Molecular interaction and conformation of molecules in polystyrene and styrene-methacrylic acid copolymers

Abstract

A study was made of universal and specific molecular interaction (MI) and the conformation structure in solid PS and styrene-methacrylic acid (MAA) copolymers, the content of the latter acid varying between 2 and 33 mole %. Experiments were carried out by IR spectroscopy using results of differential scanning calorimetry (DSC) and internal friction (IF). A spectroscopic parameter was selected for the control of variations of universal MI in the polymers studied. Hydrogen bond concentrations in the copolymers were determined according to composition and past thermal history. It was found that in addition to the main effect-increase in the entire MI as a result of hydrogen bonds, the addition of MAA units to PS produces secondary effects, a reduction in universal MI, increase in small scale mobility and chain convolution. These effects are particularly significant starting from MAA concentrations of 10–16%, when average distances between hydrogen bridges become commensurate with the size of the statistical segment.