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Preparation of zinc hydroxystannate-decorated graphene oxide nanohybrids and their synergistic reinforcement on reducing fire hazards of flexible poly (vinyl chloride).

Gao T, Chen L, Li Z, Yu L, Wu Z, Zhang Z - Nanoscale Res Lett (2016)

Bottom Line: A novel flame retardant, zinc hydroxystannate-decorated graphene oxide (ZHS/GO) nanohybrid, was successfully prepared and well characterized.In addition, the addition of ZHS/GO nanohybrids decreased the smoke products and increased the tensile strength of PVC.Above-excellent flame-retardant properties are generally attributed to the synergistic effect of GO and ZHS, containing good dispersion of ZHS/GO in PVC matrix, the physical barrier of GO, and the catalytic char function of ZHS.

View Article: PubMed Central - PubMed

Affiliation: National & Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials, Henan University, Kaifeng, 475004, People's Republic of China.

ABSTRACT
A novel flame retardant, zinc hydroxystannate-decorated graphene oxide (ZHS/GO) nanohybrid, was successfully prepared and well characterized. Herein, the ZHS nanoparticles could not only enhance the flame retardancy of GO with the synergistic flame-retardant effect of ZHS but also prevent the restack of GO to improve the mechanical properties of poly (vinyl chloride) (PVC) matrix. The structure characterization showed ZHS nanoparticles were bonded onto the surface of GO nanosheets and the ZHS nanoparticles were well distributed on the surface of GO. Subsequently, resulting ZHS/GO was introduced into flexible PVC and fire hazards and mechanical properties of PVC nanocomposites were investigated. Compared to neat PVC, thermogravimetric analysis exhibited that the addition of ZHS/GO into PVC matrix led to an improvement of the charring amount and thermal stability of char residue. Moreover, the incorporation of 5 wt.% ZHS/GO imparted excellent flame retardancy to flexible PVC, as shown by increased limiting oxygen index, reduced peak heat release rate, and total heat release tested by an oxygen index meter and a cone calorimeter, respectively. In addition, the addition of ZHS/GO nanohybrids decreased the smoke products and increased the tensile strength of PVC. Above-excellent flame-retardant properties are generally attributed to the synergistic effect of GO and ZHS, containing good dispersion of ZHS/GO in PVC matrix, the physical barrier of GO, and the catalytic char function of ZHS.

No MeSH data available.


Related in: MedlinePlus

Schematic representation of the mechanism for the improved fire-resistant properties of the ZHS/GO/PVC nanocomposite, showing that the synergistic effect between ZHS and GO can better improve the flame-retardant performance of PVC
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Fig10: Schematic representation of the mechanism for the improved fire-resistant properties of the ZHS/GO/PVC nanocomposite, showing that the synergistic effect between ZHS and GO can better improve the flame-retardant performance of PVC

Mentions: The flammability of polymer materials is commonly characterized by cone calorimeter, which is very effective to evaluate their flame-retardant properties under real-world fire conditions. Heat release rate (pHRR), total heat release (THR), smoke production rate (SPR), and total smoke release (TSR) curves for PVC and its composites are shown in Fig. 9, and some important parameters are listed in Table 2. As shown in Fig. 9a, incorporating 5 wt.% ZHS or GO into PVC generates pHRR decrease to 242.5 and 327.1 kW/m2, corresponding to a 35.7 and 13.2 % reduction compared to pure PVC, respectively. The pHRR and THR for ZHS/GO/PVC show a further decrease compared to the GO/PVC or ZHS/PVC, which are just 185.5 and 33.45 kW/m2 corresponding to a 50 and 59.7 % reduction to pure PVC, respectively. In addition, the samples having ZHS/GO nanohybrids show the lowest SPR, TSR, and AMLR compared to other nanocomposites, which conforms well to the TGA, pHRR, and THR results. The superior flame retardancy of ZHS/GO/PVC mainly includes three reasons: the barrier effect of GO, which retards the permeation of heat and the escape of volatile degradation products; the catalytic carbonization effect of ZHS to form more and better chars, which decrease the flammability of PVC; and the ZHS-contained Zn element should play an important role to eliminate volatile organic compounds and toxic gases during combustion reactions [27]. The proposed mechanism for the improved fire-resistant properties of the ZHS/GO/PVC nanocomposite is illustrated in Fig. 10. During the combustion process, the ZHS nanoparticles loaded on GO prevent the GO from re-stacking and result in the good dispersion. Meanwhile, GO can function as a physical barrier to absorb degradation products and extend contact time with ZHS catalyst. Degradation products continually collect on the GO, which serves as a template for the formation of char. Furthermore, the degradation products are catalytically converted into char by the combination of the physical barrier effect of GO and the catalytic effect of ZHS.Fig. 10


Preparation of zinc hydroxystannate-decorated graphene oxide nanohybrids and their synergistic reinforcement on reducing fire hazards of flexible poly (vinyl chloride).

