具有挑战性的异态态概念:在多聚甲 - - 八甲碳酸) kopolimers 中形成三种晶体相
Yilong Liao1, Ricardo A Pérez-Camargo1, Haritz Sardon1
1POLYMAT and Department of Polymers and Advanced Materials: Physics, Chemistry, and Technology, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel de Lardizábal, 3, Donostia-San Sebastián 20018, Spain.
Macromolecules
|October 30, 2023
概括
这项研究合成了新型的多聚 (hexamethylene-ran-octamethylene carbonate) kopo 聚合物,揭示了更高的晶度和在母聚合物中未见的新晶相. 这些发现挑战了现有的共聚物异构形态理论.
科学领域:
- 聚合物科学与工程 聚合物科学与工程
- 材料化学 材料化学
- 晶体学 晶体学是指结晶学.
背景情况:
- 随机共聚物中的异构形态通常涉及组件在各自的同聚合物形式中结晶.
- 之前对异态共聚合物的研究没有报告与母同聚合物相比增强的结晶性.
研究的目的:
- 在广泛的组成范围内合成多聚合物 ((hexamethylene-ran-octamethylene碳酸盐).
- 研究这些共聚合物的热行为,结晶性和结构特征.
- 探索偏离预期的异构形态行为,并确定新的晶体相.
主要方法:
- 化聚凝用于共聚合物合成.
- 差分扫描热度计 (DSC) 用于热分析 (化温度,结晶度).
- 宽角X射线散射 (WAXS) 和小角X射线散射 (SAXS) 用于结构特征.
- 在冷却和加热周期期间的现场WAXS实验.
- 福里埃变换红外光谱 (FTIR) 用于形状分析.
主要成果:
- 同聚合物表现出异构形的热行为,包括结晶和33mol%的聚乙烯碳酸 (POC) 的伪微学点.
- 许多共聚合物组合物观察到出乎意料的高结晶度,超过了母同聚合物的结晶度.
- 在33-73mol%POC的共聚合物中发现了一种与聚乙烯碳酸 (PHC) 和POC晶体不同的新型晶体相,呈现出类似聚乙烯的链形状.
结论:
- 合成的共聚物表现出独特的结晶性和新的结晶相,挑战了随机共聚物中等态的既定概念.
- 这些发现表明,在同一个共聚物系统内,可能存在组合结晶模式 (异构形和同构形).
- 这项工作为了解和设计具有量身定制的晶体结构和性质的共聚物开辟了新的途径.
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