Dynamic Mechanical Behavior of Photo-Cross-linked Shape-Memory Elastomers

Cross-linked elastomers containing reversibly binding side groups are capable of storing elastic energy on multiple time-scales, giving rise to shape-memory and self-healing properties. Photo-cross-linkable benzophenone side groups were incorporated into linear macromers containing reversible (2-ureido-4-pyrimidinone, UPy) side groups. This method enables melt-processing of shape-memory elastomers into complex permanent shapes, and samples can be prepared with much higher UPy-content. UV–vis spectroscopy was applied to study the efficacy of the cross-linking process. Resulting elastomer networks with variable densities of covalent cross-links and reversibly associating side groups were systematically prepared and studied. Dynamic mechanical analysis revealed the presence of two storage modulus plateaus: a high-temperature plateau attributed to covalent cross-links, and a lower temperature plateau attributed to both reversible and covalent cross-links. Results also show that dynamic cross-links behave near...

[1]  Aaron M. Kushner,et al.  Biomimetic design of reversibly unfolding cross-linker to enhance mechanical properties of 3D network polymers. , 2007, Journal of the American Chemical Society.

[2]  Patrick T. Mather,et al.  Review of progress in shape-memory polymers , 2007 .

[3]  R. Lakes,et al.  High Damping Composite Materials: Effect of Structural Hierarchy , 2002 .

[4]  A. Lendlein,et al.  Multifunctional Shape‐Memory Polymers , 2010, Advanced materials.

[5]  C. Steel,et al.  The effect of transient photoproducts in benzophenone-hydrogen donor systems , 1976 .

[6]  Craig J. Hawker,et al.  Model Transient Networks from Strongly Hydrogen-Bonded Polymers , 2009 .

[7]  T. Xie.  Tunable polymer multi-shape memory effect , 2010, Nature.

[8]  T. Ware,et al.  High‐Strain Shape‐Memory Polymers , 2010 .

[9]  Ward Small,et al.  Biomedical applications of thermally activated shape memory polymers. , 2009, Journal of materials chemistry.

[10]  A. Lendlein,et al.  Initiation of shape-memory effect by inductive heating of magnetic nanoparticles in thermoplastic polymers. , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[11]  R. Sijbesma,et al.  Preemptive Healing through Supramolecular Cross-Links , 2009 .

[12]  A. McCormick,et al.  Development and measurement of stress in polymer coatings , 2002 .

[13]  Jun Yu Li,et al.  Shape‐Memory Effects in Polymer Networks Containing Reversibly Associating Side‐Groups , 2007 .

[14]  J. Rühe,et al.  Swelling Behavior of Thin, Surface-Attached Polymer Networks , 2004 .

[15]  T. Long,et al.  Thermoreversible Poly(alkyl acrylates) Consisting of Self-Complementary Multiple Hydrogen Bonding , 2003 .

[16]  E. Brown,et al.  Thermally activated diffusion in reversibly associating polymers , 2010 .

[17]  R. Langer,et al.  Light-induced shape-memory polymers , 2005, Nature.

[18]  Q. Meng,et al.  A review of shape memory polymer composites and blends , 2009 .

[19]  E. W. Meijer,et al.  Stability and Lifetime of Quadruply Hydrogen Bonded 2-Ureido-4[1H]-pyrimidinone Dimers , 2000 .

[20]  A. Zosel,et al.  Influence of crosslinking on structure, mechanical properties, and strength of latex films , 1993 .

[21]  S. Craig,et al.  Chemoresponsive viscosity switching of a metallo-supramolecular polymer network near the percolation threshold , 2007 .

[22]  Xiaofan Luo,et al.  Triple‐Shape Polymeric Composites (TSPCs) , 2010 .

[23]  D. Burland,et al.  Hydrogen abstraction by benzophenone studied by holographic photochemistry , 1981 .

[24]  P. Mather,et al.  Shape Memory Polymer Research , 2009 .

[25]  Aaron M Kushner,et al.  A biomimetic modular polymer with tough and adaptive properties. , 2009, Journal of the American Chemical Society.

[26]  R. Vaia,et al.  Remotely actuated polymer nanocomposites—stress-recovery of carbon-nanotube-filled thermoplastic elastomers , 2004, Nature materials.

[27]  B. Love,et al.  Coumarins in polymers: from light harvesting to photo-cross-linkable tissue scaffolds. , 2004, Chemical reviews.