Any example materials that have high tan delta value over a wide temperature range?
Yes, there are several materials that have a high tan delta value over a wide temperature range. Some examples include:
Nitrile rubber (NBR): NBR is an elastomer that exhibits a high and constant tan delta value over a wide temperature range (-40 to 120°C). This makes it a popular material for applications such as seals, gaskets, and hoses.
Ethylene propylene diene monomer (EPDM): EPDM is another elastomer that exhibits a high and constant tan delta value over a wide temperature range (-40 to 150°C). It is commonly used in automotive and industrial applications.
Polyvinyl chloride (PVC): PVC is a thermoplastic polymer that exhibits a high tan delta value over a wide temperature range (-50 to 80°C). It is often used in applications such as electrical cables and pipes.
Polyurethane (PU): PU is a thermoset polymer that exhibits a high and constant tan delta value over a wide temperature range (-40 to 120°C). It is commonly used in applications such as coatings, adhesives, and foams.
Epoxy resins: Epoxy resins exhibit a high and constant tan delta value over a wide temperature range (-50 to 150°C). They are often used in applications such as coatings, adhesives, and composites.
It's important to note that the specific tan delta behavior of a material will depend on factors such as its composition, processing conditions, and testing parameters. Therefore, it's important to carefully evaluate a material's properties and suitability for a given application before making a selection.
What are typical values?
The typical values of tan delta depend on the specific material, the testing conditions, and the frequency of deformation. In general, elastomers and polymers tend to exhibit higher tan delta values than metals and ceramics. Here are some approximate values for typical materials at room temperature (25°C) and a frequency of 1 Hz:
Nitrile rubber (NBR): tan delta ~ 0.2-0.5
Ethylene propylene diene monomer (EPDM): tan delta ~ 0.2-0.5
Polyvinyl chloride (PVC): tan delta ~ 0.1-0.3
Polyurethane (PU): tan delta ~ 0.2-0.6
Epoxy resins: tan delta ~ 0.2-0.5
It's important to note that the values can vary widely depending on the specific formulation of the material and the testing conditions used. Additionally, the tan delta values can change significantly as the temperature and frequency of deformation are varied, so it's important to perform tests over a range of conditions to fully characterize the material's behavior.