Natsuko Kohara

Effect of Reduction and Succinylation on Water Absorbance of Wool Fibers

Succinylation and reduction of wool fibers increase their water absorbability and enhance the re-use of waste wool fibers for functional materials. Water absorbability of these fibers improves with simple reduction and corresponds fairly well with the SH content of the reduced wool. When wool fibers are reduced and succinylated, water absorbability rises remarkably with increased add-on of succinic anhydride. In its most absorbent state, the reduced and succinylated wool holds 39 g · water/g · wool. The carboxyl groups introduced by succinylation into the fibers significantly contribute to the increased water absorbance of reduced and succinylated wool.

Gas chromatographic and mass spectrometric behaviour of O-alkylserines as their N-trifluoroacetyl butyl esters

Abstract Four O-alkylserines were prepared from the corresponding alkyl O-alkyl-α-dehydroserinates by hydrogenation, followed by hydrolysis. The gas chromatographic behaviour of N-trifluoroacetyl butyl ester (BTFA) and N-trifluoroacetyl alkyl ester (RTFA) derivatives of the alkylserines and RTFA derivatives of the alkyldehydroserines was studied on columns of OV-17 and Dexsil 300 GC in relation to the chemical structures of the amino acids. Alkyldehydroscrine derivatives were more polar and eluted more slowly than alkylserine derivatives, which eluted as fast as alkylglycine derivatives of the same molecular weight. The stability of O-propylserine under the conditions for acid hydrolysis of proteins was compared with that of O-propyltyrosine and S-propylcysteine: the stability increased in the order O-propyltyrosine

Influence of Succinylation on the Interactions of Wool Fibers and Water

Succinylation after reduction or partial hydrolysis of wool fibers raises their water absorbability, hygroscopicity, and nonfreezing bound water content. The crystallinity of wool fibers decreases after succinylation, which suggests that the reaction affects not only the amorphous region but also the crystalline region. Both the increased amorphous region and the carboxyl groups introduced by succinylation contribute to the rise in hygroscop icity and nonfreezing water content. Water absorbability increases with the number of carboxyl groups, although it is not affected by a change in crystallinity induced by succinylation.