Studies On The Preparation And Properties Of Water Soluble Polymers

In this thesis, we have prepared a series of water soluble polymers by radical polymerization and RAFT polymerization methods and have studied their properties and applications as well. The main results are as follows:(1) We have investigated the LCST behavior of Poly(acrylamide-co-diacetone acrylamide)(P(AM-co-DAM)) chains in aqueous solution by using UV-vis, MicroDSC and FT-IR. We have prepared a series of copolymer of AM and DAM with different composition. We have studied the effects of composition and concentration on the LCST of P(AM-co-DAM). The LCST decreases with the increase of.fDAM, and the LCST have a concentration dependance in lower concentration regime. No hysteresis can be observed during the heating-cooling process.(2) We have studied the transformation behavior of phospholipid bilayer-to-vesicle on the surface of silica by using the combination technique of QCM-D and ellipsometry. The transition from vesicle to bilayer is mainly dependent on the flow rate of vesicle soluton instead of the vesicle concentration. After the introduction of hydrophobic ended polyelectrolyte to the cell, the hydrophobic end group will insert to the lipid bilayer and induce the bilayer-to-vesicle transition assisted by the electrostatic interactions between the polyelectrolyte chains and the phospholipid molecules. As a result, the bilayer will form vesicles and leave the surface.(3) We have developed a simple method to prepare a novel self-healing polymeric material possessing tunable mechanical properties. Unlike the conventional preparation of self-healing polymeric materials, no initiators and cross-linkers are required for the material preparation and no stirring and deoxygenation are required during the polymerization. The material can be easily prepared and simply processed into any desired shape. It can also resist the corrosion of various organic solvents. The formation of multiple hydrogen bonds is responsible for the high strength and remarkable self-healing properties of the material.