Molecular Dynamics Simulation Of Microscopic Glucomannan Structure

Using molecular simulation and modern instruments analysis, the chain three-dimensional structure was predicted, The influence of inorganic compound on its structure and property in solution system as well as microcosmic interaction process between KGM and carrageen were researched. The details are specified as follows:1 Prediction of KGM chain structureUsing computing molecular structure software: Hyperchem7.0 VM2.0, methods of molecular dynamics and molecular mechanics and the model of single KGM chain , polymerization degree as well as the influence of substitution group on dynamics conformation and the interaction affecting chain conformation were researched. For the first time, the dynamics changing process of KGM chain in vacuum is proposed, We obtained the following results: polymerization degree influences the stability and shapes of the chain, the chain stability drops with the increasing of polymerization degree, for the high polymerization degree KGM, KGM chain takes on irregular curl state; acetyl group is not the main factor influencing chain conformation , during the course of dynamics movement KGM chain takes on irregular curl state before and after acetyl group was doffed, Extending and curling states change periodicity and has good flexibility. The electrostatic energy is the main non-bonded function, Dihedral energy is the main bonded function, but acetyl group is the main factor influencing H-Bonds.2 Research of inorganic compound's influence on structure and property of KGM solution systemUsing computing molecular structure software: Hyperchem7.0, methods of molecular dynamics and technology of IR and NMR, SAR (Structure -activity relationships) of KGM was analyzed , the structure reason of property change was well explained. We obtained the following results combining past research and references: Under alkaline conditions the increase of intra-molecular hydrogen bond interaction improves gel strength because of chemistry function in which acetyl group was taken out, and the main intra-molecular hydrogen bond function point is between 0(6) of glucose and 0(2) of mannose; After borax and KGM functioned ,the intrinsic viscosities increases and the KGM film is more compact and uniform, the reason is that the coordination function of inter-molecules and intra-molecules and the increase of intra-molecular hydrogen bond, the coordination reaction of intra-molecules most takes place the position between glucose and mannose; when urea is added the solution system , KGM hydrogen bond network is destroyed , viscosity is dropped, the hydrogen bond numbers reduces, the main hydrogen bond function points changes O(2) . O(3)of mannose and O(3) O(6) of glucose into O(4 )of mannose and O (1)> O (2) of glucose.3 Research of KGM and carrageen mixing functionUsing computing molecular structure software: Hyperchem7.0, methods of molecular dynamics and technology of IR and DSC, the microcosmic structure of KGM and carrageen compound and interaction process was researched, the structure reason why property changes and interaction position among intra -molecules were found. We obtained the following results: The heat reversible gel which has high strength good elasticity is formed by intermolecular hydrogen bond function after KGM mixed with carrageen, comparing with single gel, mixing gel improves gel property obviously. By IR we found that chemical group does not change in essence but hydrogen-bonded function increases; By DSC analysis only one peak occurs ,two kinds polymers...