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Surface properties of two polyethers containing pyridine and pyrazine units, respectively, were compared with polysulfone. The polymers were investigated by inverse gas chromatography. The dispersive contributions of the surface free energy and the KA and KB parameters expressing the ability of the stationary phase to act as Lewis acid or Lewis base were calculated. It was shown that the polymer with pyridine units possessed extraordinarily high KB values whereas the polysulfone showed amphoteric behaviour with predominant Lewis basicity.

Fully aromatic copolyester with regular chain structure containing kinked monomer units were investigated by powder diffraction experiments combined with structure modelling. Temperature dependent X-ray measurements show the existence of low and high temperature solid state modifications of poly( p -phenylene isophthalate), (IPA-HQ) n . From the X-ray scattering data, d -spacings were determined taking some experimental corrections into account. Lattice parameters as well as atom coordinates of lt -(IPA-HQ) n were calculated and optimised by means of modelling procedures based on force field constrained RIETVELD algorithms. From this, a monoclinic unit cell of lt -(IPA-HQ) n with a = 0.775 nm, b = 0.567 nm, c = 2.410 nm, β = 91.8° was found considering the chemical structure as well as interactions between the particles. The (IPA-HQ) n polyester is a typical representative of this kind of polymer with kinked monomeric, and hence is useful for further structural investigations.

Aromatic polyesters with isophthaloyl, pyridine-2,6-dicarbonyl and pyridine,2,5-dicarbonyl units in the main chain were synthesized and were characterized by inverse gas chromatography (i.g.c.). The polyesters containing complex ‘triad’ monomers and aromatic diols were obtained by high temperature solution polycondensation. In order to investigate whether the surfaces of polycondensates act as Lewis acids or Lewis bases, the donor-acceptor interactions between various probe molecules and polyesters have been studied by means of i.g.c. Because the measurements were carried out at different temperatures, we were able to determine parameters K A and K B , which describe the donor-acceptor properties of the stationary phase. One polyester without pyridine units was amphoteric with slight predominance of Lewis-basic behaviour. Polymers containing pyridine units may be considered as Lewis bases. The glass transition temperatures of two polymers have also been determined by i.g.c.

Aromatic copolyesters with regular chain structure were investigated in order to correlate their primary chemical structure, some molecular characteristics (inherent viscosity, molecular weight) and crystallographic data as well as melting behaviour. A series of copolyesters were synthesized by polycondensation of complex aromatic dicarboxylic acid chlorides with variable diols. By means of wide angle X-ray diffraction it was found that the kind of diol component strongly influences the phase structure as well as the crystallinity of the polymers. A monoclinic symmetry was supposed for some of the high crystalline samples. Molecular modelling, including ab initio calculations and computing of the solid state, was carried out for two representatives of p-linked fully aromatic copolyesters. A good agreement of experimental and calculated scattering data was obtained by using the space group P1.

Block copolymers with poly(tetramethylene glycol) (PTMG) spacers of different length and the 4,4′-(terephthaloyldioxy) dibenzoyl unit have been synthesized by high temperature solution polycondensation. The influence of the spacer length on thermal behaviour and solid phase structure of alternating polyesters in comparison with pure PTMG has been determined by d.s.c. and WAXS investigations. Up to spacer molecular weights of 650 g mol−1 (degree of polymerization, DP ≈ 9), polymers with thermotropic liquid crystalline phase behaviour are obtained. Above spacer molecular weights of 1000 g mol−1 (DP ≈ 14), the coexistence of two crystalline phases resulting in polymers with block-like character is discussed.