A virtual transition from polypropylene glycol (PPG) to polypropylene oxide (PPO)

Abstract The paper concerns the transformation of the properties of a polymeric compound as a function of its degree of the conventional polymerization (controlled in the synthesis process), when simultaneously the compound is capable to form the supramolecular polymers through hydrogen bonds. The orientational entropy investigations performed for a series of propylene glycol-based polymers, H–[OCH(CH3)CH2]n–OH, revealed in the vicinity of the degree of polymerization n = 10, a virtual transition between the polymers of the supramolecular-type (polypropylene glycol, PPG) and the conventional-type (polypropylene oxide, PPO). The transition divides the whole range of the degree of polymerization, n = 1–68, where the tested compound exists in a liquid state, into two areas of totally different thermal stability.