Plastic is too brittle storage modulus

What is the difference between brittleness and storage modulus?

What is more, the εb term in the denominator in our definition of brittleness takes into account large deformations of a material. On the other hand, the storage modulus accounts for repetitive loading or fatigue —so important in service. This is an essential aspect as it relates to viscoelasticity of PBMs.

What is a storage modulus?

The storage modulus is a measure of how much energy must be put into the sample in order to distort it. The difference between the loading and unloading curves is called the loss modulus, E ". It measures energy lost during that cycling strain. Why would energy be lost in this experiment? In a polymer, it has to do chiefly with chain flow.

Is brittleness related to elastic modulus?

A significant concept related to brittleness is presented by Matsuoka : using styrene acrylonitrile copolymer (SAN) and acrylonitrile butadiene styrene copolymer (ABS) as examples, Matsuoka describes how for plastics the strength of a material can be unrelated to average properties such as elastic modulus.

Does bulk modulus change with temperature or strain rate?

Of all the elastic constants, the bulk modulus is the least likely to vary significantly with changing temperature or strain rate, even through the material glass transition. However, the question of how to split available bulk modulus values into α and β contributions is not a trivial one.

What is brittleness in viscoelastic materials?

Brittleness of materials—whether it occurs naturally or with aging—affects significantly performance and manifests itself in various properties. In the past, brittleness was defined qualitatively, but now a definition of brittleness for viscoelastic materials exists, enabling analysis of all types of polymer-based materials.

Which materials are brittle?

The brittleness values of the materials listed in Table 1 are depicted in Fig. 1 on a one-dimensional scale. We find that most of the PBMs are clustered at the low end of the scale. Materials with higher brittleness include SAN, PMMA, and PES along with ABS and PTFE in the middle range.