加工成型过程调控聚醚酯的结晶行为及力学性能研究

Thermoplastic poly(ether ester) elastomers (TPEEs) have been widely used in the fields of automotive and communication in recent years. However, the impact of processing conditions in industrial production on crystalline morphology, the orientational state as well as the macroscopic properties of final products still remains elusive. Herein, we propose to employ a series of typical poly(ether ester)s with different chain structures (i.e., composition, segmental concentration or length of soft and hard segments), and systematically investigate the corresponding crystallization behavior and morphological structures tuned by distinct processing routes such as injection molding and hot pressing, by means of in-situ small-angle and wide-angle X-ray scattering techniques. Moreover, this project will also focus on the mechanical properties of processed poly(ether ester)s under different drawing rates and temperatures, and give more insight into the aggregation structures formed during processing. Based on these above-mentioned investigations, we aim to establish the morphological structure model of poly(ether ester)s regulated by chain structures and processing methods. The implementation of this project will be of great significance to clarify the crystallization mechanism and reveal the rule of structural evolution during processing of poly(ether ester)s, which could and will provide theoretical and technical support for the design and production of high performance TPEEs.

近年来热塑性聚醚酯弹性体广泛应用在汽车及通讯工程等领域，但是工业生产过程中成型方式对制品的结晶态、取向态结构及宏观性能影响的研究极为欠缺。本项目拟选取一系列具有典型链结构特征（包括软段与硬段的化学组成、比例及长度等）的聚醚酯嵌段共聚物为研究对象，通过注塑、模压成型等加工手段，利用在线小角及广角X射线散射等技术系统研究样品的结晶行为和形态结构特征。并且以拉伸速率和温度为变量，考察单轴拉伸下聚醚酯的力学性能，进一步探讨加工过程中形成的聚集态结构。在此基础上，建立链结构和加工成型过程调控下聚醚酯的形态结构模型。本项目的研究成果将对揭示加工过程中聚醚酯的结晶机制与结构演化规律具有重要意义，可为设计和生产高性能聚醚酯弹性体提供理论和技术支撑。

半结晶聚合物的使用性能与其超分子结构密切相关，如何选择合适的加工方式及条件调控聚集态结构，进而优化力学性能是一个重要的课题。聚醚酯是一类嵌段共聚物，具有独特的微相分离结构和优异的耐热性、耐磨耗、高强高韧和易加工成型等优势，应用广泛。本项目以聚醚酯共聚物为研究对象，深入研究不同加工方式下其结晶行为及聚集态结构，并进一步探讨了对力学性能的影响。通过分析软硬段含量、分子量、温度及加工过程等因素，阐明了对结晶行为和力学性能的影响规律。此外，进一步结合在线小角X射线散射实验探讨了在单轴拉伸下的微观结构及力学行为，明确了最终的晶体结构与拉伸温度的依赖性。本项目的研究成果有助于为工业生产中聚醚酯弹性体的成型加工及性能调控提供理论依据，达到通过链结构和加工成型工艺进一步优化材料使用性能的目的。