Polyethylene / thermoplastic starch formulations for film blow molding applications

MAURY SABRINA HERNANDEZ NUÑEZ; CLAUDIO JAVIER PEREZ; LEANDRO NICOLAS LUDUEÑA

Mar del Plata

Simposio; XVI Latin-American Polymer Symposium (SLAP 2018), XIV Iberoamerican Polymer Congress (CIP 2018); 2018

Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA)

Petrochemical based polymers, have been increasingly used as packaging materials, owing to relatively low cost and mechanical and vapor/oxygen barrier properties that fulfill the requirements of this application. For some applications such as thin films in contact with food, recycling is impractical and economically not convenient. This situation and the non-biodegradable characteristic of these materials, has caused a major environmental problem regarding the disposal of waste. Currently there is a growing interest in the use of biodegradable polymers with functionalities and processabilities comparable to traditional petrochemical-based polymers1.Use of thermoplastic starch (TPS) as a raw material for the manufacturing of biodegradable products has been studied intensively in recent times, with clear indications of the advantages and limitations imposed by the use of this material. Due the hydrophilic nature of starch, products are sensitive to changes of ambient humidity and have poor mechanical properties. On the other hand, neat TPS is not suitable for industrial film blow molding applications due to its low extensional viscosity. The aim of this work is to develop a twin screw extrusion process at pilot plant scale to prepare low density polyethylene (LDPE) / TPS pellets compatibilized with high density polyethylene modified with maleic anhydride (MHDPE). LDPE was selected to improve the extensional viscosity of the formulation focusing on film blow molding as final application. LDPE content in the blends will be minimized up to the minimal value to become the TPS/LDPE blends suitable for film blow molding.