Preparation and characterization of self-emulsified waterborne nitrocellulose

Waterborne nitrocellulose (WNC) dispersion was successfully synthesized by self emulsification and reaction among isophorone diisocyanate (IPDI), dimethylol propionic acid (DMPA) and nitrocellulose (NC). The WNC was characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and thermal gravimetric analysis (TGA), etc. The WNC dispersion has Z-average particle size of 133 nm approximately and distribution index of 0.152. It is indicated by TEM that the cured WNC particles show a core–shell structure, in which hydrophobic component is encapsulated by the hydrophilic carboxyl. FTIR confirms that the reactions (i.e. IPDI and NC, IPDI and DMPA) have occurred, the NCO group of IPDI has been consumed totally and the backbone of NC is retained. TGA reveals that the cross-linked WNC film has better thermal resistance, and the water resistance measurement confirms that it has weaker water-sensitivity.