The Refinement Mechanism And Application Of Melt- Electrospinning Polypropylene Nanofibers

Electrospinning technology is a common method for the preparation of nanofibers, which includes the method of electrospinning and melt electrospinning. The fiber diameter of the latter is relatively large, it is the micron level and it is difficult to reach the nanometer scale. In order to reduce the fiber diameter and improve the performance of polymer fiber, in this paper, the method of the combination of melt electrospinning and phase separation is used to prepare the nanofibers (diameter less than 500 nm).The purpose is to reduce the size of the fiber diameter and achieve the purpose of fiber refinement. The application of Melt electrospinning nanofibers was explored.First of all, this paper based on the compatibility characteristics of the polymers, select polypropylene (PP) and cellulose acetate butyrate (CAB) as the main raw material, which the CAB as a matrix, PP as a dispersed phase, use screw extruder to prepare a electrostatic spinning masterbatch. In this paper, the droplet rupture mode of the dispersed phase in the blend system was proposed, and the effect of composition ratio, temperature (viscosity), shear rate, and blending time on the morphology of dispersed phase was studied. The results showed that:when the composition ratio of PP/CAB is 1/9, PP is the smallest, and the distribution is the most uniform; under the different temperature, the viscosity of them is different, when temperature is 210.0℃, the viscosity ratio close to 1.0, the size of dispersed phase particle is the smallest; Because of the coagulation phenomenon, the shear rate has little effect on the morphology of the dispersed phase, and when the screw speed is 20.0 rpm, the particle size of the dispersed phase is relatively small. In addition, at the beginning of blending, PP morphological changes, when blending time is 4.0 min, the particle size is the smallest.Then, the PP/CAB fiber was prepared by melt electrospinning, and obtained PP nanofibers after use the organic solvent (acetone) to dissolved sacrificial phase (CAB) and removed it. Choose the smallest size of the dispersed phase morphology and distribution of masterbatch as a raw material to melt electrospinning, preparation PP/CAB fibers. The effect of the spinning conditions on fiber size was studied and through experiments to explore the best spinning conditions (temperature, voltage, spinning distance). The results showed that: when voltage was 27.0 kV, temperature was 210.0℃ and spinning distance was 8.0 cm, after removed CAB, the fiber diameter was the smallest, reaching 320.0 nm, porosity was 98.6%. Fiber diameter is refined.In the end, the oil absorption properties, retention performance and reusability of PP nanofiber membrane were studied, and used commercial PP membranes as a reference. Experiment respectively with commercial PP membrane and self-made membrane for ethanol, petroleum ether, dichloromethane, bean oil and motor oil to the adsorption test, and the adsorption capacity was calculated. The maximum adsorption capacity of the five kinds of oil were 42.90 g/g、34.99 g/g,62.78 g/g,60.26 g/g and 66.50 g/g, respectively. Oil absorption were increased 4-8 times compared with commercial PP membranes(the absorption of commercial PP membranes were 11.20 g/g,9.13 g/g,16.39 g/g and 7.4 g/g,17.36 g/g). And after 10 cycles, the fibers prepared by melt electrospinning still maintains good oil absorption properties (the oil absorption capacity is still up to 81.64%).