Volumetric Determination of Free Isocyanate in Urethane Coating Resins

摘要

A procedure is described for the determination of free isocyanate in urethane coating materials. Increasingly large quantities of urethane resins are being consumed and since the presence of relatively small amounts of free toluene diisocyanate (TDI) is considered a health hazard, it was considered essential to devise a procedure for its determination. Free TDI is separated from prepolymers and resins by vacuum distillation and the isolated isocyanate is determined volumetrically.