The Use of 2,6-Toluenediisocyanate in Polyurethane Cast Elastomers

A study of the use of 2,6-toluenediisocyanate (2,6-TDI) in polyurethanes was made by comparing polymers made with pure 2,6 TDI to an 80/20 isomeric blend of 2,4/2,6- TDI and to pure 2,4-TDI. Prepolymers were prepared using three different types of polyols [polybutylene adipate, polycaprolactone, and poly(oxytetramethylene) glycol] which were end-capped with the three TDI systems. These prepolymers were cured using three types of aromatic primary diamines (MBOCA, Polacure, and Cyanacure) and a hydroxyl system composed of a 4:1 blend (based on equivalents) of 1,4-butanediol with trimethylolpropane.