Rigid polyurethane foams from a polyglycerol-based polyol

Rigid polyurethane foams (rPUs) were synthesized by replacing 35 and 70 wt.% of petrochemical polyol with polyglycerol. Two types of polyglycerol with different molecular weights and hydroxyl numbers were used to obtain new green polyurethane-polyglycerol foams. The foams were prepared by a single step method for the ratio of NCO/OH groups equal to 2. rPUs synthesized with polyglycerol showed regular cellular structure, with cell diameters comparable to those of reference foam. The apparent density and compressive strength of foams increased with increasing content of polyglycerols. The highest compressive strength of 240 kPa was observed for the foam containing 70 wt.% of polyglycerol PGK. In the case of foams comprising 35 wt.% of polyglycerols and the reference foam synthesized with petrochemical polyol only, the values of thermal stability, thermal conductivity (k value) and closed cell content were comparable. (C) 2014 Elsevier Ltd. All rights reserved.