A new strategy for the synthesis of modified novolac resin and its polymer/clay nanocomposite

A novel epoxy nanocomposite composed of epoxidized novolac (ENR), epoxidized polystyrene (EPSt), and nanoclay was fabricated and characterized successfully. For this purpose, the novolac was epoxylated using a substitution nucleophilic reaction between hydroxyl group of novolac and chlorine group of epichlorohydrin. The EPSt was synthesized through the oxidizing of an allylated PSt (All-PSt). A mixture of ENR (70 wt%), EPSt (20 wt%) and Cloisite (R) 20A (5 wt%) was cured using ethylenediamine (EDA; 5 wt%) to afford a C-ENR-EPSt/clay nanocomposite. The transition electron microscopy (TEM) as well as powder X-ray diffraction (XRD) analysis revealed that the fabricated nanocomposite has an exfoliated structure. As the thermal property studies results, the addition of EPSt as well as Cloisite (R) 20A has synergistic effect on the thermal stability of the ENR resin.