Crystallization Behavior of Bisphenol-A Polycarbonate on Nanoparticle Surface

摘要

Crystallization behavior and metastable amorphous structure of polycarbonate (PC) slowly cast from tetrahydrofuran (THF) solution was investigated by Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. The amorphous structure of PC changed to a different structure under the influence of THF as a polar solvent. We call this different structure metastable amorphous, and similar structures have been found in several polymers other than PC. A metastable amorphous has a different conformation from a normal amorphous structure and becomes a crystal nucleus. That structure was preserved on the surface of alumina nanoparticles by the interaction between different substances. The metastable amorphous preserved on the nanoparticles has a new Tg (We called L-Tg) at 0~ 60?C, which is lower temperature than normal Tg. Furthermore, these structures were crystallized by a short annealing at 120 ?C. We report this metastable amorphous structure of PC and its transformation into crystals.