Natural rubber latex foam (NRLF) was reinforced with micro- and nanofibrillated cellulose at a loading content of 5–20 parts per hundred of rubber (phr) via the Dunlop process. Cellulose powder from eucalyptus pulp and bacterial cellulose (BC) was used as a microcellulose (MC) and nanocellulose (NC) reinforcing agent, respectively. NRLF, NRLF-MC, and NRLF-NC exhibited interconnected macroporous structures with a high porosity and a low-density. The composite foams contained pores with sizes in a range of 10–500 µm. As compared to MC, NC had a better dispersion inside the NRLF matrix and showed a higher adhesion to the NRLF matrix, resulting in a greater reinforcement. The most increased tensile strengths for MC and NC incorporated NRLF were found to be 0.43 MPa (1.4-fold increase) and 0.73 MPa (2.4-fold increase), respectively, by reinforcing NRLF with 5 phr MC and 15 phr NC, whereas the elongation at break was slightly reduced. Compression testing showed that the recovery percentage was improved to 34.9% (1.3-fold increase) by reinforcement with 15 phr NC, whereas no significant improvement in the recovery percentage was observed with MC. Both NRLF-MC and NRLF-NC presented hydrophobic surfaces and good thermal stability up to 300 °C. Due to their highly porous structure, after a prolong immersion in water, NRLF composites had high water uptake abilities. According to their properties, the composite foams could be further modified for use as green absorption or supporting materials.

Green composite films of natural rubber/bacterial cellulose composites (NRBC) were prepared via a latex aqueous microdispersion process. The acid modified natural rubber/bacterial cellulose composites (ANRBC), in which lactic acid was used, showed significant improvement in mechanical properties, melting temperature, and high resistance to polar and non-polar solvents. The ANRBC films exhibited improved water resistance over that of BC and NRBC films, and possessed a higher resistance to non-polar solvents, such as toluene, than NR and NRBC films. The modification had a slight effect on the degradability of the composite films in soil. The NRBC and ANRBC films were biodegradable; the NRBC80 and ANRBC80 films were degraded completely within 3 months in soil. NRBC and ANRBC showed no antibacterial activity against Escherichia coli and Staphylococcus aureus and did not show cytotoxic effects on the HEK293 and HaCaT cell lines.