Quantifcation of identical and unique segments inethylene-propylene copolymers using two dimensionalliquid chromatography with infra-red detection

Hyphenating high temperature high performance liquid chromatography (HT-HPLC) with high temperature size exclusion chromatography (HT-SEC) (high temperature two dimensional liquid chromatography (HTHPLC x HT-SEC or HT 2D-LC)) leads to an isocratic elution in the second dimension, which in turn enables touse IR detector (quantitative detection) for monitoring the eluting polymers. Experimental data obtained fromHT 2D-LC with IR detector are usually presented as contour plots, which can be mathematically described inmatrices. Quantitative data about chemical composition, molar mass and concentration of all the segments, whichare present in a polymer, can be obtained, after calibrating the HPLC separation (HPLC elution volume vs chemicalcomposition), SEC separation (SEC separation vs molar mass) and response of the IR detector (IR response vsmass of the polymer). A new procedure based on subtraction and addition of matrices is described, which enablesquantitative comparison of different polymer materials. This procedure enables to determine, which componentsare present in both materials (i.e., identical components or segments) and which are present only in one fromboth the materials (i.e., unique segments). Moreover, molar mass distribution, as well as chemical compositiondistribution of both identical and unique segments is evaluated from experimental data. The procedure was appliedon two different ethylene-propylene copolymer samples. Polyolefns J (2016) 3: 119-133

Keywords:

ethylene-propylene copolymer , high temperature two-dimensional liquid chromatography , quantitative detection , infra-red detection , size exclusion chromatography