Aziridinyl phosphazene (NPAZ) was introduced to aqueous‐based polyurethane (PU) as a flame retardant and a postcuring agent, mainly because of the presence of phosphorus compositions, as well as the reactive aziridinyl groups on NPAZ. This dual‐function NPAZ was prepared from the substitution reaction of hexachlorocyclotriphosphazene with aziridine. Aqueous‐based PU was treated with NPAZ and its curing reaction took place upon drying. The performance properties of this NPAZ cured PU (NPAZ‐PU) were improved and better than those of the original PU. The phosphorus composition from NPAZ was evenly distributed on this NPAZ‐PU film, which was identified by the phosphorus mapping on the energy dispersion spectrum. The physical and mechanical properties of NPAZ‐PU were evaluated by the measurements of the gel content, water uptake, ethanol swelling, and tensile stress. The thermal properties of NPAZ‐PU were investigated by thermogravimetric analysis (TGA), TG analyzer‐interfaced FTIR, and dynamic mechanical thermal analysis. Furthermore, its combustion behaviors were demonstrated with the data of a cone calorimeter measurement. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 662–673, 2001

No abstract

A UV-curable polyurethane (PU)-coating system containing phosphorus is formulated by the combination of photoinitiator, PU acrylate oligomer, and UV-reactive phosphazene monomer. PU acrylate oligomer is prepared by the addition of 2-hydroxyethylmethacrylate (HEMA) to NCO-terminated PU prepolymer. UV-reactive phosphazene monomer is derived from the HEMA substitution reaction to hexachlorocyclotriphosphazene (NPCl 2 ) 3 . The curing reaction of this PU-coating system is carried out by UV irradiation. The resultant UV-cured PU-coated films demonstrated better performance properties than those of original UV-cured PU acrylate (UV-PU) without UVreactive phosphazene monomer. Furthermore, their thermal properties are investigated by a thermogravimetric analyzer and a dynamic mechanical thermal analyzer, respectively. The combustion behaviors of these UV-cured PU-coated films are evaluated by the measurements of a limiting oxygen index and a cone calorimeter.

No abstract