scholarly journals The effect of crude drugs on the angiogenic property and dynamic viscoelasticity of PEMA-based soft polymer materials

2017 ◽  
Vol 36 (6) ◽  
pp. 770-777
Author(s):  
Wei-Qi WANG ◽  
Guang HONG ◽  
Jian-Min HAN ◽  
Hiroshi MURATA ◽  
Keiichi SASAKI
Keyword(s):  
Polymer Materials ◽  
Dynamic Viscoelasticity ◽  
Crude Drugs ◽  
Soft Polymer

scholarly journals The Dynamic Viscoelasticity of Dental Soft Polymer Material Containing Citrate Ester-Based Plasticizers

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5078
Author(s):  
Guang Hong ◽  
Wei-qi Wang ◽  
Lu Sun ◽  
Jian-min Han ◽  
Keiichi Sasaki
Keyword(s):  
Polymer Material ◽  
Viscoelastic Properties ◽  
Loss Modulus ◽  
Polymer Materials ◽  
Significance Level ◽  
Dynamic Viscoelasticity ◽  
Methacrylate Polymers ◽  
Significant Difference ◽  
Tan Δ ◽  
Soft Polymer

The aim of this study was to investigate the dynamic viscoelasticity of dental soft polymer material containing citrate ester-based plasticizers. Three kinds of citrate ester-based plasticizer (Citroflex® C-2: TEC, Citroflex® A-2: ATEC, and Citroflex® A-4: ATBC), with the combination of 5 wt% ethyl alcohol, were used as the liquid phase. The dynamic viscoelastic properties of nine ethyl methacrylate polymers: (A, B, C, D, E, F, G, H, and I) were immersed in 37 °C distilled water for 0, 1, 3, 7, 14 and 30 days, respectively. The dynamic viscoelastic properties were measured at 37 °C with an automatic dynamic mechanical analyzer. The shear storage modulus (G′), shear loss modulus (G″), and loss tangent (tan δ) were determined at 1 Hz. These parameters were statistically analyzed by two-way and one-way ANOVA and Tukey’s multiple comparison test at a predetermined significance level of 0.05. A significant difference was found among the materials in terms of the dynamic viscoelasticity. The materials containing citrate ester-based plasticizer ATBC showed the most stable dynamic viscoelasticity. Considering the limitations of this study, the results suggest that the inclusion of citrate ester-based plasticizer can improve the durability of dental soft polymer materials.

scholarly journals Soft Jumping Robot Using Soft Morphing and the Yield Point of Magnetic Force

2021 ◽  
Vol 11 (13) ◽  
pp. 5891
Author(s):  
Gang-Hyun Jeon ◽  
Yong-Jai Park
Keyword(s):  
Residual Stress ◽  
Polymer Materials ◽  
Rigid Base ◽  
Release Mechanism ◽  
Transfer Energy ◽  
Deformation Control ◽  
Energy Retention ◽  
Base Jumping ◽  
Jumping Robot ◽  
Soft Polymer

In this paper, soft-morphing, deformation control by fabric structures and soft-jumping mechanisms using magnetic yield points are studied. The durability and adaptability of existing rigid-base jumping mechanisms are improved by a soft-morphing process that employs the residual stress of a polymer. Although rigid body-based jumping mechanisms are used, they are driven by multiple components and complex structures. Therefore, they have drawbacks in terms of shock durability and fatigue accumulation. To improve these problems, soft-jumping mechanisms are designed using soft polymer materials and soft-morphing techniques with excellent shock resistance and environmental adaptability. To this end, a soft jumping mechanism is designed to store energy using the air pressure inside the structure, and the thickness of the polymer layer is adjusted based on the method applied for controlling the polymer freedom and residual stress deformation. The soft jumping mechanism can transfer energy more efficiently and stably using an energy storage and release mechanism and the rounded ankle structure designed using soft morphing. Therefore, the soft morphing and mechanisms of energy retention and release were applied to fabricate a soft robot prototype that can move in the desired direction and jump; the performance experiment was carried out.

scholarly journals High-Velocity Shear and Soft Friction at the Nanometer Scale

2021 ◽  
Vol 7 ◽  
Author(s):  
Per-Anders Thorén ◽  
Riccardo Borgani ◽  
Daniel Forchheimer ◽  
David B. Haviland
Keyword(s):  
High Speed ◽  
Surface Deformation ◽  
Soft Materials ◽  
Lateral Force ◽  
Velocity Shear ◽  
Polymer Materials ◽  
Amplitude Dependence ◽  
Dynamic Force ◽  
Stick Slip ◽  
Soft Polymer

We study high-speed friction on soft polymer materials by measuring the amplitude dependence of cyclic lateral forces on the atomic force microscope (AFM) tip as it slides on the surface with fixed contact force. The resulting dynamic force quadrature curves separate the elastic and viscous contributions to the lateral force, revealing a transition from stick-slip to free-sliding motion as the velocity increases. We explain force quadratures and describe how they are measured, and we show results for a variety of soft materials. The results differ substantially from the measurements on hard materials, showing hysteresis in the force quadrature curves that we attribute to the finite relaxation time of viscoelastic surface deformation.

Quick and large electrostrictive deformation of non-ionic soft polymer materials

2003 ◽  
Author(s):  
Toshihiro Hirai ◽  
Md. Zulhash Uddin ◽  
Jianming Zheng ◽  
Masaki Yamaguchi ◽  
Shigeyuki Kobayashi ◽  
...  
Keyword(s):  
Polymer Materials ◽  
Soft Polymer

scholarly journals How accurately do mechanophores report on bond scission in soft polymer materials?

