Investigation of the effects of clay based additives on the thermal conductivity and compressive strength properties of rigid polyurethane foams

Today, it is an indisputable fact that energy is one of the most important and ongoing topic. Therefore, the efficient use and sustainability of energy and energy savings will continue to protect its relevance for quite a long time. Thermal insulation is provided with using glass/mineral wool, polystyrene foam, polyurethane foam, phenol foam etc. Among these materials, rigid polyurethane foams (SPK) becomes predominant over others due to the low thermal conductivity and the improvement of the insulation performance of them has become more important issue day by day. In this thesis study, clay added rigid polyurethane foam nanocomposites (SPKN) with lower thermal conductivity compared to SPK were synthesized. Bentonite (B) was modified with water-soluble compounds having different functional properties. X-ray diffraction, contact angle measurements, elemental and thermogravimetric analysis and infrared spectrometry were used for the characterization of modified clays. B and modified clays were used as additive for the synthesis of SPKNs. The effects of clay type and amount on the average cell size, closed cell content, thermal conductivity, density and compressive strength of foams were investigated. For almost all SPKNs, average cell size and thermal conductivity were lower than those of SPK, while closed cell content and density were higher. The lowest thermal conductivity (20,80 mW/m.K) was obtained with 7% of B- DMODAB added SPKN.