Macroscopic mechanical properties

In this section, we discuss theoretically the influence of microscopic interaction between polarized particles on the macroscopic mechanical properties of the composite gel, in particular, the elastic modulus. 

Microscopic interaction of the ER effect is correlated with macroscopic mechanical properties through Eq. 34. This states that AG is proportional to C, i or E2 and depends on e2. When e2 increases, k2 increases and then reaches a maximum. AG may perhaps become saturated. 

Yount WC, Loveless DM, Craig SL. SmaU-molecule dynamics and mechanisms underlying the macroscopic mechanical properties of coordinatively cross-hnked polymer networks. J Am Chem Soc 2005a 127 14488-14496. 

A number of PAL studies on polymers have attempted to correlate PAL parameters with macroscopic mechanical properties. The value of PAL in providing microscopic structural information for the observed macroscopic properties in polymer systems is illustrated by the examples bellow. 

When we glue a broken chair, light a match, walk on a street, or ski on snow, we make use of the mechanical properties of surfaces. These include (a) static properties such as hardness or adhesion and (b) dynamic properties such as slide, friction, lubrication, or fracture. The study of the mechanical properties of surfaces in relative motion is often called tribology. It is the purpose of surface scientists to describe and explore many of the macroscopic mechanical properties on the molecular level in order to provide fundamental answers to some simple questions Why are materials hard or soft How do the mechanical properties of surfaces enable us to walk What occurs when we repeatedly move surfaces relative to each other at variable speeds (such as the piston rod against the piston wall of the internal combustion engine) ... 

The objective of this book was to review, evaluate and improve understanding of the relationship between molecular/supramolecular architecture, and nm-scale and macroscopic mechanical properties of this uniquely versatile family of polyurethanes categorized in engineering elastomers. The study included numerous conventional block polyurethane elastomers, based on several diisocyanates, macrodiols and chain extenders. 

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