Synergistic effect of single wall carbon nanotubes/graphene oxide hybrid nano-filler on thermal stabilization and tensile strength of polyacrylonitrile copolymer

Abstract

This study reports how hybrid nano-filler can enhance the tensile strength, electrical properties and thermal stabilization of PAN (polyacrylonitrile) nanocomposite films. The nano-fillers used are graphene oxide (GO), single-wall carbon nanotubes (SWCNT), and a hybrid of both. The combination of both nano-fillers was made by dispersing GO in DMAc (dimethyl acetamide) and then adding SWCNT to the solution. The solution was mixed well using ultrasonication and high-speed stirring. 1 wt% amount of nano-filler solutions was added to PAN liquid to make PAN nanocomposite films. The films were tested for mechanical properties, electrical resistivity, thermoxidative stabilization, and thermal stability. The results showed that adding nano-fillers to PAN significantly improved its tensile strength. GO increased the tensile strength by 42.9% (38.3 MPa), while SWCNT increased it by 57.3% (42.15 MPa). The combination of both (0.5 wt% SWCNT + 0.5 wt% GO) had a remarkable effect, increasing the tensile strength by 96% (52.53 MPa). This was because the combination of both prevented SWCNT from agglomerating together and made it interact better with the PAN, forming a complete network. The combination of both also made the PAN oxidize and stabilize early and efficiently during heating, which made its residual weight increase by ~5.5% more than pristine PAN in TGA. The electrical resistivity and SEM micrograph data correlate with the thermal analysis data, showing that PCG (1 wt% combination) reached the percolation threshold because of the benefits of both GO and SWCNT. The combination of both also showed 95.6% synergy in tensile strength compared to individual nano-fillers, indicating its potential for efficient reinforcement. Highlights: Hybrid filler boosts PAN strength from 26.8 to 52.53 MPa, surpassing PC, PG. TGA: ~5.5 wt% increased residual weight in 1 wt% hybrid-reinforced PCG composites. Hybrid undergoes GO decomposition, early oxidation and improved stabilization. PCG composite: Enhanced oxidation, improved stabilization via SWCNT network. PC & PCG composites show low volumetric resistivity due to SWCNT network. © 2023 Society of Plastics Engineers.