Kinetic analysis of polymer melting using the Toda–Hikosaka–Yamada models

This work presents a new framework for the kinetic analysis of polymer melting based on the power-law and exponential Toda–Hikosaka–Yamada models. The methodology includes two steps. In the first step, the melting rate is decomposed to evaluate the conversion function and the rate constant, a procedure applicable to both isothermal and nonisothermal datasets. In the second step, the extracted rate constant is employed to estimate the Toda–Hikosaka–Yamada kinetic parameters, with optimal performance achieved for nonisothermal measurements. The validity and reliability of the proposed method were assessed using simulated polymer melting processes and further confirmed through an experimental analysis of polyethylene melting kinetics. A notable feature of the approach is its reliance solely on multiple linear regression, which guarantees unique solutions corresponding to the global minimum of the sum of squared errors. To support practical implementation, GNU Octave/MATLAB scripts are provided for the wider adoption of the proposed methodology.