Mechanical properties of polyurethane foam reinforced with natural henequen fibre

Abstract

Fibre-reinforced polyurethane (FRPU) foams with natural henequen fibres were investigated. Pull-out tests were performed with 10-mm fibres and various foam densities to identify the optimal density of 100 kg/m3. Thus, FRPU foams with this density and fibre contents of 1, 2 and 3 wt% were manufactured for mechanical testing. Compression tests showed an increase in the elastic modulus of the FRPU foam specimens compared to the unreinforced PU foam. The FRPU foams also exhibited higher yield stress attributed to the reinforcing effect of the fibres on the cell walls. A maximum increase of 71% in the compressive yield stress was observed for the FRPU foam specimens with a fibre content of 2%. In addition, FRPU foam specimens absorbed more energy for any given strain than the unreinforced PU foam. Flexural tests showed the FRPU foams exhibited increased flexural strength compared to the unreinforced PU foam. A maximum increase of 40% in the flexural strength was observed for the FRPU foam with a fibre content of 1%. The flexural strain to failure was lower for the FRPU foams than for the unreinforced PU foam, attributed to the increased fibre agglomeration with increased fibre content. These results suggest that FRPU foams incorporating natural henequen fibre exhibit promising potential as sustainable materials with enhanced mechanical properties.