Thermal Stability and Flammability Studies of MXene–Organic Hybrid Polystyrene Nanocomposites

Abstract

Polystyrene (PS) is widely used in the plastics industry, but the application range of PS is limited due to its inherently high flammability. A variety of two-dimensional (2D) nanomaterials have been reported to impart excellent flame retardancy to polymeric materials. In this study, a 2D nanomaterial MXene–organic hybrid (O-Ti3C2) was applied to PS as a nanofiller. Firstly, the MXene nanosheets were prepared by acid etching, intercalation, and delamination of bulk MAX (Ti3AlC2) material. These exfoliated MXene nanosheets were then functionalized using a cationic surfactant to improve the dispersibility in DMF. Even with a small loading of functionalized O-Ti3C2 (e.g., 2 wt%), the resulting PS nanocomposite (PS/O-Ti3C2) showed good thermal stability and lower flammability evidenced by thermogravimetric analysis (TGA) and pyrolysis-combustion flow calorimetry (PCFC). The peak heat release rate (pHRR) was significantly reduced by 32% compared to the neat PS sample. In addition, we observed that the temperature at pHRR (TpHRR) shifted to a higher temperature by 22 °C. By comparing the TGA and PCFC results between the PS/MAX and different weight ratios of PS/O-Ti3C2 nanocomposites, the thermal stability and 2D thermal- and mass-transfer barrier effect of MXene–organic hybrid nanosheets were revealed to play essential roles in delaying the polymer degradation.

Effect of ultra-sonication, vacuum drying, and carbon coating on the super-capacitive behavior of Ti3C2T x MXene

“…To investigate the potential entrapment of H 2 O molecules within the MXene structure, TGA analysis was conducted on the sonicated samples over a temperature range of 25 • C to 450 • C. The results are presented in figure 3(c). In the TGA analysis, all the samples had a mass loss of less than 1.5 wt% up to 450 • C. Based on the literature, the mass loss around 100 • C is attributed to the presence of water residues [4,57]. In this work, the mass loss was lower than 0.5 wt% for all four samples, indicating the presence of a very low concentration of water in their structure.…”

“…In this work, the mass loss was lower than 0.5 wt% for all four samples, indicating the presence of a very low concentration of water in their structure. The gradual drop afterward, observable in all examined samples, can be attributed to the detachment of unstable surface atoms such as -OH, -O, and -F [57]. The gradual loss from 150 • C to 400 • C, which is more prominent in S-A-25 • C and S-V-25 • C, is consistent with the TGA curve of O-Ti 3 C 2 (oxidized Ti 3 C 2 T x ) reported in [57].…”

Comparative Study of Octavinyl Oligomeric Sesquisiloxane Nanomaterial-Modified Asphalt Using Molecular Dynamics Method

“…It is generally accepted that nanomaterial exhibits a large specific surface area which is closely related to its uniquely small size [ 47 , 48 , 49 ]. For this study, the smaller the size of nano-OvPOSS, the larger the specific surface area, and thus the larger the contact range between asphalt molecules and organic groups on the surface of OvPOSS nanoparticles.…”

Study on the Influence of Nano-OvPOSS on the Compatibility, Molecular Structure, and Properties of SBS Modified Asphalt by Molecular Dynamics Simulation

“…The eight ethylene organic branches of nano-OvPOSS are capable of interacting with the active groups of polymers, which is why nano-OvPOSS is able to improve the compatibility between SBS and asphalt. It is well accepted that the outstanding performance of nanomaterial, such as their large specific surface area and high strain resistance, attributes to their unique small size [ 46 , 47 , 48 ]. It is also accepted that the smaller the size of nanomaterial, the larger their specific surface area will be.…”