Composites of rigid polyurethane-polyisocyanurate foams with oak bark

New polyurethane materials – rigid polyurethane-polyisocyanurate (PUR-PIR) foams modified with ground pedunculate oak bark were obtained. The amount of added bio-filler varied from 0 to 25 % of the sum of polyol and polyisocyanate masses. The thermal, mechanical, aging and flammable properties of the produced foams were investigated. The PUR-PIR foams modified by addition of oak bark were characterized by lower brittleness, compressive strength and water absorption than those of reference foam. The apparent density, aging properties and flammability of the modified foams were similar to those of reference foam.