Preparation Of Polyester Non-woven Fabric By Electrospinning And Its Hydrophilic Modification

Polyester materials and polyvinyl alcohol(PVA)are both polymers with a wide range of applications.Hydrophobic polyester fibers mainly include polyethylene terephthalate(PET)fibers and polybutylene terephthalate(PBT)fiber,in which the mechanical properties of PET fiber are stronger than PBT fiber.The flexibility of PBT fiber is better than PET fiber.The non-woven fabric prepared in this subject is intended to be used in battery separators and biological filtration.Therefore,the film is required to have certain mechanical properties and excellent hydrophilicity,and the polyester film needs to be modified.PBT fiber membrane,PET/PBT blend fiber membrane and PBT/PVA composite fiber membrane were prepared by electrospinning technology.Scanning electron microscope(SEM),gas permeability/air permeability tester,universal testing machine,water contact angle tester,infrared spectrometer and other instruments were used for testing and analysis.In the preparation of polyester PBT film by electrospinning,the effects of spinning solution concentration,spinning voltage,fiber receiving distance and polymer solution pushing rate were explored.The best process was explored: spinning the liquid concentration is 18%,the spinning voltage is 28 kV,the fiber receiving distance is 6 cm,and the spinning liquid pushing rate is 0.003 mm/s.The blending of PET and PBT is used to improve the tensile properties of polyester PBT film.The two structures are similar and the blending state is good.The influence of blending ratio on film morphology and tensile properties is discussed.The experiment proves that when the blending spinning solution is 25% and the spinning voltage is 24 kV,the fiber morphology is good.And the optimal mass ratio of polyester PET/PBT blending film is 1:1.Tensile performance test shows that the mechanical properties of polyester PET/PBT blend film are 3-4 times stronger than pure polyester PBT film.And the mechanical properties of the film have been greatly improved.Two different solvent systems,trifluoroacetic acid and dichloromethane(TFA:DCM=4:1)and hexafluoroisopropanol(HFIP),were explored to prepare PBT/PVA composite membrane.In trifluoroacetic acid solvent,the composite membrane prepared by electrospinning has good fiber morphology.But the water contact angle of the composite membrane is 120°.Although it is lower than the pure PBT membrane water contact angle of 132°,it is still a hydrophobic membrane.The infrared spectroscopy and XPS tests show that the trifluoroacetic acid solvent will react with polyvinyl alcohol(PVA).Fluorine will be grafted onto the composite film,leading to the failure of the hydrophilic modification of the polyester film.In hexafluoroisopropanol solvent,a composite fiber membrane with excellent hydrophilic properties was prepared by electrospinning technology.PBT/PVA mass ratio 5/1,total mass concentration 16%,spinning voltage 26 kV,spinning speed 0.003 mm/s,receiving distance 6cm,are the most appropriate process parameters.The prepared fiber has good morphology,and the average fiber diameter is 500-600 nm.The water contact angle of the composite membrane is 0°,and the time required for the water droplets to contact the surface of the film to completely wet the film is only within 1s.It has excellent hydrophilic properties and can be widely used in biological filtration,tissue engineering and battery separators.