Mineral oil compatibility with hydroxyl terminated polybutadiene based polyurethane

 
Hydroxyl Terminated Polybutadiene (HTPB) are type of hydrophobic polyols, these types of polyols are cured with conventional isocyanates to produce polyurethane. Hydrophobic polyols have the advantage of high hydrolytic stability compared to conventional polyols. The hydrolytic stability reduce the moisture vapor transmission rate, which make it ideal base for coatings, adhesives, sealants and elastomer (CASE) applications. Due to the hydrocarbon backbone of the HTPB these systems can be extended with hydrocarbon oils derived from crude oil feedstock. Oil Extension provides advantages such as further improving the hydrolytic stability, control premix viscosities, gel time, filler loading capacity, diluting effect and thus reducing the price of the formulation. This study aimed to evaluate HTPB based polyurethane extended with mineral oils in MDI cured systems. Eight mineral oils with different molecular structure and viscosities were included in the study. The results show that cyclic hydrocarbon structures (naphthenic) mineral oils have excellent compatibility with HTPB based polyurethane which helps control viscosity, pot-life and allows for higher oil loading in the formulation.