Molecular modeling polymer model building

Structural information at the molecular level can be extracted using a number of experimental techniques which include, but are not restricted to, optical rotation, infra-red and ultra-violet spectroscopy, nuclear magnetic resonance in the solid state and in solution, diffraction using electrons, neutrons or x-rays. Not all of them, however, are capable of yielding structural details to the same desirable extent. By far, experience shows that x-ray fiber diffraction (2), in conjunction with computer model building, is the most powerful tool which enables to establish the spatial arrangement of atoms in polymer molecules. 

Huggins Molecular Models.—In a series of, so far, 14 papers, Huggins has developed an approach to solution thermodynamics that essentially builds on lattice-graph models, removing phenomenological parameters by re-expressing them in terms of molecular quantities obtained, as far as is possible, by independent experimental means. Thus far the theory has been applied mainly to non-polymer systems. The most recent part considers benzene solutions of n-alkanes as model oligomers for polyethylene. 

CAChe can be used to visualize molecules, explore chemical reactivity and properties, elucidate reaction mechanisms, model catalysts, and teach molecular modeling. The Macintosh versions can also build and visualize crystals and estimate polymer properties. 

W. Chen, G. C. Lickheld and C. Q. Yang. Molecular modeling of cehulose in amorphous state. Part I Model building and plastic deformation study. Polymer 45, 2004, 1063. 

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