Synthesis and studies of coloured polyesters derived from bis-azo diols

A series of coloured polyesters have been synthesized by interfacial polyco ndensation reaction of terephthaloyl chloride and various bis-azo dials. Th e bis-azo dials have been prepared from two different heterocyclic dials, 7 ,7'-dihydroxy-4,4,4',4'-tetramethyl-2,2'-spirobis [chroman] and 2,9-di(2-di methyl-p-hydroxy benzyl)-5a,10b-dihydro benzofuro [2,3-b] benzofuran by cou pling with various diazotized fast bases. These bis-azo dials (dyes) were c haracterized by their m.p., % yield, elemental analysis and uv-visible spec troscopy and applied on nylon and polyester fibres and their dying performa nce were assessed. These dyes showed fair to fairly good fastness to light and very good to excellent fastness to washing, rubbing, perspiration and s ublimation. All the coloured polyesters were characterized by their element al analysis,. ir and uv-visible spectroscopy. Their viscosity, solubility, bleeding test and thermogravimetric analysis were also studied.