Synergistic effect of layered double hydroxides with micro and nano CaCO3 on the thermal stability of polyvinyl chloride (PVC) composites
A. Ahamad, C. B. Patil, V. V. Gite, P. P. Mahulikar, D. G. Hundiwale1
1 Department of Polymer Chemistry, School of Chemical Sciences, North Maharashtra University, Jalgaon 425 001, M. S., India
In the present work, evaluation of synergistic stabilizing effect of layered double hydroxides (LDH) with micro as well as nano size calcium carbonate (CaCO3) on thermal stability of PVC was studied. Nano sized CaCO3 was prepared in the laboratory by applying matrix mediated growth and controlled technique. Particle size of nano CaCO3 was estimated by studying X-ray diffraction pattern and confirmed by transmission electron microscopy (TEM). The PVC composites were compounded using Brabender Plastograph EC instrument. Various formulations were prepared by taking fixed amount of LDH and varying the composition of micro/nano sized CaCO3. PVC sheets were prepared on compression moulding machine having the dimension of 1 mm thickness. Thermal stability in terms of thermal degradation was studied by thermo-gravimetric analyzer (TGA). Surface morphology and tensile properties were studied by using scanning electron microscopy (SEM) and universal tensile machine (UTM). Increase in the onset temperature during degradation of PVC sheets, when evaluated by TGA was considered as imparting a better thermal stability to PVC. Better synergistic effect was observed in case of LDH with nano CaCO3 as compared to micron size CaCO3 on the stabilization of PVC.
Keywords: Polyvinyl chloride, layered double hydroxides, Nano CaCO3, Thermal stability, Stabilizers.
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