in the present invention , biodegradable nanocomposites are introduced which include nanoclay particles , titanium dioxide nanoparticles , polyethylene , polypropylene , starch as a biopolymer , maleic anhydride and glycerol . the obtained nanocomposites have very high physical , mechanical and antimicrobial properties . proper dispersion and distribution of nanoparticles in composite substrate would help in improving the quality of the product to a great extent . the presence of polypropylene next to polyethylene would eliminate the weak points of polyethylene / biopolymer composite as polypropylene helps to modify the physical and engineering properties of nanocomposites in the presence of nanoclay . titanium dioxide nanoparticles have antimicrobial properties and would result in products which are useful for food and pharmaceutical industries . another important aspect of this invention is the production of samples in one step by reaction extrusion method .