Abstract: With corn starch as raw material, the optimal dispersing method of starch film modified by nano-silica was studied. And the structure of the films was analyzed by infrared spectroscopy (IR), X-ray diffraction and scanning electron micrography (SEM). The results showed that the dispersion liquor, with nano-silica 2% (of starch and PVA) and PA dispersant 1.5% (of nano- silica), is obtained by mechanical grinding dispersion for 1 h. Then the dispersion liquor is put in the blend solution of ST-PVA. Properties of starch films are improved remarkably by adding a little amount of nano-silica. The tensile strength and breaking elongation of the film are 34.82 MPa and 331% respectively, which meet the national standard GB4456-84. A dense and homogeneous network is generated. The conclusion in the research will provide theoretical base and practical references for making full-biodegradable film with corn starch and nano-silica to eliminate “white pollution” problem.

Key words: corn starch, nano-silica, full-biodegradation, film, dispersant