三聚氰胺泡沫的制备及其吸声性能的研究

发布时间：2018-06-16 18:13

本文选题：三聚氰胺泡沫 + 微观结构　；参考：《江南大学》2017年硕士论文

【摘要】：三聚氰胺泡沫具有轻质阻燃、吸声、隔热等优异性能,且原材料成本低廉,在建筑、交通、航空等领域具有广阔的应用前景。而且泡沫塑料可以作为基材与轻质柔性的纺织材料复合,改善泡沫的性能,同时可以扩大两者的应用范围。但目前关于硬质三聚氰胺泡沫的研究主要集中于泡沫成型及其力学改性方面,对其吸声性能研究较少,而结构是影响吸声性能的重要因素,掌握不同结构泡沫的吸声特性,对提高三聚氰胺泡沫在不同环境下的吸音降噪效率具有重要意义。同时硬质三聚氰胺泡沫脆性大,强度低,限制了其在工业中的应用,研究泡沫的抗压性能对拓展其产品应用范围具有重要意义。因此本文通过调控三聚氰胺泡沫制备工艺制备泡沫,分析工艺参数对其结构的影响,进而研究其结构对泡沫吸声性能、压缩性能的影响。并且采用共成型制备工艺,制备短切玻纤复合三聚氰胺泡沫材料,初步探讨了纤维含量对泡沫结构与性能的影响。首先为了探究泡沫的制备工艺对发泡过程、泡沫结构的影响机制和规律,研究工艺参数对树脂及发泡混合物属性的影响。然后采用扫描电镜观察泡沫微观结构,研究制备工艺对三聚氰胺泡沫结构的影响,结果表明,树脂含水量越低,泡沫孔径越小,表观密度越大;不同催化剂作用下泡沫结构差异较大,甲酸制得闭孔结构泡沫;使用阴离子表面活性剂十二烷基苯磺酸钠3%时,泡沫结构细密均匀且闭孔率较高。在泡沫中添加短切玻纤,随着纤维含量的增加,泡沫孔径有减小的趋势。最后通过比较不同工艺条件所得泡沫的吸声系数和压缩强度,并结合泡孔结构,分析泡沫的吸声及压缩性能。研究其吸声性能结果显示,在开孔三聚氰胺泡沫中,随着其密度增加、孔径减小,泡沫对中高频声波的吸声系数先增加后降低。相同密度下,三维网状结构泡沫随着孔径减小,泡沫的吸声性能提高。与其相比,闭孔三聚氰胺泡沫在低频处的吸声性能较好,中高频处较差。且随着泡沫闭孔率降低,在整体频率范围内泡沫的吸声性能均提高。在泡沫中添加短切玻纤,纤维可以有效的改善泡沫在中低频处的吸声性能。研究其压缩性能的结果显示,相同密度下,三维网状开孔泡沫的孔径越小,泡沫压缩强度增大。且由于泡壁的支持,三聚氰胺闭孔型泡沫的压缩性能优于开孔型的。且闭孔三聚氰胺泡沫的孔径越小,其压缩性能越好,但泡壁的破裂使压缩性能降低。泡沫中添加短切玻纤发现,纤维可以有效的提高三聚氰胺泡沫的压缩强度和弹性模量。通过研究发现,泡沫的制备工艺对泡沫的结构和性能产生重要影响,不同结构的吸声性能和压缩性能差异较大。
[Abstract]:Melamine foam has excellent properties such as light flame retardant, sound absorption, heat insulation, and low cost of raw materials, so it has a broad application prospect in the fields of construction, transportation, aviation and so on. Foamed plastics can be used as substrates and light and flexible textile materials to improve the properties of foams and to expand their applications. However, at present, the research on rigid melamine foam is mainly focused on foam forming and its mechanical modification. The sound absorption properties of melamine foam are seldom studied, and the structure is an important factor affecting the sound absorption performance. The sound absorption characteristics of foam with different structures are mastered. It is of great significance to improve the sound absorption and noise reduction efficiency of melamine foam in different environments. At the same time, the rigid melamine foam is brittle and has low strength, which limits its application in industry. It is very important to study the compressive properties of melamine foam to expand the application range of its products. In this paper, the influence of process parameters on the structure of melamine foam was analyzed by controlling the preparation process of melamine foam, and the influence of structure on the sound absorption and compression properties of the foam was studied. The short cut glass fiber composite melamine foam was prepared by co-forming process. The effect of fiber content on the structure and properties of the foam was discussed. In order to investigate the influence mechanism and law of foam preparation technology on foaming process and foam structure, the effects of process parameters on properties of resin and foamed mixture were studied. Then SEM was used to observe the microstructure of the foam, and the effect of preparation technology on the structure of melamine foam was studied. The results showed that the lower the water content of resin, the smaller the pore size of foam and the greater the apparent density. Under the action of different catalysts, the foam structure varies greatly, and the closed pore structure foam is obtained by formic acid, and when the anionic surfactant sodium dodecylbenzenesulfonate is used, the foam structure is fine and uniform and the closed porosity is higher. With the increase of fiber content, the pore size of foam decreases with the addition of short cut glass fiber. Finally, by comparing the sound absorption coefficient and compression strength of foam under different technological conditions, and combining with the bubble pore structure, the sound absorption and compression properties of foam were analyzed. The results show that the pore size decreases with the increase of the density and the sound absorption coefficient of the foam increases first and then decreases with the increase of the density of the porous melamine foam. At the same density, the sound absorption of the foam increases with the decrease of pore size. Compared with the closed porous melamine foam, the sound absorption property of the closed-cell melamine foam is better at the low frequency and the lower at the middle and high frequency. With the decrease of the closed porosity of the foam, the sound absorption performance of the foam increases in the whole frequency range. Adding short cut glass fiber to foam can effectively improve the sound absorption property of foam at middle and low frequency. The results of the study show that the smaller the pore size of the three dimensional reticulated porous foam, the greater the compression strength of the foam at the same density. Because of the support of foam wall, the compression performance of melamine closed-cell foam is better than that of open-hole foam. The smaller the pore size of closed pore melamine foam is, the better its compression performance is, but the rupture of foam wall reduces the compressibility of melamine foam. It is found that the fiber can effectively improve the compressive strength and elastic modulus of melamine foam. It is found that the preparation process of foam has an important effect on the structure and properties of foam, and the sound absorption and compression properties of different structures vary greatly.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ328.0

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