Abstract
pH titrations with KOH were made of fibroin, alkali treated fibroin and urea formaldehyde resin treated Fibroin.
During alkali treatment, new groups are produced. The active groups in resin treated fibroin seem to be changed. From the slope of titration curve, we may judge the degree of denaturation and the degree of the effect of resin finishing.
The addition of metal ions lowers the pH titration curve of fibroin in the presence of KCI. The addition of metal ions to o-aminobenzoic acid which has free amino and carboxyl group lowers greatly the lower pH buffer region and appreciable chelation occures even in the strong acid region.
The pH titration curves of glycine anhydride show that no chelation occures in the cases of Cu and of Al.
Interaction of o-aminobenzoic acid with Cu and Al is greater than that of Fibroin with the same metals.
