Study On Modification Of Sisal Fiber By Nanomaterials Of Different Dimensions

In order to improve the tensile properties of sisal fiber(SF),nanomaterials were used to modify sisal fibers.The effects of graphene oxide(GO),carbon nanotube(CNT)and titanium dioxide sol three nanomaterials on the tensile properties of sisal fibers were studied in depth.First,the electrostatic self assembly(ESA)was used and cationic polyelectrolyte polyethyleneimine(PEI)as a medium to introduce GO onto sisal fibers.By adjusting the number of GO self-assembly layers,the tensile properties of the sisal fibers modified by different layers were compared.Thermogravimetric analyzer(TGA),scanning electron microscope(SEM),x-ray photoelectron spectrometer(XPS)and Instron material testing machine were used to characterize fiber properties.SEM shows that the surface coating of the modified fiber can be observed obviously.TGA and XPS show that GO is successfully coated on the fiber.The tensile test shows that the tensile modulus of a single fiber increases with the increase of the number of GO electrostatic self-assembly layers.When the number of layers is four,the tensile modulus of sisal fibers is about 70.57% higher than that of untreated sisal fibers.Second,the electrostatic self assembly was used and cationic polyelectrolyte polyethyleneimine as a medium to introduce CNT onto sisal fibers.By adjusting the number of CNT self-assembly layers,the tensile properties of the sisal fibers modified by different layers were compared.TGA,SEM,XPS and Instron material testing machine were used to characterize fiber properties.SEM shows that the surface coating of the modified fiber can be observed obviously.TGA and XPS show that CNT is successfully coated on the fiber.The tensile test shows that the tensile modulus of a single fiber decreases with the increase of the number of CNT electrostatic self-assembly layers.However,when the number of CNT electrostatic self-assembly layers is one layer,the tensile modulus of sisal fibers is increased by about 110.21% than that of untreated sisal fibers.Under the same process,the modification effect of CNT on the tensile properties of sisal fibers is better than that of GO modification.Finally,titanium dioxide sol was prepared by the sol-gel method to modify the sisal fibers.Through the design of orthogonal experiments,the influences of variables such as fiber pretreatment method,p H,glacial acetic acid dosage and curing time on the fiber modification effects was deeply analyzed.The fiber properties were characterized by TGA,SEM,Fourier Infrared Spectroscopy(FTIR)and instron material testing machine.SEM shows that the surface coating of the modified fiber by titanium dioxide sol can be observed obviously.TGA shows that the thermal stability of the fiber modified by titanium dioxide sol improves significantly.FTIR shows that,compared with the unmodified fiber,the-OH absorption peak of the modified fiber disappears obviously,and the-Ti-O-Cbond is formed on the fiber surface.The tensile test shows that when the fiber is treated with alkali,the p H is 3,the amount of glacial acetic acid is 2 m L,and the curing time is 4h,the tensile modulus is the highest,which is about 131.33% higher than that of untreated sisal fibers;when the fiber is treated with alkali,the p H is 2,the amount of glacial acetic acid is 6 m L,and the curing time is 2 h,the tensile strength is the highest,which is about60.73% higher than that of untreated sisal fibers.In summary,the nanomaterials are successfully used to modify the sisal fibers in this thesis and the mechanical properties of modified fibers improve significantly.