Abstract:
Polymerization of 20% neutralized acrylic acid (Na form), AA, in presence of Karaya gum. KG, or tamarind seed gum, TG. at AA/gum weight ratio of 1/1 and 2/1 results in PAA/KG1, PAA/KG2, PAA/TG1 and PAA/TG2 adducts, respectively (where the suffix I or 2 stands for AA/gum ratios of 1/1 or 2/1). Infra red spectra of adducts are examined. Aqueous pastes of adducts, native gums and GG are of non-Newtonian thixotropic flow within a shear rate range of 4-40 s(-1). Adduct pastes (7.5% w/v) are of higher apparent viscosities (eta) than their native gums or GG, and pastes of TG adducts are of higher eta than KG adducts. Except for PAA/TG2 adduct, the power law does not correlate well to the other pastes. Preliminary trials showed that adducts are excellent thickeners for reactive and acid printing on wool, silk and nylon 6. Prints by adducts are of higher color strength than those by native gums or GG. GG paste was completely destroyed after storing for 7 days, whereas eta of pastes of adducts and native gums were noticeably decreased upon storing. (C) 2008 Elsevier Ltd. All rights reserved.
