MOLECULAR MECHANICS ENERGY CALCULATIONS FOR THE DOUBLE-STRANDED HELICES OF ISOTACTIC POLY(METHYL METHACRYLATE) LARGE OLIGOMERS

For isotactic poly(methyl methacrylate), molecular mechanics energy ca lculations were carried out on several double-stranded helix oligomer models for analyzing the energetical stability of the polymer double-s tranded helix determined by X-ray analysis. The calculation results in dicate that the double-stranded-helix structures can exist as stable d ouble-stranded helices by the favorable intertwined interactions of th e van der Waals interactions for the large oligomers (n greater than o r equal to 10; n is the number or monomers in the oligomer). Moreover, the calculated double-stranded helix structure by the energy minimiza tion method is in good agreement with the observed structure by X-ray analysis.