标题： 在半结晶聚合物中的介电弛豫建模——理解非晶态和结晶域之间中间相的作用 显示英文标题

标题： Modeling the Dielectric Relaxation in Semicrystalline Polymers -- Understanding the Role of the Interphase between the Amorphous and Crystalline Domains

摘要： 半结晶聚合物（SCP）是一类在许多应用中重要的材料，从包装到交通运输，再到电子和制药。 理解SCP中晶体和非晶体部分的结构和动力学是对实验者和理论家的重要挑战。 最近，Cheng等人（S. Cheng等，J. Chem. Phys. 160, 114904 (2024)）利用宽频介电谱（BDS）研究了半结晶聚(L-乳酸)（PLLA）非晶体区域内的弛豫时间分布，该PLLA具有有序交替堆叠的晶体/非晶体相。 在此基础上，我们利用Doolittle自由体积理论（FVT）和可压缩自洽场理论（cSCFT）的结合来对弛豫时间分布进行建模。 我们证明，新的建模框架成功捕捉了半结晶PLLA在非晶体区域玻璃化转变温度以上的局部弛豫时间的温度和位置依赖性。 最后，我们推导出了SCP非晶体区域弛豫时间分布的新经验方程。 显示英文摘要

摘要： Semicrystalline polymers (SCP) represent important class of materials used in many applications from packaging to transportation to electronics to pharmaceuticals. Understanding the structure and dynamics of the crystalline and amorphous fractions within SCP is an important challenge for both experimentalists and theoreticians. Recently, Cheng et al. (S. Cheng et al., J. Chem. Phys. 160, 114904 (2024)) utilized Broadband Dielectric Spectroscopy (BDS) to explore the relaxation time profiles within the amorphous region of a semi-crystalline poly(L-lactic acid) (PLLA) with ordered alternative stacking of crystalline/amorphous phases. Here, we build on those initial results and model the relaxation time distribution using the combination of the Doolittle free volume theory (FVT) and the compressible Self-Consistent Field Theory (cSCFT). We show that the new modeling framework successfully captures the temperature and position dependence of the local relaxation time of the semicrystalline PLLA above the glass transition temperature of the amorphous region. Finally, we derive a new empirical equation for the relaxation time profiles in amorphous regions of SCPs.