Some solution properties of polyacetals containing poly perfluoro (oxymethylene-ran-oxyethylene) macromers (PFPE acetals) were investigated. Of the eight fractions selected dynamic light scattering in 1,1,2 trichlorotrifluoroethane and intrinsic viscosity measurements in four solvents of different thermodynamic quality and polarity, including a theta solvent, were performed. Previous results on chain flexibility of the new polymers could be reanalyzed taking into account non-negligible solvent effects. The characteristic ratio of the new PFPE-acetals was confirmed to be slightly higher than that of the corresponding fully fluorinated polyethers.
Twelve series of linear oligomers of four different degrees of polymerization ( x n = −), having a common perfluorinated random copolymeric chain as molecular body and two equal foreign end units of one of the types listed in Table 1, have been synthesized by derivatization of base samples of one of them having a diolicCH 2 OH functionality. The glass transition temperature T g of all the series was measured and thus examined as a function of x n . A clear end unit effect is observed, dominantly determined in every series by chemical nature and structure of the end units, quantitatively expressed at any x n by different positive or negative T g deviations from the common asymptotic T g ∞ value. The results are also discussed in terms of copolymer end effect and of relation between T g and end copolymeric composition.