Reactive Diluents yield superior quality Polyurethane Coatings

I found a large number of formulators get bewildered from an issue: how to come out with a high-solids polyurethane system with low viscosity for feasible application, along with excellent performance after curing process since voc component in paints and coatings became the major target of regulations.

There is a definite answer to this query is the use of low molecular weights polyols to deliver a lower viscosity formulation that requires less solvent. Unfortunately, these reductions in molecular weight sometimes lead to systems that cure very quickly and fail to perform well in the field. These polyols pose a threat related to high intrinsic viscosities without reductions in molecular weight which in turn makes it extremely difficult to extract solvent from the formulation.

Now discuss the other side of the system. Reactive diluents are low viscosity to reactants that are developed particularly to reduce VOCs with the help of a reaction with the polymer matrix. They are very much similar to solvents as they bring down polymer viscosity, but they do so without up scaling VOCs. Reactive diluents typically take the form of blocked or delayed sources of active hydrogen. For example – Aldimines and ketimines are blocked amino compounds. Oxazolidines are also a part of blocked amino alcohols.