with the PANNFs/TPU composite film,the PANNFs/TPU composite orientation film has a larger fracture stress and a smaller fracture strain.The fracture stress and fracture strain obtained by vertical fiber alignment direction were both smaller.At the 1500r/min speed of revolution,the fracture stress of the parallel fiber alignment direction reached the maximum value of 306.8MPa,and the fracture strain of the vertical fiber alignment reached the maximum value of 163.1%.The PAN nanofiber reinforced TPU composite film prepared by this method can be used in engineering materials,aerospace,automobile industry and other fields.