Zhang Zhuoran, Cao Huaixuan, Quan Yufeng, Ma Rong, Pentzer Emily B, Green Micah J, Wang Qingsheng
Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA.
Department of Materials Science and Engineering, Texas A&M University, College Station, TX 77843, USA.
Polymers (Basel). 2022 Mar 17;14(6):1213. doi: 10.3390/polym14061213.
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-TiC) was applied to PS as a nanofiller. Firstly, the MXene nanosheets were prepared by acid etching, intercalation, and delamination of bulk MAX (TiAlC) 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-TiC (e.g., 2 wt%), the resulting PS nanocomposite (PS/O-TiC) 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 (T) 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-TiC 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.
聚苯乙烯（PS）在塑料工业中被广泛使用，但由于其固有的高易燃性，PS的应用范围受到限制。据报道，多种二维（2D）纳米材料能赋予聚合物材料优异的阻燃性。在本研究中，一种二维纳米材料MXene-有机杂化物（O-TiC）作为纳米填料被应用于PS。首先，通过对块状MAX（TiAlC）材料进行酸蚀刻、插层和剥离来制备MXene纳米片。然后使用阳离子表面活性剂对这些剥离的MXene纳米片进行功能化处理，以提高其在N，N-二甲基甲酰胺（DMF）中的分散性。即使功能化的O-TiC负载量很小（例如2 wt%），通过热重分析（TGA）和热解-燃烧流动量热法（PCFC）证明，所得的PS纳米复合材料（PS/O-TiC）仍表现出良好的热稳定性和较低的易燃性。与纯PS样品相比，峰值热释放速率（pHRR）显著降低了32%。此外，我们观察到pHRR时的温度（T）升高了22℃。通过比较PS/MAX与不同重量比的PS/O-TiC纳米复合材料之间的TGA和PCFC结果，发现MXene-有机杂化纳米片的热稳定性以及二维热质传递阻隔效应在延缓聚合物降解中起着至关重要的作用。
