An Investigaion On Preparation Of Nylon Electrospun Fibers And Its Application

The chemical fibers are widely used for textile, engineering textile and reinforced material. The diamaters of fiber range from 5 to 50μm. Recently, there are great interests in the development of ultrafine fiber. There are several processing methods of producing ultrafine fibers, in which electrospinning has drawn many attention due to producing continuous ultrafine fiber. The diameters of electrospun fibers range from several microns to less than 10 nm. The nanofibers with small diameters, high surface area and porosity show promise for the applications such as filtration, drug delivery and tissue scaffiolds.Nylon 6 (NY 6) fibers were the main product in synthetic fibers. Nylon 6 fibers with excellent toughness, wear and thermal stability are widely used as wearing apparel, brush bristles, carpet, textile, composite materials and conveyor belts, which have been produced by conventional spinning techniques such as melt, wet and dry spinning. Nylon 6 electrospun nanofiber by electrospinning with small diameters and high surface area show promise for the applications such as filtration, drug delivery, tissue scaffiolds and composite materials.Electrospun nylon 6 nanofibers and its applications were investigated in this research. Firstly, the effects of mixed solvents on the properties of nylon 6 solutions and the morphological appearance of the resulting fibers were reported in this study. The effects of processing temperature on the spinnabilities and morpologies of electrospun nylon 6 fibers were also reported. Moreover, effects of interaction between nylon 6 and salt on electrospinning were investigated in this study. Finally, the adsorption behavior of nylon 6 electrospun nonwoven containing attapulgite on metal ion Cd²⁺ was discussed in this study.The main research contents of this thesis are summarized as follows:1. The effects of mixed solvents and temperature on morphologies of electrospun nylon 6 (NY6) fibers were reported in this study. An investigation of electrospinning NY6 / formic acid (FA)/ dichloromethane (DCM) solutions was conducted, wherein FA was used as solvent and DCM was used as nonsolvent for NY6. It was found that NY6 pellets could dissolve in FA/DCM mixtures with various volume ratios faster than in pure FA. Moreover, the addition of DCM to NY6/FA solution modified the solution properties, i.e., conductivity, surface tension and viscosity. The mixed solvents component has an important influence on morphological appearance and sizes of NY6 electrospun fibers. The effects of processing temperature on spinnability and morpologies of electrospun electrospun nylon 6 fiber were also reported.2.The effects of interaction between CaCl₂ and nylon 6 on nylon 6 electrospun fibers were investigated on this study. Firsly, the interaction between CaCl₂ and nylon 6 could affect the crystaline of nylon 6. FTIR, DSC and XRD revealed that the crystaline of nylon 6 reduced with inceasing CaCl₂. Moreover, the interaction between CaCl₂ and nylon 6 could modify spinning solution properties, i.e., conductivity, surface tension and viscosity. The the interaction between CaCl₂ and nylon 6 has an important influences on morphological appearance and sizes of the resulting NY6 electrospun fibers. Finally, nylon 6 resins were melt blending with CaCl₂ to prepare composites, and then were melt spinning to prepare fibers. The drawing and tenacity properties of fiber specimens were investigated.3.The attapulgite powders modified by silicane coupling agent are loaded onto the surface of nylon 6 nanofibers by immersing the nylon 6 nanofibrous nonwoven in a bath containing a attapulgite dispersion under ultrasonicating. The nylon6 nanofibrous nonwoven containing attapulgite nano particles was explored as―nano adsorbent‖to remove Cd²⁺ from aquous solution. The effects of various parameters on adsorption behaviour, such as contact time, pH values of Cd (II) solution and initial Cd (II) concentration were investigated. Finally, the adsorption of nylon6 nanofibrous nonwoven containing attapulgite and attapulgite particles on Cd²⁺ was discussed in this study.