Electrospinning Of Poly (Phthalazinone Ether Sulfone Ketone) And Its Reinforcement Modification

Electrospinning is a very important method to prepare ultra-fine fibers. Poly(phthalazinone ether sulfone ketone) (PPESK) is a new heat-resistant but soluble polymer. It has found widely a variety of applications in industry due to its excellent performances. However, so far there haven't been any reports on the electrospinning of PPESK.The objectives of this thesis are to firstly prepare the PPESK fibrous membranes, and then to investigate the influence of electrospinning on the compatibility and miscibility of polymer blends, and finally to reinforce the PPESK membranes. The following aspects were focused: the effects of solution concentration, spinning voltage, solidification distance and mixture solvents on the morphology of PPESK fibrous membranes; the effect of electrospinning on the miscibility and compatibility of both miscible and immiscible polymer systems; reinforcing treatment with multi-walled carbon nanotubes (MWCNTs) in the senses of the morphology and mechanical property of PPESK/PS composite fibrous membranes; and the lamination compounding of PET spun-bonded and electrospun PPESK nonwovens with focusing on interlayer adhesion via both styrene emulsion and solution treatments. The major results and conclusions are summarized as follows:(1) PPESK nanofibers were successfully prepared by electrospinnig. When DMAc was used as solvent, the morphology of electrospun fibers was fair good. However, the spinning process was unstable. The PPESK concentrations in the ranges of 12 - 15w/v %, spin voltage between 8 and 14kv, and solidification distance within 10 - 20cm were fit for electrospinning. Mixture solvents can effectively improve the morphology of the fibers. Among them, NMP/THF mixture system is the best solvent for the electrospinning of PPESK. The spinning process was stable when the volume ratios of NMP and THF were 7:3 and 4:6, respectively. NMP/DMAC mixture solvent can also improve the morphology of the nanofibers, especially when the volume ratio of NMP and DMAc was 3:7. The best morphology can be got with DMAc and THF mixture solvent, however, the spinning process was unstable. (2) Electrospinning improves the compatibility of immiscible polymer blend while no change happens for the miscible polymer blend. Solvent showed strong effect on the microstructure and mechanical property of both immiscible and miscible polymer membranes.(3) With the increase of the amount of MWCNTs, the average diameter of PPESK/PS fibers decreased evidently, and the tensile strength and elongation at break increased slowly.(4) Emulsion treatment successfully improved the interlayer adhesion between two different nonwovens while retaining their original morphology mostly. However, the air filtration efficiency of the lamination composite membranes was decreased due to continual release of PS latex particles. The composite membranes obtained by solution treatment showed fair good adhesion with no delamination and its air filtration efficiency improved greatly, which was up to 95.2%, yet still a little lower than that of pure fibrous membrane.The feature and innovations of the work are following:(1) PPESK fibrous membrane was successfully prepared by electrospinning technology.(2) Polymer miscibility was studied by electrospinning technology.(3) PET spun-bonded nonwoven was used as support, and the interlayer adhesion between PET and electrospun PPESK nonwovens was handled with emulsion and solution methods.