Esterification of the carboxyl groups in wool

Sorption of liquids by wool. Part I. Determination of the sorbate content by a new technique

“…The sorption is therefore non-Fickian or anomalous4~6 and cannot be interpreted in terms of a diffusion coefficient, although this has been attempted in the past for vapor sorptions.26.n However, the initial rates of sorption are 3.0% in 0.8 hr., and n-butanol (wool previously treated in n-butanol) 20.5% in 23 weeks. determined in each case from the gradient of the graph of per cent sorption versus time at zero time, and are given in Table I together with approximate values obtained in some cases.…”

The effects of esterification on the humidity-dependent glass transition of human hair

“…This, however, will be somewhat compensated by the higher boiling points of the larger alcohols. Another factor may be genuine differences of the accessibility of acidic side chains in the protein structure for alcohols of different sizes, as suggested by Alexander et al [17].…”

“…Though the plasticization effect as such occurs for each of the alcohols, the individual effect will strongly depend on the degree of conversion of the acid groups. Though at this stage the focus of the investigation was the confirmation of the IP-hypothesis through the introduction of hydrophobic groups as such, it is worthwhile to note that experiments to determine the degree of esterification of hair, based on the method by Alexander et al [17] for wool, had only limited success in our experiments of hair [14]. The experimental challenge of the method appears to be reflected in the different results obtained for wool by Alexander et al [17] and more recently by Fukuda et al [24].…”

“…The degrees of conversions were determined in the early investigations by Alexander et al [17] for wool esterified, e.g., with methanol and n-propanol under reflux. For methanol and propanol apparent equilibrium conversion was observed after 6 h. The degree of the conversion of carboxyl groups was somewhat above 60% for methanol and about 50% for n-propanol, as reviewed by Maclaren and Milligan [18].…”

“…Esterification was carried out based upon the method for wool by Alexander et al [17] as reviewed by Maclaren and Miligan [18]. Dry untreated human hair fibers were refluxed under nitrogen in a 0.2 M alcoholic hydrochloric acid solution for 6 h. Anhydrous reagent-grade solvents were used in all cases.…”