Effects of different thermoplastic binders on the processability of feedstocks for ceramic co-extrusion process
Effects of different thermoplastic binders on the processability of feedstocks for ceramic co-extrusion process
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DOI：
10.1016/j.ceramint.2011.05.084
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发表时间：
2011-12
影响因子：
5.2
通讯作者：
M. R. Ismael;F. Clemens;T. Graule;Michael J. Hoffmann
中科院分区：
文献类型：
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作者：
M. R. Ismael;F. Clemens;T. Graule;Michael J. Hoffmann
共挤出工艺涉及多种材料的同时挤出，例如可用于制造精细尺寸的压电复合材料的陶瓷-热塑性原料，用于结构和功能应用。原料开发的主要步骤是选择最佳的热塑性粘合剂，其功能是在加工过程中为陶瓷材料提供塑性以及适当的流变行为。本工作的目的是研究不同的市售热塑性粘合剂（聚苯乙烯，低密度聚乙烯，聚（乙烯-共-丙烯酸乙酯）和聚（乙烯-共-丙烯酸乙酯）和聚（甲基丙烯酸异丁酯）的共混物）的高负载锆钛酸铅（PZT）原料的加工性能的影响，适合于共挤出工艺。在用TG和DSC分析了粘结剂的热行为之后，分析了未填充聚合物的流动行为，并与相应的PZT填充混合物（58 vol.%）进行了比较PZT）施加转矩流变仪。使用阿罗修斯关系，粘度的温度依赖性被确定和计算的粘性流的活化能。由于聚乙烯具有低粘度、高固体含量、无降解迹象、强的聚合物-颗粒相互作用以及相对低的离模膨胀的事实，这种热塑性粘合剂用于PZT原料的配制中，通过共挤出技术成功地生产了薄的实心（240μm直径）和中空（800μm直径）PZT纤维。
The co-extrusion process involves the simultaneous extrusion of multiple materials, such as ceramic–thermoplastic feedstocks that can be used to manufacture fine-scaled piezocomposites, for both structural and functional applications. The primary step in the development of the feedstocks is the selection of the optimal thermoplastic binder with the function of providing plasticity as well as proper rheological behavior to the ceramic material during processing. The objective of the present work was to investigate the effects of different commercially available thermoplastic binders (polystyrene, low-density polyethylene, poly(ethylene-co-ethyl acrylate) and a blend of poly(ethylene-co-ethyl acrylate) and poly(isobutyl methacrylate)) on the processability of highly loaded lead zirconate titanate (PZT) feedstocks, suitable for the co-extrusion process. After characterizing the thermal behavior of the binders by means of TG and DSC analyses, the flow behavior of the unfilled polymers was analyzed and compared with the corresponding PZT-filled mixture (58vol.% PZT) applying torque rheometry. Using an Arrhenius relation, the temperature dependency of viscosity was determined and the energy of activation for the viscous flow calculated. Due to the fact that the polyethylene presented a low viscosity with a high solid loading, no indication of degradation, a strong polymer–particle interaction as well as a comparatively low die swell, this thermoplastic binder was used in the formulation of PZT feedstocks to successfully produce thin solid (240μm diameter) and hollow (800μm diameter) PZT fibers by the co-extrusion technique.