Study On Modification And Flame Retardant Mechanism Of Carrageenan Fiber

With the people's awareness of environmental protection and the increasing scarcity of oil resources,the green,pollution-free,healthy textile fabrics has caught the attention of experts and scholars at home and abroad.But natural fibers such as cotton,silk fibers are highly combustible,becoming potential threats to people's lives.Alginate fiber as a biomass fiber shows wide application prospects and theoretical significance due to its inherent flame retardancy.Carrageenan,the natura polysaccharides extracted from red algae,can be used in many areas,such as food,medicine and chemical industry and so on,because of its emulsification,gel,thickening,film forming,and non-toxic characteristics.This paper investigated the extraction,fiberizability and flame retardancy of carrageenan;spinning technology,flame-retardant property and flame-retardant mechanism of carrageenan fiber were also studied in this paper.1.The red alga polysaccharide were extracted from the pelvetia siliquosa using water extraction and alkali extraction method respectively,and the products were tested by the infrared spectroscopy.The results show that the polysaccharide extracted from pelvetia silquosa was carrageenan;experiments about the formation of carrageenan fiber were performed,and the properties of the fiber were also analyzed.2.The optimum spinning parameters were explored by means of an orthogonal test.According to the results of tensile test,dope concentration,draw ratio,coagulation bath concentration,and coagulation bath temperature set to 9%,1.2,5% and 15 °C,respectively,were the optimum spinning conditions.These parameters were then applied to fabricate fibers treated with epichlorohydrin in a stretch bath.The result of extension test demonstrated a positive improvement in the intensity.The values of breaking force and breaking elongation reached up to 68.03 c N and 21.84%,respectively.Molecular structures and special groups were characterized after cross-linking reaction,and the results indicated the regularity of the net structure and the increase in ether bond and methylene.3.Carrageenan fibers were obtained through the wet spinning technique with barium salt as coagulation bath.Characterization results showed that carrageenan fiber took on better flame retardancy than calcium alginate fiber and agar fiber.The LOI of carrageenan fiber was up to more than 50,and the fiber kept red state without flame in the whole CONE process.Some other CONE parameters presenting lower value,such as heat release rate,total heat release,indicated that carrageenan fiber has good flame retardancy.The sulfate ester combined with barium ion through complexing action of carrageenan fiber,and they played an important role in the formation of carbon residue and changing the breakup processes of carrageenan macromolecule.In addition,flame-retardant mechanism can be also attributed to sulfonyl free radical,which can combine with hydroxyl radicals rapidly to terminate the combustion reaction.Meanwhile,the dense structure of barium salt layer and hollow fiber structure were also crucial factors of flame retardant performance for carrageenan fiber.