Effect of renewable raw materials on reaction to fire and other properties of polyurethane rigid foams

Polyurethanes represent a very versatile class of polymers obtained from the reaction between polyols and isocyanates. Polyurethane materials with very different physical and mechanical properties can be obtained depending on the type of formulation used to produce them, varying the raw polyols, catalysis, additives and reaction conditions employed. In this thesis work, we focus on rigid blown foams, which are widely used in the thermal insulation industry both in the construction sector for roofing and floor coverings, or as insulators in refrigerated transports, panels for commercial cold rooms and industrial warehouses and freezers. To make the polyurethane industry less impacting on the environment, the demand for materials made from recycled products or derived from industrial wastes has grown in recent years. The experimental work of this thesis, developed in collaboration with Rohm and Haas Italy, focuses on the performance comparison between polyurethane foams produced with traditional and sustainable raw materials, evaluating various characteristics of the obtained foams, including reactivity, blowing efficiency, compressive strength and fire behavior. In addition to classic polyurethane materials, a comparison study was also made between traditional formulations and formulations containing recycled polyols for polyisocyanurate production, focusing on the same key output variables. Another aspect examined in this thesis work is the limitation in the use of halogen-containing additives found in the polyurethane industry. Formulations in the absence of halogen-containing flame retardants and blowing agents have been evaluated.