Copolymer Networks Based on Poly(ω‐pentadecalactone) and Poly(ϵ‐caprolactone)Segments as a Versatile Triple‐Shape Polymer System

Thermo-sensitive triple-shape polymers can perform two consecutive shape changes in response to heat. These shape changes correspond to the recovery of two different deformations in reverse order, which were programmed previously at elevated temperature levels (T mid and T high ) by the application of external stress. Recently, an AB copolymer network was described, which surprisingly exhibited a triple-shape effect despite being programmed with only one deformation at T high . Here it is explored whether a copolymer network system can be designed that enables a one-step deformation process at ambient temperature (cold drawing) as a novel, gentle, and easy-to-handle triple-shape-creation procedure, in addition to the procedures reported to date, which generally involve deformation(s) at elevated temperature(s). A copolymer-network system with two crystallizable polyester segments is synthesized and characterized, fulfilling two crucial criteria. These materials can be deformed at ambient temperature by cold drawing and show, even at T high , which is above the melting points of both switching domains, elongation at break of up to 250%. Copolymer networks with PCL contents of 75 and 50 wt% show a triple-shape effect after cold drawing with shape-fixity ratios between 65% and 80% and a total-shape-recovery ratio above 97%. Furthermore, in these copolymer networks, the triple-shape effect can be obtained after a one-step deformation at T high . Independent of the temperature at which the deformation is applied (ambient temperature or T high ), copolymer networks that have the same compositions show similar switching temperatures and proportioning of the recovery in two steps. The two-step programming procedure enables a triple-shape effect in copolymer networks for an even broader range of compositions. This versatile triple-shape-material system based on tailored building blocks is an interesting candidate material for applications in fixation systems or disassembling systems.

[1]  A. Lendlein,et al.  Degradable shape-memory polymer networks from oligo[(l-lactide)-ran-glycolide]dimethacrylates. , 2007, Soft matter.

[2]  Marc Behl,et al.  Actively moving polymers. , 2006, Soft matter.

[3]  Ingo Bellin,et al.  Dual-shape properties of triple-shape polymer networks with crystallizable network segments and grafted side chains , 2007 .

[4]  Marc Behl,et al.  One‐Step Process for Creating Triple‐Shape Capability of AB Polymer Networks , 2009 .

[5]  Ajay Kumar,et al.  Physical characterization of poly(ω‐pentadecalactone) synthesized by lipase‐catalyzed ring‐opening polymerization , 2001 .

[6]  Marc Behl,et al.  Triple-shape polymers , 2010 .

[7]  S. Kelch,et al.  Amorphous, Elastic AB Copolymer Networks from Acrylates and Poly[(L‐lactide)‐ran‐glycolide]dimethacrylates , 2008 .

[8]  A. Lendlein,et al.  Amorphous phase-segregated copoly(ether)esterurethane thermoset networks with oligo(propylene glycol) and oligo[(rac-lactide)-co-glycolide] segments: synthesis and characterization , 2009, Journal of materials science. Materials in medicine.

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

[10]  Andreas Lendlein,et al.  Shape-memory polymer networks from oligo[(epsilon-hydroxycaproate)-co-glycolate]dimethacrylates and butyl acrylate with adjustable hydrolytic degradation rate. , 2007, Biomacromolecules.

[11]  Yang-Tse Cheng,et al.  Revealing triple-shape memory effect by polymer bilayers. , 2009, Macromolecular rapid communications.

[12]  Liang Xue,et al.  Synthesis and Characterization of Three-Arm Poly(ε-caprolactone)-Based Poly(ester−urethanes) with Shape-Memory Effect at Body Temperature , 2009 .

[13]  Andreas Lendlein,et al.  Biodegradable, amorphous copolyester-urethane networks having shape-memory properties. , 2005, Angewandte Chemie.

[14]  T. Xie,et al.  Self-Peeling Reversible Dry Adhesive System , 2008 .

[15]  Andreas Lendlein,et al.  Degradable, Multifunctional Polymeric Biomaterials with Shape-Memory , 2005 .

[16]  A. Lendlein,et al.  Controlling the switching temperature of biodegradable, amorphous, shape-memory poly(rac-lactide)urethane networks by incorporation of different comonomers. , 2009, Biomacromolecules.

[17]  Thorsten Pretsch,et al.  Triple-shape properties of a thermoresponsive poly(ester urethane) , 2009 .

[18]  R. Langer,et al.  Polymeric triple-shape materials , 2006, Proceedings of the National Academy of Sciences.

[19]  H. Radusch,et al.  Multiple shape-memory behavior and thermal-mechanical properties of peroxide cross-linked blends of linear and short-chain branched polyethylenes , 2008 .

[20]  P. Mather,et al.  Two-way reversible shape memory in a semicrystalline network , 2008 .

[21]  Marc Behl,et al.  Shape-Memory Polymers and Shape-Changing Polymers , 2009 .

[22]  Christoph Weder,et al.  Shape memory polymers with built-in threshold temperature sensors , 2008 .

[23]  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.

[24]  Paul J. Flory,et al.  Thermodynamics of Crystallization in High Polymers. I. Crystallization Induced by Stretching , 1947 .

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

[26]  Shravanthi T. Reddy,et al.  Bioinspired Surfaces with Switchable Adhesion , 2007 .

[27]  S. Kelch,et al.  Synthesis, Shape‐Memory Functionality and Hydrolytical Degradation Studies on Polymer Networks from Poly(rac‐lactide)‐b‐poly(propylene oxide)‐b‐poly(rac‐lactide) dimethacrylates , 2006 .

[28]  C. P. Buckley,et al.  Novel triol-crosslinked polyurethanes and their thermorheological characterization as shape-memory materials , 2007 .