Plasma induced surface coating on carbon nanotube bundles to fabricate natural rubber nanocomposites

Carbon nanotube bundles (CNTB) with one-dimensional orientation arrangement structure were grafted a layer of polyacrylic acid (PAA) through plasma induced polymer grafting in this study. Thus, we blended these modified CNTB (CNTB-PAA) into natural rubber (NR) matrix through the silane in-situ modification-dispersion technique achieved by mechanical blending method. In this process, carboxyl groups in large quantities distributed in the surface of CNTB-PAA could be subjected to dealcoholization reaction with silicon hydroxyl (Si-OH) generated from the hydrolysis of silane coupling agent (Si69), and a single sulfur bond of Si69, meanwhile, could participate in the curing reaction of rubber. The ultimate nanocomposites had a significantly decreased network effect of fillers and an improved interfacial bonding between CNTB and rubber matrix. The tensile and dynamic-mechanical tests revealed a strong enhancement in the tensile stress and a marked reduction in the dynamic hysteresis loss of the nanocomposites.