MELT RHEOLOGY OF IMPACT MODIFIED PBT AND ITS NANOCOMPOSITES
RANJANA SHARMA *
Birla Institute of Technology, Offshore Campus, Ras al Khaimah, UAE.
School of Applied Sciences, Netaji Subhas Institute of Technology, University of Delhi, Dwarka, New Delhi-75, India.
*Author to whom correspondence should be addressed.
The melt rheological properties of impact modified poly (butylene terepthalate) (PBT) and its nanocomposites with 2, 3 and 5 wt% of organoclay loadings have been systematically investigated, focusing on rheological behaviour as an approach for characterization. The linear viscoelastic behaviours of all compositions have been measured by the parallel plate rheometer. Melt rheological studies of PBT nanocomposites showed that the loss modulus (G'') is more than the storage modulus (G') in rubber toughened PBT and its nanocomposites at higher frequency region which indicates that the viscous or liquid like behaviour dominates over the elastic behaviour. All the compositions show long term stabilities as observed in the graphical presentations of loss modulus, storage modulus, loss factor and complex viscosity values. The storage and loss moduli of 98/2 PBT/ULDPE-g-GMA (glycidyl methacrylate grafted ultra low density polyethylene) has increased with the incorporation of 3 and 5 wt% of organoclay, but the tan delta remains the same.
Keywords: Rheology, PBT, blends, nanocomposites, impact modifiers, organoclay