the microstructure and physical properties (permeability, mechanical and thermal properties) of starch/polyvinyl alcohol/nanoclay based nanocomposite films

the starch based films have some disadvantages such as weak mechanical and poor water barrier properties that restrict their applications in food packaging. in the present research, the polyvinyl alcohol (povh), as a compatible polymer, and montmorillonite (mmt) nanoclay, as a nanofiller, were added to plasticized starch film (ps) to improve its properties and also to produce ps-mmt-pvoh nanocomposits with different mmt content (3,5,7%). the results of x-ray diffraction (xrd) villustrated that the nanostructure of investigated starch based nanocomposites films has an exfoliated structure which can be attributed to the good dispersing of filler in polymer matrix. dsc results showed that with adding mmt and increasing its content from 0 to 7%, melting point and tg increased from 242ᵒc to 262ᵒc and 148ᵒc to 188ᵒc. the results of tensile test showed that addition of pvoh and mmt increased the ultimate tensile strength (uts) and decreased the water vapor permeability (wvp) of nanocomposite films.