Synthesis And Characterization Of Modified Chitosan Lyotropic Liquid Crystals Containing P And S Elements

The introduction of special elements, such as P and S, endows chitosan with special properties and functions. Synthesis phosphorylated chitosan and xanthan acidification chitosan are the two methods of introducing P and S elements into chitosan. Chitosan has biological function, antibiotic property, biocompatibility, bio-liquid crystal and other excellent features. But due to the characteristics of its own molecular structure, the solubility is poor, and thus the application of chitosan by a large degree of restriction. Introduce a certain size of the molecular groups in chitosan or its derivatives, can not only improve the particular nature of the chitosan, but also weaken the role of chitosan intermolecular hydrogen bonds, so that solubility is improved.Two thermotropic liquid crystal monomers were synthesized:the single adipic acid cholesteryl ester (M1),5-{4-[4-4-methoxyl benzoyl phenyl] phenoxy carbonyl} valerate (M2); a non-liquid crystal monomer:3-((2-isopropyl-5-methylcyclohexyl) peroxy) propanoic acid (M3). The three monomers and hyodeoxycholic acid (M4), chenodeoxycholic acid (M5) were grafted to chitosan to modify chitosan. This is the CTS-Mx series; In addition, phosphorylated chitosan is synthesized by "Nishi method". This series was named as P-CTS. Introduced S element in chitosan by chitosan xanthan acidification, marked as S-CTS. Finally, grafted P and S into CTS-Mx series separately, resulting in another two series, which were recorded as the P-CTS-Mx series and S-CTS-Mx series. There are no reports about the two series at home and abroad.The structures and properties of the Monomers (Mx), chitosan derivatives (CTS-MX), phosphorylated chitosan (P-CTS), xanthan acidification chitosan (S-CTS) and modified chitosan derivatives containing P and S elements (P-CTS-MX, S-CTS-Mx) were tested and studied by FT-IR, Polarimeter, DSC, CHNSO and POM, etc. The results showed that:(1) elemental analysis showed that the degree of substitution of phosphate chitosan is1.34; the degree of substitution of xanthan acidification chitosan is0.32, the two series of molecular structure have no report before;(2) Added chiral monomers to polymers, making the final polymers have optical activity; compared to the monomers, the optical rotation of polymers are different under the same conditions;(3) Many of the properties of phosphorylated chitosan and xanthan acidification chitosan changed, such as solubility and the critical concentrations;(4) In different acid solvents, the critical concentration of a kind of product is different:with the increase of the concentration of the acid, the critical concentration generally increases.