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

Email: ab_ahad@rediffmail.com

Abstract:

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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