Synthesis Of Antibacterial Cellulose Acetate Sorbate And Its Fiber Preparation

Cellulose acetate is one of the most important organic esters and is widely used in various fields.However,the antibacterial ability of cellulose acetate is extremely low because of its typical polyglucose structure and so limit its application.Therefore,the antibacterial modification of cellulose acetate is of great significance.In this paper,firstly,cellulose acetate(CA)with different degree of substitution(DSCA)were obtained through acid-catalyzed hydrolysis of cellulose diacetate(CDA)with the DS of 2.45.Then,sorbic acid(SA)was used as antibacterial agent and grafted onto cellulose acetate to prepare cellulose acetate sorbate(CASA)with good antibacterial properties,and the antibacterial fibers were prepared by wet-dry spinning.The specific research contents are as follows:First,acid hydrolysis of CDA showed that with the increase of hydrolysis time,the DS of hydrolyzate could be reduced to 1.75,and the products were easily dissolved in common organic solvents.The sorbic acid was activated by thionyl chloride(SOCl2)to obtain sorbic chloride,then CASA was synthesized by the reaction of CA with sorbic chloride in N,N-dimethylacetamide(DMAc).The structure of products was characterized by FTIR,1H-NMR and elemental analysis.The effects of the DSCA of cellose acetate,the molar ratio of-OH in CA unit to sorbic chloride,temperature and reaction time on the DSCASA were investigated.The results showed that when the DSCA was 1.75,the molar ratio was 1:6,the reaction temperature was 60 ? and the reaction time was 24 h,the product had the highest DS of 1.20.The antibacterial properties of the products was evaluated by contact shake test.The results showed that CASA with different DS had good antibacterial activity against Escherichia coli(E.coli)and,Staphylococcus aureus(S.aureus).The maximum bacteriostatic rate can reach 81.5%for E.coli and 95.4%for S.aureus when DSCASA was 0.81.In addition,the thermal properties and crystallinity of CASA were characterized by thermogravimetric analyzer(TG),differential scanning calorimeter(DSC)and X-ray diffractometer(XRD).The results showed that the thermal stability and percentage of crystallinity(Xc%)of CASA decreased slightly compared with pure CDA,but had no limitations in their effectiveness.Add a small amount of cellulose,the spinning solution of 10 wt%was prepared with DMAc and EmimAc,respectively,and cellulose acetate sorbate fiber was prepared by dry wet spinning technology.The results showed that the fibers had good mechanical properties and antibacterial properties,the breaking strength can reach to 2.47cN/dtex when the solvent is EmimAc,and the fibers also had good chemical resistance.