Structure and dissolution mechanism of cellulose carbamate

The structure of the cellulose carbamate(CC) were characterized by means of FTIR,(~(13)CP) MAS、 element analysis,XRD,SEM,TG,DSC etc.The results showed that the chemical formula of cellulose carbamate with nitrogen mass fraction of 3.45% is((C_7H_(11)O_6)_2N_1),namely,on average,one primary hydroxyl group of cellulose was substituted by one acyl amine.The basic structure of cellulose carbamate is cellulose,however its crystal structure was changed after reaction,and as the reaction went on,the crystalline surface of the product increased,the orientation degree,crystralline grade and thermal-stability decreased.It was observed by microscope that the dissolving process of CC was ascribed to the infinite swelling of CC molecules,which first occurred in amorphous region,then in micro-crystalline surface by the resulting solution which then penetrated into the inside of the microcrystal.Making crystal cells swell,diffuse,and finally CC was completely dissolved.