In theory, FTIR is a strong technique to characterise the functional groups as it's sensitive to functional group and easy to operate . However, I dont know what the functional groups you have in your material, but you can give it a try.
You are using heating treatment, so you should see some changes.
It depends on the experiment you are doing. In principle FTIR is sensitive to any changes in molecular level. The question is if these changes are big enough. Also the sample you are talking is not so easy to measure.