The Study Of Phenolic Resin-carbon Fibers And Prepared By Electrospinning And Its Performance

Phenolic resin is a kind of carbon material hard to graphitized,which is low density and high porosity.It is an ideal precurso of porous carbon fibers.In this paper,we use two methods including melt electrostatic spinning and solution electrostatic spinning,and we choose the corresponding thermoplastic phenolic resin and thermosetting phenolic resin as raw materials,phenolic fibers are producted finally.And then we adopted methenamine curing method and the step curing process,the final phenolic-based carbon fibers was prepared under 1000℃,and the hydrogen storage capacity was tested.Due to the fiber diameter,fiber morphology and thermal properties will influence the carbonization process,therefore in the process of the melt electrostatic spinning,orthogonal experimental method is arranged,which to explore influence on diameter,such as spinning temperature,spinning voltage and the distance.In solution electrostatic spinning process,we explored the best concentration of spinning solution.And the cured fibers produced by melt electrostatic spinning and cured fibers produced by solution electrostatic spinning were compared.We found that phenolic fibers by melt spinning are of high purity,and the morphology is better.The important order of influence on fiber diameter is temperature,voltage,and distance.And the important order of influence on fiber diameter distribution is voltage,temperature,and distance.Phenolic resin spinningable temperature range is between 120℃and 180℃.But the thermal performance of curing fibers becomes poor,and they release formaldehyde in the process of solidification,which will pollute the environment.Solution electrostatic spinning experiment device is simple,and the curing process is convenient,environmental,so it is an ideal preparation method.In the process ethanol needs to be used as the solvent,what’s more concentration of 0.5%PVB is added to improve spinnability.Spinning device needs to choose 60° angle of 19G stainless steel needle,the receiver should be inclined to receive below.When the concentration of phenolic resin is 40%,the fiber morphology.When the concentration of phenolic resin is 30%and 50%,fibers have poor morphology,and thickness.And when the concentration is lower than 30%or higher than 50%,they can’t spinning.Using direct heating method to cure the phenolic fiber,melting phenomenon is very serious,and useing step-heating curing method is more advantageous to make fibers sufficient crosslinking.After curing,the fiber morphology is better,and its thermal performance was obviously improved,the weight loss rate is smaller,and finally the amount of carbon residue is as high as 50%.Under 1000℃,curing phenolic fiber successfully change into phenolic-based carbon fiber,the fiber diameter becomes from 1.26μm to 837 n.And fiber morphology is better,and even thickness.The N2 and H₂ adsorption curve of phenolic-based carbon fibers accord with type I adsorption curve.The average pore size is 1.9 nm,and most are micro hole,and the specific surface area is higher,carbon yield is up to 49.39%.And we measured the adsorption quantity of H₂ is 3.4 wt%.