Department of Chemistry and Polymer Science, University of Stellenbosch, 7602 Matieland, South Africa
Cheruthazhekatt, S., Department of Chemistry and Polymer Science, University of Stellenbosch, 7602 Matieland, South Africa; Pasch, H., Department of Chemistry and Polymer Science, University of Stellenbosch, 7602 Matieland, South Africa
Information regarding molar mass distribution (MMD) and chemical composition distribution (CCD) of complex polyolefins such as impact polypropylene copolymer (IPC) is important in order to fully understand their properties during processing and application. Precise analysis of such polymeric materials having multiple distributions in various molecular characteristics is a difficult task and single separation methods fail to provide enough information about their microstructure. Preparative fractionation and subsequent analysis of the separated fractions was found to be an effective method for their complete characterisation. In this work, a combination of preparative TREF with high temperature two-dimensional liquid chromatography was used for the separation and analysis of the complex components in a commercial IPC sample. In addition to the ethylene-propylene (block or segmented) copolymers and low molar mass isotactic polypropylene (iPP) homopolymer (as expected in the semicrystalline TREF fraction of an IPC), significant amounts of high molar mass iPP and polyethylene (PE) homopolymer were observed. The results showed that the TREF-HT-2D-LC combination can be used as a powerful analytical tool for the complete microstructural analysis of such complex EP copolymers. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.