High resolution solution and solid state NMR characterization of ethylene/1-butene and ethylene/1-hexene copolymers fractionated by preparative temperature rising elution fractionation

Preparative TREF was used to fractionate 2 commercial LLDPE polymers. These polymers had similar MFI values, density and comonomer content, but differed in comonomer type, 1-butene vs 1-hexene. High resolution solution NMR and solid state NMR was used to characterize the copolymer fractions. Distinct differences in chemical composition distribution could be observed from solution NMR results, and these correlated well with solid state analyses. Conclusions regarding the molecular make-up and crystallization phenomena are made.