TIB KAT 721 E

TIB KAT 721 E – Water-Soluble Bismuth Catalyst for Polyurethane Systems:

TIB KAT 721 E is a proprietary, liquid, bismuth-based catalyst that is non-carboxylate and water-soluble, setting it apart from common bismuth carboxylates like TIB KAT 716 (bismuth neodecanoate) and TIB KAT 728 (bismuth octoate). Supplied as a 50% active bismuth catalyst in 50% ethylene glycol, it is ideal for curing solvent-borne polyurethane formulations. Widely used in polyurethane applications,

TIB KAT 721 E is suitable for coatings, adhesives, sealants, elastomers, foams, and plastics. It is preferred where low toxicity, water solubility, and extended shelf life are critical, compared to organotin catalysts.

Although chemically different from traditional bismuth carboxylates, TIB KAT 721 E offers a similar, bismuth-like reactivity profile, delivering a balanced cure with optimized pot life and final cure. Reactivity, especially back-end cure, improves significantly with added or exothermic heat. Like other bismuth catalysts, it selectively catalyzes polyol–isocyanate and water–isocyanate reactions, similar to tin-based catalysts. Additionally, its enhanced water stability provides a longer polyol-side shelf life than bismuth carboxylates.