Toluene Diamine Research Articles

Gas Phase Reaction of Toluene Diisocyanate with Water Vapor

A study of the gas phase reaction of toluene diisocyanate (TDI) with water vapor has been conducted in a large (17.3 m3) environmental chamber. A number of analytical procedures were employed to follow the decay of TDI and to search for toluene diamine (TDA) and other reaction products. Experiments were conducted at ambient temperatures (27±1°C); relative humidity was varied from 7 to 70 percent. Four TDI concentrations were examined i.e. 0.6,0.2,0.1 and 0.05 ppm. No evidence was found for a gas phase reaction between TDI and H2O. This finding appears to contradict earlier studies of the reaction of TDI with water vapor. The observed TDI loss rate in the present study has been ascribed to physical removal process i.e. surface adsorption onto the walls of the environmental chamber. The results of this study cannot exclude the possibility that TDI reacts slowly with water vapor, but under the conditions of these experiments, adsorption on the wall surfaces takes place first. TDA and TDI-urea were searched for as possible reaction products; neither was observed.

Gas Phase Reaction of Toluene Diisocyanate with Water Vapor

A study of the gas phase reaction of toluene diisocyanate (TDI) with water vapor has been conducted in a large (17.3 m3) environmental chamber. A number of analytical procedures were employed to follow the decay of TDI and to search for toluene diamine (TDA) and other reaction products. Experiments were conducted at ambient temperatures (27±1°C); relative humidity was varied from 7 to 70 percent. Four TDI concentrations were examined i.e. 0.6,0.2,0.1 and 0.05 ppm. No evidence was found for a gas phase reaction between TDI and H2O. This finding appears to contradict earlier studies of the reaction of TDI with water vapor. The observed TDI loss rate in the present study has been ascribed to physical removal process i.e. surface adsorption onto the walls of the environmental chamber. The results of this study cannot exclude the possibility that TDI reacts slowly with water vapor, but under the conditions of these experiments, adsorption on the wall surfaces takes place first. TDA and TDI-urea were searched for as possible reaction products; neither was observed.

Polyurethane waste recycling. 1. Glycolysis and hydroglycolysis of water-blown foams

In this paper, glycolysis of toluenediisocyanate based water-blown polyurethane foam has been examined by high performance liquid chromatography and gel permeation chromatography to determine the product distribution. Glycolysis with diethylene glycol (DEG) yields toluenediamine (TDA), TDA mono- and di- DEG carbamates, a series of urea-linked mono- and di- DEG carbamate TDA oligomers, and polyether triol (polyol). The complexity of the product mixture suggests problems in applying simple glycolysis to the recovery of mixed and/or contaminated polyurethane wastes. A simpler product mixture results when water and a base catalyst are added to the glycolysis reaction (hydroglycolysis). Hydroglycolysis yields TDA and polyol as principal products. Data for the rate of the hydroglycolysis reaction are presented in the temperature range of 150 to 190/sup 0/C. These results suggest that hydroglycolysis could be used to recover polyols from mixed and/or contaminated water-blown polyurethane wastes.

Chemical interference effects in the measurement of atmospheric toluene diisocyanate concentrations when sampling with an impregnated paper tape

The effect of toluene diamine (TDA) on the measurement of toluene diisocyanate (TDI) concentrations has been evaluated for a commercially available TDI paper tape. The effects of a range of solvents and catalysts, commonly used with TDI in the polyurethane industry, on the TDI paper tape were also examined. TDA produces a significant attenuation of the tape stain intensity when present in TDI atmospheres. No interference effects were observed from the range of solvents and catalysts studied.

In vitro cell transformation screening of 4 toluene diamine isomers

2,4-, 2,5-, 2,6- and 3,4-Toluene diamine (TDA) were tested for their ability to enhance the transformation of primary hamster embryo cells (HEC) by Simian adenovirus 7 (SA7) when administered either prior to or after virus inoculation and for their ability to transform secondary HEC. 2,4-TDA was inactive when given prior to SA7, but active if given after. 2,5-TDA was active in both protocols. 2,6-TDA was marginally active if administered before virus and was the most active of the isomers when administered after virus. 3,4-TDA was the most active compound when added prior to SA7, and was also active when given after virus. All the isomers were capable of producing good dose—responses and absolute increases in the number of virus-transformed foci per dish in one or both of the experimental regimens. Each isomer chemically transformed secondary HEC but good dose—responses were rare, and none of the chemicals were active in more than 50% of the 5 or 6 separate tests performed on each.