Diisocyanate Monomer Research Articles

Determination of occupational exposure to toluene diisocyanate by biological monitoring

Exposure of workers to toluene diisocyanate monomer in a factory producing flexible polyurethane was measured using impinger and reagent-impregnated filter sampling. These techniques yielded highly concordant results so that the facile filter techniques can be recommended. The personal exposures were compared with the individual excretion of amine metabolites from the parent toluene diisocyanates. The excretion was linearly related to the product of sampling time and concentration. The biological half-lives of the amines proved to be short so that urine should be sampled 2 h after the exposure. The percutaneous absorption of the monomers could also be controlled.

Allergic Contact Dermatitis to New Plastic Resins

To the Editor.— The high technology electronics industry requires the use of fast-curing resins in the production of the newer electronic hardware. I saw a patient who had allergic contact dermatitis to an aliphatic diisocyanate monomer that was recently introduced into the manufacture of a new electronic part. Report of a Case.— A 48-year-old woman (an engineering aid) began working with the monomer, methylene bis (4-cyclohexylisocyanate) (Flurane 88202A), and a polyol-type catalyst (Flurane 88202B). She had been working with these compounds for one week when she suddenly had a pruritic, erythematous dermatitis on her right forearm, face, and neck. She had been instructed to take precautions with the use of these new compounds by working under a hood and wearing gloves, since they were known to have irritating effects on the skin, eyes, and respiratory tract. The eruption cleared following a course of corticosteroids given for systemic effect. Three weeks

Wool Stabilization by Aqueous Exhaust Systems Based on Reactive Aliphatic Diisocyanates

The development of a single-bath, exhaust treatment for shrink-resisting wool is described. The process involves dispersing a solvent solution containing a fully-reactive cycloaliphatic diisocyanate monomer and cationic emulsifying agent into water, exhausting the monomer on fabric at low tem perature, and then adding a polyamine to form, in situ, a wash-fast polyurea finish on the fiber surfaces. Following polymerization, the fabric is scoured, rinsed, neutralized, and tumble-dried. In its present state of development, the process seems most suitable for treating knitwear; however, it also exhibits a potential for dyebeck application to woven fabrics. Effective shrinkage control is obtained on both clear-worsted and wash-finished knit constructions with tightness factor ranging from 9.0 to 17.3.

Quantitative Determination of Small Amounts of Toluene Diisocyanate Monomer in Urethane Adhesives by Gel Permeation Chromatography

Existing quantitative methods for determining isocyanate monomers are either too insensitive for small quantities, tedious, or give partially erroneous results due to sample reaction with moisture in the reagents or decomposition of sample where elevated temperatures are employed in the analysis. The objective was to develop a basic quantitative method which, with a minimum of modification, could be adapted to a variety of polyurethane products for quality control. Before chromatographing, the sample is treated with specially dried ethanol to convert the free monomer and any isocyanate groups on the prepolymer chain to the respective urethane derivatives. The sample is then diluted with tetrahydrofuran and chromatographed at room temperature on a 200, 200, 100, 100, 60 angstrom column series using a differential refractive index detector. Essentially, the basic procedure is not new or unique but its conversion to a quantitative reproducible method represents a breakthrough as far as a practical approach is concerned.