The influence of molecular interactions on the viscosity of aliphatic polyisocyanate precursor

 
For the production, processing and application of aliphatic polyisocyanate-based materials such as polyurethane coatings and adhesives, the viscosity of the monomer is a key property. However, despite its importance, surprisingly little is known about the underlying molecular interactions that influence the viscosity of isocyanate-based precursors. In this work, molecular interactions involving the isocyanate functional group are investigated, as well as their influence on viscosity. Using a combined experimental and theoretical approach, a model is presented for the cause of the relatively high viscosities observed for isocyanurate based polyisocyanates, as compared to polyisocyanates, based on other structural elements such as uretdiones, allophanates and iminooxa-diazinediones.