Effect of Branching and Molecular Weight on Heterogeneous Catalytic Deuterium Exchange in Polyolefins

摘要: Small-angle neutron scattering (SANS) is a powerful method for probing the structural properties of polymeric materials. Contrast between polymer chains can be obtained by labeling with deuterium, which provides an opportunity analyzing individual chain behavior in bulk. A transition metal (Pt/Re)-catalyzed reaction isooctane was used to exchange deuterium hydrogen various saturated hydrocarbon polymers, including commercial polyethylene. We have investigated role two forms molecular heterogeneity on using narrow dispersity hydrogenated polybutadiene (hPBD) samples controlled weight and ethyl branch content (short branching). These materials were prepared anionic polymerization, followed catalytic hydrogenation. monotonic increase from 65% 84% observed when increased 4000 216 000. Increasing 635 000, however, resulted almost no exchange, is...