Blending of Polylactide with Different Elastomeric Materials for Toughening

2016-07-21
Meyva, Yelda
Kaynak, Cevdet
Polylactide (PLA) is an important biopolymer used especially for biomedical and food packaging applications. The main problem to be used in other industrial applications is its very high level of brittleness. Therefore, the main purpose of this work is to compare rubber toughening influences of five different elastomeric materials. For this purpose PLA was blended by three ethylene copolymers, i.e. ethylene vinyl acetate (EVA), ethylene methyl acrylate (EMA), ethylene-n-butyl acrylate glycidyl methacrylate (EBA-GMA); and two thermoplastic elastomers, i.e. thermoplastic polyurethane (TPU), thermoplastic polyester (TPE). Blends having various amounts of elastomeric materials (5, 10, 15, 20 phr) are prepared by melt-mixing method in a laboratory scale twin-screw extruder. Specimens for testing and analysis are shaped in required dimensions by using a laboratory scale injection molder. Morphological analysis conducted by scanning electron microscopy (SEM) indicated that all elastomeric materials were immiscible forming round shaped domains in the PLA matrix, with certain level of agglomeration at higher contents such as 15 and 20 phr. Strength and elastic modulus of the blends were determined by tensile and flexural tests, while toughness values were determined by using two different methods; KIC and GIC fracture toughness tests and Charpy impact toughness tests. It was observed that generally all elastomeric materials decreased strength and modulus values of PLA with a certain degree, while leading to significant increases in the toughness values due to their efficient rubber toughening mechanisms. For example, GIC fracture toughness of PLA increased by 90% and 130% with 15 phr TPU and TPE; while increases were as much as 158%, 136% and 133% with 20 phr EVA, EMA and EBA-GMA, respectively. Acknowledgement: Authors gratefully acknowledge financial support from TUBITAK the Scientific and Technological Research Council of Turkey as part of the Project 113M586.
Citation Formats
Y. Meyva and C. Kaynak, “Blending of Polylactide with Different Elastomeric Materials for Toughening,” presented at the 46th IUPAC World Polymer Congress – MACRO 2016 (17 - 21 Temmuz 2016), İstanbul, Türkiye, 2016, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/84651.