STRUCTURAL STUDIES OF OPTICALLY ACTIVE AND RACEMIC POLY(PROPYLENE SULFIDES)

The crystal structure of optically active poly(propylene sulfide) and racemic poly(propylene sulfide) were studied by X-ray diffraction. All reflections of X-ray fiber photographs of the optically active polymer were indexed by the orthorhombic unit cell; the cell dimensions are a = 9.95 Å, b = 4.89 Å, and c (fiber axis) = 8.20 Å, and the space group is P212121-D24. Two molecular chains characterized by a twofold screw axis pass through the unit cell. The crystal structure of the optically active polymer is very similar to that of racemic poly(propylene oxide). The fact that the fiber photograph of the racemic polymer gives the same X-ray pattern as the optically active polymer suggests that the both polymers have the same crystal structure. Namely, it may be concluded that the racemic polymer sample consists of the two kinds of optically active crystallites, R (rectus) and S (sinister). © 1969, American Chemical Society. All rights reserved.