Disperse dyes as structure probes for a modified polyester film

Six azo and anthraquinone disperse dyes were used as probes to study changes in the morphology of a polyester film modified by treatment with aqueous 5% sodium hydroxide, 70% ethylamine, or 70% N, N-dimethylformamide (DMF) solutions. Aqueous sodium hydroxide-treated polyester was less accessible to these dyes and dyed to different shades than untreated polyester suggesting that the non-crystalline content of the film surface is slightly greater than that of the interior of the film. Aqueous ethylamine and DMF-treated polyester tended to dye to deeper and different shades than untreated polyester demonstrating that these treatments provide greater access to the non-crystalline regions within the polyester depending on the particular treatment and the dye used.