A starch-polyester graft copolymer and chemically modified starch-polyester graft copolymer composition comprising a chemically modified starch or chemically modified starch-nanoclay product is described. The composition can be produced continuously in a twin-screw co-rotating extruder. The starch-polyester graft copolymer can be solvent cast, melt cast and blown into clear transparent film particularly for use in single use disposable applications and can be biodegradable.