Catalytic Degradation Of Chitin Biomass

With the depletion of fossil resources,people are focusing on renewable resources.China is rich in marine resources and the annual yield of chitin biomass from the ocean is abundant.It is natural and renewable,can be produced continuously,has biodegradability and excellent biocompatibility.Therefore,it has been applied to many fields.However,the exploration of converting chitin biomass into high value-added compounds is still in its infancy.In the current study,chitin biomass and its derivatives has been converted into a variety of platform compounds,of which the nitrogen-containing compound 3-acetamido-5-acetylfuran?3A5AF?has attracted our attention due to the presence of valuable nitrogen.By designing and synthesizing functional ionic liquids and highly catalytic catalysts to transform chitin and its monomer N-acetylglucosamine?NAG?into3A5AF with high yield is the main research content of this subject.In this project,the catalytic activity of three catalysts on the reaction system was studied.Firstly,a series of ionic liquid was prepared by one-step method and used as a catalyst for the degradation of chitin and its monomer NAG.Under atmospheric reflux conditions,it was found that the yield of NAG was 43.22%when the reaction time was 10 min and no additive was added in the presence of[Gly]Cl.And in the presence of Ca Cl₂,the yield was as high as 52.61%.In addition,the catalyst still had excellent stability and catalytic performance after eight recyclings.The intermediate products and by-products of the reaction were analyzed by high performance liquid chromatography-mass spectrometry to verify the reaction mechanism.At the same time,[TMG]Cl ionic liquid was synthesized.And the catalytic performance of this type of ionic liquid was studied.By optimizing the reaction conditions such as reaction temperature,reaction time,and amount of catalyst,the highest yield of 3A5AF was obtained,which was up to 72.62%.The target product was verified by proton nuclear magnetic resonance.Moreover,for the first time,Na₂B₈O₁₃.4H₂O was used as a catalyst to catalyze NAG to 3A5AF.It was found that in the presence of a small amount of additive HCl,Na₂B₈O₁₃.4H₂O can be successfully and effectively applied to the conversion of NAG with a product yield of 42.77%.These results provide a new approach for the study of chitin biomass transformation.