2021 ◽  
Author(s):  
Friso F. C. Dubach ◽  
Wouter G. Ellenbroek ◽  
Cornelis Storm
Keyword(s):  
Polymer Materials ◽  
Bond Scission ◽  
Soft Polymer

scholarly journals Nano- and microgels: a review for educators

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Denis M. Zhilin ◽  
Andrij Pich
Keyword(s):  
Drug Delivery ◽  
Building Blocks ◽  
Polymer Chains ◽  
Polymer Materials ◽  
Soft Polymer ◽  
Application Fields ◽  
Learning Projects

Abstract Nano- and microgels are promising soft polymer materials for different application fields: stabilizers, sensors, catalysts, selective sorbents, drug delivery carriers etc. They are composed of cross-linked polymer chains swollen with a solvent. The building blocks, synthesis approaches and architecture of nano- and microgels are reviewed. The mechanisms of responsiveness to various stimuli are described, examples of applications are provided. Micro- and nanogels are good objects for learning projects and the ideas for learning projects with microgels are described.

scholarly journals Static and dynamic mechanical behavior and constitutive model of polyvinyl chloride elastomers for design processes of soft polymer materials

2020 ◽  
Vol 12 (6) ◽  
pp. 168781402092678
Author(s):  
Jingfa Lei ◽  
Yan Xuan ◽  
Tao Liu ◽  
Feiya Duan ◽  
Hong Sun ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Mechanical Behavior ◽  
Polyvinyl Chloride ◽  
Mechanical Performance ◽  
Polymer Materials ◽  
Dynamic Loads ◽  
Design And Development ◽  
Dynamic Mechanical ◽  
Static And Dynamic Loads ◽  
Soft Polymer

Soft polymer materials are often used in shock absorption, cushioning, and so on. During the design and development process, determining the mechanical behavior and constitutive properties under static and dynamic loads is important to improve product performance. This study aims to analyze the static mechanical performance of polyvinyl chloride elastomers with different Shore hardness levels. Static and dynamic mechanical performance experiments with loading strain rates of 0.1, 1650, 2000, and 2700 s−1 were performed in polyvinyl chloride elastomers (57A, 52A, and 47A) using an electronic dynamic and static fatigue tester and an improved Split Hopkinson pressure bar. Microstructures were observed by scanning electron microscopy. Results showed that the addition of plasticizers to polyvinyl chloride promoted the crystallization of the polymer. The presence of plasticizer in the crystal also reduced crystallization. The material plasticity, elastic modulus, yield stress, and flow stress increase with increasing hardness/strain rate, whereas the hardness decreases. The mechanical behavior of polyvinyl chloride elastomers under static and dynamic loads exhibited superelastic and viscoelastic characteristics, respectively. The Mooney–Rivlin, Neo–Hookean, and Yeoh models were selected for the superelastic constitutive model, whereas the Zhu–Wang–Tang model was used for the viscoelastic one. Finally, the applicability of the model was explained. This study can provide theoretical model and method support for the design and development of soft polymer materials.

scholarly journals Experimental testing of self-healing ability of soft polymer materials

Meccanica ◽  
2019 ◽  
Vol 54 (13) ◽  
pp. 1959-1970 ◽  
Author(s):  
Nikolay V. Perepelkin ◽  
Jose M. Martin-Martinez ◽  
Alexander E. Kovalev ◽  
Feodor M. Borodich ◽  
Stanislav N. Gorb
Keyword(s):  
Experimental Testing ◽  
Polymer Materials ◽  
Self Healing ◽  
Soft Polymer

Fast Fracture in Slow Motion

2008 ◽  
Author(s):  
Ariel Livne ◽  
Gil Cohen ◽  
Jay Fineberg
Keyword(s):  
Slow Motion ◽  
Polymer Materials ◽  
Polyacrylamide Gels ◽  
Translational Invariance ◽  
Slowing Down ◽  
Fracture Dynamics ◽  
The Common ◽  
Soft Polymer ◽  
Rayleigh Wave Speed ◽  
Fast Fracture

We present recent results of fracture experiments in polyacrylamide gels. Polyacrylamide gels are soft polymer materials in which the characteristic sound speeds are on the order of a few meters/sec — thereby slowing down fracture dynamics by 3 orders of magnitude. We first demonstrate the universality of rapid fracture dynamics, comparing dynamics observed in gels with those seen in “classic” brittle materials such as glass. Among the common features are the appearance and form of branching instabilities as well as characteristic attributes of the resulting fracture surface that provide evidence for crack front inertia when translational invariance along the front is broken. We then demonstrate a number wholly new aspects of the fracture process, whose study is only made possible by utilizing the “slow motion” inherent in the fracture of these materials. These include both a new oscillatory instability at about 90% of the Rayleigh wave speed and measurements of the nonlinear zone at the tip of dynamic cracks.

A Review of 3D Printing Technologies for Soft Polymer Materials

2020 ◽  
Vol 30 (28) ◽  
pp. 2000187 ◽  
Author(s):  
Lu‐Yu Zhou ◽  
Jianzhong Fu ◽  
Yong He
Keyword(s):  
3D Printing ◽  
Polymer Materials ◽  
Soft Polymer
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