Synthesis of a Novel Limonene Based Mannich Polyol for Rigid Polyurethane Foams

A novel bio based Mannich polyol using limonene was synthesized. Mannich polyols are a group of amino polyols with aromatic structure which provide fire resistance, good thermal and superior physico-mechanical properties. The synthesized Mannich polyol was structurally characterized using wet methods (hydroxyl number, acid value and viscosity), gel permeation chromatography, and FT-IR spectroscopy. The Mannich polyol was successfully used for preparation of rigid polyurethane foams. Thermal analysis of the rigid polyurethane foams indicated that they were thermally stable up to 250 °C. Studies based on dynamic mechanical analyses indicated that these rigid polyurethane foams have high glass transition temperature (~200 °C). These foams have also high compressive strength and very regular cell structure with uniform size distribution. The closed cell content of these foams was higher than 90 %. The synthesized Mannich polyol based on limonene was very reactive, indicating that it is very suitable for preparation of rigid polyurethane foams using “spray” process.