Light scattering and intrinsic viscosity investigation of polymethyl‐3, 3, 3‐trifluoropropylsiloxamer

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Abstract
Solution parameters for the polymer poly‐γ‐trifluoro‐propylmethylsiloxamer has been determined in cyclohexyl acetate, methyl hexanoate, and ethyl acetate. Interpretation of data follows the theory of Fox and Flory. In contrast to poly‐dimethylsiloxane, an increased steric hindrance to rotation about the siloxane bond occurs as evidenced by the characteristic ratio of root‐mean‐square end to end dimensions, (r02/r0f2)1/2, found to be 1.90 and 1.96 at 25.0 and 72.8°C, respectively. This increase is considered to be primarily due to nearest‐neighbor interaction of the polar substituent on the silicon atom. The relation, [η]θ ∝ M1/2, was observed to hold for this polymer system. The hydrodynamic model appropriate for the polymer is a random coil considerably more permeable to solvent flow than is generally reported for linear polymers. The universal parameter ϕ was determined to be 1.5 × 1021. The effect of temperature on polymer configuration is indicated to be negligible.