Modeling and Simulation of Structurally Dynamic Crystallizable Shape Memory Polymers With Light-Induced Bond Exchange Reaction

2015 ◽  
Author(s):  
Fangda Cui ◽  
I. Joga Rao ◽  
Swapnil Moon
Keyword(s):  
Shape Memory ◽  
Exchange Reaction ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Memory Polymers ◽  
Infrared Light ◽  
Covalent Bonds ◽  
Thermally Induced ◽  
New Class ◽  
Original Shape

Shape Memory polymers (SMPs) is a novel class of smart polymeric materials that have been attracted tremendous scientific interest within the last decades. SMPs have the ability to “remember” their original shape even after undergoing significant deformation into a temporary shape. For most first generation of SMPs, the shape memory effect was accomplished by a thermally induced process, triggered in many different ways, such as heating/cooling, electromagnetic field and infrared light. The transient shape in thermally induced SMPs is due to a glassy phase or a semi-crystalline phase. The thermally induced SMPs which temporary shape is fixed through crystallization is called crystallizable shape memory polymers (CSMPs). For traditional CSMPs, their original shape is predefined and is not able to be reprogrammed. This limits the applications of the CSMPs. Recently, a new class of CSMPs has been developed. These materials can perform a typical thermally induced shape memory cycle, but their original shape can be reprogrammed through exposing to UV light. The shape reprogramming effect is governed by light induced covalent bonds exchange reaction, while the shape memory effect-as typical CSMPs-is due to solid-phase crystallization. In this work, we focus on modeling the mechanical behavior of this new class of structurally dynamic CSMPs. The framework used in developing the model is built upon the theory of multiple natural configurations[1]. The model has been applied to solve a specific boundary condition problem, namely uni-axial tension. Furthermore, we implement our model through Abaqus (commercial finite element package) subroutine UMAT to simulate 3D behavior of this attractive material.

scholarly journals Thermally-Induced Shape-Memory Behavior of Degradable Gelatin-Based Networks

2021 ◽  
Vol 22 (11) ◽  
pp. 5892
Author(s):  
Axel T. Neffe ◽  
Candy Löwenberg ◽  
Konstanze K. Julich-Gruner ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Polymer Networks ◽  
Water Soluble ◽  
Compression Tests ◽  
Thermally Induced ◽  
Thermomechanical Process ◽  
Triple Helices

Shape-memory hydrogels (SMH) are multifunctional, actively-moving polymers of interest in biomedicine. In loosely crosslinked polymer networks, gelatin chains may form triple helices, which can act as temporary net points in SMH, depending on the presence of salts. Here, we show programming and initiation of the shape-memory effect of such networks based on a thermomechanical process compatible with the physiological environment. The SMH were synthesized by reaction of glycidylmethacrylated gelatin with oligo(ethylene glycol) (OEG) α,ω-dithiols of varying crosslinker length and amount. Triple helicalization of gelatin chains is shown directly by wide-angle X-ray scattering and indirectly via the mechanical behavior at different temperatures. The ability to form triple helices increased with the molar mass of the crosslinker. Hydrogels had storage moduli of 0.27–23 kPa and Young’s moduli of 215–360 kPa at 4 °C. The hydrogels were hydrolytically degradable, with full degradation to water-soluble products within one week at 37 °C and pH = 7.4. A thermally-induced shape-memory effect is demonstrated in bending as well as in compression tests, in which shape recovery with excellent shape-recovery rates Rr close to 100% were observed. In the future, the material presented here could be applied, e.g., as self-anchoring devices mechanically resembling the extracellular matrix.

Optimization of the shape memory effect in shape memory polymers

2011 ◽  
Vol 49 (16) ◽  
pp. 3574-3581 ◽  
Author(s):  
L. Sun ◽  
W. M. Huang ◽  
C. C. Wang ◽  
Y. Zhao ◽  
Z. Ding ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Memory Polymers

Designing Multiple-Shape Memory Polymers with Miscible Polymer Blends: Evidence and Origins of a Triple-Shape Memory Effect for Miscible PLLA/PMMA Blends

2014 ◽  
Vol 47 (19) ◽  
pp. 6791-6803 ◽  
Author(s):  
Cédric Samuel ◽  
Sophie Barrau ◽  
Jean-Marc Lefebvre ◽  
Jean-Marie Raquez ◽  
Philippe Dubois
Keyword(s):  
Polymer Blends ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Memory Polymers ◽  
Miscible Polymer Blends ◽  
Triple Shape Memory ◽  
Pmma Blends

Study on Polylactide/Poly(ether block amide) Composite Biomaterials and Shape-Memory Effect

