Lignin modified whole biological base PBS (polybutylene succinate) biodegradable plastic and preparation method thereof

The invention discloses a preparation method of a lignin modified whole biological base PBS (polybutylene succinate) biodegradable plastic. The method comprises the following steps of (1) selecting whole biological base PBS biodegradable resin synthesized by a biological base route as a monomer raw material; (2) performing vacuum drying on the whole biological base PBS and lignin; (3) sufficiently mixing the whole biological base PBS and lignin dried in a highly mixing machine with a chain extender, an antioxidant, a plasticizer, a lubricating agent and a thermal stabilizer; (4) performing extrusion and granulation through a double-screw extruding machine to prepare composite plastic particles; (5) performing film blowing on the composite plastic particles at a certain temperature to obtain the lignin modified whole biological base PBS biodegradable plastic. The biomass material of lignin and a lignin-PBS composite film material prepared through compounding modification are introduced; the complete degradatio