Flexible polyurethane foams reinforced with organic and inorganic nanofillers

The effect of three different types of cellulose nanofillers on the morphology, mechanical, and thermal properties of flexible polyurethane foam was studied. Cellulose nanocrystals (CNC), cellulose nanofibrils (CNF), and cellulose filaments (CelFil) were used as fillers at 0.1–0.8 wt% loading levels. The comparison of the results showed that smaller loading levels resulted in foams with better performance in almost all cases. In the next step, the properties of foams containing CNC, CNF, or CelFil at 0.025%–0.1% loading levels were compared with those made with inorganic nanofillers including nanosilica (nSi), reduced graphene oxide, and halloysite nanotubes (HNT). Among all the properties evaluated, the tensile modulus of the foams was improved up to 40% by adding HNT at 0.05 wt% loading level whereas the addition of CNF resulted in a 44% increase in the compressive modulus of the foams at 0.1 wt% loading level. In this work the influence of different organic and inorganic fillers on the mechanical and thermal properties of flexible polyurethane foams was compared.