Development Of Polylactic Acid And Polypropylene Special Materials For Melt Differential Electrospinning And Preparation Of Corresponding Nanofibers

Nanofibers have been widely used in the fields of biomedicine,high efficiency filter materials and nano components.In recent years,because of the large demand of nanofibers,electrostatic spinning,as a simple and effective process for the production of nanofibers,has been widely concerned at home and abroad.Among them,melt electrospinning technology has become the focus of research because of its advantages such as no solvent,environmental protection,high production efficiency and good fiber appearance.At present,there are some problems in melt electrospinning,such as limited spinnable materials,difficult to reach nanometer level and uneven diameter.Therefore,by changing the flow properties of two materials of poly(lactic acid)(PLA)and polypropylene(PP),the melt electrostatic spinning special material is developed by studying the influence of the flow properties on the diameter and uniformity of the fiber.At the same time,the bulk preparation of nanofibers is realized by improving the existing melt spinning device.First,according to the requirement of melt differential electrostatic spinning for material fluidity,PLA and PP are treated with viscosity reduction.It is found that three butyl ester of acetyl citrate(ATBC)has the best viscosity reduction effect on PLA and PP.Using molecular simulation,the viscosity reduction mechanism of ATBC to PLA is studied.The result shows that the extension of ATBC in PLA leads to the extension of the PLA molecular chain.And migration indicated that ATBC played a role in lubricating the PLA chain.At the same time,the crystallinity and thermal weightlessness of PLA and PP after ATBC viscosity reduction were tested,which provided a basis for subsequent processing technology.On this basis,using a self-made melt differential electrostatic spinning device,the effects of ATBC content and air flow on the diameter of PLA and PP fibers are investigated by experiments.The results show that PLA and PP nanofibers can be successfully prepared by the melt differential electrostatic spinning device in improving the fluidity and the rational distribution of the airflow velocity.At last,in order to improve the uniformity of fiber diameter,a sawtooth guided non needle melt spinning device was designed by ourselves.Through the orthogonal experiment and the process condition refining experiment,the optimum spinning parameters of the PP fiber were obtained.Using this device,the nanoscale PP fiber could be obtained by combining with the material modification.The research results provide some reference value for industrial production.The small batch production of polylactic acid nanofibers was realized by the self-made melt differential electrospinning device,which was the leading level in the technology field of poly lactic acid fiber.The preparation methods of polylactic acid nanofibers are not involved in the use and recovery of toxic solvents in the solution electrospinning,and after the treatment of residual solvent after the treatment of the residual solvents.The polylactic acid nanofibers via this method are widely used in more fields,especially in the field of biological medicine.Polylactic acid is a bioenvironment-friendly material,and it is not pollute the environment and is of great significance to the development of green,low-carbon and environmental friendly life.