Enhancement of polyurethane mechanical properties through optimization of its pristine microstructure

Polyurethane (PU) has been widely used for various insulation applications ranging from high-temperature to cryogenics. The material offers unique characteristics where its ability to accept modification presents it as a good candidate for use in numerous insulation applications either as a standalone or composite. However, the material has a problem with a certain porosity that allows water permeation into the insulation matrix which eventually leads to Corrosion under Insulation (CUI) and inadequate mechanical strength. Previous work succeeded in improving mechanical strength through introduction of nanomaterials into the PU, but the composites fall short to address the problem of increase in material thermal conductivity due to the relatively high conduction of such particles in addition to water ingress. The present work tried to reformulate the pristine Polyurethane to have improved hydrophobicity and compressive strength by enhancing the PU microstructure. It was found that Ethylene Glycol (EG) as a chain extender enhances material compressive strength, and cell geometry is defined by the amount of blowing agents use in the synthesis. In this study optimal amount of EG and blowing agent was determined that enhances polyurethane compressive strength, hydrophobicity and density. The PU will serve as a base matrix where other nanomaterials can be incorporated.