Humidity‐Activated Shape Memory Effects on Thermoplastic Starch/EVA Blends and Their Compatibilized Nanocomposites. Issue 24 (15th November 2017)

• Record Type: Journal Article
• Authors: Sessini, Valentina; Raquez, Jean‐Marie; Lourdin, Denis; Maigret, Jean‐Eudes; Kenny, José Maria; Dubois, Philippe; Peponi, Laura
• Is Part Of: Macromolecular chemistry and physics. Volume 218:Issue 24(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-11-15
• Subjects: blends -- compatibilizer effect -- EVA -- humidity‐mechanical cycles -- shape memory -- TPS; Polymers -- Periodicals; Polymerization -- Periodicals; Synthetic products -- Periodicals; Macromolecules -- Periodicals; 547.7
• DOI: 10.1002/macp.201700388
• Languages: English
• ISSNs: 1022-1352

Abstract

Abstract: In this work, a systematic study on the humidity‐activated shape memory properties of dual‐responsive shape memory bionanocomposites with both humidity‐ and thermally‐activated shape memory effects is reported. The study is performed through humidity‐mechanical cycles in an Instron machine with a temperature chamber equipped with an ultrasonic humidity generator. In particular, the bionanocomposites studied are based on blends of ethylene–vinyl acetate (EVA) and thermoplastic starch reinforced with natural bentonite. In our previous work, thermomechanical cycles are performed by using EVA‐induced crystallization and a preliminary humidity‐activated shape memory test is designed. Herein, the shape memory results of both blends and their nanocomposites reflect the very good ability to humidity‐activated recover of the initial shape with values higher than 80%. Moreover, the ability to fix the temporary shape of this systems is very good, especially when nanofillers are added. The compatibilizer effect of natural bentonite is demonstrated by means of different techniques such as scanning emission microscopy and mapping by confocal Raman spectroscopy. Abstract : The humidity‐response of multiresponsive shape memory blends based on thermoplastic starch and ethylene–vinyl acetate and their compatibilized nanocomposites is successfully characterized by humidity‐mechanical cycles, showing excellent properties. This kind of material can be used for biomedical applications exploiting the hydrophilic character of starch to activate their shape memory effect by means of only humidity at the human body temperature.