A pop-up rubbery material that can unpop

Physics Today ◽  
2015 ◽  
Vol 68 (5) ◽  
pp. 19-19
Author(s):  
Steven K. Blau
Keyword(s):  
Rubbery Material

Orientation Effects in Rubber Double Networks

1990 ◽  
Vol 63 (2) ◽  
pp. 285-297 ◽  
Author(s):  
C. M. Roland ◽  
M. L. Warzel
Keyword(s):  
Network Formation ◽  
Double Network ◽  
Stable Orientation ◽  
Enhanced Strain ◽  
Strain Induced Crystallization ◽  
Failure Properties ◽  
Residual Strains ◽  
Low Levels ◽  
Double Networks ◽  
Rubbery Material

Abstract The utilization of network structure to impart stable orientation to a rubbery material has been largely unexploited to date. It is demonstrated that the presence of a double network will amplify both the modulus and strain crystallizability of an elastomer, presumably without the disadvantages encountered in achieving these through simple increases in crosslink density. The high residual strains obtained via double-network formation are accompanied by surprisingly low levels of birefringence. The extent of molecular orientation necessary to engender high residual strain is evidently quite low, at least in so far as the former is reflected in a bulk macroscopic measurement such as birefringence. This low equilibrium birefringence, along with the absence of any measurable thermal crystallization effects, indicate that double networks are actually not highly oriented. As seen from their higher moduli and higher strain optical coefficients relative to single networks, and from their enhanced strain crystallizability, double networks are evidently very orientable. Investigation of this aspect of the behavior of double networks would likely prove fruitful, not only concerning these materials, but also with regard to obtaining a broader understanding of rubber elasticity. While the enhancement of strain-induced crystallization might suggest that rubbers with double networks will exhibit superior failure properties, this remains to be demonstrated. The crystallization results described herein clearly raise more questions than can presently be answered concerning the behavior of rubbers with double networks.

Stability of a sandwich plate composed of rubbery material

1973 ◽  
Vol 7 (2) ◽  
pp. 291-293
Author(s):  
A. N. Guz' ◽  
A. V. Stepanov
Keyword(s):  
Sandwich Plate ◽  
Rubbery Material

Nature and hydrocarbon content of blooms of the alga Botryococcus braunii occuring in Australian freshwater lakes

1981 ◽  
Vol 32 (3) ◽  
pp. 353 ◽  
Author(s):  
LV Wake ◽  
LW Hillen
Keyword(s):  
Linear Chain ◽  
Detailed Comparison ◽  
Botryococcus Braunii ◽  
Dry Mass ◽  
Gas Chromatography Mass Spectrometry ◽  
Simultaneous Occurrence ◽  
Strong Resemblance ◽  
Branched Chain ◽  
Australian Freshwater ◽  
Rubbery Material

Under Australian conditions blooms of B. braunii were found to have hydrocarbon oil contents between 27 and 40% of the dry mass. The highest oil content was observed in a red bloom and the lowest in a green bloom of the organism. A number of branched-chain hydrocarbons of the general formula Cm H2n-10. where n equals 30. 34. 35. 36 and 37, have been found in both red and green blooms of the alga. Twelve of these hydrocarbons are novel to the present study and analysis by gas chromatography-mass spectrometry indicates that these compounds are closely related to or isomeric with botryococcene. Straight-chain hydrocarbons were present only in the green stage of the organism. Evidence for the simultaneous occurrence of branched- and linear-chain hydrocarbons in the same plant is inconclusive as blooms which revealed both types of hydrocarbons were known to contain both stages of the alga. The chemical parameters measured, both of the cell material and of the waters in which they grow, have thus far failed to explain why conditions are sometimes more favourable to the formation of B. braunii blooms than at other times. B. braunii has been observed to form shoreline deposits which undergo a change in pigmentation during desiccation to produce a black rubbery material bearing a strong resemblance to Coorongite. A detailed comparison has yet to be undertaken.

