Arrigo Rossella, Malucelli Giulio, Mantia Francesco Paolo La
Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, Viale Teresa Michel 5, 15121 Alessandria, Italy.
National Interuniversity Consortium of Materials Science and Technology, Via Giusti 9, 50121 Firenze, Italy.
Polymers (Basel). 2021 Oct 14;13(20):3529. doi: 10.3390/polym13203529.
Polymer-processing operations with dominating elongational flow have a great relevance, especially in several relevant industrial applications. Film blowing, fiber spinning and foaming are some examples in which the polymer melt is subjected to elongational flow during processing. To gain a thorough knowledge of the material-processing behavior, the evaluation of the rheological properties of the polymers experiencing this kind of flow is fundamental. This paper reviews the main achievements regarding the processing-structure-properties relationships of polymer-based materials processed through different operations with dominating elongational flow. In particular, after a brief discussion on the theoretical features associated with the elongational flow and the differences with other flow regimes, the attention is focused on the rheological properties in elongation of the most industrially relevant polymers. Finally, the evolution of the morphology of homogeneous polymers, as well as of multiphase polymer-based systems, such as blends and micro- and nano-composites, subjected to the elongational flow is discussed, highlighting the potential and the unique characteristics of the processing operations based on elongation flow, as compared to their shear-dominated counterparts.
以拉伸流动为主导的聚合物加工操作具有重要意义，尤其是在一些相关的工业应用中。吹膜、纺丝和发泡是聚合物熔体在加工过程中受到拉伸流动作用的一些例子。为了全面了解材料的加工行为，评估经历这种流动的聚合物的流变性能至关重要。本文综述了通过不同以拉伸流动为主导的操作加工的聚合物基材料的加工-结构-性能关系的主要研究成果。特别是，在简要讨论了与拉伸流动相关的理论特征以及与其他流动状态的差异之后，注意力集中在最具工业相关性的聚合物在拉伸时的流变性能上。最后，讨论了均相聚合物以及多相聚合物基体系（如共混物、微复合材料和纳米复合材料）在拉伸流动作用下的形态演变，突出了基于拉伸流动的加工操作相对于以剪切为主导的操作的潜力和独特特性。
