Vitrification and crystallization of poly(butylene-2,6-naphthalate)

Abstract

The differential fast scanning calorimetry (DFSC) technique has been successfully applied to study the vitrification and crystallization of poly(butylene-2, 6-naphthalate) (PBN). The cooling rate larger than 6000 K/s could make the PBN vitrify and the cooling rate larger than 30, 000 K/s reduced effectively the development of the active nuclei. The critical cooling rate of 30, 000 K/s is three times as large as that of the recently reported poly(ϵ-caprolactone) (PCL)'s. Namely, it turned out that PBN is a hard-to-vitrify polymer. The heating rate faster than 7000 K/s could prevent the cold crystallization from the proper glassy state. In the less severe cooling and heating rates than 30, 000 K/s and 7000 K/s, respectively, a variety of structure formations, such as the nucleation, the mesophase formation, the crystallization and their multiple melting behaviors, have been observed.