Yes, there is a US-based company called LaserThermal providing both relevant tools and services of such measurements. https://laserthermal.com/

Greeting

Dear Dr.Asaad Sayer

There is a simplified method that uses two solid cylindrical pieces between which the required test piece is placed with the same diameter, Thermally insulate the cylinders with the cylinder sample, taking into account the critical diameter of the thermal insulator as it is a cylindrical shell.. What is required is to measure the temperature of the two surfaces of the test piece while providing control over the amount of heat transferred through the two surfaces of the test piece and applying Fourier's law, the only unknown is thermal conductivity.

The most accurate method is to use DSC, or what is known as a differential scanner calorimeter, by placing a sample in a special crimp in the device.

With appreciation

Many thanks Dr. Ali for the accurate answer, in your answer, I really found the use of DSC very interesting. Can I ask kindly, what is the exact relationship with DSC I can consider to find the K from the chart and the results of DSC>

Please accept My very kind wishes

Greeting Dr. Asaad

There are many research centers, colleges and universities in Iraq, in addition to the Ministry of Science and Technology in Baghdad. I remember the Materials Department there having a DSC device, a specialized device capable of determining many physical and thermal properties, including thermal conductivity, specific heat, density, latent heat (if it is melting), and other properties.

After placing the material in a small container, it is then placed in the DSC device.

The operator can then find the results within curves and convert them to equations or use them directly.

I can suggest another method: If two materials with known thermal properties are mixed, the thermal conductivity can be found using what is known as Keff, or effective thermal conductivity. The equations are available in both research papers.

With my appreciation

DSC would be appropriate to extract the specific heat and latent heat of phase change from a sample of the material, but thermal conductivity is normally not a direct output of this method. It can sometimes be extracted from DSC measurements configured appropriately, especially for low thermal conductivity materials (e.g., see https://www.mt.com/us/en/home/supportive_content/matchar_apps/MatChar_UC226.html), but I'm not certain this would be appropriate for your materials.

for bulk materials, the simpler setup for thermal conductivity would be the 1D steady state method mentioned in Dr. Salman's first answer. such a setup can be constructed with acceptably precise machining and simple implementation according to ASTM D5470 test method. see also

Conference Paper Comparison of Test Methods for High Performance Thermal Inte...

Many thanks Dr. Nicholas, I really appreciate your detailed and useful answer

Many thanks Dr. Adam for your answer and for the recommended company to do the test