The present research is aimed at studying the structural effect of two phosphoramidate derivatives diethyl 3hydroxypropylphosphoramidate EHP and dimethyl 3-hydroxypropylphosphoramidate MHP as flame retardants for cotton fabric. EHP and MHP were obtained in very high yield and purity by one step procedures. Cotton twill fabrics treated with the two compounds at different add-ons (5−20 wt %) were characterized. Vertical flammability, limiting oxygen index, thermogravimetric, and microscale combustion calorimeter analyses were performed, and all resulted in better flame retardancy and thermal behavior for MHP compared to EHP. A study of the functional groups which appeared on the treated fabrics by attenuated total reflection infrared spectroscopy revealed different binding mechanisms between each compound and cotton cellulose. Analysis of the released gas products by thermogravimetric analysis-Fourier transform infrared spectroscopy showed some distinctive details in the degradation of the treated fabrics during the burning process.

Ester derivatives of the hydroxylamine metabolic oxidation products of heterocyclic amines (HCAs) are the ultimate mutagenic and carcinogenic compounds derived from this ubiquitous class of chemical carcinogens that are produced during the cooking of protein‐containing foods. Considerable work has been done on the mechanism of formation of the HCAs during cooking processes, their detection at ppb levels in food products, the metabolism of the HCAs and the detection and characterization of DNA adducts of the HCA metabolites, but until recently very little work had been done to characterize the chemistry of the carcinogenic/mutagenic metabolites themselves. This paper reviews our recent work on the chemistry of model carcinogens from this class. The kinetics of their decomposition in aqueous solution, identification of reaction products and the characterization of the reactivity and selectivity of heterocyclic nitrenium ions generated during their reactions are presented. The implications of these results with respect to mutagenicity and carcinogenicity are discussed. Copyright © 2004 John Wiley & Sons, Ltd.

A novel flame retardant diethyl 4-methylpiperazin-1-ylphosphoramidate (CN-3) containing phosphorous and nitrogen was prepared. Its chemical structure was confirmed by nuclear magnetic resonance ( 1 H-, 13 C-, and 31 P-NMR), Fourier transform infrared spectroscopy, and elemental analysis. Print cloth and twill fabrics were treated with CN-3 to achieve different levels of add-on (7-22 wt% add-ons for print cloth and 3-18 wt% add-ons for twill). Thermogravimetric analysis, vertical flame test, and limiting oxygen index (LOI) were performed on the treated cotton fabrics and showed promising results. When the treated print cloth and twill fabric samples were tested using the vertical flame test (ASTM D6413-08), we observed that the ignited fabrics self-extinguished and left behind a streak of char. Treated higher add-ons fabrics were neither consumed by flame nor produced glowing ambers upon selfextinguishing. LOI (ASTM 2863-09) was used to determine the effectiveness of the flame retardant on the treated fabrics. LOI values increased from 18 vol% oxygen in nitrogen for untreated print cloth and twill fabrics to maximum of 28 and 31 wt% for the highest add-ons of print cloth and twill, respectively. The results from cotton fabrics treated with CN-3 demonstrated a higher LOI value as well as a higher char yield because of the effectiveness of phosphorus and nitrogen as a flame retardant for cotton fabrics. Furthermore, FT-IR and SEM were used to characterize the chemical structure on the treated fabrics as well as the surface morphology of char areas of treated and untreated fabrics. Published 2012. This article is a US Government work and is in the public domain in the USA.