Characterization of viscoelastic behavior of shape memory epoxy systems

Song, Weibin; Wang, Z. D.

doi:10.1002/app.38158

Cited by 12 publications

(8 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most of the studies have focused on the synthesis and optimization of this type of amine-cured epoxy system (Fan et al, 2013; Jing et al, 2014; Leonardi et al, 2011; Liu et al, 2010; Pandini et al, 2013; Song et al, 2011; Song and Wang, 2013; Sun et al, 2014; Wei et al, 2013c; Zhang et al, 2012), in which a diamine was usually used as a curing agent, namely, crosslinked the EP, and a linear or flexible monoamine was used to adjust the crosslink density, T g , and shape memory behaviors of the SMEP systems. This system resulted in easy polymerization reactions, low curing temperatures, and short times to generate the amine-cured epoxy systems.…”

Section: Typical Thermoset Smpsmentioning

confidence: 99%

Thermoset shape memory polymers and their composites

Xie

Huang

Leng

et al. 2016

Journal of Intelligent Material Systems and Structures

View full text Add to dashboard Cite

This article reviews the main progress in the development of typical thermoset shape memory polymers. Thermoset polymers are usually stronger in their microstructure than thermoplastic polymers due to their covalently crosslinked three-dimensional networks. The virtues of thermoset polymers make them great source materials for shape memory polymers. However, their three-dimensional networks endow thermoset shape memory polymers with not only high shape fixity rates and shape recovery rates but also low deformation abilities and brittleness. In the past decade, many breakthroughs have been made regarding thermoset shape memory polymers. Typical thermoset materials, such as epoxy resin, cyanate resin, thermoset polyurethane, polyimide, and polystyrene, have been studied as raw materials for shape memory polymers. Studies on thermoset shape memory polymers have been carried out to not only improve their fundamental properties (i.e. broadening of their operating temperatures and service environments and enhancing their thermal stabilities and mechanical properties) but also introduce functional performance properties (e.g. responsiveness to light, electricity, magnetism, and chemical stimuli). This article aims to present a brief review of the development of thermoset shape memory polymers, including the selection and preparation of materials, the improvement of properties, the functionalization of their composites, and their potential applications.

show abstract

Section: Typical Thermoset Smpsmentioning

confidence: 99%

Thermoset shape memory polymers and their composites

Xie

Huang

Leng

et al. 2016

Journal of Intelligent Material Systems and Structures

View full text Add to dashboard Cite

show abstract

“…Shape‐memory polymers (SMPs) represent an advanced class of stimuli‐responsive materials, which can be deformed or fixed into a temporary shape and recover their original permanent shapes only upon appropriate external stimulus, such as thermal treatment, light, electricity and vapor . Although above various forms of external stimuli may be utilized as the recovery trigger, the thermally induced shape‐memory effect is most typical where the recovery takes place with respect to a certain critical temperature.…”

Section: Introductionmentioning

confidence: 99%

A new method to improve the stability, tensile strength, and heat resistant properties of shape‐memory epoxy resins: Two‐stages curing

Sun

Liu

Tan

et al. 2013

J of Applied Polymer Sci

View full text Add to dashboard Cite

In this article, we design a new thermal curing method: two-stage curing. The purpose of using this approach is to maintain the excellent shape-memory property of epoxy resin system after first stage curing, and the material can be folded in small size to storage or transportation and recovery its original shape commodiously by heating temperature. Then, after second stage curing, the stability, glass transition temperature(T g ), and tensile strength of material can be improved effectively. For this aim, a series of mixtures have been prepared. Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), tensile test, scanning electron microscope (SEM), dynamic mechanical analysis (DMA), and fold-deploy shape-memory test have been used to characterize the feasibility of two-stage curing process, curing degree, tensile strength, morphology, thermodynamic properties, and shape-memory performance of these polymers. DSC results show that two independent curing stages can be achieved successfully. Tensile tests and DMA results suggest that tensile strength and heat resistance have been improved after the second curing stage. SEM results reveal that the addition of latent curing agent do not change the fracture mechanism. Furthermore, the fold-deploy shapememory tests prove that the composites after first stage curing possess eximious shape-memory property.

show abstract

“…As long as the rate of change for the contributive stress (thermal stress and memorized stress) is larger than that of the relaxed stress, i.e., dr memorized / dt 1 dr T /dt > dr relaxed /dt, the recovery stress will increase; Once the rate of change of the contributive stress equals that of the relaxed stress, i.e., dr memorized /dt 1 dr T /dt 5 dr relaxed /dt, the recovery stress will reach its peak. This is what happened at around 7 min since heating, and the recovery stress reaches a peak of 0.3 MPa; upon further heating to 80 C (8-20 min), the thermal stress reaches a stabilized level due to little change of temperature, and the memorized stress also gradually reaches a stabilized level due to fully release of stored energy, and yet the stress is still relaxing due to the hysteresis nature of the relaxation process, 62,63 leading to dr memorized /dt 1 dr T /dt < dr relaxed / dt, and the recovery stress decreases until, eventually, the relaxed stress reaches a stabilized level, i.e., dr memorized /dt 1 dr T / dt 5 dr relaxed /dt again, and the recovery stress is stabilized at about 0.22 MPa.…”

Section: Modeling Resultsmentioning

confidence: 88%

Stress memory of a thermoset shape memory polymer

Wang

2015

J of Applied Polymer Sci

View full text Add to dashboard Cite

The performance of stress recovery and shape recovery are equally important for high performance shape memory polymers (SMPs) in emerging applications. However, unlike shape recovery, stress recovery does not always follow a monotonic behavior, i.e., “stress plateau,” “stress overshoot,” and “stress undershoot” can be observed. In order to reveal the complicated stress memorization and recovery behavior, this study employs a phenomenological model which considers the recovery stress as the sum of residual programming stress, memorized stress, thermal stress, and relaxed stress for amorphous crosslinked SMPs. This model is demonstrated by a stress recovery experiment in which a polystyrene based SMP was programmed at two prestrain levels above the glass transition temperature, i.e., 20% (neo‐Hookean hyperelastic region) and 50% (strain‐hardening region), and two fixation temperatures, i.e., 20°C (below Tg) and 45°C (within the Tg region), respectively. In addition, a clear distinction between the memorized stress and recovery stress is presented. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42112.

show abstract

Characterization of viscoelastic behavior of shape memory epoxy systems

Cited by 12 publications

References 28 publications

Thermoset shape memory polymers and their composites

Thermoset shape memory polymers and their composites

A new method to improve the stability, tensile strength, and heat resistant properties of shape‐memory epoxy resins: Two‐stages curing

Stress memory of a thermoset shape memory polymer

Contact Info

Product

Resources

About