X-ray CT microtomography and mechanical response of foamed polysiloxane elastomers
X-ray CT microtomography and mechanical response of foamed polysiloxane elastomers
复制标题
泡沫聚硅氧烷弹性体的 X 射线 CT 显微断层扫描和机械响应
DOI：
10.1016/j.polymertesting.2011.09.008
复制
发表时间：
2012
期刊：
影响因子：
5.1
通讯作者：
S. Pitts
中科院分区：
文献类型：
--
作者：
P. Morrell;M. Patel;S. Pitts
三维x射线计算机微断层扫描（CT）实验已经完成，以评估鳞状细胞聚硅氧烷弹性体的微观结构，并预测关键形态特征如何改变作为压缩载荷的函数。本文采用可提取的尿素颗粒制备了全尺寸（名义孔径为600 μm）和半尺寸（名义孔径为300 μm）聚二甲基硅氧烷泡沫（M97），并对其进行了测试。开发了不同压缩水平下泡沫结构的CT测试方法。一维磁共振成像（MRI）实验也在全尺寸泡沫上进行了基线表征。记录了材料孔隙率、体积密度和动态力学分析（DMA）应力/应变响应作为压缩的函数。我们的研究结果表明，当材料微观结构（细胞大小和形状）不均匀和复杂时，不良的工程应力响应是明显的。当使用非球形尿素颗粒时，这一点尤其明显，这会导致不受欢迎的鳞状泡沫微结构，其机械响应与“全尺寸”版本所显示的不匹配。通过使用x射线CT和MRI，我们的研究提供了制造，聚合物结构（细胞大小/形状）和缩放M97细胞材料的机械响应之间联系的见解。收集的数据将支持材料FEA（有限元模型）代码开发活动，以及帮助确定如何修改材料架构以实现更可控和均匀的机械响应。
3D X-ray computer microtomography (CT) experiments have been performed to assess the microstructure of scaled cellular polysiloxane elastomers and to predict how key morphological features alter as a function of compressive loading. In the work reported here, full scale (nominally 600 μm pore size) and half scale (nominally 300 μm pore size) polydimethylsiloxane foams (M97) were prepared using extractable urea particles, and tested. CT test methodology was developed to image foam microstructure at different levels of compression. 1D magnetic resonance imaging (MRI) experiments have also been performed on full scale foams for baseline characterisation. Material porosity, bulk density and dynamic mechanical analysis (DMA) stress/strain responses as a function of compression were recorded. Our results show that undesirable engineering stress responses are evident when the material microstructure (cell size and shape) is non-uniform and complex. This is particularly evident when non-spherical urea particles are used, leading to undesirable scaled foam microstructures with mechanical responses that do not match that shown by ‘full scale’ versions. Through the use of X-ray CT and MRI, our studies have provided insights into the link between manufacturing, polymer architecture (cell size/shape) and mechanical response of scaled M97 cellular materials. The data collected will support materials FEA (finite element model) code development activities, as well as help identify how the material architecture can be modified to achieve more controlled and uniform mechanical responses.