Investigation of ultraviolet radiation effects on thermomechanical properties and shape memory behaviour of styrene-based shape memory polymers and its composite

2018 ◽  
Vol 165 ◽  
pp. 266-273 ◽  
Author(s):  
Wessam Al Azzawi ◽  
J.A. Epaarachchi ◽  
Jinsong Leng
Keyword(s):  
Ultraviolet Radiation ◽  
Shape Memory ◽  
Radiation Effects ◽  
Shape Memory Polymers ◽  
Thermomechanical Properties ◽  
Shape Memory Behaviour

scholarly journals Thermomechanical Properties and Shape-Memory Behavior of Bisphenol A Diacrylate-Based Shape-Memory Polymers

2015 ◽  
Vol 217 (1) ◽  
pp. 39-50 ◽  
Author(s):  
David Santiago ◽  
Silvia De la Flor ◽  
Francesc Ferrando ◽  
Xavier Ramis ◽  
Marco Sangermano
Keyword(s):  
Bisphenol A ◽  
Shape Memory ◽  
Shape Memory Polymers ◽  
Thermomechanical Properties ◽  
Shape Memory Behavior

Effects of Discontinuous Fiber Reinforcement on the Mechanical and Thermomechanical Properties of a Shape Memory Polymer

2007 ◽  
Author(s):  
Michael B. Lyons ◽  
Robin Shandas
Keyword(s):  
Shape Memory ◽  
Production Cost ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Thermomechanical Properties ◽  
Large Strains ◽  
Cardiovascular Stents ◽  
Clot Removal ◽  
Discontinuous Fiber ◽  
Removal System

Over the last few years, we have developed shape memory polymers (SMPs) with several properties suitable for use in minimally-invasive biomedical devices. These properties include biocompatibility, the ability to fully recover large strains, the potential to serve as medication reservoirs for drug delivery, and low production cost. We and others have proposed use of shape memory polymers for various applications including cardiovascular stents, an endovascular clot removal system, and a self-tying suture.

A simplified constitutive model for predicting shape memory polymers deformation behavior

2015 ◽  
Vol 04 (01) ◽  
pp. 1550001 ◽  
Author(s):  
Yunxin Li ◽  
Siu-Siu Guo ◽  
Yuhao He ◽  
Zishun Liu
Keyword(s):  
Shape Memory ◽  
Deformation Behavior ◽  
Constitutive Models ◽  
Shape Memory Polymers ◽  
Element Model ◽  
Small Strain ◽  
Thermomechanical Properties ◽  
Mechanical Coupling ◽  
Functional Textiles ◽  
Complex Forms

Shape memory polymers (SMPs) can keep a temporary shape after pre-deformation at a higher temperature and subsequent cooling. When they are reheated, their original shapes can be recovered. Such special characteristics of SMPs make them widely used in aerospace structures, biomedical devices, functional textiles and other devices. Increasing usefulness of SMPs motivates us to further understand their thermomechanical properties and deformation behavior, of which the development of appropriate constitutive models for SMPs is imperative. There is much work in literatures that address constitutive models of the thermo-mechanical coupling in SMPs. However, due to their complex forms, it is difficult to apply these constitutive models in the real world. In this paper, a three-element model with simple form is proposed to investigate the thermo-mechanical small strain (within 10%) behavior of polyurethane under uniaxial tension. Two different cases of heated recovery are considered: (1) unconstrained free strain recovery and (2) stress recovery under full constraint at a strain level fixed during low temperature unloading. To validate the model, simulated and predicted results are compared with Tobushi's experimental results and good agreement can be observed.

Shape recovery characteristics for shape memory polymers subjected to high intensity focused ultrasound

RSC Advances ◽  
2014 ◽  
Vol 4 (62) ◽  
pp. 32701-32709 ◽  
Author(s):  
Guo Li ◽  
Guoxia Fei ◽  
Bo Liu ◽  
Hesheng Xia ◽  
Yue Zhao
Keyword(s):  
Shape Memory ◽  
High Intensity ◽  
Shape Recovery ◽  
Focused Ultrasound ◽  
Shape Memory Polymers ◽  
Random Copolymer ◽  
High Intensity Focused Ultrasound ◽  
Shape Memory Behaviour

A random copolymer shape memory behaviour triggered by high intensity focused ultrasound (HIFU) was studied in detail.

