酚醛泡沫的压缩性能研究及其在泡沫夹芯复合材料中的应用

发布时间：2018-06-07 00:21

本文选题：酚醛泡沫 + 粘弹性　；参考：《江南大学》2017年硕士论文

【摘要】：酚醛泡沫作为一种常见的泡沫夹芯材料,具有轻质、隔热隔音、高比强度、价格低廉等优点,广泛用于建筑工程领域。然而这种材料存在易粉化和力学强度不高的缺陷,使酚醛泡沫夹芯复合材料在使用过程中易芯材受损而导致失效,极大程度上限制了该复合材料的广泛应用。为了解决这个问题,本课题提出从不同的研究角度对酚醛泡沫的压缩性能进行改性,并制备一体式三维中空织物/酚醛泡沫夹芯复合材料。论文针对酚醛泡沫的压缩性能改性涉及两种思路,均相改性和异相改性。均相改性采用端羟基聚硅氧烷共混酚醛树脂进行发泡,需重点解决可发性树脂体系的粘弹性及组分相容性对泡孔结构及压缩性能的影响。实施方法有:一是通过流变测试分析可发性树脂体系中的端羟基聚硅氧烷与树脂的物理相容性,阐述体系粘弹性对泡孔成核、生长及稳定的影响;二是通过动态热力学性能(DMA)分析酚醛树脂样条的玻璃化转变温度及储能模量,分析不同质量分数的端羟基聚硅氧烷与酚醛树脂的化学相容性;三是通过傅里叶红外光谱、热失重分析酚醛泡沫基体的性能,证明端羟基聚硅氧烷可与酚醛树脂产生化学键,形成结构稳定的IPN互穿网络结构。四是通过扫描电镜及压缩性能分别研究酚醛泡沫的泡孔结构及压缩性能的变化规律,并总结出端羟基聚硅氧烷改性酚醛泡沫的压缩机理。结果显示添加15%的端羟基聚硅氧烷可明显改善可发性树脂体系的粘弹响应,能够与树脂交联形成结构稳定的IPN网络结构,有利于形成尺寸均一的小泡孔,使酚醛泡沫的压缩性能得到提高。异相改性选用石墨烯作为成核剂,需重点解决成核剂表面能及含量对泡孔结构及压缩性能的影响规律。主要实施方法有:一通过粉末表面接触角测试法测量并计算石墨烯及氧化石墨烯的表面能;二是通过可发性树脂体系的动态流变性能分析石墨烯及氧化石墨烯与树脂基体之间的界面性能;三是通过扫描电镜及压缩测试表征酚醛泡沫的泡孔结构及压缩性能,分析石墨烯及氧化石墨烯对酚醛泡沫压缩性能的作用机理。结果显示,氧化石墨烯较高的表面能可以减小树脂体系成核所需的吉布斯自由能,提高成核速率,因而会减少泡孔尺寸;而较多的成核粒子在树脂基体中会阻碍泡孔的生长,导致破孔;同时石墨烯及氧化石墨烯在树脂基体中能够传递载荷,提高酚醛泡沫的压缩性能。将氧化石墨烯预分散在端羟基聚硅氧烷中,再与酚醛树脂共混进行发泡。动态流变性能、泡孔形态结构、压缩性能结果表明一定量的氧化石墨烯与端羟基聚硅氧烷在树脂基体中可发挥协同作用,获得更优的粘弹响应,有效改善泡孔结构,提高酚醛泡沫的压缩性能。根据改性酚醛泡沫的制备工艺,通过手工灌注法将其填充三维中空织物,然后密闭发泡制备三维中空织物/酚醛泡沫夹芯复合材料。结果表明三维织物起到了物理加固支撑作用,并且能够有效传递载荷,使复合材料能够整体抗压以实现压缩性能的提高。
[Abstract]:As a common foam core material, phenolic foam has the advantages of light quality, heat insulation, sound insulation, high specific strength, low price and so on. It is widely used in the field of construction engineering. However, this material has the defects of easy powder and low mechanical strength, which causes the failure of the core material damaged by the phenolic foam sandwich composites in the process of use. In order to solve this problem, in order to solve this problem, we propose to modify the compression properties of the phenolic foam from different research angles, and prepare the integrated three-dimensional hollow fabric / phenolic foam sandwich composites. The paper deals with the modification of the compression properties of the phenolic foam with two ways of thinking and the homogeneous modification. The effect of the viscoelasticity and compatibility of the soluble resin system on the structure of the bubble and the compressive properties of the blends with hydroxyl terminated polysiloxane blend should be focused on. The first is to analyze the hydroxyl polysiloxane and resin in the hair tree by rheological test. Physical compatibility, the effect of viscoelasticity on the nucleation, growth and stability of the bubble hole, two is to analyze the glass transition temperature and storage modulus of the phenolic resin sample by dynamic thermodynamic properties (DMA), and analyze the chemical compatibility of hydroxyl terminated polysiloxane and phenolic resin with different mass fraction, and three through Fourier infrared spectroscopy. The performance of weightless analysis of phenolic foam matrix shows that hydroxyl terminated polysiloxane can produce chemical bonds with phenolic resin to form a stable structure of IPN interpenetrating network structure. Four the changes of pore structure and compression properties of phenolic foam are studied by scanning electron microscopy and compression properties, and the modified phenolic aldehyde modified by hydroxyl polysiloxane is summarized. The compression mechanism of the foam shows that the addition of 15% hydroxyl terminated polysiloxane can obviously improve the viscoelastic response of the resinous system, and can cross link the resin with the resin to form a stable structure of IPN network, which is beneficial to the formation of a homogeneous small bubble hole and improve the compression properties of the phenolic foam. The influence of the surface energy and content of the nucleating agent on the pore structure and compressive properties of the nucleating agent should be focused on. The main implementation methods are as follows: first, the surface energy of graphene and graphene oxide is measured and calculated by the surface contact angle test of powder. Two the analysis of graphene and graphene oxide through the dynamic rheological properties of the hair resin system The interfacial properties between the resin matrix and the pore structure and compression properties of the phenolic foam were characterized by scanning electron microscopy and compression test. The mechanism of the effect of graphene and graphene oxide on the compressive properties of the phenolic foam was analyzed. The results showed that the higher surface of graphene oxide was able to reduce the Gibbs freedom required for the nucleation of the resin system. It is possible to increase the nucleation rate, thus reducing the size of the bubble hole, and more nucleated particles will impede the growth of the pores in the resin matrix and lead to holes, while graphene and graphene oxide can transfer loads in the resin matrix to improve the compressibility of the phenolic foam. The dynamic rheological properties, the pore shape structure and the compression properties show that a certain amount of graphene oxide and hydroxyl terminated polysiloxane can play a synergistic effect in the resin matrix, obtain better viscoelastic response, improve the pore structure and improve the compressive properties of the phenolic foam. The three-dimensional hollow fabric was filled with the manual perfusion method, and then the three-dimensional hollow fabric / phenolic foam sandwich composite was prepared by the closed foam. The results show that the three-dimensional fabric has the effect of physical reinforcement and support, and can effectively transfer the load, so that the composite can be compressed as a whole to improve the compression performance.
【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;TB332

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