Dynamic Viscoelasticity for Nylon6 During Isothernal Crystallization
Hisahiko KASHIHARA, Masaoki TAKAHASHI, Kenji URAYAMA and Toshikazu TAKIGAWA
Abstract:The variation of dynamic viscoelasticity during isothermal crystallization of Nylon6 is investigated. The time dependence of the crystallinity evaluated from DSC (xH) is compared with that of the crystallinity defined by dynamic measurements (xG ) as (Gt - G0) / (Ginf- G0) where Gt, G0 and Ginf are the moduli at concerning time, in the initial molten and fully crystallized states, respectively. The onset of the increase in xG is retarded as compared with xH, while xG becomes identical with xH in the later crystallization process. These features are commonly observed in Nylon6 and polybutene-1 varying significantly in viscoelasticity before crystallization as well as the size of spherulites. The relation between xG and xH is well explained by considering the morphological change of system resulting from the growth of spherulite domains. Key Words:Isotheramal crystallization, Viscoelasticity, Nylon6, Polybutene-1, DSC