The invention belongs to the technical field of biodegradable materials, and particularly relates to an environment-friendly degradable modified
composite material, a preparation method and application. The material comprises PBAT, PBS, PLA, an inorganic mineral filler, natural
plant fibers, PBAT-PTMO, nano-silica, an auxiliary agent and a
plasticizer. In the preparation process, PLA is prevented from being hydrolyzed in
vacuum drying,
calcium carbonate and
nano silicon dioxide are preheated and activated, natural
plant fibers are dispersed through
steam explosion and
ethanol treatment, and
raw material pretreatment comprises high-speed mixing and agglomeration breaking and medium-speed secondary premixing so as to realize uniform distribution. The co-rotating twin-screw extruder accurately controls the temperature, the speed, the rotating speed and the length-
diameter ratio, and ensures melting plasticizing, uniform mixing and stable
extrusion molding. According to the invention, by adopting accurate proportioning of multiple raw materials and a modification treatment process, the properties of
mechanics, degradation,
processing and the like of the material are synergistically improved, and the material is widely applied to multiple fields such as packaging bags, disposable tableware and agricultural plastic mulching films.