Flame retardant properties of expandable polystyrene composite insulation materials

Flame Retardant Properties of Expandable Polystyrene Composite Insulation Materials Zeng You, Yan Ying, Zheng Yaxuan, Xie Guiyuan, Yan, Liu Yunxue (School of Materials Science and Engineering, Shenyang Jianzhu University, Shenyang 110168, China) with flame retardant effect, thermal insulation properties and mechanics The impact of performance. Provided for the development of building energy-saving insulation materials. The foamed polystyrene composite thermal insulation material was prepared by pre-blending the composite flame retardant on the surface of the pre-expanded polystyrene beads, and the polystyrene composite sheet was formed by steam hot pressing, and observed by scanning electron microscopy. Thermal analysis, flame retardant performance test, thermal conductivity and mechanical properties test, comprehensive evaluation and analysis of composite sheet properties. Results The polystyrene composite sheet with decabromodiphenyl ether/antimony oxide/expandable graphite has excellent flame retardancy (only 1.3s from the fire self-extinguishing time), which is due to the porous structure of expanded graphite. The non-combustible gas decomposed by the flame retardant is effectively restrained and the flame retarding efficiency is remarkably improved. At the same time, polystyrene composite sheets have superior thermal insulation properties and mechanical properties. Considering the influence of the addition of the composite flame retardant on the mechanical properties and process performance, the flame retardant is added in an amount of 15% (mass fraction) of decabromodiphenyl ether/antimony trioxide and 11% of expandable graphite. Conclusion The polystyrene composite sheet prepared by the flame retardant coating method has obvious advantages of obvious flame retardant effect, convenient operation and good controllability of performance.

Fund Project: National Natural Science Foundation of China (51072122); Excellent Personnel Project of Liaoning Provincial Department of Education (LQ2011060); EPS composite of DBDPO/Sb2O3 flame retardant compared with the smooth surface of pure EPS sheet burning products of Liaoning Provincial Department of Education The residual product in the remaining product after burning of the sheet exhibits obvious pore structure, which is caused by the continuous escape and diffusion of the non-combustible gas generated by the bromine-based flame retardant during the decomposition process; compared with the EPS composite containing the EG composite flame retardant The combustion products in the sheet have abundant pore structure and carbon layer inclusion morphology, which can bind the non-combustible gas generated by the decomposition of the flame retardant into the pores, reduce the diffusion and escape to the outside, and significantly improve the polymerization of the non-combustible gas. The surface aggregation and isolation effect greatly improves the flame retardant efficiency, which greatly shortens the self-extinguishing time of the EPS composite sheet (such as the thermal stability of the burned carbon microstructure 2.3EPS composite sheet is pure EPS and added Thermal weight loss curve of EPS sheet of EG composite flame retardant under air atmosphere.

It can be seen that the thermal decomposition temperature of pure EPS in air is about 330 ° C, compared with the thermal weight loss behavior of EPS sheet with EG composite flame retardant, there is no significant difference, and the decomposition temperature is only 330C, indicating that the addition of EG composite flame retardant did not significantly improve the thermal stability of EPS. Although it can be seen from the middle, the addition of EG composite flame retardant can significantly improve the self-extinguishing performance of EPS sheet, but the contribution of EG composite flame retardant to EPS flame retardant does not substantially improve the thermal decomposition stability of EPS. Sex, but through the surface of the non-combustible gas generated by the decomposition of the flame retardant, to isolate the fire source, to isolate the flame retardant effect of air, which is consistent with the results reported by other M. 4EG dosage to EPS composite The influence of the thermal conductivity of the sheet is the effect of the amount of EG on the thermal conductivity of the EPS composite sheet. It can be seen that as the EG content continues to increase, the thermal conductivity of the composite sheet tends to increase slowly, which is due to the higher thermal conductivity of EG compared to EPS. It is worth noting that when the EG addition amount reaches 17.2%, the thermal conductivity of the EPS composite sheet is 0.02785Wm, I, which is only 1.9% higher than that of the EPS sheet without EG added, indicating that the EG has not been added. Significantly improve the thermal conductivity of EPS sheets. This is because although the addition amount (mass fraction) of the EG composite flame retardant is as high as 30%, the volume fraction of the EPS composite sheet is only 0.7%, and the main body of the thermal insulation is foam polyphenylene. Ethylene, so the addition of EG does not significantly increase the thermal conductivity of the composite sheet. It can be seen that the addition of EG significantly improves the thermal insulation performance of the EPS composite sheet while significantly improving the flame retardant effect.

The effect of 2.5EG content on the compression modulus of EPS composite sheet is the compression modulus curve of EPS composite sheet with different EG content. It can be seen that EPS composite sheet with EG is added compared with EPS composite sheet without EG. The compressive modulus is significantly reduced from the initial 14.8 MPa to 7 MPa. Theoretically, the compression modulus of EG is usually much higher than EPS, and the addition of EG will play a mechanical reinforcement role, but it can be seen from this. The addition of EG reduces the compression modulus of the EPS composite sheet, which is closely related to the decrease in the bond strength between the EPS beads. The forming of EPS sheet is to make the surface of EPS bead melt and bond together by hot pressing steam. Once the inorganic flame retardant such as EG is added to the surface of the bead, the fusion bonding ability of EPS bead surface is reduced, and it is impossible to form dense. The interface is bonded, which reduces the overall mechanical properties of the composite sheet. In the experiment, as the content of EG increases and the bonding performance decreases, the compressive modulus of the composite sheet decreases. Therefore, while adding flame retardant to improve the flame retardant performance, it is necessary to take into account the bond mechanical strength and other comprehensive properties of the EPS composite sheet. In the experiment, the suitable amount of EPS composite sheet flame retardant is: DBDPO/Sb2O3 3 Conclusion The composite flame retardant surface coating method can be used to obtain EPS composite sheet with high flame retardant performance. It can be reduced to 1.3 s due to the high efficiency flame retardant synergistic effect of expandable graphite with decabromodiphenyl ether / antimony trioxide.

The addition of EG composite flame retardant does not significantly improve the thermal stability of EPS sheets. The high-efficiency flame retardant effect on EPS sheets is mainly manifested by the high porosity and high specific surface area of ​​expanded graphite to bind the non-combustible gases generated by the decomposition of flame retardants. And coating, greatly reducing the diffusion and loss of non-combustible gas, thereby significantly improving the flame retardant effect.

The added EPS composite sheet has high flame retardant performance while maintaining high insulation performance. Considering the influence of the addition of composite flame retardant on mechanical properties and process performance, the amount of flame retardant added is decabromo Phenyl ether / antimony trioxide 15%, expandable graphite 11% is preferred.

Acknowledgement: Thanks to Chen Yanwen and Gao Fei for their help in thermal conductivity and thermogravimetric testing; thanks to Wu Chao, Qi Xuhui and Zhao Lijia for their help in experimental preparation and data analysis.

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