Using Agrawal integral equation, dynamic mechanical analysis (DMA), and differential scanning calorimeter (DSC) methods to study the glass transition kinetics of nanocomposites of polybenzoxazine and exfoliated montmorillonite from a polyhedral oligomeric silsesquioxane surfactant and click chemistry

Abstract In this study, we used a singly azido-functionalized polyhedral oligomeric silsesquioxane (POSS) derivative and a montmorillonite intercalated by propargyldimethylstearylammonium bromide to prepare an exfoliated montmorillonite through click chemistry. This exfoliated montmorillonite was then introduced into a benzoxazine matrix prepared from paraformaldehyde, aniline, and phenol to form polybenzoxazine/exfoliated clay nanocomposites. Dynamic mechanical analysis, differential scanning calorimetry, and Agrawal integral equation revealed that the glass transition kinetics had a close relationship to the structure, assembly process, and anchoring effect of montmorillonite layers, the compatibility between polybenzoxazine and intercalator, and the methods of dynamic mechanical analysis and differential scanning calorimetry. The polybenzoxazine/exfoliated clay nanocomposites presented the same mechanism function at different weight ratios between polybenzoxazine and exfoliated clay, and the kinetic compensation effect equations revealed the nature of glass transition.