The effect of formulation and processing parameters on thermal stability of PVC/Poly(epichlorohydrin-co-ethylene oxide)/organoclay nanocomposites prepared by melt mixing

In this work, nanocomposites of polyvinyl chloride poly(epichlorohydrin-co-ethylene oxide)(ECO)/organoclay were prepared via melt processing and various parameters including nanoclay and rubber content (ECO) as well as rotor speed were tuned to find the optimum formulation for the highest thermal stability. The prepared products were characterized by X-ray diffraction as well as thermogravimetric analysis (TGA), derivative thermogravimetric (DTG) and differential thermal analysis XRD results showed that rotor speeds higher than 70 r/min are crucial for obtaining highly intercalated products with good thermal stability. From DTG analyses, it was observed that at lower concentrations of rubber, the rate of mass loss is higher which results in faster dehydrochlorination of the composite. The sample prepared with 2 phr OMMT, 30 phr rubber, and 70 r/min rotor speed showed the highest thermal stability. The selected nanocomposite showed the first weight loss at 294 degrees C. Results of this research showed that even a slight change in each parameter has a great influence on thermal properties of the nanocomposites. The hydrogen bonding mode between ECO and organoclay were estimated by theoretical calculations using GAUSSIAN software. From the obtained results, the miscibility of OMMT and ECO polymer is related to the hydrogen bonds which are more preferred at chlorine atom of ECO polymer.