Effect of POSS-NH₂ functionalization of MWNTs on reinforcing properties in epoxy nanocomposites

Abstract

The research focuses on multiwalled carbon nanotubes (MWNTs) functionalization with aminoethyl aminopropyl polyhedral oligomeric silsesquioxane to increase their compatibility with epoxy polymers and enhancement of interface adhesion. Functionalization of MWNTs consisted of a three-stage reaction by oxidation and further amidation through acylation with thionyl chloride. The new nanomaterials were dispersed as reinforcing agent in a weight ratio of 0.3% related to the epoxy matrix, which was further cured with an aromatic polyamine. Characterization of functionalized MWNTs by infrared spectroscopy revealed the presence of POSS cages bonded to the MWNTs through the formation of amide groups, these findings were also proved by transmission electron microscopic images. Although catalytic influence of the reinforcing agent on the curing reaction was not significant at this level of reinforcement, scanning electron microscopic images of the nanocomposites fracture surface revealed strong interfacial adhesion and crack retardant effect of POSS-functionalized MWNTs.

A facile approach to the synthesis of multi-walled carbon nanotube-polyhedral oligomeric silsesquioxane (POSS) nanohybrids

“…Recently, the functionalization of MWCNTs with POSS reagents has been found to significantly improve the mechanical, thermal and electrical properties of MWCNT-polymer nanocomposites [4][5][6][7][8]. Li et al [4] reported an improved dispersion of MWCNTs throughout a poly(L-lactide) polymer after POSS-treatment of nanotubes, resulting in a higher tensile modulus, yield strength and electromagnetic interference shielding effectiveness.…”

“…The dielectric properties of composite was enhanced by controlling the thickness of the POSS layer. The Incorporation of a small amount of POSS-MWCNT hybrid into an epoxy polymer was found to improve the thermal properties of neat polymer [6]. The grafting of POSS-CNT onto carbon fiber (CF) surface and the interfacial properties between CF and epoxy matrix was also studied [7,8].…”

Effects of carbon nanotube/polymer interfacial bonding on the long‐term creep performance of nanophased glass fiber/epoxy composites

“…As per Iovu et al, functionalization of CNT with polyhedral silsesquioxane‐[3‐(2‐aminoethyl)amino] propyl‐heptaisobutyl (POSS‐NH 2 ) substitute lead to increase in T g of epoxy composite due to the stiffness of the POSS cages and better crack pinning and crack retardant effect was observed. As reported by Deng et al,Multi‐walled Nanotube (MWNTs) showed well dispersion in polymer matrix when observed in scanning electron microscope and transmission electron microscope images.…”

Superior thermomechanical and wetting properties of ultrasonic dual mode mixing assisted epoxy-CNT nanocomposites

“…5 CNTs-reinforced polymer matrices became attractive structural composite materials for various industries such as aerospace, automobile, marine, defense armor, civil engineering, and sporting goods. [6][7][8][9][10][11][12][13][14] Epoxy-CNT nanocomposites were first time reported in 1994 15 and thereafter many researchers' reported the improved thermal and mechanical properties of the epoxy-CNT nanocomposites. [16][17][18][19] CNTs are generally nonreactive because of their defect-free smooth structure of sidewall aromatic rings.…”