The Effect of Crystallization on the Thinning-Thickening Phenomena of Plastic Blend Film in Water Media

摘要

Accidentally, we have found a plastic blend film of highly syndiotactic poly [(R,S)-3-hydroxybutyrate] (s-PHB; diad syndiotacticity is 0.6) and atactic poly (4-vinylphenol)(PVPh), which shows spontaneous and reversible thinning-thickening phenomenon in the aqueous media.~1 When the film with the thickness of 0.1-0.2 mm was put on the water surface, the film can float on water just by the surface tension even if it has a little higher density than that of water. It was observed that the frontal dimension of the film became larger and the film became thinner in course of time. However, when the film with the same dimension was sunk in water, the frontal dimensiona became smaller and the film became thicker. Furthermore, the film has the ability to transfer between the thinned and thickened states.