Study On The Preparation And Properties Of Antibacterial Cellulose/Chitosan Derivatives Composites Films

Both cellulose and chitin with good properties are the most naturally occurring biopolymers.The process of cellulose solved by system of sodium hydroxyl,urea and thiourca is easy without pollution.Chitosan shows both excellent antibacterial activity with broad spectra and safety to human body.But its application is limited because of its structurc propcrty.Degraded cellulose/ soluble chitin and cellulose/O-carboxymethyl chitosan biomedical composite films with good compatibility applied to new functional materials were prepared by wetting.In this papcr,cellulose was firstly pretreated by kinds of activation methods,and then activated cellulose was dissolved by system of sodium hydroxyl,urea and thiourea. Finally,cellulose/soluble chitin and cellulose/O-carboxymethyl chitosan composite films werc prepared.In terms of FT-IR,SEM and transparent tares,the miscibility between soluble chitin,O-carboxymethyl chitosan and cellulose was studied,and mechanical properties,moisture-adsorption rate and moisture-retention rate and antibacterial property of composite films were tested.At the same time,the rheological properties of soluble chitin.O-carboxymethyl chitosan and cellulose blend solutions were analyzed by high cffeet rheometcr and Dâ…¤-â…¡rotation viscometer,and then the optimum temperature of preparing membrane was determined.The result showed that cellulose was better dissolved with activation,and the best method was activation by ultrasonic.Both cellulose/soluble chitin blend solution and cellulose/O-carboxymcthyl chitosan belonged to non-Newtonian fluid at some temperature range.There was better miscibility when the concentration of soluble chitin and O-carboxymcthyl chitosan reached 15%and 30%,respectively.At the concentration, the tensilc strength,the breaking elongation,moisture-adsorption rate and moisture-retention rate of composite films were well accepted.Furthermore,the antimicrobial activities against St.aureus and E.coli of the composite films were cxcellent.And the cellulose/O-carboxymethyl chitosan composite film was better than that of cellulose/soluble chitin composite film.