Effects of Al(OH)O nanoparticle agglomerate size in epoxy resin on tension, bending, and fracture properties
Effects of Al(OH)O nanoparticle agglomerate size in epoxy resin on tension, bending, and fracture properties
复制标题
DOI：
10.1007/s11051-017-3831-9
复制
发表时间：
2017-04-08
影响因子：
2.5
通讯作者：
Schilde, Carsten
中科院分区：
文献类型：
--
作者：
Jux, Maximilian;Finke, Benedikt;Schilde, Carsten
在捏合机中生产环氧树脂中的几种环氧 Al(OH)O（勃姆石）分散体，以研究所制备的纳米复合材料的纳米颗粒尺寸和机械性能之间的机械相关性。附聚物尺寸是通过分散过程中固体含量和温度的目标变化来设定的，从而导致不同水平的应力强度，从而在该过程中产生不同的最终附聚物尺寸。悬浮液粘度用于估计层流剪切流中的应力能。通过动态光散射进行附聚物尺寸测量，以确保所生产的分散体的质量。此外，还制备了各种纳米复合材料样品用于三点弯曲、拉伸和断裂韧性测试。尺寸效应的筛选是针对每种附聚物尺寸和测试方法至少使用七个样品来进行的。研究发现，改变固体含量是在分散过程中将附聚物尺寸调节在 138-354 nm 之间的可靠方法。尺寸对杨氏模量和临界应力强度的影响很小。然而，统计上相关的趋势显示随着附聚物尺寸的减小而线性增加。相反，尺寸效应对失效时样品的应变和应力更为主导。与导致复合材料脆化的微米级附聚物或颗粒不同，纳米级附聚物或颗粒导致复合材料的伸长率几乎与基材相同水平。观察到的效果对于 138-354 nm 之间的附聚物尺寸和 10 wt% 的颗粒质量分数有效。
Several epoxy Al(OH)O (boehmite) dispersions in an epoxy resin are produced in a kneader to study the mechanistic correlation between the nanoparticle size and mechanical properties of the prepared nanocomposites. The agglomerate size is set by a targeted variation in solid content and temperature during dispersion, resulting in a different level of stress intensity and thus a different final agglomerate size during the process. The suspension viscosity was used for the estimation of stress energy in laminar shear flow. Agglomerate size measurements are executed via dynamic light scattering to ensure the quality of the produced dispersions. Furthermore, various nanocomposite samples are prepared for three-point bending, tension, and fracture toughness tests. The screening of the size effect is executed with at least seven samples per agglomerate size and test method. The variation of solid content is found to be a reliable method to adjust the agglomerate size between 138-354 nm during dispersion. The size effect on the Young's modulus and the critical stress intensity is only marginal. Nevertheless, there is a statistically relevant trend showing a linear increase with a decrease in agglomerate size. In contrast, the size effect is more dominant to the sample's strain and stress at failure. Unlike microscaled agglomerates or particles, which lead to embrittlement of the composite material, nanoscaled agglomerates or particles cause the composite elongation to be nearly of the same level as the base material. The observed effect is valid for agglomerate sizes between 138-354 nm and a particle mass fraction of 10 wt%.