Hydroxyl group determination in high molecular weight alcohols and complex organic mixtures

Acetylation of complex organic mixtures and high mol wt alcohols is inconsistent by existing procedures because of sample insolubility. By choosing a suitable mixed paraffin-ethyl acetate solvent to bring about nearly instantaneous solu-tion, and utilizing the known catalysis property of perchloric acid, acetylation is quantitative in 10 min or less at room temp. The effect of per-chloric acid concn on these high mol wt systems was studied, and from 0.05-0.45M consistent results were obtained without difficulty. Acetylation of polyethylene oxide (P.E.O.) ad-ducts of straight chain monohydric alcohols pro-ceeds normally and without degradation by the prescribed procedure. Extended reaction time re-sults in partial degradation of the polyether link-ages and amounts to nearly 8% after 30 min.