The present work shows the role of MMT in physical properties and biodegradation of bionanocomposites. An
increase in the Ultimate tensile strength (UTS) was observed when 1- 5% (w/w) of MMT was added to the PVA/S/CMC. With the increase of the MMT concentration from 0 t o 5%, the UTS increased 5 from 18.36 to 20.38 MPa, however, the strain to break (SB) decreased noticeably from 35.56 to 5.22%. The MMT content significantly impacted on the rate of starch solubilistion. The decrease of the degradation rate observed in the final stage can be explained to the lower degradability of the MMT-PVA-CMC domains that remain in the material. After 8–72 h, the variation is almost negligible,
nearly zero as demonstrated before. The reduction of the degradation rate is also influenced by the water uptake ability of these polymers. The water uptake ability of blends was decreased significantly as the MMT percentage increased from 0 to 5% (W/W). At the level of 5% (W/W) MMT, the films showed the lowest WAC% values and DED% decreased from 27.69 μg/ml h for the film without MMT to 18.95 μg/ml h for that containing 5% MMT. Based on these results, the PVA:S:CMC:MMT bionanocomposite films show better physicochemical properties than PVA:S:CMC films and they can be potentially replaced of PVA:S:CMC films.