Relaxation and retardation time for polymeric liquids

[hanson]

Hi all, I am wondering what the typical values of relaxation and retardation time for different real materials?
I know these times depend on quite a number of things.
But I just want to have a sense of the ratio of the two time scales for different real materials like blood, cervical mucus and other materials...

Do you have some good references for these data? I am kind of confused when I search online about it.

 

[chemisttree]

What do you mean by relaxation time and retardation time?

 

[quicknote]

Relaxation and retardation time are important properties of polymeric liquids that can provide insight into their behavior and properties. These times are related to the viscoelastic nature of polymeric liquids, which is a combination of both viscous and elastic behavior.

The relaxation time is the time required for a polymeric liquid to return to its original shape after being deformed. It is related to the mobility of the polymer chains and can vary greatly depending on the type of polymer and its molecular weight. For example, high molecular weight polymers will have longer relaxation times compared to low molecular weight polymers.

On the other hand, retardation time is the time required for a polymeric liquid to reach equilibrium after being subjected to a constant external force. It is related to the resistance of the polymer chains to deformation and can also vary depending on the type of polymer and its molecular weight.

The ratio of relaxation to retardation time can vary significantly for different real materials. For example, blood is a complex mixture of proteins, cells, and other components, and therefore its relaxation and retardation times will be different compared to a simple polymer solution. Additionally, the ratio can also be affected by external factors such as temperature and pressure.

As for references, there are many research articles and textbooks that discuss relaxation and retardation times for different polymeric materials. Some good starting points could be "Viscoelastic Properties of Polymers" by John D. Ferry and "Polymer Science and Technology" by Joel R. Fried. Additionally, consulting with experts in the field or reaching out to polymer research organizations may also provide valuable information and resources.