Multifunctional Properties of Polyhedral Oligomeric Silsesquioxanes (POSS)-Based Epoxy Nanocomposites

Abstract

In this study, a tetrafunctional epoxy resin was loaded with 5 wt% of three different types of polyhedral oligomeric silsesquioxane (POSS) compounds, namely, DodecaPhenyl POSS (DPHPOSS), Epoxycyclohexyl POSS (ECPOSS), Glycidyl POSS (GPOSS), and 0.5 wt% of multi-walled carbon nanotubes (CNTs) in order to formulate multifunctional structural nanocomposites tailored for aeronautic and aerospace applications. This work aims to demonstrate how the skillful combination of desired properties, such as good electrical, flame-retardant, mechanical, and thermal properties, is obtainable thanks to the advantages connected with nanoscale incorporations of nanosized CNTs with POSS. The special hydrogen bonding-based intermolecular interactions between the nanofillers have proved to be strategic in imparting multifunctionality to the nanohybrids. All multifunctional formulations are characterized by a Tg centered at values close to 260 °C, fully satisfying structural requirements. Infrared spectroscopy and thermal analysis confirm the presence of a cross-linked structure characterized by a high curing degree of up to 94% and high thermal stability. Tunneling atomic force microscopy (TUNA) allows to detect the map of the electrical pathways at the nanoscale of the multifunctional samples, highlighting a good dispersion of the carbon nanotubes within the epoxy resin. The combined action of POSS with CNTs has allowed to obtain the highest values of self-healing efficiency if compared to those measured for samples containing only POSS in the absence of CNTs.

A Comprehensive Review on the Thermal Stability Assessment of Polymers and Composites for Aeronautics and Space Applications

“…Owing to numerous advantages surpassing conventional materials like metals or ceramics [15,[100][101][102][103][104][105][106][107][108], epoxy composites are increasingly playing a primary role in the aeronautical and aerospace sectors. Some of their pivotal benefits include [109][110][111][112]:…”

“…Owing to numerous advantages surpassing conventional materials like metals or ceramics [ 15 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 ], epoxy composites are increasingly playing a primary role in the aeronautical and aerospace sectors. Some of their pivotal benefits include [ 109 , 110 , 111 , 112 ]: Exceptional strength-to-weight ratio, giving them a fusion of robustness and lightness, thus minimizing the overall weight and fuel consumption of aircrafts.…”

Thermo-Mechanical Performance of Epoxy Hybrid System Based on Carbon Nanotubes and Graphene Nanoparticles

“…Notably, even with a low amount of nanoparticles (0.1 wt%), the hybrid nanofiller concentration demonstrated a significant synergy, resulting in an increased cure degree for the hybrid epoxy samples compared to their single nanofiller counterparts, which had a higher percentage by weight (0.5 wt%) corresponding to the percentage above the EPT [6,9,39,40]. For instance, the sample EP 0.5% CNT exhibited a cure degree of 89% [41], while the sample EP 0.5% GN shows a cure degree of 86% [11]. In contrast, the unfilled resin EP exhibited a cure degree of 93% [41].…”

“…For instance, the sample EP 0.5% CNT exhibited a cure degree of 89% [41], while the sample EP 0.5% GN shows a cure degree of 86% [11]. In contrast, the unfilled resin EP exhibited a cure degree of 93% [41]. This result is particularly important as it shows that even with the lowest weight percentage (0.1 wt%) of the nanofiller mixture, it is possible to obtain hybrid formulations with cure degrees meeting the requirements imposed by the aeronautical industries, with values close to or even exceeding those exhibited by binary formulations based on a single nanofiller, loaded with the higher weight percentage of 0.5 wt%.…”

Flame-Retardant GF-PSB/DOPO-POSS Composite with Low Dk/Df and High Thermal Stability for High-Frequency Copper Clad Applications

“…The results suggested that POSS had great potential to be used as a modifier to decrease the Dk and Df of CCLs, ensuring high-frequency and high-speed information transmission in communication. Furthermore, the flame-retardant performance of the POSS could be improved by introducing tunable side groups such as P-containing, N-containing, B-containing, or aromatic groups [ 30 , 31 , 32 , 33 , 34 , 35 ].…”