Poly(butylene terephthalate)-clay nanocomposites prepared by melt intercalation: morphology and thermomechanical properties

Nanocomposites based on poly(butylene terephthalate)(PBT)and an organoclay (Cloisite 30B)were prepared by melt blending using a twin-screw extruder. Two kinds of PBTs, ie PBT-A and PBT-B, with different inherent viscosities (çinh), were used for this study (çinh of PBT-A and PBT-B were 0.74 and 1.48, respectively). Dispersion of the clay layers in the PBT nanocomposites was characterized by using X-ray diffraction (XRD)and transmission electron microscopy (TEM). Tensile and dynamic mechanical properties and non-isothermal crystallization temperatures of the nanocomposites were also examined. Nanocomposites based on the higher-viscosity PBT (PBT-B)showed a higher degree of exfoliation of the clay and a higher reinforcing effect when compared to the composites based on the lower-viscosity PBT (PBT-A). The clay nanolayers dispersed in PBT matrices lead to increases in the non-isothermal crystallization temperatures of the PBTs, with such increases being more significant for the PBT-B nanocomposites than for the PBT-A nanoocomposites.