2009 ◽  
Vol 610-613 ◽  
pp. 1312-1314 ◽  
Author(s):  
Wei Zhang ◽  
Long Chen ◽  
Yu Zhang
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Tensile Load ◽  
Dissipation Process ◽  
Elongation At Break ◽  
High Deformation ◽  
Original Shape ◽  
As Stress ◽  
Heating Up

Melt blending of PLA and biodegradable PE-b-A has been performed in an effort to toughen the PLA. With the PE-b-A contents increasing, the elongation at break of composites increased and the brittle break became ductile break. When the PE-b-A content is 10%, the tensile strength of composite is similar with neat PLA, and the elongation increased significantly. The composites showed wonderful shape-memory effect. The composites occurred to deformation upon tensile load, and recovered to original shape quickly with temperature increasing. PE-b-A acts as stress concentrator in system with the stress release locally and energy-dissipation process. These will prevent PLA matrix from breaking under high deformation and make the PLA molecular orientation. Consequently, releasing the stress by heating up the material will reform the shape back to the original shape.

Application of a Constitutive Modeling for Light Activated Shape Memory Polymer to Circular Shear

2012 ◽  
Author(s):  
Fangda Cui ◽  
I. J. Rao
Keyword(s):  
Shape Memory ◽  
Constitutive Modeling ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Polymer Chains ◽  
Covalent Bonds ◽  
The Past ◽  
Original Shape ◽  
Multiple Natural Configurations ◽  
New Type

Shape memory polymers (SMP’s) are polymers that have the ability to retain a temporary shape, which can revert back to the original shape on exposure to specific triggers such as increase in temperature or exposure to light at specific wavelengths. A new type of shape memory polymer, light activated shape memory polymers (LASMP’s) have been developed in the past few years. In these polymers the temporary shapes are fixed by exposure to light at a specific wavelength. Exposure to light at this wavelength causes the photosensitive molecules, which are grafted on to the polymer chains, to form covalent bonds. These covalent bonds are responsible for the temporary shape and act as crosslinks. On exposure to light at a different wavelength these bonds are cleaved and the material can revert back to its original shape. A constitutive model of LASMP’s which based on the notion of multiple natural configurations has been developed (see Sodhi and Rao[1]). In this work we use this model to analyze the mechanical behavior of LASMP’s under a specific boundary value problem, namely, the problem of circular shear. We use this model problem to study the behavior of the LASMP’s when a temporary configuration is formed by exposing the polymer to light. In addition we show that these materials are able to undergo complex cycles of deformation due to the flexibility with which these temporary configurations can be formed and removed by exposure to light.

Smart polymers with thermally induced shape-memory effect

Polimery ◽  
2008 ◽  
Vol 53 (11/12) ◽  
pp. 793-798
Author(s):  
RYSZARD UKIELSKI ◽  
PAWEL P. SOBECKI
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Smart Polymers ◽  
Thermally Induced

scholarly journals Vitrimer-Like Shape Memory Polymers: Characterization and Applications in Reshaping and Manufacturing

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2330
Author(s):  
Tao Xi Wang ◽  
Hong Mei Chen ◽  
Abhijit Vijay Salvekar ◽  
Junyi Lim ◽  
Yahui Chen ◽  
...  
Keyword(s):  
Solid State ◽  
3D Printing ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Memory Performance ◽  
Shape Memory Polymers ◽  
Cross Linking ◽  
Potential Applications ◽  
Actual Shape

The shape memory effect (SME) refers to the ability of a material to recover its original shape, but only in the presence of a right stimulus. Most polymers, either thermo-plastic or thermoset, can have the SME, although the actual shape memory performance varies according to the exact material and how the material is processed. Vitrimer, which is between thermoset and thermo-plastic, is featured by the reversible cross-linking. Vitrimer-like shape memory polymers (SMPs) combine the vitrimer-like behavior (associated with dissociative covalent adaptable networks) and SME, and can be utilized to achieve many novel functions that are difficult to be realized by conventional polymers. In the first part of this paper, a commercial polymer is used to demonstrate how to characterize the vitrimer-like behavior based on the heating-responsive SME. In the second part, a series of cases are presented to reveal the potential applications of vitrimer-like SMPs and their composites. It is concluded that the vitrimer-like feature not only enables many new ways in reshaping polymers, but also can bring forward new approaches in manufacturing, such as, rapid 3D printing in solid state on space/air/sea missions.

A mechanically robust hydrogel with thermally induced plasticity and a shape memory effect

Soft Matter ◽  
2017 ◽  
Vol 13 (11) ◽  
pp. 2135-2140 ◽  
Author(s):  
Kang Peng ◽  
Hansen Yu ◽  
Haiyang Yang ◽  
Xiang Hao ◽  
Akram Yasin ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Thermally Induced
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