Abstract

A new compound, N-thioureidomaleinamic acid, has been synthesized from maleic anhydride and thiosemicarbazide, and a low molecular weight copolymer suitable for blending with aluminium sulfate solution has been obtained by copolymerizing the compound with acrylic acid and 2-hydroxypropyl acrylate. The structures of the synthesized compound and copolymer have been confIrmed by EI-MS, 1H NMR, 13C NMR, IR, GPC spectra. The effect of the copolymer on aluminium tanning has been investigated. The results show that shrinkage temperature and Al2O3 content as well as dyebath stability of the aluminium-tanned leather can be greatly improved by the addition of the synthesized copolymer to citrate-masked aluminium sulfate solution. A white leather with shrinkage temperature up to 90°C can be obtained by tanning with 0.3mol/L citrate-masked aluminium sulfate solution containing 2.2% of the synthesized copolymer.