Study On Preparation And Properties Of Carboxymethyl Cellulose Medical Dressing

In recent years, research and application of water absorbing materials developed quicklyin medical and surgical field. Natural and regenerated cellulose fabrics modified with highwater absorption became the hot topic of high-performance medical dressing. Cellulose fabricscarboxymethylated with lower degree could obtain good water absorption without changingtheir fibrous form. And the carboxymethyl cellulose medical dressing was the mostrepresentative material.Several types of cellulose fabrics （medical cotton gauzes, viscose nonvowens, and cottonknitted fabrics） were carboxymethylated with different methods. Firstly, carboxymethylmedical cotton gauze （CM-gauze） was successfully prepared in aqueous medium with onebath process. The optimal preparation condition was confirmed through single factor analysisand orthogonal experiment. The effect of （substitution degree）DS on the structure andproperties of CM-gauze were investigated. The results showed that, with DS of0.84, waterabsorption of CM-gauze was13.91g·g^-1（distilled water） and14.22g·g^-1（normal saline）, andbreaking strength and breaking elongation were respectively133.1N and41.1%.Compared with medical cotton gauzes, viscose nonvowens have loose structure, goodphysical adsorption characteristics, and more reactive hydroxy groups. Carboxymethyl viscosenonwoven （CM-VN） was successfully prepared in aqueous medium with one bath process.The optimal preparation condition was confirmed through single factor analysis andorthogonal experiment. The effect of （substitution degree）DS on the structure and properties ofCM-VN were investigated. The results showed that, compared with CM-gauze, CM-VN withlower DS of0.35could form uniform and semitransparent hydrogel after absorbing water.And its water absorption reached25.44g·g^-1（distilled water） and24.38g·g^-1（normal saline）,breaking strength and breaking elongation were respectively85.7N and47.5%. In addition, ithas good water vapor permeability and blocking performance.Compared with medical cotton gauze, cotton knitted fabrics with higher fabric countmodified by carboxymethylation could obtain high water absorption within unit area, which could meet different need of wound therapy. Cotton knitted fabrics were modified in organicsolvent through padding method with two-step alkalization. The optimal preparation conditionwas confirmed through single factor analysis and orthogonal experiment. The effect of DS onthe structure and properties of CM-VN were investigated. The results showed that, comparedwith CM-gauze, water absorption of carboxymethyl cotton knitted fabrics with higher DS of0.86reached15.98g·g^-1（distilled water） and16.42g·g^-1（normal saline）, breaking strengthand breaking elongation were respectively191.5N and131.4%. Based on different types ofcellulose fabrics, series of gradient properties of carboxymethyl cellulose wound dressingswere prepared, which could further expand the application of those dressings. And the resultsprovide experimental and theoretical basis for high performance medical dressings requiredfor different types of wound healing.