Rheological techniques for the determination of the crystallization kinetics of a polypropylene–EPR copolymer

In this article, we show that the crystallization behaviour of a rubber-filled polypropylene, under isothermal conditions, can be monitored by means of parallel plate rheometry and differential scanning calorimetry. Data collected with different instruments can be compared only after performance of accurate temperature calibration. The complex modulus as obtained from dynamic mechanical measurements can be related to the crystalline content by use of appropriate mathematical relationships. An empirical power law model is used to correlate the crystalline content to the rheological function. Excellent agreement between rheological and calorimetric data is found. Furthermore, it is shown that rheology can be used to achieve additional information on the structural evolution of the crystallizing system.