Preparation And Study Of Electrospinning Fibers Of Poly (Arylene Ether Ketone)s

Since the first patent on electrospinning has been applied by Formhals, Electrospinning, as a simple and effective method for organic/inorganic nanofibers, has gained special attention. Additionally, electrospun nanofiber can act as a bridge between the nanoscale and macroscale for their nanoscale diameters and macroscale lengths.Aromatic poly (arylene ether ketone)s have achieved remarkable positions among other thermoplastic polymers because of their unique combination of toughness, stiffness, thermooxidative stability, electrical performance, flame retardancy and retention of physical properties at high temperatures. So they have been successfully applied to many fields such as aviation, spaceflight, nuclear energy, communication, telecom, petroleum, machine manufacturing and traffic, in order to renew the old produces. Meanwhile, sulfonated poly (arylene ether ketone)s are also considered as promising alternative materials because of their advantages of low cost, easy preparation, good mechanical strength and high chemical and thermal stabilities. They are promising proton exchange membrane materials.In chapter 2, we have successfully prepared SPAEK polymers with different sulfonated degrees by directly polymerization of sulfonated monomers. SPAEK mainly include SPEEK and SPEEKK. Further we have characterized the structures in detail. The results showed that: the direct-sulfonation method is a powerful method to prepare SPAEK polymers moreover this method can avoid the cross-linking and other side reactions.In chapter 3 of the dissertation, fabrication of sulfonated poly(arylene ether ketone) electrospun membranes was studied. Recently, researches have been focused on elctrospinning because of the preparation of ultrafine and uniform polymer fibers or sphere membranes. So far, more than fifty different polymers have been successfully elctrspun into ultrafine fiber or sphere membranes. However, there is no work related to electrospinning of any kinds of sulfonated poly(arylene ether ketone). SPAEK usually contain two domain regions: hydrophilic and hydrophobic ones. The hydrophobic domains formed by none sulfonated polymer segment provide materials with mechanical strength whereas the hydrophilic domains contain sulfonated groups ensure the proton conductivity. Here, we reported the preparation of SPEEKK membranes by electrospinning for the first time. The results showed that all of the membranes can be easily obtained via electrospinning method. The morphology of resulted membranes varies from nanospheres to nanofibers with increasing concentration of SPEEKK. The results showed that the electrospun membranes had much more clearly phase separation structures than the convenient SPEEKK membranes according to their SAXS studies, and the proton conductivity of all membranes obtained by electrospinning was much higher than that of membranes prepared by solutions casting. The membranes prepared by this method should hold immense promise for the PEMFC applications.