Understanding the Mechanisms Involved in Shape Memory Starch: Macromolecular Orientation, Stress Recovery and Molecular Mobility

• Published in: Macromolecules Vol. 44; no. 23; pp. 9384 - 9389
• Main Authors: Véchambre, Cyril, Buléon, Alain, Chaunier, Laurent, Gauthier, Catherine, Lourdin, Denis
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 13.12.2011
• Subjects: Applied sciences; Engineering Sciences; Exact sciences and technology; Materials; Natural polymers; Physicochemistry of polymers; Starch and polysaccharides; Glass transition; Shape memory effect; Potato starch; Mechanical properties; Temperature effect; Oside polymer; Tensile property; Experimental study; Molecular relaxation; Mechanism; Deformation; Starch; Shape memory; Macromolecules; Glass; Stimuli-responsive; Residual stresses; Deformation temperatures; Recovery; Local structure; Molecular orientation; Temporary shapes; Molecular mobility; Stress recovery; Recovery stress; Macromolecular orientation
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma202019v

The effect of a deformation near and above the glass transition on macromolecular orientation, residual stress, and molecular mobility was investigated on amorphous stimuli-responsive starch. The recovery stress, linked to the residual stress in the temporary shape, evolves linearly with the macromolecular orientation. Increasing the deformation temperature decreases the residual stress and the macromolecular orientation. This also leads to a higher glass transition temperature induced by a decrease in molecular mobility. The local structures potentially involved in orientation and stress recovery and their behavior during deformation at different temperatures are discussed.