Effect of Epoxy Resin on the Mechanical Properties and Melt Viscoelastic Behaviour of Poly(butylene terephthalate)/Montmorillonite Nanocomposites
Poly(butylene terephthalate)/epoxy/montmorillonite ternary nanocomposites (PCNs) were prepared by melt intercalation. Their morphologies were investigated using XRD and TEM. The results reveal that with epoxy resin as a compatibilizer, the clay is easily intercalated and disperses well in the matrix. Therefore, the PCNs exhibited better tensile and impact properties than neat PBT, although any surplus epoxy dispersed in the PBT matrix reduces the material performance. The melt viscoelastic behaviour of the PCNs was measured by means of a parallel plate rheometer. The PCN ternary hybrids showed a stronger solid-like response in the lower frequencies than samples without epoxy, for two reasons: the enhancement of percolation network density, and the bridge-like effect of the epoxy linking the clay and the polymer chains. The compatibilizer content influenced the morphology and performance of the nanocomposites. The optimum compatibilizer dosage of 4 wt% was decided by a novel 'crossover point' rheological method.