Structural studies of crystalline poly(<i>p</i>‐phenylene oxides) I. Poly(<i>p</i>‐phenylene oxide)

Abstract

Abstract Using X‐ray diffraction the structure of crystalline poly( p ‐phenylene oxide), magnified image has been determined. The unit cell is orthorhombic, with the dimensions: a = 8.07 Å, b = 5.54 Å, and c (fiber axis) = 9.72 Å. The unit cell contains four monomeric units. Two molecular chains pass through a unit cell, one through the center, the other through a corner. Two monomeric units are contained in the fiber identity period. The space group is Pbcn – D . The oxygen atoms and the centers of gravity of the phenylene groups are at special positions. The oxygen atoms of one molecular chain are arranged in a zig‐zag manner in the ( 100 ) plane. The oxygen bond angle is about 124°. The rotation angle of the phenylene groups round the O–O axis has been determined by comparing calculated and observed intensities.