  The experimental setup for examining the low-molecular-weight fluoropolymer
CF$_{3}$(CF$_{2})_{3}$-O-CF$_{2}$-O-(CF$_{2})_{3}$CF$_{3}$, which is a
promising coating material for the walls of storage chambers for ultracold
neutrons, is described. The results are detailed. The measurement data are
interpreted in the model of a multilayer complex quantum-mechanical potential
of the chamber walls.
