Preparation And Application Of Cellulose/Chitin Blending Membranes

Today, petrochemical resources reduce day by day and the polymer materialsbased petrochemical resources raw materials are difficult to degradation of polymerwhich result in the shortage of resources and the ever-increasing pollution. Therefore,searching and developing a cheap material based on renewable energy is impending.Search and development of substitution for the petrochemical resource materials havebecome a key issue in polymer science field of research. Cellulose and Chitin arewidely applied in medical environmental protection due to abundant resource、degradability、biological compatibility and non-toxic. However，the application ofcellulose is restricted due to insoluble in water and common solvents. The materialmechanics performanceis can be improved when the nanoparticles are added into thematerials because nanoparticles can uniformly disperse in the base materials andstrong interfacial interaction can be formed with the base materials due to the highsurface area. In this thesis, blend membrane was prepared with mixture of nanocrystallite and cellulose for the material of separation of organics and water aspervaporation membrane. Research work can be divided into three aspects:(1) Chitin nanocrystalline with stable structure was preparated usinghydrochloric acid degraded chitin.The morphorlogy、structure and properties ofblend membranes have been investigated by AFM, XRD, FTIR, TGA;(2)The blend membrane was preparated with chitin nanocrystalline andcellulose in the water solvent of7wt%NaOH and12wt%urea. The morphorlogy、structure and properties of blend membranes have been investigated by SEM, XRD,TGA, FTIR, Mechanics Performance Testing and Bibulous performance test;(3)Cellulose blend membrane with the chitin nanocrystalline content5%wasused for the separation of water and organics. Decrease of water was tested by Carlfee Hugh method used Moisture tester.Through the study of the method and characterization, the main conclusions are asfollows:(1)Chitin molecules of the hydrogen bonding is destroyed and the glycosidicbond is broken by hydrochloric acid degradation chitin, the crystallization area of themolecules is not changed. Chitin nanocrystalline of the low degree of polymerizationand the high crystallinity is obtained. (2) The blend membrane of mechanical properties is obviously improved withChitin nanocrystalline which uniformly disperses into cellulose, mainly because thestrong interaction is formed between nanocrystalline and cellulose.(3) The separation of organics and water blend content can be improved by theblend membrane with5%chitin and95%cellulose.In a word, the preparation of nanocrystallite chitin and chitin nanocrystalline andcellulose blend membrane preparation and application in pervaporation separationorganics and water are studied in this paper，the results further widened theapplication of chitin and natural polymer film application and meet the goals ofsustainable development requirements.