Preparation And Properties Of Temperature Adaptable Calcium Alginate Fiber And Calcium Alginate/Gelatin Blend Fiber

Because of excellent properties of calcium alginate fiber-high water absorbability andgel forming, removed easier from wound, high oxygen permeation, biocompatibility,biodegradation, high ion adsorption and environmental production process, calcium alginatefiber has applied widely in medical treatment as gauze and dressings. Therefore, themodification to add on new properties of calcium alginate fiber such as antibacterial andfar-infrared on the base of excellent properties of alginate fiber has been as an importantresearch direction in this area. Also calcium alginate fiber has some disadvantages onmechanical properties such as low strength. Blending technique is an effective method toimprove the properties of macromolecule materials.Considering the above, two calcium alginate fibers-temperature adaptable calciumalginate fiber and calcium alginate/gelatin blend fiber were prepared. Temperature adaptablemicrocapsules were synthesized and the influent factors were studied. Based on this,temperature adaptable calcium alginate fiber was prepared and the relation of microcapsulescontent and properties of fiber was researched. Calcium alginate/gelatin blend fiber wasprepared via wet spinning, the optimal spinning processing parameters were determined byevaluating the water absorption and the mechanical properties of the blend fiber. The mainresearch work was summarized in the following statements:1. By using liquid paraffin as a core material, monomers ethylenediamine(EDA) andtoluene-2,4-diisocyanate(TDI) react with each other as a shellmaterial by using interfacialpolycondensation method to prepare polyurea microcapsules containing phase changematerial. The results showed that the optimal processing parameters: core material(wt):shellmaterial(wt)=3:1, the mixture of 0.6% sodium carboxymethylcellulose(CMC) and 0.2%polyvinylalcohol(PVA)was used as protective colloid and peregal O was used as theemulsifier, emulsifying speed was 3200rpm, emulsifying time was 8min and reacttemperature was 60℃. Particle size and size distribution were characterized by laser particle size analyzer. Size distribution was mainly in the range of 1.5μm～4μm, the average particlesize is 2μm, the shape of microcapsules was mainly spheric viewed by optical microscope.2. Microcapsules were mixed with sodium alginate to make the temperature adaptablecalcium alginate fiber. The relationship between the dosage of microcapsule and rheology ofspinning solution, fineness, breaking strength, rupture elongation and moisture absorptionwere investigated. The results showed that the mechanical property of temperature adaptablecalcium alginate fiber was good when the dosage of microcapsule was 12%～16%(wt).Differential scanning calorimetry(DSC) showed that the range of adaptable temperature was18℃～38℃. The longitudinal direction and cross-section were viewed by opticalmicroscope. There were some uneven grooves on the appearance of the fiber. When viewedin cross-section, the fiber has no shell-core structure and is usually round, the edge wasanomalous hackle.3. Calcium alginate/gelatin blend fiber was prepared via wet spinning by using CaCl₂ andBTCA as coagulators. The effect of pH value, alkaline agent, coagulator, coagulation timeand drying time were determined by evaluating the water absorption and the mechanicalproperties of the blend fiber. The results showed that a good property blend fiber was madewhen the alkaline agent of gelatin was triethanolamine, pH value was 8.0～8.3. Breakingstrength was 1.55cN/dT and rupture elongation was 33.68% when the proportion of sodiumalginate and gelatin is 7/3. The optimal coagulation factors were: the metal coagulation agentis CaCl₂, the concentration of CaCl₂ is 4%, crossing time is 50s; the acid coagulation agent isBTCA and the coagulation time is 60s to 100s. The breaking strength and the breakingelongation of blend fiber increased when ethanol added into CaCl₂ coagulation bath, dryingtime is 50℃. There were some uneven grooves on the appearance of the longitudinaldirection. When viewed in cross-section, the fiber is even and is usually round, the edge wasanomalous hackle.