Gao T, Chen L, Li Z, Yu L, Wu Z, Zhang Z - Nanoscale Res Lett (2016)

Schematic representation of the mechanism for the improved fire-resistant properties of the ZHS/GO/PVC nanocomposite, showing that the synergistic effect between ZHS and GO can better improve the flame-retardant performance of PVC
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4829567&req=5

Fig10: Schematic representation of the mechanism for the improved fire-resistant properties of the ZHS/GO/PVC nanocomposite, showing that the synergistic effect between ZHS and GO can better improve the flame-retardant performance of PVC
Mentions: The flammability of polymer materials is commonly characterized by cone calorimeter, which is very effective to evaluate their flame-retardant properties under real-world fire conditions. Heat release rate (pHRR), total heat release (THR), smoke production rate (SPR), and total smoke release (TSR) curves for PVC and its composites are shown in Fig. 9, and some important parameters are listed in Table 2. As shown in Fig. 9a, incorporating 5 wt.% ZHS or GO into PVC generates pHRR decrease to 242.5 and 327.1 kW/m2, corresponding to a 35.7 and 13.2 % reduction compared to pure PVC, respectively. The pHRR and THR for ZHS/GO/PVC show a further decrease compared to the GO/PVC or ZHS/PVC, which are just 185.5 and 33.45 kW/m2 corresponding to a 50 and 59.7 % reduction to pure PVC, respectively. In addition, the samples having ZHS/GO nanohybrids show the lowest SPR, TSR, and AMLR compared to other nanocomposites, which conforms well to the TGA, pHRR, and THR results. The superior flame retardancy of ZHS/GO/PVC mainly includes three reasons: the barrier effect of GO, which retards the permeation of heat and the escape of volatile degradation products; the catalytic carbonization effect of ZHS to form more and better chars, which decrease the flammability of PVC; and the ZHS-contained Zn element should play an important role to eliminate volatile organic compounds and toxic gases during combustion reactions [27]. The proposed mechanism for the improved fire-resistant properties of the ZHS/GO/PVC nanocomposite is illustrated in Fig. 10. During the combustion process, the ZHS nanoparticles loaded on GO prevent the GO from re-stacking and result in the good dispersion. Meanwhile, GO can function as a physical barrier to absorb degradation products and extend contact time with ZHS catalyst. Degradation products continually collect on the GO, which serves as a template for the formation of char. Furthermore, the degradation products are catalytically converted into char by the combination of the physical barrier effect of GO and the catalytic effect of ZHS.Fig. 10

Bottom Line: A novel flame retardant, zinc hydroxystannate-decorated graphene oxide (ZHS/GO) nanohybrid, was successfully prepared and well characterized.In addition, the addition of ZHS/GO nanohybrids decreased the smoke products and increased the tensile strength of PVC.Above-excellent flame-retardant properties are generally attributed to the synergistic effect of GO and ZHS, containing good dispersion of ZHS/GO in PVC matrix, the physical barrier of GO, and the catalytic char function of ZHS.

View Article: PubMed Central - PubMed

Affiliation: National & Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials, Henan University, Kaifeng, 475004, People's Republic of China.

ABSTRACT
A novel flame retardant, zinc hydroxystannate-decorated graphene oxide (ZHS/GO) nanohybrid, was successfully prepared and well characterized. Herein, the ZHS nanoparticles could not only enhance the flame retardancy of GO with the synergistic flame-retardant effect of ZHS but also prevent the restack of GO to improve the mechanical properties of poly (vinyl chloride) (PVC) matrix. The structure characterization showed ZHS nanoparticles were bonded onto the surface of GO nanosheets and the ZHS nanoparticles were well distributed on the surface of GO. Subsequently, resulting ZHS/GO was introduced into flexible PVC and fire hazards and mechanical properties of PVC nanocomposites were investigated. Compared to neat PVC, thermogravimetric analysis exhibited that the addition of ZHS/GO into PVC matrix led to an improvement of the charring amount and thermal stability of char residue. Moreover, the incorporation of 5 wt.% ZHS/GO imparted excellent flame retardancy to flexible PVC, as shown by increased limiting oxygen index, reduced peak heat release rate, and total heat release tested by an oxygen index meter and a cone calorimeter, respectively. In addition, the addition of ZHS/GO nanohybrids decreased the smoke products and increased the tensile strength of PVC. Above-excellent flame-retardant properties are generally attributed to the synergistic effect of GO and ZHS, containing good dispersion of ZHS/GO in PVC matrix, the physical barrier of GO, and the catalytic char function of ZHS.

No MeSH data available.


Related in: MedlinePlus