Polyurethane prepolymers: an efficient dispersant core for sublimation inkjet inks

In this study, the modification of toluene diisocyanate “TDI”-based prepolymers was performed using three different polyols (trimethylol propane “TMP,” glycerol and castor oil). The prepared modified prepolymers were terminated using amino-polyether (Jeffamine M-2070) and maleic acid-modified polyethylene glycol “PEG 1000” to obtain dispersing agents for water-based disperse dye inkjet inks. Dispersants T1–T5 (based on TMP), dispersants G1–G5 (glycerol) and dispersants C1–C5 (castor oil) were characterized using FTIR to monitor the reaction progress. Inkjet inks made using these dispersants were characterized by particle size, dynamic surface tension, rheology profile and accelerated stability against commercial dispersant. The results revealed that glycerol and TMP-based dispersants provided optimum performance as compared to commercial standard, while castor oil-based dispersants failed the wettability and dispersion stability tests.