Abstract. 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.

Abstract.A series of nanocrystalline cellulose (NCC) reinforced natural rubber/butadiene rubber/styrene-butadiene rubber (NR/BR/SBR) blends were prepared via mastication of NR/NCC, BR/SBR and other ingredients. Resorcinol and hexamethylene tetramine (RH) was adopted to modify the interface between NCC and rubber matrix. The morphology, dynamic viscoelastic behavior, apparent crosslink density, mechanical performance and dynamic mechanical property of NR/BR/SBR/NCC blends were discussed in detail. The results showed that NCC was uniformly dispersed in composites and RH could enhance the adhesion of NCC and matrix. According to the dynamic mechanical analysis, NCC performed comparable reinforcing effect with carbon black (CB), and the modulus was improved with modification of RH. Mechanical tests showed that the replacement of CB by NCC in the blends did not deteriorate mechanical properties of composites. Besides, the blends exhibited best mechanical properties, when 10 phr NCC substituted CB.

A complex of resorcinol and hexamethylenetetramine (RH) was utilized to modify nanocrystalline cellulose (NCC). The modified NCC (MNCC) was then mixed with natural rubber (NR) filled silica. The structure, processing properties, mechanical properties, and dynamic compression fatigue properties of the NR/MNCC/Silica nanocomposites were characterized by scanning electron microscopy (SEM), rubber processing analyzer, electronic tensile machine, and dynamic compression fatigue performance tester. The results showed that the processing properties, mechanical properties, and dynamic compression fatigue properties of NR/MNCC/Silica nanocomposites were substantially improved over NR/Silica composites. Their better performances in terms of processing, mechanical properties, heat build-up, and permanent set were correlated to the better dispersion of MNCC and stronger interface interaction between NR and MNCC than NR/Silica composites. POLYM. COMPOS., 00:000-000, 2014.