Preparation And Properties Of Aminocellulose-based Materials

Lignocellulosic biomass,as the most abundant renewable biomass resources,mainly contains cellulose,hemicelluloses,and lignin.Aminocellulose(AC)is a cellulose derivative with terminal amino groups.The structure of AC is similar to that of chitosan.Because of the active amino groups in cellulose,AC exhibits good solubility,film-forming property,heavy metal ions adsorption property,and has a good application prospect in the field of biology,such as immobilizing enzyme and controlling drug release.In this study,cellulose as the raw material is chemically modified to prepare AC.The AC-based composite films and hydrogels were successfully prepared by chemical methods.This research can provide theoretical basis on the preparation and application of AC.The two-step method for the preparation of AC is introduced in this study.After the cellulose was dissolved in DMAC/LiCl solvent system,p-toluenesulfonyl chloride was added to produce p-toluenesulfonyl cellulose(TC).Then ethylenediamine was added to substitute for p-toluenesulfonyl group,and the AC was successfully prepared.In this study,the maximum substitution degree of TC are 0.90,and AC prepared from TC exhibits excellent water solubility.AC is a good candidate to prepare biomass-based renewable functional materials.Composite films were prepared by crosslinking AC and polybenzoxazine(MCBP),and the crosslinking networks are fomed by chemical and hydrogen bond.The crosslinking density,tensile strength and thermal stability of composite films were adjusted by changing the reaction temperature and reactant contents.Then,thermogravimetric analysis suggested that the film with the best thermal stability was obtained when the ratio of AC and MCBP was 7:3.The tensile test indicated that the tensile strength of composite films could be improved by 109%under high temperature.These properties demonstrated that the composite films have potential applications in the fields of dewatering,water treatment,and membrane separations.The eomposite hydrogels were prepared through Schiff-Base reactions among the amino groups of AC and the aldehyde groups of dialdehyde carboxymethyl hemicellulose(DCMH).Aftr immersing the prepared hydrogels in AgNO3 solution,Ag particles could be evenly distributed in the hydrogels,which was due to the reduction of Ag ions by the aldehyde groups of DCMH.Ag particles-containing composite hydrogels possess antibacterial property.The SEM images showed that Ag particles evenly distribute in the hydrogels.According to the swelling test and thermogravimetric analysis,Ag partieles-containing composite hydrogels exhibited high thermal stability ang low swelling property.The experiment developed a green approach to prepare antibacterial Ag particles-containing composite hydrogels.