Jones Chris D, Fothergill Jenny W, Barrett Rainier, Ghanbari Lina N, Enos Nicholas R, McNair Olivia, Wiggins Jeffrey, Jankowski Eric
Micron School of Material Science and Engineering, Boise State University, Boise, ID 83725, USA.
School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS 39406, USA.
Polymers (Basel). 2025 Jan 5;17(1):117. doi: 10.3390/polym17010117.
Carbon-fiber composites with thermoplastic matrices offer many processing and performance benefits in aerospace applications, but the long relaxation times of polymers make it difficult to predict how the structure of the matrix depends on its chemistry and how it was processed. Coarse-grained models of polymers can enable access to these long-time dynamics, but can have limited applicability outside the systems and state points that they are validated against. Here we develop and validate a minimal coarse-grained model of the aerospace thermoplastic poly(etherketoneketone) (PEKK). We use multistate iterative Boltzmann inversion to learn potentials with transferability across thermodynamic states relevant to PEKK processing. We introduce tabulated EKK angle potentials to represent the ratio of terephthalic (T) and isophthalic (I) acid precursor amounts, and validate against rheological experiments: The glass transition temperature is independent to T/I, but chain relaxation and melting temperature is. In sum we demonstrate a simple, validated model of PEKK that offers 15× performance speedups over united atom representations that enables studying thermoplastic processing-structure-property-performance relationships.
具有热塑性基体的碳纤维复合材料在航空航天应用中具有许多加工和性能优势，但聚合物的长弛豫时间使得难以预测基体的结构如何取决于其化学组成以及加工方式。聚合物的粗粒化模型能够研究这些长时间动力学，但在其验证范围之外的系统和状态点的适用性有限。在此，我们开发并验证了一种航空航天热塑性聚醚酮酮（PEKK）的最小粗粒化模型。我们使用多状态迭代玻尔兹曼反演来学习在与PEKK加工相关的热力学状态间具有可转移性的势函数。我们引入表格化的EKK角势函数来表示对苯二甲酸（T）和间苯二甲酸（I）前体的比例，并通过流变学实验进行验证：玻璃化转变温度与T/I无关，但链松弛和熔点与T/I有关。总之，我们展示了一个简单且经过验证的PEKK模型，其性能比联合原子表示法快15倍，能够研究热塑性加工-结构-性能关系。
