Studies of atkytated and esteritit'd wo ols shcvvecl an increased affinity for dyes 1. 2. S I. V'c eskrilied Tussar silk with ntcthanol in the presence of 0.1 A HCI and studied its effect c>n dyeahility with Brilliant Ponn'aux .31t (('I Acid Red 18), So)BBay H)ueBBS(CIAcidB!ue45),and(~roceinScar)et.< .;BS ((_'I I Arid Red 2,S). The (1B-(,s were purili,'d Iw the nwt hod of Roltinwn and Mills ~ ~ I. T'uw;cr silk yarn was (leguninic(i by treatment with textile soap (.i.5 gli.) in the presence of sodium hexametaphosphate (0.$ t:/1.) at thc boil for I hr with a material:liquor ratio of 1:50 131. The v:rmplc wa, rinscc) lir~t with hot and then with cold water and thu c1c-Humming was rcltcatccl. The dt-~umnll'd Tussar silk was hll'arlwd 1.B I with hvclro~cn Iwroxide 1 2 val) in thc pre~l'nce of sodium silicate ( 2 1:/1) and sodium carhonate ( 5.3 gill.) at 80 C for I hr with a material:liquor ratio. of 1:,10. After washing su(,ccssiB-elB-with hot and cald water, the samplc was bteached with sodium hwlrowltitc (5 t:/I.) at 60 C for 10 min and washed. Thc residual alkali was remond 1)B* treatment with 0.01 .1' HCI, followed hy washin~: free of acid. The dl'gumnwd samplc (20 g) was conclitioncd at 30&dquo;C and 657(-RH. Esterilication was carried out at 65&dquo;C for 3 hr with a matl'rial: liquor ratio of I: 50. The simple was washed, dried at 30'C and conditioned.Hsterined and unesterihed 1-g santltlcs of Tussar silk were treated with a solulion containing the purined dye (2j1, owf) and sulfuric acid (O.5j{) at 27, 60, and 98°(' for .<0 min. The initial and final dye concentrations in the dyebath were determined colorimetrically with a Hilgcr Biochem Ahsorptiometer. The amount of the dye taken up by the fiber was calculated from these values. Figure 1 shows that esterified silk takes up more acid dye than the uncstcrificd silk at all temperatures.Esterification affects the extent of dyeing to different del;rees: at 60°C, the effect is more pronounced, but at 98°C (near the boil), the uptake increase drops, presumably due to partial hydrolysis of the ester groups by the sulfuric acid. At each temperature, the relative increases in the dye uptake for Crocein Scarlet 3 BS, Solway Blue B 1S and Brilliant Ponceaux 3 R are in the ratio 2.8:1.8:1.0, respectively.Further work on other varieties of Indian wild silks and with other alcohols is in progress and will be reported later. Ft'. ! 1. Effect of the dyeing temperature on the cfvc uptake of esteritted and unestcrificd Tussar silk: Brilliant Ponn'aux -i R 1 p unesteritied, Vesterifie(i) ; Sotway Blue B BS (6 unesterified, A csterified) ; and Crocein Scarlet .1 RS (0 unesterific(l. 0 esterified).