Rigid polyurethane foams reinforced with industrial potato protein

Potato protein (PP), the main product of thermal and acidic coagulation of potato juice obtained from potatoes during starch production, was selected as a reinforcement filler in polyurethane (PU) foams. Rigid polyurethane foams (RPUFs) were successfully obtained from a two-component system and modified with PP, in the range of 0.1-5 wt% of total polymer mass content. The influence of PP on the RPUFs morphology and on physical and mechanical properties of the obtained porous materials were studied. PU foams were characterized using morphological, mechanical and thermal analysis. The results show that an addition of 0.1 wt% PP improves compressive strength (the final strength up to 230 kPa) due to the strengthening effect of the filler, low thermal conductivity (0.029 W/m·K) and low water absorption (14.3%). The results obtained in this study confirm that the addition of PP over a certain optimal level has a negative effect on the cell morphology, leading to a deterioration of the physico-mechanical properties of the modified foams.