Dear Prajna Deepthi many thanks for posting this interesting technical question. As a synthetic inorganic chemist I'm absolutely not an expert in this field enough to give you a qualified answer. However, I just came across this potentially useful reference which migth help you in your analysis:

Role of crystallinity on wear behavior of PTFE composites

Conference Paper Role of crystallinity on wear behavior of PTFE composites

This paper has been posted as public full ext on RG, so you can freely download a pdf file. In this study differential scanning calorimetry (DSC) has been employed to investigate the thermal transition of the polymers and to evaluate the crystallinity of the semi-crystalline composite materials. I hope this helps answering your question. Good luck with your work and best wishes!

But the formula mentioned is not working for the filler. Can someone shared sample calculation if the graphite content is 25% of total composite