Preparation and characterization of poly(lactic acid) blends

Poly(lactic acid) (PLA) is one of the most consumed biopolymers. Its biodegradable structure makes it a sustainable, promising and popular raw material for various applications from packaging to the textiles industry. The wide range of applications basically caused by its processability. PLA films can be fabricated by extrusion film blowing, extrusion film casting. 3D products can be produced by blow molding, thermoforming and injection molding. Also PLA is a proper polymer for fiber production and various processes can be used including melt spinning and solution spinning. It has many advantages compared to other traditional polymers in terms of energy requirement and carbon footprint. Since PLA is a rigid polymer, its flexibility is low and tensile strain values are generally low. This is one of the most important problems for PLA-based products. Although PLA has good mechanical properties such as elastic modulus and tensile strength, its low flexibility restricts its applications in flexible packaging. In order to modify the thermal, morphological, and mechanical properties, PLA is blended with other different polymers. Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) is one of the commonly used polymers in industrial applications is an important polymer in terms of its elastomeric and thermoplastic properties. SEBS is a block copolymer, that contains styrene and ethylene-butylene blocks have good resilience and high tensile strain values. In this study, SEBS was used in order to tune the properties of PLA. Polymer films, from the blends at various PLA/SEBS ratios, were fabricated and morphological, strcutural, thermal and mechanical properties of the films were characterized. Keywords: Polymer blends, Poly(lactic acid), Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS), Solution mixing