Mobility and orientation of semi-rigid polyesters

Mobility and orientational behavior of semi-flexible polyesters from diphenyl-dicarbonic acid and some branched propyl-and butyl spacers have been investigated using static NMR techniques. Increasing molar mass of the polymers was found to influence the mobility of the rigid parts of the polymer chain while the spacer remains almost unaffected by the degree of polymerization. The mobility of the spacer carbons depends, however, on the length of the side chains. Even a magnetic field of 7 Tesla was not able to cause a reasonable macroscopic orientation in most of the samples, probably hindered by the high viscosity of the melts.     

The Use of Pressure-Volume-Temperature Measurements in Polymer Science

The importance of the knowledge of thermodynamic parameters from p-V-T experiments is shown in different fields of polymer science with special emphasis on determination of the phase behaviour of polymer systems.     

Polymer-modification of an anti-cancer drug: effects on hydrodynamic properties

Coupling of a hydrophobic pharmaceutical agents with the hydrophilic poly(ethylene oxide) chain can make the drug water soluble which is necessary for some applications. The modification of the polymer chain results in a different solution behaviour of the macromolecules compared with the unmodified polymer. There are strong indications that shape and rigidity of the modified molecule differ significantly from the simple chain. Some results from measurements of the self-diffusion coefficient and solution viscosity are discussed. The results are important for further engineering on active drug systems.