Morphology And Dyeing Properties Of Calotropis Gigantea Fiber

Calotropis gigantea fiber belongs to natural cellulose fiber.Owing to its soft luster and comfortable hand-feel,the fiber was paid more attention of researchers in textile industry.The structure,properties and application researches of calotropis gigantea fiber weren't reported in detail.Therefore,the structure and properties of calotropis gigantea fiber will be studied in this paper by modern testing technology,providing theoretical basis for extensive application of fiber and improving the added value of the products.The element content,morphology structure,supermolecular structure and mechanical properties of calotropis gigantea fiber were investigated by Element analyzer,Fourier Transform Infrared(FTIR),Scanning Electron Microscope(SEM),X-ray Diffraction(XRD),Thermo gravimetric Analysis(TG)and fiber strength tester.Main chemical compositions of calotropis gigantea fiber were analyzed by chemical method,and compared with cotton and kapok.In the basis on researches about structure and properties of the fiber,spinning performance of calotropis gigantea fiber were studied preliminarily.Lastely,Calotropis gigantea,kapok and cotton fibers were dyed by direct and reactive dyes,and analysed the difference of fibers in dyeing rate from the structure and properties.The results show that the main elements of calotropis gigantea fiber contain C,H,O elements;The mass fraction of lignin is about 8-9%,cellulose is about 64%,hemicelluloses is about 20%,waxy is about 2?3%;Cellulose characteristic peak are marked in infrared spectrum;The above analysis shows allotropis gigantea fiber belongs cellulose fiber.The degree of hollowness of calotropis gigantea fiber is up to 80?90%and no natural crimps existed;Crystallinity of calotropis gigantea fiber is 42.54%and its crystallinity orientation index is 85.40%,crystallinity of calotropis gigantea fiber was lower compared fiber and cotton fiber,which contributes to dye of calotropis gigantea fiber;The initial thermal decomposition temperature of calotropis gigantea fiber is 301.1?,lower compare with cotton fiber,which heat stability of calotropis gigantea fiber is poor.Strengh tests found that breaking strength of calotropis gigantea fiber only is half of cotton fiber,much Lower intensity and larger degree of hollowness structure are not good for spinning of fibers,so,calotropis gigantea fiber must have pretreatment process.The results of spinning performance for fiber pretreated show that:The weight gain rate and the friction coefficient of calotropis gigantea fibers pretreated by spray process have a certain degree increase,which were 14.76%,0.5919 respectively;and achieve the aim of improving weight increase rate,80/20 blended yarn was spunned by Spinning machines.Dyeing performances of pretreated fiber were studied by three kinds of reactive dyes and three direct dyes respectively,and compared with cotton and kapok fibers.The results show that dyeing and fixation rate of calotropis gigantea fiber were lower than that of cotton and kapok fibers because calotropis gigantea fibers contain much lower cellulose and much higher crystallinity degree.Dyeing rate of calotropis gigantea fiber for direct dyes were higher than that of cotton fiber,when the dye concentration is lower than 1%,owing to higher hollowness degrees in calotropis gigantea fiber.Dyeing rate of calotropis gigantea fiber for direct dye were lower than that of cotton fibers when the dye concentration is more than 1%,owing to lower cellulose component in calotropis gigantea fibers.