Effect of castor oil enrichment layer produced by reaction on the properties of PLA/HDI-g-starch blends

► It has no report about the location of castor oil (CO) in PLA/starch blends. ► The grafting content of hexamethylenediisocyanate (HDI) determined the properties of the PLA/starch/CO blends. ► The size of CO droplets in PLA matrix became smaller and less CO droplets for the blend with HDI grafted starch.