CRAMPS and 13C CP/MAS NMR Examination of Solid-Solid Transitions in n-Hexatriacontane (C36H74)

摘要

The normal paraffins can undergo several transitions before melting and may thusserve as interesting model compounds for polyethylene, which also undergoes solid-solid transitions, the strongest and best-known being the so-called alpha transition. Our examination of n-Hexatriacontane (C36) has been greatly furthered by the use of the solid-state (1)H NMR technique known as CRAMPS (Combined Rotation And Multiple Pulse Spectroscopy). This technique, combined with DSC and (13)C CP/MAS NMR, has allowed us to make tentative assignments for the molecular motions occurring at different temperatures below the melting point.