Reactive Diluents – Ideal for Polyurethane Coatings

A large number of formulators come across a question about developing a high-solids polyurethane system with low viscosity for feasible application, as well as incredible performance after curing process since voc component in paints and coatings became the prime focus of regulations.

Scientists have found an answer to this problem by making the use of low molecular weights polyols to deliver a lower viscosity formulation that need less solvent. Unfortunately, these reductions in molecular weight sometimes lead to systems that cure too quickly and unable to perform well in the field. These polyols pose a threat of high intrinsic viscosities without reductions in molecular weight which makes it very intrinsic to eliminate solvent from the formulation.

On the other hand, Reactive diluents are low viscosity co reactants that are developed purposefully to reduce VOCs with the help of a reaction with the polymer matrix. They are very much similar to solvents as they reduce polymer viscosity, but they do so without increasing VOCs. Reactive diluents typically take the form of blocked or delayed sources of active hydrogen. For example – Aldimines and ketimines are block-amino compounds. Oxazolidines are also a part of blocked amino alcohols.