Effects of lithium perchlorate on poly(ethylene oxide) spherulite morphology and spherulite growth kinetics

摘要

Effects of lithium perchlorate (LiClO_4) on the crystallization behaviors of poly(ethylene oxide) (PEO) were investigated by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and polarized optical microscopy (POM) in PEO/LiClO_4 system. DSC results indicate that there are nucleation effects of LiClO_4 on the crystallization of PEO. But, on the other hand, the coordination of lithium ion with the oxygen ether atoms of PEO can obviously reduce the crystallinity and spherulite growth rate of PEO. This contrary effect of LiClO_4 on the crystallization of PEO in PEO/LiClO_4 complexes system was analyzed and discussed in detail. The Laurizen-Hoffman theory was used to describe the Li-coordinated crystallization kinetics of PEO spherulite. It showed that the nucleation constant (K_g) and folding surface free energy (ω_e) decreased with increasing LiClO_4 contents, and the energy necessary for the transport of segments across the liquid-solid interface (ΔE) increased on increasing the contents of LiClO_4.