New Energy-Absorbing Materials Obtained by Valorisation Raw Materials from the Polyurethane Biofoam Chemical Recycling

In the described studies, raw material from chemically recycled petrochemical foam and biobased polyurethane foams (100% of rapeseed oil polyol were used in polyol premix) were utilised in order to obtain viscoelastic foams. The recycled foams exhibited differences in chemical structure, resulting in the formation of four different repolyols. The obtained repolyols were employed as replacements for 10 to 30 wt.% of the petrochemical polyol in the mixture utilised to produce viscoelastic polyurethane foams. It was determined that the chemical structure of the polyol utilised for the foam’s initial production influences the properties of the repolyols obtained and thus also the properties of the viscoelastic foams obtained using them. It was found that foams obtained with the addition of 10 wt.% repolyols were characterized by the best properties among the obtained modified foams, comparable or even better than in the case of petrochemical reference foam. The apparent density of such foams was about 70 kg/m3. Depending on the type of repolyol used, the hardness of the foams ranged from 2 to 8 kPa, and the comfort factor was between 2.5 and 5.0. The foams obtained were characterised by their ability to absorb energy, as evidenced by a resilience of no more than 10% in most cases. However, increasing the percentage of repolyol in the reaction mixture caused too many changes in the structure of the polymer chains, disrupting the arrangement of rigid and elastic segments, which caused the hardness to increase significantly, and the foams were therefore more susceptible to permanent deformation.