Reactive Disperse Dyes Bearing Various Blocked Isocyanate Groups for Digital Textile Printing Ink

Area of Science:

• Textile Chemistry
• Dye Synthesis
• Sustainable Printing Technologies

Background:

• Wastewater management is a significant economic and environmental challenge in the textile dyeing industry.
• Digital textile printing (DTP) offers a wastewater-free alternative but is limited in its application to natural fibers like cotton.
• Expanding DTP to natural fibers requires novel reactive disperse dyes capable of effective fabric interaction.

Purpose of the Study:

• To synthesize novel reactive disperse dyes with blocked isocyanate functional groups for enhanced fabric binding.
• To evaluate the sublimation transfer properties of these new dyes on various fabrics (PET, nylon, cotton) at different temperatures.
• To assess the color strength and fastness properties of the synthesized dyes compared to commercial alternatives.

Main Methods:

• Synthesis of reactive disperse dyes incorporating blocked isocyanate groups using pyrazole derivatives (pyrazole, di-methylpyrazole, di-tert-butylpyrazole).
• Sublimation transfer printing of coated fabrics (PET, nylon, cotton) at temperatures of 190°C, 200°C, and 210°C.
• Color strength measurement and assessment of washing and light fastness properties.

Main Results:

• The synthesized DHP-A dye demonstrated superior color strength (2.1) on cotton at 210°C compared to commercial dyes and other synthesized variants (DMP-A, DTP-A).
• DHP-A exhibited enhanced washing and light fastness values on cotton relative to existing commercial dyes.
• The study confirmed the successful introduction of isocyanate groups into reactive disperse dyes, enabling improved fabric interaction.

Conclusions:

• Novel reactive disperse dyes with blocked isocyanate groups can be effectively synthesized and applied via DTP.
• These dyes show significant potential for expanding DTP applications to natural fibers, particularly cotton.
• The developed dyes offer improved color strength and fastness, contributing to more sustainable and efficient textile printing processes.