Polymer orientation is a fundamental and key issue, exhibiting crucial impacts on physical properties of polymeric parts. Current methods are limited in transparent materials and fail to measure the dynamic orientation in industrial polymer processing in situ. Herein, we reported an innovative strategy that dynamic orientation for polymer molecular chains was successfully characterized in situ by dielectric method. A key dielectric-orientation theoretical model was established, and a facile interdigital electrode capacitor (IDEC) array sensor was designed. The experimental results not only agreed well with the classic elastic dumbbell model and the traditional optical measurement method, but also showed a universal applicability for different polymer solutions and a good application prospect in injection molding process. Investigated results showed that the orientation difference of 1 wt% PVDF/DMF, 1 wt% PVC/DMF and 1 wt% PS/DMF solution was 0.57, 0.97 and 0.75 at shear rate 0 ∼ 407 1/s, respectively. Additionally, the method was successfully applied in injection molding (Δε, 0.25 ∼ 0.88 under shear rate 56.6 ∼ 250 1/s). Our strategy built a new ‘decoding fingerprint’ to the dynamic orientation of polymer.

聚合物取向是一个基本而关键的问题，对聚合物零件的物理性能具有至关重要的影响。当前的方法仅限于透明材料，无法测量原位工业聚合物加工中的动态取向。在这里，我们报告了一种创新的策略，可以成功地原位表征聚合物分子链的动态取向通过介电法。建立了关键的介电取向理论模型，并设计了一种简便的叉指电极电容器（IDEC）阵列传感器。实验结果不仅与经典的弹性哑铃模型和传统的光学测量方法吻合良好，而且在不同的聚合物溶液中具有普遍的适用性，在注塑工艺中具有良好的应用前景。研究结果表明，在剪切速率为0〜407 1 / s时，1 wt％PVDF / DMF，1 wt％PVC / DMF和1 wt％PS / DMF溶液的取向差分别为0.57、0.97和0.75。另外，该方法成功地应用于注射成型（Δε，在剪切速率56.6〜250 1 / s下为0.25〜0.88）。我们的策略为聚合物的动态取向建立了新的“解码指纹”。