Analysing the chemical composition distribution of ethylene-acrylate copolymers: Comparison of HT-HPLC, CRYSTAF and TREF

摘要

HT-HPLC is an attractive technique to analyse CCD of olefin copolymers and offers the possibility to shorten analysis times compared to fractionation techniques based on crystallisation. We have found that HT-HPLC enables the selective elution of EMA and EBA copolymers according to their content of the polar comonomer. This fractionation could be confirmed by coupling the gradient HPLC system with FT-IR spectroscopy. The CCDs obtained by this new method were then compared to the results from CRYSTAF. Both methods, HT-HPLC and CRYSTAF, can discriminate between sets of samples having a narrow or a broad CCD. They can also prove the presence of acrylate-poor fractions.