Non-isothermal Crystallization and Degradation Kinetics of Fe3O4-Thymolblue Functionalized Poly(ε-caprolactone)

The Fe3O4-thymolblue (TB) functionalized or end capped poly(epsilon-caprolactone) (PCL) was synthesized by ring opening polymerization (ROP) of epsilon-caprolactone (CL) with Fe3O4-TB nanohybrid as an effective initiator in the presence of stannous octoate (SO) as a catalyst. The main aim of the present work is to analyze the influence of polymer chain end capping agent or functionalization agent on the structure-property relationship particularly, crystallization and thermal degradation behavior of PCL under non-isothermal condition. The structure of the polymer was analyzed using FTIR and NMR spectra. The particle size of the incorporated Fe3O4-TB nanohybrid in PCL matrix was found to be less than 20nm by TEM. The surface morphology, skewness moment and surface roughness were analysed by AFM. The spherulitic growth of the nucleated polymer crystals was confirmed by POM. The spherulitic growth was further verified with various kinetic models. The melting and crystallization behaviors under non-isothermal condition were assessed by DSC. Various kinetic models were employed to comprehend the degradation behavior of Fe3O4-TB functionalized PCL and its associated kinetic parameters under non-isothermal condition. The energy of activation (E-a) for the crystallization and thermal degradation of PCL were found to be 132 and nearly 140kJ/mol respectively.