The inclusion of a synthetic fluoromica clay in PET affects its processability via biaxial stretching and stretching temperature (95°C and 102°C) and strain rate (1s -1 and 2s -1 ) influence the structuring and properties of the stretched material. The inclusion of clay has little effect on the temperature operating window for the PET-clay but it has a major effect on deformation behaviour which will necessitate the use of much higher forming forces during processing. The strain hardening behaviour of both the filled and unfilled materials is well correlated with tensile strength and tensile modulus. Increasing the stretching temperature to reduce stretching forces has a detrimental effect on clay exfoliation, mechanical and O 2 barrier properties. Increasing strain rate has a lesser effect on the strain hardening behaviour of the PET-clay compared with the pure PET and this is attributed to possible adiabatic heating in the PET-clay sample at the higher strain rate. The Halpin-Tsai model is shown to accurately predict the modulus enhancement of the PET-clay materials when a modified particle modulus rather than nominal clay modulus is used.
- A. Nanoclays
- A. Nanocomposites
- B. Mechanical properties
- D. Transmission electron microscopy (TEM)