Electrospinning Preparation / Of Mwnts Nano-composite Materials And Their Performance

Polyurethane(PU) is one of the most versatile materials today.It is widely used in coatings,adhesives,thermoplastic elastomers and so on.But the mechanical properties and thermal stability are need to be modified for its more widely use.Here we added Multi-walled carbon nanotubes(MWNTs) to PU matrix for improving the properties of PU.MWNTs were first treated by an optimized H₂SO₄/HNO₃ acid.Acid treated MWNTs was maxed with PU in N,N-Dimethylacemide(DMAc),and found that treated MWNTs can be more efficiently dispersed in PU solutions than untreated.PU nanofibers were spun by electrospinning.In order to obtain the better electrospinning condition,the morphology of electrospinning nanofibers were studied by scanning electron microscopy(SEM) to research the relationship of morphology of electrospinning nanofibers with PU concentrations,electrostatistic voltage,electrospun distance and temperature.The rheological behavior of PU/MWNTs with different content slution was also studied.The results show that the solution is non-newtonian fluid.The viscosity decreased with the increase of shear rate,which is common for polymer.PU/MWNTs composite nanofibers were prepared by the electrospinning technology and collected as the form of membranes.The morphology and microstructure of the composite nanofibers were analyzed by SEM and TEM.Composite ultrafine fibers can be obtained and also MWNTs should be well dispersed in nanofibers but not orientated. XRD was used to confirm the exist of MWNTs in nanofibers.The characteristic of contace angle found hydrophilic property of PU improved with the adding of MWNTs. The relationship between the tensile properties of the membranes and the mass fraction of the MWNTs was revealed by tensile testing,with the increase of MWNTs content in the hybrid nanofibers,the adding of MWNTs improves the mechanical property.Thermal property of the membranes was examined by thermogravimetric analysis(TGA).With the adding of MWNTs increasing,the degradation temperature of the composite nanofibers increases.