Optimization of run parameters of temperature-rising elution fractionation with the aid of a factorial design experiment

The effects of start temperature for crystallization, cooling rate, heating rate, and elution speed on the separation quality of temperature-rising elution fractionation (TREF) were studied using a heterophasic ethylene/propylene copolymer. The results derived by the aid of a factorial design plan were judged by the separation quality and visibility of the various peaks and shoulders in the overall diagram. Optimized run parameters were found which finally led to a remarkable increase in resolution of the TREF curve of the copolymer.