Oyster Shell Extraction Of Chitin And Application Of Its Derivatives In Dyeing And Finishing

Chitin is the second-largest biological resources after cellulose in the nature. Its productions and application are hot topics in recent years due to its potential applications in many areas. However, the relative high production cost limits its applications. The solution to high cost is to find its easy-get and cheap raw materials, and the other features of the shell include simple pretreatment, anti-moldy and stable quality of its chitin and chitosan, so it could be turned from waste into treasure and reasonably developed and utilized.In this paper, the production processes of chitin, chitosan or derivatives from oyster shells of Guangdong has been reported. The process to identify the optimal process parameters. This paper discusses about the dyed fabric pretreated with chitosan, dipping dyeing with reactive dyes, the optimum process of chitosan treatment, its dyeing depth, dyeing brightness and its fastness.This paper focuses on the crease-resistant treatment process of cotton textiles with chitosan. The study items included different crease-resistant agents, different additives, different concentration of chitosan. The application of chitosan as a flocculant in waste water treatment is also discussed in detail. Chitosan is modified by copolymerization of chitosan and acrylamide to form a new polymer of flocculant.The results showed that the production processes of chitin, chitosan or derivatives from oyster is as follow:oyster shell→1st washing→drying→crushing→de-mineralization (using dilute HCl)→2nd washing→protein removal (usingdilute NaOH)→degreasing→raw chitin→bleaching→refined chitin→acetyl removal→drying→chitosan; The optimum process of chitosan treatment is that immersing cotton fabric in 1% chitosan solution at 60℃for 30 minutes.The dyed cotton fabric is undergone chitosan immersion. Its dyeing process could be carried out lower salt addition. It's good for environmental protection.The K/S value Before and after soaping of dyed fabric pretreated with chitosan varies smaller. The dyeings feature better levelness, Higher utilization rate of dye, less loose dye and higher color fastness to rubbing; The results showed that the treatment gives remarkable crease-resistant effect of cotton plain fabrics using chitosan as crease-resistant agent, CGF or 6520 as a softness additives and MgCl2 as a catalyst; The best performance was got under these conditions, pH of 6 through 7, PAC concentration of 400 mg/L, and the concentration of PAC solution is 50 and 100 mg/L.Chitosan-acrylamide graft copolymer showed better performance than the unmodified chitosan in both CODCr removal and declorization. Chitosan-acrylamide graft copolymer has higher capacity of adsorption with stronger bridging effect, as a result, it is possible to be used on large scale in wastewater treatment.