Fabrication of green alginate-based and layered double hydroxides flame retardant for enhancing the fire retardancy properties of polypropylene

2020 ◽  
Vol 234 ◽  
pp. 115891 ◽  
Author(s):  
Sheng Xu ◽  
Si-Yu Li ◽  
Min Zhang ◽  
Hong-Yan Zeng ◽  
Kun Wu ◽  
...  
Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 801 ◽  
Author(s):  
Kai Zhu ◽  
Yunhe Wang ◽  
Daquan Tang ◽  
Qiang Wang ◽  
Haihang Li ◽  
...  

The flame retardancy of asphalt binders with layered double hydroxides (LDHs) was investigated using limiting oxygen index (LOI) and cone calorimeter tests. The flame-retardant mechanism of the LDHs was also studied with thermogravimetry and differential scanning calorimetry (TG–DSC), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The cone calorimeter testing results indicated that 2 wt.% of the LDHs can decease the peak heat and smoke release rate of asphalt binders. Because a low dose of LDHs can be well dispersed in asphalt binder and favor the formation of polyaromatic structures during combustion, the thermal oxidation resistance and compactness of the char layer can be improved. The LOI of asphalt binder can be increased and the heat and smoke release during combustion can be decreased with 25 wt.% LDHs. The decomposition of LDHs can absorb the heat release of the initial two stages of asphalt combustion and reduce the burning rate of asphalt. Due to the loss of loosely bound water in the LDHs during the blending process and the decrease of dispersibility at a high LDH dose, the improvement of thermal stability is limited.


2018 ◽  
Vol 47 (42) ◽  
pp. 14827-14840 ◽  
Author(s):  
Yuan Liu ◽  
Yanshan Gao ◽  
Qiang Wang ◽  
Weiran Lin

The current synergistic effect and mechanism between LDHs and other flame retardant additives for polymers are summarized.


2017 ◽  
Vol 31 (10) ◽  
pp. 1295-1309 ◽  
Author(s):  
Yi Qian ◽  
Shaojie Zhou ◽  
Xilei Chen

Layered double hydroxides (LDHs) were synthesized by a coprecipitation method. The synergistic flame retardant effect of nano-silicon dioxide (nano-SiO2) on ethylene vinyl acetate (EVA)/LDHs composites was studied using limiting oxygen index (LOI), cone calorimeter test (CCT), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Results showed that the LOI values of the EVA/LDHs/nano-SiO2 composites were basically higher than that of the EVA/LDHs composite, and the EVA composite with 48% LDHs and 2% nano-SiO2 reached an LOI value of up to 31.2%. The CCT results indicate that the addition of nano-SiO2 greatly reduced the heat release rate, total heat release, mass loss, smoke production rate, total smoke release, and smoke factor. The morphology and structures of residues investigated by SEM gave positive evidence that char layers formed from the EVA/LDHs/nano-SiO2 composites were improved. The TGA data showed that the EVA/LDHs/nano-SiO2 composites show a higher thermal stability than the EVA/LDHs composites.


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