Dilute solution parameters of polymethylphenylsiloxamers

Dilute solution parameters were determined for polymethylphenylsiloxamer fractions (5 × 104 < M < 1.5 × 106) in toluene, cyclohexane, and diisobutylamine (θ ≈ 30.4°C). The data are interpreted by the procedure suggested by Flory and Fox. Minor deviations from theory are noted. Polymers from both cis‐ and trans‐cyclotrisiloxanes were investigated. The major portion of the work, however, was concentrated on fractions derived from the trans form. From the data obtained, a characteristic ratio of dimensions (r /r )½ of 1.56 was determined. The hydrodynamic parameter Φ was determined to be (2.0 ± 0.3) × 1021. The appropriate model for the polymer is indicated to be the impermeable random coil with slight hindrance to rotation about backbone skeletal bonds.