Preparation And Thermal Sensitivity Of PAN / PU Transparent Membrane

Electrospinning method can be more easily prepared nanofibers,but its mechanical properties are not good enough.Polyacrylonitrile(PAN)is considered to be the most important precursor for the preparation of carbon fibers today.It is characterized by a high degree of molecular orientation and a high melting point,as well as good chemical,thermal and mechanical stability.Therefore PAN After the solution is used in electrospinning,its spinnability is good,and the fiber forming property obtained is also good,which is a commonly used raw material in the electrospinning process.Polyurethane(PU)is synthesized from polyols,diisocyanates and other materials.It has a unique block structure of soft and hard segments,good mechanical properties,good flexibility and fatigue resistance.Therefore,in the preparation of various films Has a wide range of applications.PU and PAN doping not only improve the poor strength of PAN is not wear-resistant,PU electrospinning chatter without good formability and other shortcomings also greatly improve the appearance of fiber membrane features.In this paper,polyacrylonitrile nanofiber reinforced polyurethane-based transparent composite membrane was prepared by electrospinning and heat treatment.The process of preparing transparent membrane,the morphology,mechanical properties and transparency of the membrane were studied.The mechanism of membrane transparency was also analyzed.In order to prepare the electrospinning solution,weighed a certain amount of PAN powder and 0.516 gPU powder were dissolved in two containing 2.5mlDMF reagent bottle,the two reagent bottles placed in a magnetic stirrer uniformly stirred at room temperature for 12 h,According to different electrospinning methods,different electrospinning solutions were prepared,in which the PAN concentration varied from 8% to 14% and the concentration gradient was 2%.The spinning parameters of high-voltage power supply 15 kv,spinneret and receiving plate distance 18 cm,spinning rate of 0.6ml / h.The resulting composite film was placed in an oven for heat treatment to form a transparent film.In order to investigate the effect of temperature on the transparent film,the other parameters were kept unchanged.The heating temperature during the heat treatment rose from 190 ° C to 230 ° C at a temperature gradient of10 ° C Analysis of the impact of heating time on the transparency.In this paper,nanofiber-reinforced transparent films were prepared by electrospinning and heat treatment.The results show that the optical transmittance of the films prepared by this technique can reach at least 90%.When the concentration of PAN in the electrospinning solution is 12% The heat treatment temperature is 200 ?,the heat treatment time is 10 min,the light transmittance of the composite film reaches up to 95%,while the mechanical properties of the composite film reach a good state,which can be applied to temperature-sensitive materials.And when a certain temperature-sensitive ink is applied to the surface of the composite transparent film,the color of the composite film will change as the temperature increases,which makes it a better application prospect as a temperature-sensitive material.