Preparation, Structure And Properties Of Carboxymethyl Cellulose Fibre And Fabric

With the development of medical treatment and public health and the profoundunderstanding of wound healing process, people demand for multifunctional dressings, whichnot only protecting the wound but also accelerating the wound healing, reducing the switchingfrequency, alleviating the pain and leaving less scar, They also request the dressings have wellbiocompatibility and biodegradability. One of the main materials of the preparation of medicaldressings was cellulose and cellulose derivative. To modify the cellulose fiber or fabric bycarboxymethylation could give the cellulose fiber or fabric high water absorbent withoutdestroying the original style of the cellulose. The carboxymethlyl medical dressing could formwater gel after absorbing water, which would keep the wound in a moist environment toaccelerate the healing of the wound. This type of medical dressing was also easy to apply andremove without conglutinating the wound. Although the carboxymethyl medical dressingshave many advantages, they are very expensive and mainly used in burns and some clinicalsurgical wounds. This research has selected the raw material (polyester/cotton blended knittedfabrics and viscose filament) on the basis of our original work to carboxymethylate, in orderto prepare high performance carboxymethyl medical dressings through two different wayswhich could decrease the cost.Different blended fiber ratio of Carboxymethyl polyester/cotton have been successfullyprepared in organic solvent through one bath process. The influence of seven main factors(the ratio of ethanol to water, the concentration, time and temperature of alkalization, molarratio of NaOH to chloroacetic acid and the temperature, time of the etherification) on thewater absorbent and appearance of carboxymethyl polyester/cotton blended fabrics wasinvestigated. The result showed, the optical condition of preparation of carboxymethylpolyester/cotton (65:35) blended fabrics was with ratio of ethanol to water of2.5:1,alkalization temperature50℃, alkalization time25min,6wt%concentration of sodiumhydroxide solution,1.5:1of the molar ratio of NaOH to MCA, etherification temperature andtime were respectively70℃and6h, under which condition the DS and water absorption ofthe carboxymethyl polyester/cotton blended fabrics were respectively0.54and13.15g.g-1.The optical condition of preparation of carboxymethyl polyester/cotton (50:50) blendedfabrics was with volume ratio of ethanol to water of3:1, alkalization temperature30℃andalkalization time25min,10wt%concentration of sodium hydroxide solution, the molar ratio of NaOH to MCA was2:1, etherification temperature and time were respectively40℃and5h, at that condition, the DS and water absorption of sample were respectively0.61and21.43g.g-1.According to the standards tests of medical dressings, we not only investigated but alsocompared the influence of DS on sample’s water absorption, water diffusion property, watervapor permeability and mechanical property. The result showed, with the DS ofcarboxymethyl polyester/cotton blended fabrics (50:50) of0.61, its water absorption andwater retention were respectively21.43g.g-1and15.53g.g-1, water vapor permeability was0.38Kg/(24h m2), water diffusion property was3.24cm and breaking strength and elongationwere76.71N and355.04%respectively. Also the sample of DS of0.61has well appearanceand hand feeling which performed perfectly among all the samples.Carboxymethyl rayon viscose filaments (CM-RVFs) have been successfully prepared inaqueous medium via one bath process. Six main factors (the concentration, time andtemperature of alkalization, molar ratio of NaOH to chloroacetic acid and the temperature,time of the etherification) which impact on the water absorbency and appearance ofCM-RVFs were investigated. The result showed, the optical condition of preparation ofCM-RVFs was with alkalization temperature and time respectively25℃and5min,10wt%concentration of sodium hydroxide solution, the molar ratio of NaOH to MCA was2.5:1,etherification temperature and time were respectively70℃and5h. The structure ofCM-RVFs were studied by Fourier Transform Infrared Spectroscopy (FTIR), X-raydiffraction (XRD) and scanning electron microscope (SEM). And the influence of substitutiondegree (DS) on water absorption, water retention and the mechanical properties of CM-RVFshave also been investigated according to the standards of medical dressing tests, then westeeped the CM-RVFs with DS of0.51in CuSO4solution in order to prepare antimicrobialCM-RVFs and its antimicrobial properties were tested. The research result indicated that withthe increasing DS, CM-RVFs’ crystallinity degree decreased gradually, the surface and crosssection of modified viscose fiber became more rough and irregular along with various whitecrystal-like protuberances appeared in its surface, and CM-RVFs’ water absorption and waterretention both rose a lot, but its breaking strength first increased then decreased comparedwith breaking elongation rarely change. With DS of0.51, the water absorption of CM-RVFsreached13.01g·g-1and its breaking strength and breaking elongation were respectively at 8.54cN and15.27%, this kind of CM-RVFs have great water uptake property and spinnability,after steeping into the0.10g/LCuSO4solution, the CM-RVFs’ antimicrobial rate was more than99.99%.