Aromatic polymers obtained by precipitation polycondensation. 6. Morphology of polyketone particles

Syntheses of aromatic polyketones in the form of particles were performed using a very small monomer concentration (0.05 mol/1) by the precipitation polycondensation method. Some of these particles present highly ordered elongated needle-like structures (whiskers) particularly for the all-para polyketone samples. The use of isophthaloyl instead of terephthaloyl for the same low monomer concentration produces, in addition to the globular particles, bundles of ribbon-like structures. The average size of the needle-like particles is 1−5 μm in width and 150−250 μm in length. The factors controlling the morphology texture and size of the whiskers and ribbons are shown to be the polymer structure and the reaction conditions. Formation mechanisms are discussed.