Wang Sai, Ameli Amir, Shaayegan Vahid, Kazemi Yasamin, Huang Yifeng, Naguib Hani E, Park Chul B
Microcellular Plastics Manufacturing Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8, Canada.
Advanced Composites Laboratory, School of Mechanical and Materials Engineering, Washington State University Tri-Cities, Richland, WA 99354, USA.
Polymers (Basel). 2018 Mar 2;10(3):261. doi: 10.3390/polym10030261.
We developed a simple analytical model to describe the instantaneous location and angle of rod-like conductive fillers as a function of cell growth during the foaming of conductive polymer composites (CPCs). First, we modelled the motion of the fillers that resulted from the growth of one cell. Then, by taking into account the fillers located at the line that connected the centres of the two growing cells, we found the final filler's angle and location. We identified this as a function of the corresponding cell size, filler size, and the filler's initial angle and location. We based the model's development on the assumption that a polymer melt is incompressible during cell growth. The two-cell growth model is better than the one-cell growth model because it describes the filler's movement in the cell wall between the two growing cells. The results revealed that the fillers near the cell were the ones most affected by the cell growth, while those at the midpoint between the two cells were the least affected. As a cell grows, its affected polymer area also increases. A dimensionless factor η was introduced to demonstrate the effects of the cell size and the filler length on the filler's interconnectivity in the CPC foams. It is vital to keep the filler length comparable to the cell size when preparing CPC foams with the desired electrical conductivity. Our research provides a deeper understanding of the mechanism through which foaming influences the filler connections in CPC foams.
我们开发了一个简单的分析模型，用于描述在导电聚合物复合材料（CPC）发泡过程中，棒状导电填料的瞬时位置和角度与细胞生长的函数关系。首先，我们对单个细胞生长导致的填料运动进行了建模。然后，通过考虑位于两个正在生长的细胞中心连线处的填料，我们确定了最终填料的角度和位置。我们将其确定为相应细胞大小、填料大小以及填料初始角度和位置的函数。该模型的开发基于这样一个假设：在细胞生长过程中聚合物熔体是不可压缩的。双细胞生长模型比单细胞生长模型更好，因为它描述了填料在两个正在生长的细胞之间的细胞壁中的运动。结果表明，靠近细胞的填料受细胞生长影响最大，而位于两个细胞中点的填料受影响最小。随着细胞生长，其影响的聚合物区域也会增加。引入了一个无量纲因子η来证明细胞大小和填料长度对CPC泡沫中填料互连性的影响。在制备具有所需电导率的CPC泡沫时，保持填料长度与细胞大小相当至关重要。我们的研究为发泡影响CPC泡沫中填料连接的机制提供了更深入的理解。
