To illustrate the complex phase evolution of polyamide 6 (PA6)‐based thermoplastic elastomer (TPAE‐50) with a three‐phase system (a pure PA6 crystalline phase, a phase‐separated mesophase, and a mixed phase) during cooling and heating, the in situ IR spectroscopy combined with moving‐window 2D correlation analysis is employed. The mixing of PA6 amorphous domains with soft domains and the melting of imperfect PA6 crystalline domains of TPAE‐50 occur from 60 °C with the increasing temperature. Brill transition happens to the elastomer during heating and cooling at 140–160 and 170–135 °C, respectively. Microphase separation of TPAE‐50 during cooling is formed and can be composed of three processes: the first process (200–180 °C) is motivated by the crystallization of the elastomer; the second process (170–140 °C) results from the transition of homo‐mixed domains in the mixed phase to PA6 amorphous and soft domains; the third process (125–60 °C) leads to the formation of imperfect PA6 crystalline domains in phase‐separated mesophase.

中文翻译：

---

通过移动窗口二维相关红外光谱研究加热和冷却过程中基于聚酰胺6（PA6）的热塑性弹性体的相变

为了说明在冷却和加热过程中具有三相体系（纯PA6结晶相，相分离的中间相和混合相）的聚酰胺6（PA6）基热塑性弹性体（TPAE-50）的复杂相演化，采用原位红外光谱结合移动窗口二维相关分析。随着温度的升高，温度从60°C开始，PA6非晶域与软域的混合以及TPAE-50的不完美PA6晶体域的熔化。弹性体在140–160和170–135°C的加热和冷却过程中分别发生过渡转变。形成了TPAE-50冷却过程中的微相分离过程，该过程可以由三个过程组成：第一个过程（200–180°C）是由弹性体的结晶引起的；第二个过程是由弹性体的结晶引起的。第二个过程（170–140°C）是由于混合相中的均相混合畴向PA6非晶和软畴转变的结果。第三个过程（125–60°C）导致在相分离的中间相中形成不完善的PA6晶域。