Shape memory effect of thermoplastic segmented polyurethanes with self-complementary quadruple hydrogen bonding in soft segments.
This paper describes the fact that a kind of thermoplastic shape memory polyurethane with self-complementary quadruple hydrogen bonding units in soft segments can present a significant shape memory effect under the usually used thermodynamic programming condition. Compared with the control sample, it was observed that the introduction of self-complementary quadruple hydrogen bonding into soft segments increases the glass transition temperature from 28.3 degrees C to 73.3 degrees C. Therefore, the temporary deformation can be fixed well after cooling at room temperature; subsequently thermal responsive shape memory recovery can be triggered by heating up to 86 degrees C. The immediate shape recovery ratio and shape fixity ratio can be 95.8% and 95.9%. Even after 24 hours relaxation for the stretched films, the corresponding R(r) and R(f) can be 94% and 60%. In contrast, the sample without quadruple hydrogen bonding shows that the elasticity and the deformation cannot be fixed after 24 hours relaxation.
Zhu
Yong
Y
Institute of Textiles and Clothing, Hong Kong Polytechnic University, Kowloon, Hong Kong, PRC.
Hu
Jinlian
J
Liu
Yijun
Y