Effect of Mixing Ratio and the Addition Ration of Magnesium Oxide on the Properties of The Rigid Polyurethane Foam in Open Medium. engsc [Internet]. 2025 Nov. 24 [cited 2026 Aug. 28];47(5):115-26. Available from: https://journal.latakia-univ.edu.sy/index.php/engsc/article/view/20267