Effect of the Crystallization Induction Time on Viscoelastic Behavior of PBT (Poly butylene terephthalate) Film

Concerning PBT (Poly butylene terephthalate) film with three kinds of crystallization induction time, the effect of the crystallization induction time on temperature dependence of storage modulus was investigated. The storage modulus above glass transition temperature ca. 40°C was inclined to decrease seriously as the crystallization induction time was higher. The size of crystal and its deviation, which are influenced by the crystallization induction time, were seriously related to temperature dependence of storage modulus. Storage modulus of PBT molded under exposed temperature in use depended on the crystallization induction time.