Poly(butylene terephthalate)/montmorillonite nanocomposites: Effect of montmorillonite on the morphology, crystalline structure,isothermal crystallization kinetics and mechanical properties

摘要

Nanocomposites (PCNs), based on poly(butylene terephthalte) (PBT) and organoclay (Cloisite-15A) MMTwere prepared by melt intercalation compounding process. The nanoscale dispersion and the micro-crystal structure studied qualitatively using; X-ray diffraction (XRD) and electron microscopy (SEM,TEM and AFM). The XRD results indicated that the crystal size is highly dependent on the crystalliza-tion temperature. The isothermal crystallization kinetics of PBT in PCNs analysis indicated that theoverall crystallization of PBT involved heterogeneous nucleated three-dimensional spherical primarycrystallization growth process. The crystallization rate, however, is dependent on the PCN-composition,crystallization temperature and the dispersion state of clay in PCNs. Further analysis, based on Hoffman-Lauritzen theory revealed that the neat PBT and PBT in PCNs crystallization follow regime-II kineticsfor temperature 195°C-205°C and enters the regime-III kinetics in lower Tcrange, 185°C-195°C. Theimprovement in mechanical properties is highly dependent on the level of clay exfoliation in PBT matrix.