Nanocomposite of Polyacrylonitrile/Modified Polyethersulfone and Carbon Nano-onion: Effect of Dispersion on Physical Features, Interface and Fracture Behavior

Abstract

In this effort, novel blend of polyacrylonitrile and modified polyethersulfone (PAN/mod-PES) were designed. Two series of nanocomposite were prepared using resin infiltration technique with 0.5-5wt.% carbon nano-onion (CNO) and functional carbon nano-onion (F-CNO) i.e. PAN/mod-PES/CNO 0.5-5 and PAN/mod-PES/F-CNO 0.5-5. Microstructure studies revealed pattern of small beads homogeneously dispersed in form of arrays. Inclusion of 5wt.% nanofiller decreased molecular weight of PAN/mod-PES/CNO 5 and PAN/mod-PES/F-CNO 5 to 110 × 10³ and 71 × 10³g/mol, respectively, relative to neat blend (160 × 10³g/mol). Shear stress of PAN/mod-PES/F-CNO 0.5-5 was found higher than neat blend. Thermal stability of functional nanocomposite was considerably enhanced with nanofiller loading compared with non-functional CNO and attained V-0 rating. Maximum thermal stability was achieved with 5wt.% F-CNO content i.e. T₀, T₁₀, and T_max of 503, 539, and 615 °C, respectively. Higher functional nanofiller loading also enhanced tensile, flexural, and impact strength of nanocomposite up to 63, 189, and 9.7 J/m. Fracture toughness of PAN/mod-PES/F-CNO also significantly improved with bonding time and annealing temperature owing to intermolecular reactions, molecular diffusion occurring at interface, and bonding mechanism. At 200 °C, energy of adhesion attained high value of 930 J/m² (1h). Besides, PAN/mod-PES with 5 wt.% F-CNO own higher K_IC of 0.87MPa m^0.5 among nanocomposite.

Graphical Abstract

Keywords:

• Polyacrylonitrile
• polyethersulfone
• carbon-nano-onion
• dispersion
• fracture toughness