Effects of moisture on the thermomechanical properties of a polyurethane shape memory polymer

Yang, Bin; Huang, Wei; Li, C.; Li, L.

doi:10.1016/j.polymer.2005.12.051

Cited by 442 publications

(359 citation statements)

References 20 publications

Supporting

Mentioning

344

Contrasting

Unclassified

Order By: Relevance

“…very good plasticizer, interfering with hydrogen bonds between the chitosan macromolecular chains. The chains acquire greater mobility, and the free volume increases, leading to a decrease in the glass transition temperature and the stiffness [15]. In others studies, which compared wet with dry conditions, the stiffness of similar CHT membranes systematically decrease with increasing hydration [16].…”

Section: Mechanical Propertiesmentioning

confidence: 96%

Chitosan Membranes Exhibiting Shape Memory Capability by the Action of Controlled Hydration

2014

View full text Add to dashboard Cite

Abstract:Chitosan membranes can undergo a glass transition at room temperature triggered by hydration. The mechanical properties of the membranes were followed by a tension test and dynamic mechanical analysis (DMA), with the sample in wet conditions after being immersed in varying compositions of water/ethanol mixtures. Results show that with the increasing of water content, the Young's and storage modulus decrease systematically. For water contents of ca. 35 vol%, chitosan (CHT) exhibits a glass transition, showing an elastomeric plateau in the elastic modulus above this hydration level and the occurrence of a peak in the loss factor. Due to the semi-crystalline nature of CHT, membranes of this biomaterial present a shape memory capability induced by water uptake. By fixation of the permanent shape by further covalent cross-linking, the membranes can have different permanent shapes appropriate for different applications, including in the biomedical area.

show abstract

Section: Mechanical Propertiesmentioning

confidence: 96%

Chitosan Membranes Exhibiting Shape Memory Capability by the Action of Controlled Hydration

2014

View full text Add to dashboard Cite

show abstract

“…A typical SME cycle for a heating-responsive SMM includes two parts, namely programming and shape recovery [1,4,45,74,75]. As illustrated in Figure 4, in the first step "a", a piece of SMM is strained to a maximum strain of ε m at high or low temperatures.…”

Section: Basic Working Mechanismsmentioning

confidence: 99%

Mechanisms of the Shape Memory Effect in Polymeric Materials

et al. 2013

View full text Add to dashboard Cite

Abstract:This review paper summarizes the recent research progress in the underlying mechanisms behind the shape memory effect (SME) and some newly discovered shape memory phenomena in polymeric materials. It is revealed that most polymeric materials, if not all, intrinsically have the thermo/chemo-responsive SME. It is demonstrated that a good understanding of the fundamentals behind various types of shape memory phenomena in polymeric materials is not only useful in design/synthesis of new polymeric shape memory materials (SMMs) with tailored performance, but also helpful in optimization of the existing ones, and thus remarkably widens the application field of polymeric SMMs.

show abstract

“…The former is responsible for memorizing the original shape and is usually achieved via chemical or physical cross-linking (e.g., chain entanglement and crystallization), and the latter corresponds to shape change under stimulus. Shape memory behavior can be observed in several polymers, including polyurethane-based, 12 styrene-based, 13 and epoxy-based 14 polymers. Among these SMP, the epoxybased is a high-performance thermosetting polymer with a unique thermo-mechanical property, excellent shape memory effect, and short response time.…”

Section: Theory Modelmentioning

confidence: 99%

Monitoring static shape memory polymers using a fiber Bragg grating as a vector-bending sensor

Yan

Zhou

et al. 2013

Opt. Eng

View full text Add to dashboard Cite

Abstract. We propose and demonstrate a technique for monitoring the recovery deformation of the shape-memory polymers (SMP) using a surface-attached fiber Bragg grating (FBG) as a vector-bending sensor. The proposed sensing scheme could monitor the pure bending deformation for the SMP sample. When the SMP sample undergoes concave or convex bending, the resonance wavelength of the FBG will have red-shift or blue-shift according to the tensile or compressive stress gradient along the FBG. As the results show, the bending sensitivity is around 4.07 nm∕ cm −1 . The experimental results clearly indicate that the deformation of such an SMP sample can be effectively monitored by the attached FBG not just for the bending curvature but also the bending direction. © 2013 Society of Photo-Optical Instrumentation Engineers (SPIE).

show abstract

Effects of moisture on the thermomechanical properties of a polyurethane shape memory polymer

Cited by 442 publications

References 20 publications

Chitosan Membranes Exhibiting Shape Memory Capability by the Action of Controlled Hydration

Chitosan Membranes Exhibiting Shape Memory Capability by the Action of Controlled Hydration

Mechanisms of the Shape Memory Effect in Polymeric Materials

Monitoring static shape memory polymers using a fiber Bragg grating as a vector-bending sensor

Contact Info

Product

Resources

About