In this study, polymer composites comprised of polyurethane (PU) foam and two kinds of biomass (coco peat and sphagnum) were prepared. PU industry heavily depends on the petroleum industry. Coco peat and sphagnum are renewable resources. Their use as a reinforcing filler to increase PU foam’s renewable content is yet to be explored. The PU foam was produced via a reaction between 2,4-diphenylmethane diisocyanate and palm kernel oil-based polyol (PKOP). The filler varied from 0–1.2 g. Fourier-transform infrared spectroscopy, morphological analysis, and determination of the mechanical properties of PU foam composites were conducted to identify the effect of the fillers on the PU foam. The results showed that sphagnum has more impact than coco peat on cell structure and the apparent density of the PU foams. The foam cell lost its regular hexagonal ‘bee-hive’ structure, and the apparent density increased to approximately 30% more than the reference sample at 1.2 g filler loading. The PU foam filled with 1.2 g coco peat exhibited significantly improved mechanical properties, with 120% increase in tensile strength compared to the reference sample of the PU foam.
