A Novel Method of Extraction of Blend Component Structure from SANS Measurements of Homopolymer Bimodal Blends

Macromol Chem Phys. 2014 May;215(9):859-866. doi: 10.1002/macp.201300787. Epub 2014 Apr 3.

Abstract

A new method is presented for the extraction of single-chain form factors and interchain interference functions from a range of small-angle neutron scattering (SANS) experiments on bimodal homopolymer blends. The method requires a minimum of three blends, made up of hydrogenated and deuterated components with matched degree of polymerization at two different chain lengths, but with carefully varying deuteration levels. The method is validated through an experimental study on polystyrene homopolymer bimodal blends with [Formula: see text]. By fitting Debye functions to the structure factors, it is shown that there is good agreement between the molar mass of the components obtained from SANS and from chromatography. The extraction method also enables, for the first time, interchain scattering functions to be produced for scattering between chains of different lengths. [Formula: see text].

Keywords: bimodal blends; polystyrene; small-angle neutron scattering (SANS).