Novel Bismaleimide-Based Shape Memory Polymers: Comparison to Commercial Shape Memory Polymers

2011 ◽  
Author(s):  
Amber J. W. McClung ◽  
Joseph A. Shumaker ◽  
Jeffery W. Baur
Keyword(s):  
Shape Memory ◽  
Memory Performance ◽  
Shape Memory Polymers ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Transition Temperatures ◽  
Thermal And Mechanical Properties ◽  
Glass Transition Temperatures ◽  
Tan Δ ◽  
Heat Loads

A series of novel shape memory polymers, synthesized from 4-4-bismaleimidodiphenyl-methane, an extended chain aliphatic diamine, and a bis-isocyanate, have been created and characterized with the aim of providing a family of robust high temperature shape memory polymers with tailorable transition temperatures for use in reconfigurable aerospace structures. In the present study, three of the polymers are chosen for more detailed study of their thermomechanical properties. These materials are compared to commercial resins Veriflex® and Veriflex-E® which are styrene- and epoxy-based proprietary formulations, respectively. The thermal and mechanical properties are determined utilizing thermogravimetric analysis and dynamic mechanical analysis. The temperatures at which 2% weight loss is observed in dry air ranges from 272 to 305 °C for the synthesized polymers, and occurs at 242 and 317 °C for the commercial Veriflex® and Veriflex-E® respectively. The glass transition temperatures, as measured by the peak in the tan(δ) curve, for the synthesized polymers range from 110 to 144 °C which is a higher than the Veriflex® and Veriflex-E® achieve at 84.3 and 100 °C respectively. With operation temperatures of subsonic structural aircraft components often reaching 121 °C (250 °F), the transition temperatures of the bismaleimide-based shape memory polymers are clearly desirable to ensure that shape memory polymers used in aircraft structures will not be prematurely triggered by the existing heat loads. In addition, the shape memory performance of the bismaleimide-based shape memory polymers compares well with the Veriflex® and Veriflex-E® resins.

scholarly journals Principles for Controlling the Shape Recovery and Degradation Behavior of Biodegradable Shape-Memory Polymers in Biomedical Applications

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 757
Author(s):  
Junsang Lee ◽  
Seung-Kyun Kang
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Memory Performance ◽  
Shape Memory Polymers ◽  
Hydrolytic Activity ◽  
Thermomechanical Properties ◽  
Property A ◽  
High Tunability ◽  
Wide Range ◽  
Permanent Implant

Polymers with the shape memory effect possess tremendous potential for application in diverse fields, including aerospace, textiles, robotics, and biomedicine, because of their mechanical properties (softness and flexibility) and chemical tunability. Biodegradable shape memory polymers (BSMPs) have unique benefits of long-term biocompatibility and formation of zero-waste byproducts as the final degradable products are resorbed or absorbed via metabolism or enzyme digestion processes. In addition to their application toward the prevention of biofilm formation or internal tissue damage caused by permanent implant materials and the subsequent need for secondary surgery, which causes secondary infections and complications, BSMPs have been highlighted for minimally invasive medical applications. The properties of BSMPs, including high tunability, thermomechanical properties, shape memory performance, and degradation rate, can be achieved by controlling the combination and content of the comonomer and crystallinity. In addition, the biodegradable chemistry and kinetics of BSMPs, which can be controlled by combining several biodegradable polymers with different hydrolysis chemistry products, such as anhydrides, esters, and carbonates, strongly affect the hydrolytic activity and erosion property. A wide range of applications including self-expending stents, wound closure, drug release systems, and tissue repair, suggests that the BSMPs can be applied as actuators on the basis of their shape recovery and degradation ability.

Tissue Integration of Two Different Shape-Memory Polymers with Poly(ε-Caprolactone) Switching Segment in Rats

2008 ◽  
Author(s):  
Bernhard Hiebl ◽  
Dorothee Rickert ◽  
Rosemarie Fuhrmann ◽  
Friedrich Jung ◽  
Andres Lendlein ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymers ◽  
Tissue Integration
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