Environmental Effects on Mechanical Properties

Some information is available about the environmental effects on the mechanical properties of PPy. For most intelligent polymer systems, mechanical properties need to be stable with time in the service environment. One study has tracked the changes 

FIGURE 3.10 In situ cell for mechanical testing. (From Polymer Vol. 36, No. 25, Film substrate and mechanical properties of electrochemically prepared PPy, M. Ghandhi and coworkers, p. 4762. With permission from Elsevier Science Ltd., Oxford, England.) 

FIGURE 3.11 (a) Young s moduli of PPy/pTS films tested immediately after immersion in 

FIGURE 3.12 Effect of applied potential on tensile strength. 

FIGURE 3.13 Changes in force recorded for a stretched PPy film subjected to a cyclically varying potential. 

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The published work on the mechanical properties of PPy is reviewed below. Most of this work has been conducted on dry films, which is discussed first. Some recent work on the adhesion of PPy to electrode materials is also presented along with the results of investigations into environmental effects on mechanical properties. 

Ceramics and composites for engine applications Design and life prediction methodologies Environmental effects on mechanical properties Mechanical behavior of porous ceramics Reliability of small scale systems Ultra high temperature ceramics Ternary compounds... 

Dry state mechanical properties Environmental effects on mechanical properties Conclusions References... 

The environmental effects on mechanical properties once again demonstrate that the interrelationships between various mechanical properties are material specific and rely on many factors, from temperature to humidity. A higher yield strength for one alloy under one environmental condition might imply better fatigue resistance however, specific supporting data are required to draw any inference to any other alloy in different circumstances. In summary, the demonstration of equivalent material durability and part life limitation in reverse engineering requires part-specific substantiation data. 

The third part of the book deals with the properties and applications of polymers. It starts with a discussion of polymer solution properties through the mechanical properties of polymers and concludes with an overview of the various applications of polymer materials solids. The viscoelastic nature of polymers is also treated. This section also includes a discussion of polymer fracture. The effects of various molecular and environmental factors on mechanical properties are examined. 

VI. Effects of Structural and Environmental Factors on Mechanical Properties... 

VI. EFFECTS OF STRUCTURAL AND ENVIRONMENTAL FACTORS ON MECHANICAL PROPERTIES... 

C. Cappelli B. Mennucci, S. Monti, Environmental effects on the spectroscopic properties of gallic acid A combined classical and quantum mechanical study. J. Phys. Chem. A 109, 1933 (2005)... 

Stamboulis A, Baillie CA, Peijs T (2001) Effects of environmental conditions on mechanical and physical properties. Compos A 32(8) 1105-1115... 

Further aspects of the environmental effects on the mechanical and physical properties of GFRP are discussed in the following section. 

Ellyin F, Maser R (2004) Environmental effects on the mechanical properties of glass-fiber epoxy composite tubular specimens . Composites Science and Technology, 64, 1863-1874. 

The Mechanical Behavior and Performance of Ceramics Composites symposium addressed the cutting-edge topics on mechanical properties and reliability of ceramics and composites and their correlations to processing, microstructure, and environmental effects. The symposium included over 100 presentations representing 10 countries. Symposium topics included ... 

In the structural design of Generation IV nuclear plants, evaluation of environmental effects is also important. In the case of sodium-cooled reactors, sodium environmental effects on structural materials have to be taken into account. Asayama et al. proposed an evaluation procedure for sodium environmental effects on the integrity of Modified 9Cr-lMo steel [28]. It gave a corrosion allowance as a function of temperature, oxygen content, and service time, based on corrosion tests. It determined that no correction factors that correspond to sodium environment on design allowable stresses, etc. are needed, because no adverse effects of sodium on the mechanical properties of... 

Environmental Effects on the Mechanical Properties of Spider Silk... 

It mainly remains to be discussed in this section the nature of the effect which the simultaneous action of mechanical and environmental parameters may have on mechanical properties. One of the most interesting phenomena in this field, the environmental stress crazing (ESC), will be treated in the final chapter. 

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