A simple method of evaluating non-isothermal crystallization kinetics in multicomponent polymer systems

A new simple method of evaluating non-isothermal crystallization kinetics is proposed. The procedure based on mathematical treatment of DSC cumulative crystallization curves at their inflection point provides three kinetic parameters: temperature of start of crystallization (T_s), temperature of maximum crystallization rate (T_i) and numerical value of the maximum crystallization rate (s_i), and also final crystallinity after cooling (CR_c). The method is demonstrated on the system poly(ɛ-caprolactone)/poly(lactic acid)/clay C15 and related microfibrillar composite. The method provides the values of T_s and T_i with standard deviation σ = 0.3 and 0.4 °C, respectively. The coefficient of variation v of s_i and CR_c is 5.8 and 1.5%, respectively. The proposed method does not refer to any crystallization model and does not require exact determination of the starting time. It is particularly useful for characterizing a series of samples derived by modification of the neat polymer.