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矿用充填堵漏风新型复合泡沫的研制

Study on a New Composite Foam for Air-leakage Blocking in Mine

【作者】 胡相明

【导师】 王德明;

【作者基本信息】 中国矿业大学 , 安全技术及工程, 2013, 博士

【摘要】 煤炭自燃是影响矿井安全开采的主要灾害之一,控制漏风是防治煤炭自燃的关键手段。有机固化泡沫依靠其施工速度快,密封效果好等特点在国内外广泛应用于煤矿充填堵漏风。然而,现有的有机固化泡沫都存在不同程度的缺陷,如聚氨酯泡沫成本高、易燃、且燃烧释放出有毒烟气,酚醛泡沫脆性大、成本较高,脲醛泡沫的抗压强度低等。本文针对现有矿用有机固化泡沫的不足,研制了一种充填堵漏风新型复合泡沫,该泡沫具有密闭性好、抗压强度高、难燃、成本低等优点。本文以苯酚、脲素和多聚甲醛为聚合单体通过一步法创新性的合成了酚-脲-醛树脂。采用正交试验分析了脲素用量、催化剂用量、反应温度、反应时间对树脂发泡性能的影响规律,得出了酚-脲-醛树脂合成的最佳条件。通过红外光谱和核磁共振碳谱分析了酚-脲-醛树脂的化学结构,揭示了酚-脲-醛共聚树脂的合成机理。为优化酚-脲-醛树脂的催化体系,论文研究了不同固化剂、表面活性剂、发泡剂等对泡沫固化行为、力学性能和微观结构的影响规律,找出了最优的固化剂、表面活性剂、发泡剂配比及用量,揭示了固化剂和表面活性剂对泡沫的作用机理,探讨了酚-脲-醛树脂的成泡和固化机制。针对酚-脲-醛泡沫韧性差的问题,通过添加聚乙二醇(PEG)对酚-脲-醛泡沫进行改性,研究了不同分子量的PEG对酚-脲-醛泡沫的基本性能、力学特性、燃烧性能的影响规律,揭示了聚乙二醇的增韧机理,找到了聚乙二醇的最优添加量。PEG中的-OH与树脂中的-OH能够形成部分氢键,在树脂中导入长的柔性醚链,从而提高了泡沫的韧性和冲击强度,降低了粉化率。为了提高泡沫的阻燃性和承压强度,通过玻璃纤维与纳米粘土对酚-脲-醛泡沫进行改性,制备了玻璃纤维/纳米粘土复合泡沫,研究了玻璃纤维和纳米粘土对泡沫的力学特性、密封性能、热稳定性和阻燃性的影响规律,探讨了玻璃纤维与纳米粘土对酚-脲-醛泡沫的阻燃、增强机理。玻璃纤维与纳米粘土表现出良好的协同作用,能显著提高泡沫的压缩强度、热稳定性和阻燃性,降低泡沫的粉化率和收缩率,并改善复合泡沫的泡孔结构,提高泡沫的密封性能。为了验证实验室制备复合泡沫的性能,本文对比分析了酚醛泡沫、聚氨酯泡沫、脲醛泡沫与复合泡沫的综合性能。实验表明:四种泡沫中复合泡沫具有最低的发泡温度和收缩率,最高的抗压强度、阻燃性和热稳定性,但是,其发泡倍数和粉化率略低于聚氨酯泡沫。煤矿井下的工程实践表明,复合泡沫具有充填密闭效果好、施工简单、安全可靠、成本低等特点,极具广泛的应用前景。

【Abstract】 The spontaneous combustion of coal is one of major natural disasters in coal mines ofChina. Controlling air-leakage is the key to prevention of coal spontaneous combustion.Organic curing foams are widely used to filling and air-leakage blocking in mine at home andabroad due to its rapid construction and good sealing. However, there are different defects inthe existing organic curing foams, such as high cost, flammable and releaseing toxic gases ofpolyurethane foam, brittleness and high cost of phenolic foam, low compressive strength ofurea-formaldehyde foam. Accord to lack of of existing organic curing foam in mine, a newtype of air-leakage blocking composite foam is developed in this paper, which combinesadvantages of polyurethane foam, phenolic foam and urea-formaldehyde foam, such as goodsealing performance, high compressive strength, flame retardant, low cost, and overcomestheir insufficients. In this thesis, firstly, phenol-urea-formaldehyde resin is synthesized, andresin catalyst system is optimized. Secondly, phenol-urea-aldehyde foam is modified bytoughener and enhancer to improve the overall performance of composite foam. Finally,property of composite foam, polyurethane foam, phenolic foam and urea-formaldehyde foamis comparative analyzed to clarify advantages of the composite foam, and sealing performanceof composite foam is verified through engineering practice in mine.To reduce production cost of foaming resin, phenol-urea-formaldehyde resin issynthesized by phenol, urea and paraformaldehyde. Effect of amount of urea, amount ofcatalyst, reaction temperature and reaction time on foaming properties of resin is analyzed byorthogonal experiments, and synthesis conditions of phenol-urea-formaldehyde resin isobtained. Chemical structure and synthesis mechanism of phenol-urea-formaldehyde resin arerevealed by infrared spectroscopy and13C NMR spectrum. Due to paraformaldehyde insteadof liquid formaldehyde, preparation process of phenol-urea-formaldehyde resin reducesdehydration links, saving energy and cost, to achieve a zero waste water discharge, a greensynthetic resin process.In order to optimize catalyst system of phenol-urea-formaldehyde resin, the influence ofdifferent curing agents, surfactants, foaming agents on curing behavior, mechanical propertiesand microstructure of foam are investigated, and the optimal ratio and amount of curing agent,surfactant and foaming agent are gived. Foaming and curing mechanism ofphenol-urea-formaldehyde resin is revealed.In order to solve poor toughness of phenol-urea-aldehyde foam, the effect of different molecular weight polyethylene glycol (PEG) on foaming behavior, impact strength,combustion properties of phenol-urea-formaldehyde foam is analyzed. The tougheningmechanism and optimal added amount of PEG are obtained. PEG can significantly improvestoughness and compression strength of foam, and reduces shrinkage ratio. When adding PEG,the thermal stability and flame retardant of phenol-urea-aldehyde foam reduce, and fire risk isenhanced.In order to improve compression strength and flame retardant of foam, glass fiber andnano-clay are used to prepare composite foam. The effect of glass fiber and nanoclay onmechanical properties, sealing performance, thermal stability and flame retardancy areinvestigated to reveal reinforced and flame retardant mechanism of glass fiber and nanoclay tophenol-urea-formaldehyde foam. Combined use of glass fiber and nano-clay shows a bettersynergistic effect, significantly improving compressive strength, miscostructure, thermalstability and flame retardant of foam, and reducing shrinkage rate.Comparative experiment among phenolic foam, polyurethane foam, urea-formaldehydefoam and composite foam shows that: composite foam has the lowest foaming temperatureand shrinkage, the highest compressive strength, flame retardancy and thermal stability.However, the expansion ratio and chalking rate of composite foam is slightly lower thanpolyurethane foam. Engineering practice in mine shows that composite foam has an excellentsealing performance and compression strength, being an excellent air-leakage blockingmaterial.

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