Effect of native and oxidized corn starch-polystyrene blends under reactive extrusion conditions using zinc octanoate as catalyst for the development of composite materials at pilot scale with application to food packaging

LEANDRO LUDUEÑA; MARÍA PAULA GUARÁS; VERA ALEJANDRA ALVAREZ; ANDRÉS TORRES NICOLINI; TOMY GUTIERREZ

San Martín - Prov. Buenos Aires

Simposio; The Fifth International Symposium on Environmental Biotechnology and Engineering; 2016

UNIVERSIDAD NACIONAL DE SAN MARTIN (UNSAM)

Starch is considered a promising source to carry out biodegradable polymeric materials due to its low cost and easy accessibility. Nevertheless, starch-based films have poor mechanical properties and high sensitivity to moisture to be applied as food packaging. As an alternative to improve their properties, they have been blended with traditional synthetic polymers (Polystyrene - PS). Nonetheless, it is well known phase separation that occurs between hydrophobic polymers (PS) and hydrophilic (starch). In this sense, currently has been making efforts for compatibility of both polymers using conventional processes at industrial level, i.e. extrusion. Likewise, the use of catalysts such as zinc octanoate could improve the compatibility between these polymers under reactive extrusion conditions [1, 2]. In this work the effect of the application of a catalyst (zinc octanoate) employed two matrices of starch (native and oxidized corn starch) were evaluated. Thermogravimetric analysis (TGA), swelling behavior, contact angle, moisture and X-ray diffraction (XRD) were the assays performed in this study. Based on the results obtained zinc octanoate improve compatibility of oxidized corn starch-PS blend, leading to a higher contact angle and thermal resistance and lower sensitivity to moisture.