Abstract
Light scattering and viscometry were used to examine properties of solutions of poly-(4,4′-hydroxydiphenylene)pyromellitic amido-acid (PAA PM) and methyl and ethyl esters in DMAA and DMF. Esters were obtained by reactions in PAA PM chains. It was shown that storing PAA PM solutions and esters obtained by reactions in PAA chains, the weight average molecular weight of polymers is reduced, which is evidence of the validity of the degradation mechanism of ageing PAA in solutions. For PAA PM in DMAA and mixture of DMAA: dioxane (1:2·5) equations were derived which relate intrinsic viscosity with molecularly weight. Using the Stockmayer-Fixman extrapolation method for PAA PM unperturbed dimensions of molecular spheres were determined in solution. From the value of ( h 0 2/M) 1 3 and the steric factor σ it was concluded that there is practically no rotation around ester oxygen bridges.
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