Unperturbed dimensions of poly(phenyl acrylate)

Abstract

Thirteen fractions of poly(phenyl acrylate) have been prepared with weight-average molecular weight ranging from 0.158 × 10 6 to 2.57 × 10 6 g mol −1. The temperature coefficient of the unperturbed dimensions and the glass transition temperature were found to be −1.8 × 10 −3 deg −1 and 55.6°C respectively. Good accord was obtained among different methods for establishing θ-conditions of 11.5°C in ethyl lactate. From viscometry, osmometry and light scattering under θ-conditions, as well as in a good solvent, the unperturbed dimensions were determined via several procedures yielding a value of [〈r 2〉 0w M ̄ w] 1 2 = 6.0 (±0.2) × 10 −9 cm g −1 2 mol 1 2 . This corresponds to a steric factor υ = 2.37 (±0.08) and a characteristic ratio C ∞ = 11.3 (±0.8). The polymer chain is thus more rigid than poly(methyl acrylate), but less rigid than poly(phenyl methacrylate). With respect to its T g and flexibility, poly(phenyl acrylate) bears a strong similarity to poly(benzyl methacrylate).