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.