Effects of partial replacement of silica with surface modified nanocrystalline cellulose on properties of natural rubber nanocomposites

Nanocrystalline cellulose was modified by 3-aminopropyl-triethoxysilane (KH550). The modified nanocrystalline cellulose (MNCC) was further investigated to partially replace silica in natural rubber (NR) composites via coagulation. NR/MNCC/silica and NR/nanocrystalline cellulose (NCC)/silica nanocomposites were prepared. Through the comparison of vulcanization characteristics, processing properties of compounds and mechanical properties, compression fatigue properties, dynamic mechanical performance of NR/MNCC/silica and NR/NCC/silica nanocomposites, MNCC was proved to be more efficient than NCC. MNCC could activate the vulcanization process, suppress Payne effect, increase 300% modulus, tear strength and hardness, and reduce the heat build-up and compression set. Moreover, fine MNCC dispersion and strong interfacial interaction were achieved in NR/MNCC/silica nanocomposites. The observed reinforcement effects were evaluated based on the results of apparent crosslinking density (V-r), thermo-gravimetric (TG) and scanning electron microscopic (SEM) analyses of NR/MNCC/silica in comparison with NR/NCC/silica nanocomposites.