Abstract
Some experiments were carried out to find out the relationship between sulfhydryl group and supercontraction of wool in phenol solution. The results obtained are summarized as follows:
1) Supercontraction of wool by phenol depends rather on the total contents of sulphydryl groups of wool than the amounts of cross-linkages between keratin molecules, thus Burley's conclusions in regards to supercontraction are accepted to be adequate.
2) The fact that the degree of supercontraction increases in alkaline phenol solution could be explained not only by the action of ionic states of phenol, but also by increase of sulfhydryl-groups, generated by the hydrolysis of disulphide bonds.
3) Those wools which are less damaged, having small alkali solubility, have not always better-shrink-resisting properties, and vice versa. The best way to improve both properties of reduced wool are to use in one process the oxidation of sulphydryl groups and formalization.
4) The mechanism of setting of wool fabrics on the case of crabbing have been hitherto explained by the formation of cross-linkages between-SOH and -NH2 groups, but in our conclusions from the experiment, parts played by sulfhydryl groups are mainly responsible for crabbing, just as in the case of setting by thioglycollic acid and of supercontraction by phenol.
After all, the appearent difference between setting processes and supercontraction occurs by whether wool samples were tensed or not during these processes.
