High molecular weight aromatic poly(ether ketone ketone)s were synthesized by the Friedel-Crafts polyacylation condensation of iso-and terephthaloyl chlorides with diphenyl ether, 1,4-and 1,3-bis(4-phenoxybenzoyl)benzenes. Depending on the monomers used for polycondensation, polyketones of regular structure with different iso-/tereisomer repeating unit ratio (100/0, 50/50, 0/100) in the main chain were obtained. Polymers of each repeating isomer unit were prepared in two different ways. All the polymer syntheses were performed as precipitation polycondensations and the resulting polymers were obtained in particle form. The influence of reaction conditions and preparation route on the polymer properties were examined. The monomer concentration and monomer stoichiometric ratio were found to affect the polymer viscosity. The size and shape of the polyketone particles obtained were also found to be governed by reaction conditions and preparation route.
In the second part of this series the influence of monomer concentration on the chemical structure and the shape and size of poly(aryl ether ketone ether ketone ketone) (PEKEKK) particles was reported. The present study of the thermal behavior and microstructure of aromatic polyketone samples in the form of particles has been carried out by means of differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD). Samples before and after reprecipitation and annealing were investigated. Similar to other polyketones, PEKEKK shows two polymorphic forms: form II, less stable, is currently observed in the samples, while the reprecipitated polymer preferentially shows form I. Form II is partially converted into form I upon short annealing treatment of the material. The semicrystalline materials show melting points and glass transition temperatures which are higher for the samples with higher molecular weight and more regular chain structure. A comparison of thermal properties of "as obtained" and "reprecipitated" samples reveals the influence of the particle architecture on the chain mobility. The latter determines the ability of polyketone chains to crystallize. Infrared dichroism was also used to characterize the arrangement of polymer chains inside the polyketone particles showing crystal habits.
The cold drawing of a poly(ether ester) block copolymer was studied by in-situ simultaneous small-and wide-angle X-ray scattering techniques in combination with a tensile stretching apparatus. The results obtained revealed three distinct regions in the stress-strain relationship. At low strains (0 < < 18%), the applied stress caused extension of the amorphous regions, formed by PTMO and some noncrystallizable segments of PBT, and subsequently reorientation of PBT crystalline lamellae. At slightly higher strains the lamellae become perpendicularly aligned to the drawing direction. At intermediate strains (18% < < 80%), the elongation gradually leads to breakage of the lamellae into smaller pieces, which eventually formed microfibrils containing linear assembly of layered lamellae. At large strains ( > 80%), a further extension of the PTMO amorphous chains resulted in the fracture of the sample. The pathway of the structural changes by deformation in the present study was slightly different than those observed in the predrawn samples.
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