Synthesis And Application Of The Polymethylol Dyes

Polycarboxylic acid dye is a kind of high dye fixation efficiency reactive dyes, but the applications of polycarboxylic acid dyes are limited, because the ester between polycarboxylic acid dye are easy to hydrolysis under alkaline condition. Based on the hydrolysis resistance of N-methylol groups, multiple N-methylol groups are introducted to the polycarboxylic acid dye molecule to synthesis a novel high dye fixation efficiency reactive dye-polymethylol dye. Due to the introduction of N-methylol groups, polymethylol dyes have better anti-hydrolysis stability than polycarboxylic acid dyes. Therefore, the research of synthesis and application of polymethylol dyes has important practical value.In this thesis, two naphthyl phenol red chromophore R1 and R2, and an anthraquinones blue chromophore B1 were designed and synthesized. These three new chromophore molecules containing amino can react with polymaleic anhydride to product polymaleic acid dyes PMA-R1, PMA-R2 and PMA-B1; H acid chromophore were grafted onto the polymaleic anhydride, and then polymaleic acid dyes PMA-R3, PMA-R4 and PMA-R5 were sythesized via the macromolecular intermediate by coupling and high-temperature reactions; N, N-diethyl-p-phenylenediamine was grafted onto the polymaleic anhydride, and then polymaleic acid dye PMA-R6 was sythesized via the macromolecular intermediate by coupling and high-temperature reactions. The polymaleic acid dyes were modified into the five polymaleic imide dye and the seven polymaleic amide dyes by respectively using urea imide method and ammonia amidation method. The twelve polymethylol dyes were synthesized via hydroxymethyl modification by using the polymaleic imide dye/polymaleic amide dyes. The synthesiszed polymethylol dyes were confirmed by IR and 1H NMR, and the parameters of polymethylol dyes were calculated by using the nitrogen content of the polmethylol dyes and its corresponding polymaleic acid dyes.According to the characteristics of polymethylol dyes, the cotton fabrics were dyed via two-bath one-step dyeing process by the polymethylol dyes. The dye fixation eficiencies of the polymethylol dyes could reach up to 97%～99% after heated at 180℃ for 5 min under 40 g/L of zinc nitrate and 30 g/L dicyandiamide. The number of sulfonic groups in chromophores will affect the solubilities and fastness of the polymethylol dyes, the higher the number of sulfonic groups in chromophores were, the better the solubilities of the polymethylol dyes were and the better the corresponding the washing fastness and rubbing fastness of the dyed cotton fiber were.The polymethylol dyes were applied to single-step process for dyeing and DP finishing cotton fabric (SDDP process) with cross-linking agent DMDHEU (or etherified DMDHEU). Because the reaction condition of polymethylol dye is similar with that of cross-linking agent DMDHEU (or etherified DMDHEU) due to the same (or similar) reactive group. So, in the SDDP process, the dyeing of the polymethylol dye would be almost unaffected by cross-linking agent DMDHEU (or etherified DMDHEU). The dye fixation efficiencies of the polymethylol dyes were 96.8%～97.9% via the SDDP process, which were 20.3%～21.4% higher than the dye fixation efficiencies of the reactive dyes via the traditional two-step process. At the same time, the fastness of cotton fabric treated by the SDDP process were similar with those obtained from the two-step process.By virtue of the high dye fixation efficiency, the polymethylol dyes were applied to replace the commercial reactive dyes and to work along with the disperse dyes to dye PET/cotton blends in one-pass two-bath continuous dyeing process (OTC process). Polymethylol dyes were observed to be suitable for dyeing PET/cotton blends when used in low concentrations; the lowest required concentrations of polymethylol dyes were 5 g/L, which was only 20% of the concentrations of commercial reactive dyes required to reach a given colour level on PET/cotton blends. The wash and crocking fastness of PET/cotton blends dyed with polymethylol dyes were similar to those of PET/cotton blends dyed with reactive dyes and the amout of free and released formaldehyde were less than 40 mg/kg, below the Oeko Tex-100 type Ⅱ(direct contact with the skin textiles) standards.