The Preparation And Characterization Of Starch Based Full-biodegradable Film

Starch, as an abundant raw material, has been used in the field of biomaterials, but the application of starch in the preparation of starch-based biomaterials such as packaging films and agricultural plastic films is limited because of its multi-hydroxyl and regular crystal structure. In this paper, starch based full-biodegradable films were prepared by sol-gel method. The main conclusions were as follows:1. The process optimization for the preparation of starch based full-biodegradable films.(1) The paper studied the physical properties and surface morphology of the starch based full-biodegradable films. The results indicated that the optimum feed concentration was 8%, under these conditions, the starch based full-biodegradable films has the best physical properties, and its tensile strength and elongation at break were 7.9MPa and 171%, respectively.(2) With the increase of stirring speed and stirring time, the physical properties of the starch based full-biodegradable films was improved, but when the stirring speed exceeded 500 per minute(stirring time>120min), the physical properties have no changes.(3) From the FTIR analysis and physical properties test, with the increase of drying temperature,the crystal structure and tensile strength of the starch based full-biodegradable films were also increase, but the elongation at break was decreased seriously,when the drying temperature was 40-90℃,the tensile strength of the starch based full-biodegradable films increase at a small scale.2. Prepared starch based full-biodegradable films by sol-gel method(1) Several starch based full-biodegradable films were prepared by sol-gel method, and the effect of SiO₂ on the physical properties of starch based full-biodegradable films was tested. The results indicated that SiO₂ can improve the physical properties of starch based full-biodegradable films, the biodegradable test showed that the addition of SiO₂ has no significant influence on the biodegradability of the films; The result of aging test indicated that the aging of films was delayed by the addition of SiO₂.(2) The structures of the films were characterized by Fourier transform infrared spectrometry (FTIR), scanning electron microscopy (SEM) and energy spectrum analysis. The results indicated that the gel network was formed in the films. The crystal structure of the films was also increased by the addition of SiO₂. Gel network was the primary factor to improve the physical properties of starch based full-biodegradable films.