Evaluating PE/PLA interfacial tension using ternary immiscible polymer blends. Issue 26 (26th February 2021)

• Record Type: Journal Article
• Authors: Gu, Liangliang; Macosko, Christopher W.
• Is Part Of: Journal of applied polymer science. Volume 138:Issue 26(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-02-26
• Subjects: biopolymers and renewable polymers -- blends -- microscopy -- surfaces and interfaces; Polymers -- Periodicals; Polymerization -- Periodicals; 668.9
• DOI: 10.1002/app.50623
• Languages: English
• ISSNs: 0021-8995

Abstract

Abstract: Blending with ethylene‐based flexible polymers such as polyethylene (PE) is one of the strategies to toughen poly(lactic acid) (PLA), an inherently brittle biodegradable plastic enjoying growing demands worldwide. Interfacial tension plays a crucial role in blend formulation. Yet several literature reports on the PE/PLA interfacial tension contradict each other, giving ~5 mN/m and ~11 mN/m. In this work, we demonstrate that the PE/PLA interfacial tension is at least 9 mN/m. We use a cocontinuous PE/polystyrene (PS)/PLA ternary blend. Scanning electron microscopy (SEM) revealed complete wetting morphology with PS phase separating PE and PLA phases in the ternary blend. In addition, the complete wetting behavior was maintained at a PS volume fraction as low as 3%. This morphology together with the Harkins equation, indicate that the PE/PLA interfacial tension is higher than 10.5 ± 1.4 mN/m at 180°C. Abstract :