Thiourea Dioxide Supplier South Africa

What Is Thiourea Dioxide?

Thiourea dioxide (TDO, formamidine sulfinic acid) is a stable, sulphur-based reductive bleaching agent that is more stable in dry storage and less sensitive to moisture than sodium dithionite. In solution at elevated temperature and alkaline pH, TDO decomposes to release powerful reducing species that bleach azo dyes, vat dye oxidised forms, and colour bodies in paper and textile substrates. Its relatively stable dry form makes it easier to store and handle in smaller operations.

Advantages Over Sodium Dithionite

TDO has a longer shelf life than sodium dithionite under ambient storage conditions, making it preferable for operations with low consumption rates or remote locations with infrequent deliveries. It is activated at temperatures above 50°C in alkaline solution (pH > 9), giving a degree of control over when bleaching action begins — the powder can be safely stored and mixed cold before the bleach bath is heated to activate it. This thermally-controlled activation also reduces premature decomposition during formulation mixing.

Toepassingen en levering

Thiourea dioxide is used in textile discharge printing (printing a pattern by selectively destroying vat dye colour), in wood pulp brightening as a supplement or alternative to sodium dithionite, and as a selective reducing agent in specialty chemical synthesis. Terracore Chemicals supplies technical-grade thiourea dioxide in 25 kg bags for textile processors, paper mills, and industrial chemical users across South Africa.