Optimisation in catalysed low temperature hydrogen peroxide bleaching of cotton with different stabilizers by using design expert 6.0

Abstract

The present study investigates the potential of employing gelatin-metal complexes as catalysts for cotton bleaching with low-temperature hydrogen peroxide (H₂O₂). Eight gelatin-metal complexes were developed and tested against sodium silicate and silicate-free stabilizers such as RUCOSTAB OKM and LENETOL GLAD-LQ-(TH). Using the Design-Expert 6.0 programme, a statistical model was created to maximise the bleaching process at lower temperatures (70–80°C). The optimized results showed that sodium silicate stabilised with gelatin-copper/cobalt complex can be a viable method for bleaching cotton at low temperatures, producing necessary whiteness with less damage to fibre and perhaps less energy. Furthermore, the optimized mix design of gelatin–copper complex with RUCO-STAB OKM emerged as the most effective formulation among all the optimized mix designs that outperformed the conventional bleaching the best. It recorded a whiteness index of 71.27%, the lowest fabric weight loss at 6.4%, and the highest bursting strength of 104.1 psi.Besides, the copper-based systems consistently outperformed cobalt counterparts in whiteness, fabric preservation, and mechanical strength attributed to the controlled radical generation by Cu²⁺ ions.