A Molecular Understanding of the Flame Retardant Mechanism of Zinc Stannate/Polypropylene Composites via ReaxFF Simulations
Jun Li,
Meilin Zhu,
Chang Geng,
Yingjie Yuan,
Zewei Fu,
Shu Yan,
Rou Feng,
Yingwu Wang,
Ying Zhou,
Liangliang Meng,
Hui Zhang,
Hongcun Bai
Affiliations
Jun Li
Yunnan Tin Industry Group (Holding) Co., Ltd., R & D Center, Kunming 650200, China
Meilin Zhu
College of Basic Medical Sciences, Ningxia Medical University, Yinchuan 750004, China
Chang Geng
State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
Yingjie Yuan
Yunnan Tin Industry Group (Holding) Co., Ltd., R & D Center, Kunming 650200, China
Zewei Fu
Yunnan Tin Industry Group (Holding) Co., Ltd., R & D Center, Kunming 650200, China
Shu Yan
State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
Rou Feng
State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
Yingwu Wang
Yunnan Provincial Academy of Science and Technology, No. 488 Dianchi Road, Kunming 650051, China
Ying Zhou
Yunnan Provincial Academy of Science and Technology, No. 488 Dianchi Road, Kunming 650051, China
Liangliang Meng
State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
Hui Zhang
State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
Hongcun Bai
State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
As an important new flame retardant, zinc stannate (ZS) shows wide application prospects due to its many advantages. However, the flame retardant mechanism of composites made with polymer combined with ZS is still unclear. In particular, there is a lack of molecular level description of the micro-scale flame retardant mechanism. The combustion mechanism through molecular simulation technology has become an important research paradigm in the field of fire, which can provide new insights for the development of new materials. This work studied the flame retardant mechanism of composites consistent with polypropylene (PP) and ZS using reactive force field molecular dynamics (ReaxFF MD) simulations. A new force field incorporating Sn/Zn/C/H/O components for ZS/PP composites combustion reactions was developed. Twenty different ZS/PP composites were analyzed for their combustion reactions at various temperatures. To investigate the flame retarding mechanism of ZS in composites, the evolutions of reactants, products, and reaction intermediates at the molecular scale were collected. It was revealed that the combustion temperature controlled the degree of oxidation by regulating the consumption of molecular oxygen during PP cracking. An increased combustion temperature reduced the oxygen consumption rate and overall oxygen consumption. As the PP component of composites exceeded 56%, oxygen consumption increased. Evolutions for carbon-containing intermediates and the products in combustions of PP/ZS composites were analyzed. The small carbon-based fragments were more likely to be produced for composites with low PP contents at high temperatures. These results are beneficial to design ZS/PP composites as flame retardant materials.
