螺杆转速对淀粉基纳米TiO2/Cu2O复合膜结构及性能的影响研究OA

To investigate the influence of twin-screw extrusion process parameters on the properties of starch-based composite films,potato starch-carboxymethyl cellulose-nano-TiO2-Cu2O composite films were prepared using a twin-screw extrusion combined with hot pressing method.The effects of screw rotation speed(80-140 r·min⁻¹)on the microstructure and physicochemical characteristics of the films were systematically evaluated.Results showed that the shear forces generated during twin-screw extrusion effectively improved nanoparticle dispersion and reduced agglomeration of nano-TiO2 and Cu2O.A dense hydrogen bonding networks between potato starch and carboxymethyl cellulose,significantly enhancing the tensile strength by 339.4%(from 5.63 MPa to 24.74 MPa)and increasing elastic modulus by 45.77%.High shear conditions also induced a crystal transformation in potato starch from B-type to V-type,improving film crystallinity.Furthermore,increased screw speed partially oxidized nano-Cu2O,leading to a decrease in the surface color parameter a* value from 0.56 to-3.18 and a visible color shift from red to green.This study clarified the mechanism by which screw speed regulates microstructure to influence the properties of composite films,which provides a theoretical basis for the controllable processing of starch-based food packaging materials.