Structural studies on syndiotactic 1,2-poly(1,3-butadiene) by X-ray measurements and molecular mechanics calculations

摘要

Two samples of syndiotactic 1,2-poly(1,3-butadiene) with different constitutional and configurational regularities were characterized by DSC analysis and X-ray powder diffraction. Possible models of the crystal structure were obtained by molecular mechanics calculations performed with various sets of potential functions. X-ray powder profiles calculated for these models were in good agreement with experiments. The agreement between simulated and experimental X-ray powder profiles was improved by taking into account, in the calculated models, the presence of configurational defects. This indicates that configurational defects can be included in the crystal phase.