Construction Of The Network Structure Based On Cellulose Derivatives And Applications Of It

In recent years, cellulose, chitosan and their derivatives have been widely used in hydrogel and its derived materials for their properties of good water solubility, biocompatibility and biodegradability. In this paper, we used the water-soluble carboxymethyl cellulose, hydroxyethl cellulose and chitosan quaternary ammonium salt as raw materials and successfully constructed hydrogel and fibrous material, which have three-dimensional network structure,by the method of polyelectrolyte complex. We also studied the controlling factors of constructing a three-dimensional network structure and the relations between structure and properties of the materials. Therefore, the study has laid a good foundation for the applications of such a composite polymer electrolyte material. The main work is as follows:A novel carboxymethyl cellulose/ hydroxyethyl cellulose-Al3+(CMC/HEC-Al3+)hydrogel was prepared through the electrostatic complexing between the anionic polyelectrolyte CMC and cationic crosslinking agent Al3+. A sponge and membrane were prepared from the CMC/HEC-Al3+hydrogel by freeze-drying and oven drying,respectively.The structure and property of the hydrogel were characterized by FTIR, TGA and SEM. The viscoelasticities of the swollen hydrogel were measured by the rheology test. The results indicate that electrostatic effect,physical entanglement and intra- and intermolecular hydrogen bonds contribute the crosslinking network structure and the electrostatic effect is the dominant. In all, both superabsorbent sponge and membrane prepared from CMC/HEC-Al3+hydrogel showed an excellent swelling behavior and could be used as a wound dressing.Carboxymethyl cellulose/chitosan quaternary ammonium salt(CMC/HACC)polyelectrolyte complex fiber was prepared through the electrostatic between the anionic polyelectrolyte CMC and the cationic polyelectrolyte HACC. The structure and property of the polyelectrolyte complex fiber were characterized by FTIR, 13C-NMR, XPS and SEM. The effects of sodium chloride concentration on CMC/HACC fibers’ space network structure were measured by XRD and pyrolysis analysis. The results indicate that sodium chloride undermined the hydrogen bonds between polymer chains, which led to a disordered molecular chain arrangement. In the case of a low concentration of Na Cl, the apparent activation energy of CMC/HACC fiber is higher. When the concentration of Na Cl was higher than 0.05mol/L, the fibrous network structure disappeared, and the CMC/HACC polyelectrolyte complex was mainly in the presence of the sheet structure. At this time the CMC/HACC fibers showed a lower activation energy.