Poly(ethylene terephthalate) (PET) and polyamide (PA) are immiscible polymers, which requires the use of compatibilizers to stabilize the morphology and achieve acceptable property levels. Therefore, controlling the degree of dispersion, especially the size of the disperse PA droplets in the PET matrix is of paramount importance. This study aims to improve the mixing, i.e., minimize PA droplet size, in immiscible and compatibilized PET/PA and PET/Nylon-MXD6 (MXD6) blends by resorting to extension-dominated mixing in twin-screw extrusion (TSE). MXD6 is an aromatic polyamide similar in polarity to PET, so it is expected that it will blend more effectively than is the case with aliphatic nylon-6 and PET. Two screw configurations are used, a benchmark shear-dominated screw with kneading blocks (KBs) in an aggressive configuration, and an extension-dominated screw configuration with static mixers with hyperbolic C–D channels, recently developed by our group, in place of the KBs. The results show that the use of extensional mixing elements (EMEs) in place of KBs results in a significant decrease of both average and maximum droplet size for all blends, and up to more than one order of magnitude between the most extreme cases of the KB-processed immiscible blend and EME-processed compatibilized blends.

中文翻译：

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通过延伸支配的双螺杆挤出相容的聚对苯二甲酸乙二酯/聚酰胺共混物的形态优化

聚对苯二甲酸乙二醇酯（PET）和聚酰胺（PA）是不混溶的聚合物，需要使用相容剂来稳定形态并达到可接受的性能水平。因此，控制分散度，特别是控制PET基质中分散的PA液滴的尺寸是至关重要的。这项研究旨在通过在双螺杆挤出（TSE）中采用扩展控制的混合方式，改善不混溶和相容的PET / PA和PET /尼龙-MXD6（MXD6）混合物的混合，即最小化PA液滴的大小。MXD6是一种极性与PET相似的芳族聚酰胺，因此预计它将比脂族尼龙6和PET更有效地共混。使用了两种螺钉配置，一种是激进配置的带有捏合块（KBs）的基准剪切控制螺钉，我们小组最近开发的带有双曲线C-D通道的静态混合器的扩展控制螺杆配置代替了KBs。结果表明，使用扩展混合元素（EME）代替KB会导致所有混合物的平均液滴大小和最大液滴大小显着减小，并且在最极端的KB情况之间最多下降一个数量级。加工的不混溶共混物和EME加工的相容性共混物。