Raman structural study of random copolymers of ethylene with 1-hexene

Ethylene/1-hexene copolymers, which differ significantly in 1-hexene content (from 1.9 to 37.0 mol %), are studied by Raman spectroscopy. The copolymer spectra are compared with the Raman spectra of polyethylene at elevated temperatures. We have found that the phase and conformational order of the copolymer macromolecules depends strongly on the 1-hexene content. In particular, an increase in 1-hexene content leads to a decrease in content of the PE-like orthorhombic crystalline phase and in content of trans-conformers in the amorphous phase. The Raman signature at about 800 cm^?1 provides information about the end conformers for the ethylene/1-hexene copolymers with high 1-hexene content.