Abstract <p>Knowledge of thermal transformations and reactivity of polyacrylonitrile (PAN) during heat treatment is critical for the ability to optimize processes for the preparation of graphene nanoplatelets based on PAN. Here we present our findings on the thermal properties of PAN and its interaction with solvents. Using UV and IR spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and molecular modeling, we have shown that the nitrile group CN is the key reactive center influencing the structure of PAN. According to calculation results, heat treatment reduces the total energy of the system from 14.87 to 12.51 J/g. The total energy per atom for interaction of PAN with dimethylacetamide (DMAA) and dimethylformamide (DMF) is 6.02 and 5.64 J/g. The temperature of solvent removal from the PAN/DMF film containing 0.2 wt % PAN is 141.56°C and its carbonization temperature is 300°C. The highest reactivity is offered by the hydrogen atoms linked to tertiary C atoms and located near CN groups. Combining the experimental analytical methods and molecular modeling, we have identified the key features of the thermal transformations of PAN and its interaction with the solvents. The results we obtained can be helpful in improving methods for the preparation of graphene-like materials.</p>