Some Elastomeric Quantities

The majority of studies of mechanical properties of elastomers have heen carried out in elongation because of the simplicity of this type of deformation. 121-123 Results are typically expressed in terms of the nominal or engineering stress f = f/A, which, in the simplest molecular theories, is given by 

1 The simplest model assumes affine deformations, in which the cross links move in parallel with the macroscopic dimensions. This approach has been revisited recently. There are a fewer studies using other types of deformation such as biaxial extension or compression, shear, and torsion. 

Swelling is a nonmechanical property that is frequently used to characterize elastomeric materials. Swelling is an unusual defor- 

A number of specialized elastomeric quantities have also been investigated. PDMS networks have been particularly useful in investigating the Mullins Effect, in which filler-reinforced elastomers exhibit a reduction 

PDMS and the origins of the failure of silica-filled PDMS elastomers have also been elucidated from first principles, specifically using Car-Parr inello molecular dynamics In an unusual example of biomimicry, 

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Some PHAscl may be too rigid and brittle and may lack the superior mechanical properties required for biomedical and packaging film applications. In contrast, as described before, PHAmcl may be elastomeric but have very low mechanical strength. It is reported that the stress-strain curve for P(3-hydroxy-octanoate) containing minor quantities of other MCL monomers was typical of those observed for elastomers with no yield stress appearing in the stress-strain curve. A Young s modulus of 17 MPa and an elongation to break of 250-350% were also determined. ... 

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