“…Polyurethane foams (PUFs) are usually produced by the reaction of a polyisocyanate with a polyol or other reactants containing reactive groups with isocyanate. As a hydroxyl‐containing component, which is usually used as a reactive material with polyisocyanate, can have a wide range of molecular weights, functionalities, and types (ether and ester) and polyisocyanate is also variable in its structure (e.g., aromatic, aliphatic, or polycyclic),1 a variety of rigid PUFs can be produced with excellent characteristics, such as heat insulation, sound absorption, lightness, and shock proofing, and they are widely used in applications such as building insulation, appliances, transportation, and furniture 2, 3. However, the biggest disadvantages of PUFs when they are used as structural or semistructural materials are their low mechanical strengths (e.g., compressive strength and tensile strength), which are key physical properties of materials for withstanding strain during use 4.…”