Influence of the chemical composition and comonomer distribution on the dipole moments of 3,3‐dimethyloxetane/tetrahydrofuran copolymers

Abstract

AbstractExperimental values of the dipole moment ratio 〈μ2〉/nm2 and its temperature coefficient d ln 〈μ2〉2/dT, where 〈μ2〉 is the mean‐square dipole moment of a chain with n skeletal bonds and m2 is the mean square of the skeletal bond dipole moments, are reported for well‐characterized random copolymers of 3,3‐dimethyloxetane and tetrahydrofuran. The results are interpreted in terms of the rotational isomeric state theory in a manner consistent with that developed for the parent homopolymers. The theory gives a good account of the experimental results corresponding to copolymers in which the mole fraction of tetrahydrofuran lies in the range 0.11–0.89. It is found that whenever the copolymerization obeys Bernouillan statistics, the dipole moments are quite insensitive to the comonomer distribution. The theoretical analysis suggests, however, that the value of the dipole moment ratio of alternating copolymers of 3,3‐dimethyloxetane and tetrehydrofuran should be near that of the parent homopolymer of lower polarity.