Molecular motion, morphology and properties of 3-isocyanato-propyltriethoxysilane-modified multi-walled carbon nanotube/epoxy composites

In this study, both epoxy resin and multi-wall carbon nanotubes (MWCNTs) were modified with 3-isocyanato-propyltriethoxysilane (IPTES). Scanning electron microscopy and transmission electron microscopy microphotographs show that the MWCNTs dispersed well in the epoxy matrix. The molecular motion of silane-modified MWCNT/epoxy composites was studied using high-resolution solid-state ¹³C NMR. Results show that 1 wt silane-modified MWCNT/epoxy composite exhibits less molecular motion than composite with a lower silane-modified MWCNT content. The glass transition temperature (T_g) of the neat epoxy is 192.6°C and increases to 212.5°C with 1°wt° IPTES-MWCNT content. Dynamic mechanical analysis data of the MWCNT/epoxy composites show the storage modulus at 50°C and the T_g of the IPTES-modified epoxy increased with IPTES-MWCNT content.