Abstract

Perval 20 and Perval 30 are oxidized degraded products of valonia extract prepared using 20% and 30’ H20, (w;w). Single—bath combination tannages of Perval 20 with Cr( 111 ) or Al( III ) and tanning using Perval 30 Cr( Ill ) complex were studied. The combination of I .5—3.0% Perval 20 and 1.0- 1.5/ C3r,0 produced leathers with shrinkage temperatures above 110 C. so did the Perval 30 — Cr( Ill) complex in similar offers. The combination tannage of I .8% Perval 20 and 1.5 Al( III ) in a single bath prodiLced leather of Ts = 96 C. 26 C higher than aluminium tanning. The more remarkable synergistic effects of these two products with Cr( Ill) and Al( Ill) are due to their increasing carboxyl contents, as shown in the paper. It could be seen that the reduced chrome and chrome-free tannages established here would be more practical because of simplified processes alike to chrome tanning and elimination of the vegetable tanned character of leathers.