Abstract
Factors affecting the molecular motion of styrene-hydroxystyrene copolymers were studied. Glass transition temperature (Tg) of copolymer increased with increasing amount of hydroxyl group. Main chain motion of the copolymer was affected by absorbed water: Tg of the copolymer decreased with increasing amount of absorbed water. By applying the mixture rule reported by Wood and Fox to the copolymer-water, it was found that the lowering of Tg by absorbed water was due to the plasticizing effect and also to breakage of hydrogen bonds among the polymers. The amount of hydrogen bonding between the hydroxyl groups was estimated quantitatively from the relation between the amount of absorbed water and the lowering of Tg of the copolymer.
