Sorption of liquids by wool. Part IV. Sorption of ethanol by modified wool

Abstract

INTRODUCI'IONThe sorption of polar liquids and vapors by proteins is considered to occur initially by hydrogen bonding at polar groups in the protein.'-l These polar sorption sites are mainly side-chain amino, carboxyl, and hydrmyl groups and peptide l i i g e s of the polypeptide ohaiins. However, there is some doubt as to whether it is side-chain polar groups or peptide links which form the main attractive sites for initial sorption.'-'There is some reported research on the.effect of side-chain masking on water sorption properties of proteins. Mellon et a1.6 found that. blocking of amino groups of casein by benzoylation decreased the sorption of water vapor. Modifications of the polar side-chains of wool results in decreased equilibrium sorption of water vapor at low or intermediate vapor pressureas-" usually without greatly affecting rate or equilibrium sorption at saturated vapor pressure. Kanagy and C a~s e l '~ found that sorption of water vapor by collagen is decreased by deamination, acetylation, and methylation.With wool, the surface scale structure can be a complicating factor in sorption studies. Although chemical and physical attack on these surface scales increases the rate of uptake of dyes1a-16 the sorption of water is unaffected. 11*18It might also be expected that physical modification of wool would produce changes in sorption behavior due to rearrangement of the polar groups and alterations in accessibility, but it has been found that severe physical changes, including supercontraction, reduction and even complete dissolution and reprecipitation, do not greatly affect the equilibrium sorption of water vapor at relative humidities up to 93%.16 Heat denaturation of egg albumin results in very little change in water-sorbing properties, but surprisingly, the sorption of ethanol is greatly This can be explained by assuming that because of their sma? size and high polarity, water molecules are sorbed extremely rapidly, attaching to polar sites with strong hydrogen bonds in such a way that even large changes in the chemical and physical properties of proteins produce little observed effect on the rate of sorption of water. By using larger and less polar molecules such as alcohols, which are sorbed much more slowly 2053

Natural protein fibers

“…The CMC plays an important role mechanically, because it provides the adhesion between cortical cells and hence transmits applied external stress to these cells. Because the CMC is only about 6% of the cortex structure, 5 the bulk mechanical properties of the cortex of wool and other ␣-keratin fibers correspond in their behavior in terms of the prime parameters of moisture content, temperature, and time to a continuum of cortical cells.…”

The efficiency of a non‐aqueous shrink‐resist treatment in controlling the moisture regain of wool

“…It has been demonstrated that the CMC has a great influence on mechanical and chemical properties of wool [2]. It has been demonstrated that the CMC has a great influence on mechanical and chemical properties of wool [2].…”

Effect of low‐temperature plasma and chitosan treatment on wool dyeing with Acid Red 27

“…The exocuticle is hydrophobic because it contains a high degree (Ϸ35%) of disulfite crosslinkage in the A-layer. 2 The epicuticle surrounds each cuticle cell of the wool fiber, and it consists of fatty acid (Ϸ25% by mass) and protein (Ϸ75% by mass). The main component of the fatty acid fraction (Ϸ65%) is 18-methylei-cosanoic acid, which is covalently bound to the fiber as a thioester to cysteine residues of the protein.…”