Silicate-free bleaching of jute — Stabilization of peroxide by DTPMPA

摘要

Optimum conditions for bleaching jute with alkaline peroxide, using diethylenetriaminepentamethylene phosphonic acid (DTPMPA) as stabilizer, have been identified. The best brightness (67.1) was achieved by applying 0.10% DTPMPA during pretreatment and the rest (0.15%) during bleaching. Pretreatment removed detrimental metal ions and polyphenols from fibres, thereby enhancing stability of peroxide and consequently the performance of bleaching. Measurement of metal ions and polyphenols in raw and treated jute, and kinetics of peroxide consumption during bleaching confirmed the above findings. Undesired properties imparted by silicates in conventionally bleached jute such as stiffness, harshness, low dyeability and poor spinnability were decreased when DTPMPA was used during bleaching. Fibres bleached with DTPMPA as stabilizer proved to be more bright, soft and pliable, ensuring smooth spinning into uniform and strong yarn.