Up-to-Date Review of Recent Developments Related to Content, Structure and Processing Conditions on the Resultant Thermal Conductance of Rigid Polyurethane

Abstract

Insulation materials are constructed from either fibers or foams. Foamed materials come into panels of open or closed cells. Rigid polyurethane foam is a standard insulation that eliminates heat and thermal bridging for specific building applications. The thermal conductivity of polyurethane foams may be sensitive to many pronounced parameters related to their components and conditions of formation. This article presents an up-to-date review of recent articles related to the importance of thermal conductivity of polyurethane foam changes due to many parameters based on content and structure. The study collected contemporary sources (within the last six years) and only reliable and relevant investigations. The study has found that specific parameters, such as operating temperature and pressure, polyols content, isocyanate index, amount of blowing agent and mixing speed, are essential. These parameters make the thermal conductive value of rigid polyurethane foam between 0.02-0.04 W/m.K. Some studies have witnessed potential work to minimize the coefficient of thermal conductivity even more. However, the efficiency of polyurethane foam is dependent on the type, size, and distribution of its cells. Manufacturers of insulation foam seek to form closed-cell foams to reduce thermal conductivity. Furthermore, the current study's concluded remarks have noticed that most works focused on blowing agents on the k-values or thermal properties. Some researchers investigated improving foam features involving many contents, such as nanoparticles and soft segments.