Toughening of Polylactide by Bio-Based and Petroleum-Based Thermoplastic Elastomers

Meyva, Y.
Kaynak, Cevdet
The purpose of this study was to improve toughness of inherently very brittle polylactide (PLA) without sacrificing strength and thermal properties, so that biopolymer PLA could be used in engineering applications. For this purpose, PLA was blended with various amounts of two different thermoplastic elastomers; TPU (petroleum-based thermoplastic polyurethane) and TPE (bio-based thermoplastic polyester). Melt blending and specimen shaping were achieved by using a twin-screw extruder and injection molder, respectively. SEM analysis indicated that TPU and TPE were immiscible forming fine and uniform round domains in the PLA matrix. It was revealed that rubber-toughening mechanisms of TPU and TPE were very effective. For instance, using only 10 phr of TPU or TPE increased Charpy impact toughness of PLA more than 300 %, while increases in fracture toughness (K-IC and G(IC)) values of PLA were as much as 35 % and 130 %, respectively. Other mechanical tests (tension, flexure, hardness) and thermal analyses (DSC) revealed that there were no significant detrimental effects of using 10 phr TPU or TPE on the engineering performance of PLA.


Toughening of polylactide by blending with various elastomeric materials
Meyva, Yelda; Kaynak, Cevdet; Department of Polymer Science and Technology (2014)
The purpose of the first part of this thesis was to investigate influences of three different ethylene copolymers on the toughness and other properties of very brittle biopolymer PLA (polylactide). For this aim, PLA was melt blended by twin-screw extruder with various amounts of ethylene vinyl acetate (EVA), ethylene methyl acrylate (EMA) and ethylene-n-butyl acrylate-glycidyl methacrylate (EBA-GMA). SEM and DSC analyses indicated that these ethylene copolymers were thermodynamically immiscible with phase s...
Process characterization of composite structures manufactured using resin impregnation techniques
Miskbay, Adem Onur; Parnas, Kemal Levend; Department of Mechanical Engineering (2009)
The aim of this study is to investigate and compare the properties of two layer carbon epoxy composite plates manufactured using various resin impregnation techniques; Resin Transfer Molding (RTM), Light RTM (LRTM), Vacuum Assisted RTM (VARTM) and Vacuum Packaging (VP). Throughout the study a different packaging method was developed and named Modified Vacuum Packaging (BP). The mechanical properties of composite plates manufactured are examined by tensile tests, compressive tests, in-plane shear tests and t...
Nanowires assembled from iron manganite nanoparticles: Synthesis, characterization, and investigation of electrocatalytic properties for water oxidation reaction
Çetin, Asude; Önal, Ahmet Muhtar; Nalbant Esentürk, Emren (Cambridge University Press (CUP), 2019-09-30)
The development of stable and effective earth-abundant metal oxide electrocatalysts is very crucial to improve competence of water electrolysis. In this study, iron manganite (FeMnO3) nanomaterials were synthesized as an affordable electrocatalyst for water oxidation reactions. The structural and chemical properties of FeMnO3 nanomaterials were studied by transmission electron microscopy, scanning electron microscopy, energydispersive X-ray, X-ray diffraction, X-ray photoelectron spectroscopy, inductively c...
Fatigue Cracking of Hybrid Plasma Gas Metal Arc Welded 2205 Duplex Stainless Steel
Yurtışık, Koray; Tirkeş, Süha (2014-01-01)
Contrary to other keyhole welding applications on duplex stainless steels, a proper cooling time and a dilution were achieved during hybrid plasma gas metal arc welding that provided sufficient reconstructive transformation of austenite without sacrificing its high efficiency and productivity. Simultaneous utilization of keyhole and metal deposition in the hybrid welding procedure enabled us to get an as-welded 11 mm-thick standard duplex stainless steel plate in a single pass. Me examination on hybrid plas...
Elastic-plastic finite element analysis of semi-hot forging dies
Halisçelik, Murat; Darendeliler, Haluk; Department of Mechanical Engineering (2009)
Semi-hot or warm forging is an economical alternative to the conventional forging processes by combining advantages of hot and cold forging processes. In this study, a new forging process sequence and design of the preform die for a part which has been produced by hot forging are proposed to be produced by semi-hot forging. Thermo-mechanical finite element analyses are performed over the stages of forging process. The billet and the dies are modeled as elastic-plastic bodies. Effects of preform die geometry...
Citation Formats
Y. Meyva and C. Kaynak, “Toughening of Polylactide by Bio-Based and Petroleum-Based Thermoplastic Elastomers,” INTERNATIONAL POLYMER PROCESSING, pp. 593–602, 2015, Accessed: 00, 2020. [Online]. Available: