| Popis: |
A fresh appraisal of the analytical temperature rising elution fractionation (TREF) technique is presented. It is shown that by using linear paraffins and low molecular weight polyethylenes as standards, a new, generalized calibration procedure for TREF can be defined. This allows polyethylene copolymers to be characterized in terms of the length of the methylene sequences between branches. Such a calibration relates directly to the crystallization behaviour of the copolymer, and is very useful for a proper understanding of chain structure in linear low density polyethylene materials. |
