Syhthesis And Optical Properties Of Colored Waterborne Polyurethane

Due to excellent performance and prominent environmental friendly usefulness, the studies on waterborne polyurethane (WPU) develop rapidly and its applied fields expand gradually. Although the application of the WPU varies, its colors are achromatous, and the colors influenced by impurities often tend to change at random.Thus, research on intrinsically colored WPU with chromophores covalently is proposed. Relatively little research of it has been reported until now. Some studies are to graft or end capping the PU chain with the mono-functional chromophore, the others are to block the chromophore into PU chain. However, those reports got the same problems: The number of chromophoric moieties attached is limited and the density of it is only about 1-2 molecules per polymer chain resulted in the color is not brilliant. In general, the large volume, the poor solubility in water and the low reactivity of colorants lead to such problems as the complexity of the conditions needed and the monotonous color for the product. As a result, the obtained dyed material is difficult to be applied in practice.This paper has fabricated a bi-functional chromogen which can be incorporated into PU chain. In addition, according to the quantum chemical calculation results, three colored diols were synthesized successfully. The red diol 1,5-bis (2-hydroxyethylamino) anthracene-9,10-dione (1,5-HAAD) , the blue diol 1,4-bis (2-hydroxyethylamino) anthracene-9,10-dione (1,4-HAAD) and the yellow 1,4-bis (2-hydroxyethyloxyl) anthracene-9,10-dione (1,5-HOAD) were reported in the paper. The FTIR and 1H NMR were used to confirm the structure of colored diols. The content versus absorbance value of 1,5-HAAD, 1,4-HAAD and 1,5-HOAD was characterized by UV-VIS absorbance spectrums.As a result, 1,5-HAAD, 1,4-HAAD, 1,5-HOAD have a similar structure and can be seen as anthraquinone derivates. Take 1,5-HAAD for example and block it into PU chain for investigating the basic performance of the related PU. Owing to the effective reaction between the -OH group in 1, 5-HAAD and–NCO in IPDI, a stable and homogeneous red aqueous polyurethane dispersion IPDI-HAAD-PU with full color was fabricated conveniently and successfully. Moreover, 1, 5-HAAD content and density can be modulated independently via stepwise polymerization, a series of IPDI-HAAD-Puss were prepared based on IPDI, PTMG and DMPA with different ratios of 1, 5-HAAD to BDO. It's found from research that IPDI-HAAD-PU have good performances on thermal migration, emulsion stability and color stability which could be applied in coatings, artificial leather, dyed fiber and other fields. Also, effect of the content of 1,5-HAAD on the thermal properties, mechanical behavior and water-resistance of IPDI-HAAD-PU were investigated systematically.To study the optical performance of the colored WPU, three colored WPUs named as RPU, BPU and RPU were prepared based on the three colored diols. The difference of three colored diols'UV-VIS spectra was studied when they was incorporated into the PU chain. Then the content of 1,5-HAAD,1,4-HAAD and 1,5-HOAD in each polyurethane were analyzed by quantitative analysis of UV-VIS absorbance spectrum which the result is in accordance with the designed values. Moreover, to analysis the relationship between the structure and color, the UV-VIS spectra of the colored WPU with different ratios of 1,5-HAAD/1,4-HAAD/1,5-HOAD were analyzed by comparing with the UV-VIS absorbance of three color diols ,RPU, BPU and YPU. And then, the related results and discussions were conducted in this paper.