Water-Driven Programmable Polyurethane Shape Memory Polymer: Demonstration and Mechanism

by W. M. Huang & B. Yang Applied Physics Letters, 14 March 2005 We demonstrate the new features of a polyurethane shape memory polymer: water-driven actuation and recovery in sequence (i.e., programmable). Hydrogen bonding is identified as the reason behind these features. In addition, the absorbed water is quantitatively separated into two parts, namely, the free water and bound water. Their individual contribution on the glass transition temperature is identified. Read the article