Effect of chitosan coating of on the surface properties of native and phosphorylated thermoplastic starch films obtained by reactive extrusion

ALVAREZ, VERA A.; TOMY J. GUTIERREZ; MERINO, DANILA

Barcelona

Congreso; Polymers: Design, Function and Application; 2018

An agricultural mulch film is a thin plastic film that is placed directly on the ground in the early stages of plant growth. The insulating effect of the film helps to maintain the temperature, humidity and structure of the soil, preventing erosion and improving water management, an important issue in areas with limited water resources1. For the most part, these films are made of polyethylene and do not biodegrade. In this work, the possibility of developing a film for its replacement based on biopolymers such as starch and chitosan was studied. The first is a natural polymer from renewable, abundant and low-cost resources, capable of forming continuous thermoplastic films by the processing methods currently used for petroleum-derived polymers2. For its part, chitosan is a linear chain cationic polymer derived from chitin3,4. Its main properties are as bactericide, fungicide, antiviral, and biostimulant or growth stimulant and inducer of defense mechanisms in plants. Such properties confer high potential for its application in agriculture5. The objective of this work was to obtain films of native and phosphatized thermoplastic starch by reactive extrusion and to study the effect of a chitosan coating on the interaction of these materials with water. For this purpose, Fourier Transform infrared spectroscopy, thermogravimetric analysis, water contact angle, moisture absorption and scanning electron microscopy of the surface assays were carried out.