A series of superabsorbent polymer composites (SAPCs) were synthesized via emulsion polymerization of partially neutralized acrylic acid onto polystyrene in the presence of Hectorite (HT) clay powder and mung bean starch (MBSt) using Ammonium Persulphate and N’N,-Methylenebisacrylamide as initiator and crosslinker, respectively. The aim of this study is to prepare a hydrogel composite using Hectorite clay as the reinforcement and to study the effect of Hectorite clay on the thermal properties of the composite. FTIR analysis confirmed that the grafting polymerization took place among acrylic acid, polystyrene, mung bean starch and Hectorite clay. From DSC ad TGA analysis, the glass transition temperature (Tg) increased and the weight loss of the composite reduced upon incorporation of Hectorite clay.