Polymerization of aromatic nuclei. XIII. X‐ray analysis and properties of poly(<i>p</i>‐phenylene) pellets

Abstract

Abstract X‐ray diffraction experiments with poly( p ‐phenylene) pellets demonstrated an increase in crystallinity with increase in molding temperature or annealing temperature. The increase in crystallinity may be attributed to annealing effects and loss of chlorine under severe conditions. Lattice constants for the crystalline polymer are presented, and the crystallographic data are compared with those of the lower oligomers. Poly( p ‐phenylene) was investigated also in relation to oxidative thermal stability, chemical and solvent resistance, and the effect of temperature and variation in molding conditions on fracture strength. The decrease in strength at elevated temperatures appears to be related to the increase in crystallinity.