Chain dimensions, entanglement molecular weights and molecular weight distributions of poly(aryl ethers). A combined rheological and MNDO analysis

The viscoelastic melt properties of a series of different poly(aryl ethers) were analyzed to obtain information on the corresponding chain statistics, i. e. entanglement molecular weights and characteristic ratios C∞. The consistent result is that all chain molecules behave as freely rotating chains with values of C∞ of the order of two to three. MNDO‐calculations were used to obtain a detailed insight into the origin of such a behaviour. The relationship between chemical structure and the corresponding rotational potentials was analyzed. Finally, using a combination of rheological and MNDO (Modified Neglect of Diatomic Overlap) studies, information was derived on the molecular weight distribution of the poly(aryl ethers).