Research On Preparation And Characterization Of Cellulose-Based Degradable Biomaterials

In recent years, environmental concerns, such as pollution and decreases in natural resources, have resulted in an increased demand for renewable materials. Cellulose-based degradable biomaterials prepared by cellulose and calcium-based degradable biomaterials have gained more interest as environmentally friendly renewable materials due to its interesting properties such as biocompatibility, biodegradability and promising potential applications in various fields. In this study, the synthesis of cellulose-based degradable biomaterials was mainly discussed. The products were characterized by XRD, FT-IR, SEM, TGA/DTA, CP/MAS13C-NMR, and1H-NMR. The biological activity of cellulose/CaCO3bionanocomposites was also investigated. The influences of several reaction parameters, such as the heating time, the heating temperature, cellulose concentration, and the different types of additives on the products were investigated. The results of this study were summarized as follows:Cellulose/carbonated hydroxyapatite (CHA) nanocomposites have been successfully synthesized using cellulose, CaCl2, and NaH2PO4in NaOH/urea aqueous solution by hydrothermal method and microwave-assisted method, respectively. Compared with hydrothermal method, the microwave-assisted method is more simple and rapid for the preparation of cellulose/CHA nanocomposites. The XRD and FT-IR results indicated that the obtained products were the cellulose/CHA nanocomposites. The CHA prepared by hydrothermal method had a better crystallinity. The SEM micrographs showed the CHA particles were homogeneously dispersed in the cellulose matrix. Compared with hydrothermal method, the cellulose/CHA nanocomposites synthesized by microwave-assisted method had a higher thermal stability.Cellulose/calcium silicate nanocomposites have been rapidly synthesized using cellulose, Ca(NO3)2·4H2O, and Na2SiO3·9H2O in ethylene glycol by a microwave-assisted method. The calcium silicate nanoparticles were homogeneously dispersed in the cellulose matrix. The experimental results showed that the additive of ionic liquid favored the composite of cellulose and calcium silicate. The weight loss of nanocomposites was decreased with the increasing ionic liquid concentrations.Cellulose/calcium silicate nanocomposites have been synthesized in pure and recycled ionic liquids by a rapid and green microwave-assisted ionic liquid method. The influences of pure and recycled ionic liquids on the products were investigated. These calcium silicate nanoparticles or nanosheets as prepared were homogeneously dispersed in the cellulose matrix. The experimental results confirmed that ionic liquids can be used repeatedly. The slight differences between pure and recycled ionic liquids were researched.Cellulose/calcium carbonate (CaCO3) nanocomposites have been synthesized using cellulose, Ca(NO3)2·4H2O, and Na2SiO3·9H2O in NaOH/urea aqueous solution by hydrothermal method. The urea also acts as the CO32-source for the synthesis of CaCO3. The experimental results demonstrated that the hydrothermal conditions had effects on the morphologies of the bionanocomposites. Cytotoxicity experiments indicated that the cellulose/CaC03bionanocomposites had good biocompatibility.