Nanocrystalline cellulose isolated from different renewable sources to fabricate natural rubber composites with outstanding mechanical properties

Although nanocellulose has the advantages of rich source and high modulus, choosing a good nanocellulose source and preparing high performance composites for industrial rubber remains a huge challenge. In this study, four different nanocrystalline cellulose (NCC) were successfully isolated from softwood pulp, microcrystalline cellulose, bagasse and cotton straw, respectively. Four different NCCs showed as long rods and maintained a high crystallinity, and four different composites with outstanding mechanical properties were fabricated from natural rubber (NR) and different NCCs. The effect of four different NCCs on NR composites were comparatively studied, and it was found that the addition of NCC accelerated the vulcanization and improved the mechanical properties of NR composites. When the resorcinol-hexamethylenetetramine (RH) was added, the dispersion state of NCC in NR matrix and the interfacial interaction between NR and NCC was significantly improved, resulting in an outstanding mechanical properties and rolling resistance for NR/NCC/RH. This result will play a good guide in selecting the source of NCC for reinforcing polymers, and we envision that this NCC-rubber composites with outstanding mechanical properties may have potential for the industrial rubber.