The surface of untreated wool has been investigated using x-ray photoelectron spec troscopy (XPS) and static secondary ion mass spectrometry (SSIMS). The wool surface is covered in a thin layer of lipid estimated to be approximately 0.9 nm thick. Mass spectral peaks are consistent with the presence in the lipid layer of saturated C20, C21, and hydroxylated C21 fatty acids, presumably bound as esters. This lipid layer can be partially, but not completely, removed by treatment with potassium tert-butoxide in tert-butanol or potassium hydroxide, reagents that cause oxidation of the surface cys tine. XPS indicates that the surface protein (epicuticle) is rich in sulfur, suggesting a half-cystine content of about 35%.

The isolation and characterization of 19 new alkaloids from the bark of Galbulimima species is described. After some corrections to previous work, the number of alkaloids from this source now stands at 28.

As part of a program directed at zero-AOX shrinkproofing treatments, we have compared the reactivity of different oxidants with wool by following their disappearance under similar conditions. The reactivity series was as follows: aqueous chlorine > DCCA ~ permonosulfate > permanganate / salt > peracetic acid > permanganate > persulfate ~ hydrogen peroxide. This series was not related to redox potentials but generally followed the level of shrink resistance imparted by the oxidant. Fourier transform infrared spectroscopy using the attenuated total reflectance technique showed significant differences in the amounts of cystine oxidation products formed in the oxidations above. One new finding was the direct formation of low concentrations of Bunte salts by the oxidation of wool with persulfate. We further studied the surface of permonosulfate-treated fibers with scanning electron microscopy and frictional measurements. Permonosulfate treated wool fibers produce Allwörden sacs with chlo rine water, whereas aqueous chlorinated fibers do not. We suggest that the most likely mechanism for shrink resistance in permonosulfate treatments is the removal of de graded protein from below the exocuticle, producing a modified surface with a reduced differential friction between the "for" and "against" scale directions.

In addition to alphitonin and ceanothic acid, the wood of Alphitonia excelsa Reiss. also contains betulic acid. The wood of A. petriei Braid & White yields in addition to these substances, alphitolic acid and β-sitosterol, but the wood of A. whitei Braid is rather different, containing maesopsin instead of alphitonin. There is also present ceanothic acid, betulic acid, alphitolic acid, betulin, and β-sitosterol. The structures of maesopsin and alphitolic acid are deduced.

Aliphatic isocyanates react rapidly and quantitatively with aqueous bisulphite solutions to form stable water-soluble adducts which are salts of N-alkylcarbamyl sulphonio acids. Phenyl isocyanate gives lower yields of the corresponding adduct which is less stable in water. The rate of reaction of n-butyl isocyanate with bisulphite increases with increasing p H and is proportional to [OH-] over the pH range from 5 to 8. The rate of decomposition of the butyl isocyanatebisulphite adduct increases with increasing temperature and pH. A plot of the logarithm of the initial first-order rate constant for the decomposition of the adduct against pH is linear over the pH range from 2 to 7 and has a slope of 0.57&0.05. Water-insoluble polymers with aliphatic isocyanate groups do not form bisulphite adducts under the conditions which are suitable for simple isocyanates. However, the addition of water-soluble organic solvents such as dioxan and the lower alcohols enables the preparation of water-soluble bisulphite adducts which are indefinitely stable a t room temperature and low pH. The relative quantity of the organic solvent must be kept within specific limits which depend on the nature of the prepolymer, the solids content of the final product, and the nature of the organic cosolvent.Polymers with isocyanate groups are used extensively to produce polyurethane coatings, elastomers, adhesives, and foams.la This use of polyisocyanates results from the ease with which condensation polymers form from the reactions of the isocyanates with nucleophiles (e.g. with alcohols to give polyurethanes). Hence isocyanates react readily with water (Scheme 1). This reaction with water can be RNCO + H 2 0 -RSHC02H -RSH2 + C02 RNHz + RSCO -RNHCONHR Scheme 1