Structural studies of crystalline poly(p‐phenylene oxides) I. Poly(p‐phenylene oxide)

Abstract

AbstractUsing 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.