In the present study, some thiol surfactants were prepared. Polyester / (nano bentonite) nano composite (A), polyester/(5% nano Bentonite) / thiol surfactant (I) nano composite (B), polyester / (5% nano Bentonite)/thiol surfactant (II) nano composite (C) and Polyester/(5% nano Bentonite)/thiol surfactant (III) nano composite D were fabricated. The mechanical, thermal properties and morphological structure of fabricated composites were studied. The results showed that nano Bentonite powder / polyester composite improve these properties at 5% weight and begins to weaken as the filling ratios increased. However using thiol surfactants as additives to polyester / (nano bentonite) nano composites improve the thermal and mechanical properties of nano composites. But nano composite (D) gave the optimum thermal and mechanical properties which can be used in manufacture of drinking water pipes.