The Synthesis of Diaminoanthraquinone Coloured Cross Linked Epoxy Resins and Their Application in Paint and Selected Polymers

Abstract

Novel polymeric pigments were synthesized in xylene by cross linked epoxy resin with 1,4 and 1,5-diaminoanthraquinones, by varying weight fractions from 5% to 20% of the diaminoanthraquinone derivatives. FTIR, UV and solubility tests were carried out. The pigments were then used to colour PLA, PMMA, PE and also in emulsion paints using polyvinyl alcohol as binder. Their light fastness, surface drying time and surface hardening time were assessed. It was found that λ max of the 1,4-diaminoanthraquinone shifted towards longer wavelength after the cross linkage, in contrast to the 1,5-diaminoanthraquinone which suffered a blue shift. However in all the cases, the λ max was not affected by the weight fractions of the anthraquinones, but the absorptivity coefficients was significantly increased as the weight fractions of the anthraquinones increased. The light fastness properties of the coloured plastics varied from 4 to 7, indicating a trend of increase with the weight fractions of the anthraquinones. Similar observations were seen with the emulsion paints produced. In all the cases, the 1,4-diaminoanthraqunione produced better result.

Facile synthesis and dyeing performance of some disperse monomeric and polymeric dyes on nylon and polyester fabrics

“…Therefore, the shift of λmax and deepened in colour of the polymeric dyes compared to monomeric dyes as shown in Table 4 indicates a bathochromic shift of the wavelength of maximum absorption. This indicates an increase in conjugation and confirmed polycondensation has been achieved as reported previously [14,26]. Table 5.…”

“…The monomeric/polymeric dyes are soluble in acetone, ethanol, and methanol this might be attributed to the polar nature of some of the dyes and solvents but insoluble in n-hexane, benzene, and water. Their insolubility in an aqueous medium confirmed the dispersed nature of these dyes [14,26].…”

“…The colour, yield, and melting point of the synthesised monomeric/polymeric dyes are given in Table 1. The colour of the dyes was brown with the polymeric dyes having deeper shades and both the monomeric/polymeric dyes were of good yield and relatively low melting points but an increase in melting points were observed when comparing the monomeric dyes with corresponding polymeric dyes which might be as a result of an increase in molecular weight [26].…”

UV Fluorescent Epoxy Adhesives from Noncovalent and Covalent Incorporation of Coumarin Dyes

“…Bisphenol A based epoxies exhibit a slight innate fluorescence, , but it is not enough to be readily visible to the eye. However, the addition of small amounts of a fluorescent dye can make the epoxy fluoresce. − Noncovalently attached dyes can leach or be extracted from the resin attenuating or eliminating the fluorescent signature. In addition, leaching of dyes from the resins can potentially cause environmental or health problems.…”

“…Furthermore, adding even small amounts of organic additives to the epoxy can change the mechanical properties of the resulting thermoset, often weakening it through plasticization . Covalent incorporation of dyes, relying on carboxylic acid, hydroxyl, or amine − groups on the dye to react with epoxide groups in the resin formulation or epoxy or other electrophilic groups on the dye reacting with the amine groups in the hardener, , should eliminate plasticization while maintaining fluorescence.…”