Green method for preparing starch grafted polycaprolactone copolymer

The invention discloses a green method for preparing a starch grafted polycaprolactone copolymer, and belongs to the field of modification of biodegradable high polymer materials. The preparation method comprises the following steps: by taking ball-milled pretreated starch and caprolactone as raw materials, adding a high-efficiency catalyst under the protection of N2, and carrying out ring opening polymerization on the caprolactone through mechanical stirring under a solvent-free condition, so as to generate the starch grafted polycaprolactone copolymer (St-g-PCL). And dissolving the obtained product with dichloromethane, and carrying out Soxhlet extraction and drying to obtain the pure starch grafted polycaprolactone copolymer. The starch subjected to ball milling pretreatment is adopted, so that the reaction degree of the starch and caprolactone is increased, and the grafting efficiency can reach up to 49.5%. The St-g-PCL can be used as a compatilizer of the starch modified biodegradable polyester material,