The effects of starch with different amylose/amylopectin ratios on the microstructure and properties of starch/agar composite films prepared by casting method are studied. Scanning electron microscope (SEM) observation, Fourier transform infrared spectrum (FTIR) test, X-ray diffraction (XRD) test, mechanical property test and hydrophilic and hydrophobic property test are carried out. The microstructures and properties of starch/agar composite films with different ratios are compared. Results show that the value of elongation at break of waxy/agar composite film is lower than the other two when the agar content is fixed. With the increase of agar content, the tensile strength of each composite film increases, and the water contact angle of G50/agar composite film increases significantly, while the weak hydrophilicity of agar reduces the hydrophilicity of the composite film surface.

starch/agar composite film  /  amylose/amylopectin ratio  /  hydrophilicity