A Case of Intestinal Obstruction due to Phytobezoar - An Alternative Surgical Approach

Swiss Surgery ◽  
2003 ◽  
Vol 9 (1) ◽  
pp. 35-37 ◽  
Author(s):  
Aslan ◽  
Ünal ◽  
Karagüzel ◽  
Melikoglu
Keyword(s):  
High Risk ◽  
Acute Appendicitis ◽  
Intestinal Obstruction ◽  
Surgical Approach ◽  
Alternative Treatment ◽  
Terminal Ileum ◽  
Large Bowel ◽  
Postoperative Course ◽  
Vegetable Fibers ◽  
Rubbery Material

We report a 5-year-old patient with phytobezoar mimicking acute appendicitis preoperatively. During laparotomy, it was detected that terminal ileum was obstructed by several fragments of rubbery material. Bezoar was milked into the large bowel, and phytobezoar including tangerine residues was evacuated via appendix stump because of severe distended cecum, and high risk of the anastomotic leakage and intraperitoneal contamination following enterotomy of the inflamated and ischemic ileum. Postoperative course was uneventful. To date, such a procedure has not been described. We suggest that milking of vegetable fibers into the cecum and then emptying via appendix stump may be an alternative treatment of phytobezoar localizing in terminal ileum.

High Strength - Low Hardness Thermoplastic Elastomers from Ethylene-Butene Copolymers and Low Density Polyethylene

2008 ◽  
Vol 81 (1) ◽  
pp. 60-76 ◽  
Author(s):  
Sandeep Tembhekar ◽  
Madhuchhanda Maiti ◽  
Jinu Jacob George ◽  
Anjan Biswas ◽  
Anil K. Bhowmick ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Functional Performance ◽  
High Strength ◽  
Thermoplastic Elastomer ◽  
Ethylene Vinyl Acetate ◽  
Thermoplastic Elastomers ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Vulcanized Rubber ◽  
Rubbery Material

Abstract A thermoplastic elastomer (TPE) is a rubbery material with final properties and functional performance similar to those of a conventional vulcanized rubber at ambient temperature, yet it can be processed as a thermoplastic at elevated temperature. The main objective of the present investigation was to prepare novel olefinic thermoplastic elastomers based on blends of a thermoplastic i.e. low density polyethylene (PE) and new ethylene-butene copolymers (PEB), which would have higher strength and lower hardness compared to the existing TPEs. The 70:30 PEB: PE blend exhibited the best properties. Ethylene vinyl acetate was found to work as compatibilizer at lower loadings in these blends. The resultant blends were of low hardness (60–80 Shore A) and high strength (26–33 MPa). The interaction parameter and the morphology of the blends were the key parameters, which governed the final properties of blends.

Deformation Index—Concept for Hysteretic Energy-Loss Process

1991 ◽  
Vol 64 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Shingo Futamura
Keyword(s):  
Energy Loss ◽  
Physical Process ◽  
Viscoelastic Property ◽  
Complex Energy ◽  
Hysteretic Energy ◽  
Loss Process ◽  
Deformation Index ◽  
Dynamic Viscoelastic Property ◽  
Rubbery Material

Abstract The concept of deformation index can be effectively used to determine the relevant dynamic viscoelastic property which best correlates with the performance of the rubbery material. The concept also indicates the type of deformation that may govern a complex energy loss process, although, in this study, the underlying physical process was not experimentally identified.

Modelling and Experimental Validation of Buckling Dielectric Elastomer Actuators

2011 ◽  
Author(s):  
Rocco Vertechy ◽  
Antonio Frisoli ◽  
Massimo Bergamasco ◽  
Federico Carpi ◽  
Gabriele Frediani ◽  
...  
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Experimental Validation ◽  
Element Model ◽  
Mechanical Analysis ◽  
Dielectric Elastomer ◽  
Elastic Instability ◽  
Dielectric Elastomer Actuators ◽  
Out Of Plane ◽  
Rubbery Material

Buckling dielectric elastomer actuators are special type of electro-mechanical transducers that exploit electro-elastic instability phenomena to generate large out-of-plane axial-symmetric deformations of circular membranes made of non-conductive rubbery material. In this paper a simplified explicit analytical model and a monolithic finite element model are described for the coupled electro-mechanical analysis and simulation of buckling dielectric elastomer membranes which undergo large electrically induced displacements. Experimental data are also reported which validate the developed models.

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