Xu Jie, Liu Xiangrong, Yao Xuehui, Chen Liqing, Guo Fanhui, Zhang Yixin, Xie Zhipeng, Liang Feng, Wu Jianjun
College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, Xi'an 710054, China.
School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China.
Int J Biol Macromol. 2024 Aug 5:134442. doi: 10.1016/j.ijbiomac.2024.134442.
The principal component of cotton fibers is the cellulose biological macromolecule. However, its highly flammable nature has significantly constrained its utilization in fields where flame retardancy is essential. Herein, in this work, a highly effective binary composite flame retardant coating (APP/MEL-SWCNHs) with ammonium polyphosphate and modified single-walled carbon nanohorns (MEL-SWCNHs) was chemically attached to cotton fabric. With the add-on of 11.3 %, the treated cotton fabric (APP/MEL-SWCNHs)4 exhibited remarkable flame-retardant and self-extinguishing properties. Its LOI value increased to 23.7 ± 0.1 %, and the damage length was significantly reduced from 30.0 ± 0.1 % cm to 7.9 ± 0.1 % cm compared to the pristine cotton fabric. Despite partial carbonization, (APP/MEL-SWCNHs)4 preserved its original structure. Importantly, in the cone calorimeter test, both the pHRR and THR of (APP/MEL-SWCNHs)4 were drastically decreased by 71.8 % and 35.8 %, respectively. The APP/MEL-SWCNHs coating functioned as a flame retardant by inhibiting the emission of flammable volatiles, releasing non-flammable gases, and encouraging the formation of char layer during combustion. Significantly, thermal degradation kinetic analysis revealed that the third-order kinetic equation (O3) was found to have the strongest correlation with (APP/MEL-SWCNHs)4 in both air and N atmospheres. The higher activation energy (E) for (APP/MEL-SWCNHs)4 confirmed that incorporating MEL-SWCNHs improved the thermal stability of the char layer.
棉纤维的主要成分是纤维素生物大分子。然而，其高度易燃的特性严重限制了它在阻燃至关重要的领域的应用。在此工作中，一种由聚磷酸铵和改性单壁碳纳米角（MEL-SWCNHs）组成的高效二元复合阻燃涂层被化学附着在棉织物上。添加量为11.3%时，处理后的棉织物（APP/MEL-SWCNHs）4表现出显著的阻燃和自熄性能。其极限氧指数（LOI）值提高到23.7±0.1%，与原始棉织物相比，损毁长度从30.0±0.1%厘米显著降低到7.9±0.1%厘米。尽管有部分碳化，（APP/MEL-SWCNHs）4仍保留了其原始结构。重要的是，在锥形量热仪测试中，（APP/MEL-SWCNHs）4的峰值热释放速率（pHRR）和热释放总量（THR）分别大幅降低了71.8%和35.8%。APP/MEL-SWCNHs涂层通过抑制可燃挥发物的释放、释放不可燃气体以及促进燃烧过程中炭层的形成来起到阻燃作用。值得注意的是，热降解动力学分析表明，在空气和氮气气氛中，三阶动力学方程（O3）与（APP/MEL-SWCNHs）4的相关性最强。（APP/MEL-SWCNHs）4较高的活化能（E）证实了加入MEL-SWCNHs提高了炭层的热稳定性。
