Beta - Cyclodextrin Polymer Preparation And Its Electric Control Electrorheological Performance Research

Electrorheological materials have attracted more attentions due to their broad industrial application prospects in automotive engineering, medical equipment, hydraulic engineering, robotics engineering and other fields. According to the principle of electrorheological phenomenon and from the viewpoint of chemistry design, we synthesized polymer-based electrorheological materials with suitable crosslinking degree and easier polarization into chains properties. Additionally, we prepared the water-soluble β-CD polymers with better properties under electric field, which will provide a new method for the synthesis of electrorheological materials.In this thesis, a series of β-CD polymers were synthesized using traditional solution method under electric fields. The structures and morphology of the as-prepared polymers were characterized by infrared absorption spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Vis absorption spectroscopy (UV-Vis) and NMR. With the β-CDPs as the dispersed phase, we prepared electrorheological fluids and evaluated their rheological properties like dielectric coefficient, dielectric loss, shear stress and yield stress. The effects of the electric field on the rheological properties were analyzed and discussed and interpreted the reasons. The details are as follows:(1) Five water-soluble β-cyclodextrin polymers I under electric field were synthesized and their microstructures and morphologies were characterized by FT-IR SEM, NMR and XRD techniques. The electrorheological properties of the electrorheological fluids, prepared by using silicone oil as dispersion medium and the as-synthesized P-CDPs as dispersion phase, were investigated and the resulted showed that the morphology and microstructure of I are different from those of normal β-CDP and that the dielectric coefficient, dielectric losses and shear stresses of the electrorheological fluids with P-CDPs as dispersion phase were higher than those of the electrorheological fluids with I as dispersion phase. However, no regular tendency was found.(2)3water-soluble P-CDPs II with modified synthetic procedure were prepared in electric fields and their microstructures and morphologies were characterized by SEM and FT-IR techniques. The electrorheological properties of the electrorheological fluids, prepared by using silicone oil as dispersion medium and β-CDPs Ⅱ as dispersion phase, were investigated and the resulted showed that the morphology and microstructure of II are considerably different from those of traditional β-CDP and that the dielectric constants, dielectric losses and shear stresses of the electrorheological fluids with β-CDPs II as dispersion phase were significantly higher than those of the electrorheological fluids with traditional β-CDP as dispersion phase. A new way for preparation of disperse medium has therefore been found.(3) The inclusion interaction of β-CDP II for3-hydroxyl-2-naphthoic acid (HNA) or1-(2-pyridylazo)-2-naphthol (PAN) was investigated and morphology and microstructure of the inclusion complexes were characterized by FT-IR, SEM and XRD analyses. The results indicated that a supramolecular interaction is found between β-CDP Ⅱ and two guests. The rheological performances of the electrorheological fluid with the inclusion compound as disperse medium exhibits a much lower shear stress and even no yield stress and a better precipitation resistance property.