Morphology of poly(oxyethylene) methyl-n-alkyl ethers as determined by small-angle X-ray and Raman scattering

Abstract

Poly(oxyethylene) methyl-n-alkyl ethers with oxyethylene block lengths of 13, 27, 40 or 53 oxyethylene units and n-alkyl end-block lengths in the range 12 to 21 methylene units have been studied in their solid state by low-frequency Raman scattering and small-angle X-ray diffraction. The low-frequency Raman transitions observed are assigned to longitudinal acoustical modes of unfolded chains in either monolayer or bilayer lamellae or of folded chains probably in bilayer lamellae, the morphology being dependent on the molecular structure and the crystallisation conditions.