Beta Chitin Extraction And Dissolve The Performance Test And Fiber Cotton Spinning

Of reserves and biosynthesis of chitin is very abundant, is the second largest on Earth after cellulose renewable resources. Due to the characteristics of the molecular structure of chitin, the hydrogen bonds between the molecular chains strong, making difficult to dissolve chitin, which is also the problem of chitin application process,β-chitin extracted from squid cartilage in different crystal structure of chitin, with the more lively and to the ordered crystal structure to the physical and chemical properties. Therefore, compared with the traditional alpha-type of β-chitin has a new meaning.This thesis, from the preparation of β-chitin, β-chitin prepared by acid and alkali methods, and to study the physical and chemical properties of beta-chitin. Ubbelohde viscometer prepared β-chitin with a viscosity average molecular weight Mη=1.10*106, by means of infrared spectra (FTIR) and thermal gravimetric analysis (TGA) of β-chitin characterization, and a-chitin compared.The papers the next study the solubility of β-chitin, compare three solvent system:formic acid, freeze-thaw cycle system of concentrated alkali, the LiCl/the NMP system dissolved. By comparison, the effect of the LiCl/NMP system is best to finalize the system for β-chitin dissolved system. This paper studied the β-chitin dissolved in LiCl/NMP system conditions and its viscosity characteristics of these tests to determine the best dissolution conditions of chitin swelling at room temperature, about4-5h at40℃under stirring to dissolve5h, with the constraints of2%concentration of chitin to clarify a transparent solution. The preparation of the solution system using rotational rheometer to characterize their rheological properties, of LiCl/the NMP solution of β-chitin in the low shear rate Newtonian fluid, n=1, with the shear rate increased, the viscosity decreased, n<1is a typical shear-thinning fluid. Comparison test to determine the coagulation bath conditions, the coagulation bath system for ethanol:NaOH=9:1.Fiber cotton spinning, wet spinning method. Experimental conditions determined by experiments with restricting the clear and transparent solution of2%concentration of β-chitin After filtration, the vacuum deaeration of about10h, nitrogen pressure0.2-0.6Pa spinneret with1200holes,0.07mm size coagulation bath using ethanol:of NaOH=9:1coagulation bath system for the first coagulation bath, ethanol for the second coagulation bath. Spun fibers have not been drawing, so it is not the strict sense of the fibers, called fiber cotton. The infrared spectra (FTIR), scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA), the shape, structure and strength of the fiber strength testing and other means of fiber cotton.