本實驗研究聚醯胺-6(Polyamide-6, PA6)分別熔融共混熱塑性聚氨酯(Polyurethane, TPU)與熱塑性聚脲(Polyurea, PUA)，並製備成薄膜探討其形狀記憶功效，熱塑性彈性體主要分為TPU與PUA兩大類，以化學結構來看，兩者最大差別在於PUA擁有較多的N-H鍵，且PUA與PA6極性相近，可產生較多與強的氫鍵作用力，使其兩相相容性佳，因此PA6與TPU或PUA熔融共混後會有不同兩相微結構、儲存模量以及交聯密度等特性，更進一步影響形狀記憶效能。
本研究發現在偏光光學顯微鏡下可觀察到PA6/PUA呈現共連續相的結構，特別在50 % PA6與50 % PUA(50PUA)的混摻比例下，擁有半互穿網絡結構(semi-IPN)，有助於形狀記憶功效的提升；本研究也藉由溶脹實驗計算出交聯密度，將TPU與TPU兩系統比較後發現，PA6/PUA薄膜有較高的交聯密度，因PA6與PUA極性相近，相容性較高，兩相間能產生更多的物理交聯點，可於形狀記憶機制中做為固定相，有利於回復率的提升，最終比較發現PA6/PUA共混系統擁有較佳形狀記憶特性，其中50 PUA薄膜固定率為96.8 %，回復率則高達99.2 %。
本研究使用雙組份熔融紡絲機搭配核殼型紡嘴，生產出PA6/TPU及PA6/PUA核殼複合纖維，在熔融紡絲加工中，會給予纖維一定牽伸力，可促進分子鏈順相度，因此纖維型態的形狀記憶效能高於薄膜型態，PA6/TPU纖維經過熱延伸後加工後，固定率為78.8 %，而回復率高達99.9 %，另外，PA6/PUA核殼纖維的固定率為84.4 %，回復率為96.9 %，先前相關研究大多製備高分子形狀記憶薄膜，本研究成功生產成核殼型複合纖維，期望能增加形狀記憶材料應用領域。

Thermally responsive shape memory polymers have widely been applied in many fields. Polyamide 6 (PA6) was blended with various amount of thermoplastic polyurethane (TPU) or polyurea (PUA) via twin-screw extruder, and hot pressed into film to evaluate shape memory properties. The crosslinking density was analyzed by swelling experiments. Dynamic mechanical analysis (DMA) in tensile loading mode was used to determine the shape memory effect. Results of morphology were examined by polarized optical microscope (POM).
This study found that 1) the degree of crosslinking, 2) compatibility and 3) phase of the microstructure affect the shape memory. 1) The physical crosslinking can act as the fixing phase, while the soft segment of PU and the amorphous of PA6 can act as the reversible phase. Improving crosslinking density of the material can also effectively increase the recovery ratio 2) The polarity of PUA is similar to PA6, it make PUA have better compatible with PUA than TPU. Better compatibility helps to enhance the shape memory properties. 3) PA6 induce phase separation of PUA soft and hard segments, and PA6/PUA blends form IPN-like structure. Co-continuous phase can achieve better shape memory. After evaluating, the PA6/PUA film has optimal shape memory effect.
In this study, PA6/TPU and PA6/PUA core-shell fibers were produced by bicomponent melt spinning. In the melt spinning process, the fibers were given a drawing force, which could increase degree of molecular orientation. The shape memory effect of the fiber type is higher than that of the film type. After the PA6/TPU fiber is processed by thermal extension, the fixation ratio is 78.8 %, and the recovery ratio is 99.9%. In addition, The fixation ratio of the PA6/PUA core-shell fiber is 84.4%, and the recovery ratio was 96.9 %. Shape memory material were mostly prepared into film in previous studies. This study successfully produced core-shell fibers, and it is expected to increase the application of shape memory materials.

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