Development of smart polyurethane foam with combined capabilities of thermal insulation and thermal energy storage by integrating microencapsulated phase change material

Polyurethane (PU) foam is most commonly used in thermal insulation in cold storage applications whereas it lacks thermal energy storage characteristics. In the present work, a phase-changing material n-pentadecane is microencapsulated with poly (methyl methacrylate-co-methacrylic acid) using oil in water (O/W) emulsion polymerization followed by the incorporation into the polyurethane foam formulation to fabricate a composite. The purpose of the study is to combine thermal insulation along with thermal energy storage characteristics into polyurethane foam. The phase change enthalpy of polyurethane foam has been improved from 44.80 to 60.40 J/g by changing the microcapsule loading fraction from 10 to 30%. The composite PU foam exhibits good thermal reliability even after 100 thermal cycling tests. The morphological observation confirms the decrease in the cell size while increasing the microcapsule content. A prototype has been fabricated and tested, showing an enhancement in the thermal energy storage capacity of PU composite foam. This performance makes this PU-PCM system feasible for cold energy storage applications.