Department of Materials Science and Engineering, Clemson University, Clemson, SC, 29634, USA.
Adv Sci (Weinh). 2021 Sep;8(17):e2101399. doi: 10.1002/advs.202101399. Epub 2021 Jul 6.
Although dipolar forces between copolymer chains are relatively weak, they result in ubiquitous inter- and/or intramolecular interactions which are particularly critical in achieving the mechanical integrity of polymeric materials. In this study, a route is developed to obtain self-healable properties in thermoplastic copolymers that rely on noncovalent dipolar interactions present in essentially all macromolecules and particularly fluorine-containing copolymers. The combination of dipolar interactions between C─F and C═O bonds as well as CH /CH entities facilitates self-healing without external intervention. The presence of dipole-dipole, dipole-induced dipole, and induced-dipole induced dipole interactions leads to a viscoelastic response that controls macroscopic autonomous multicycle self-healing of fluorinated copolymers under ambient conditions. Energetically favorable dipolar forces attributed to monomer sequence and monomer molar ratios induces desirable copolymer tacticities, enabling entropic energy recovery stored during mechanical damage. The use of dipolar forces instead of chemical or physical modifications not only eliminates additional alternations enabling multiple damage-repair cycles but also provides further opportunity for designing self-healable commodity thermoplastics. These materials may offer numerous applications, ranging from the use in electronics, ion batteries, H fuel dispense hoses to self-healable pet toys, packaging, paints and coatings, and many others.
尽管偶极力相对较弱,但它们会导致无处不在的分子间和/或分子内相互作用,这对于实现聚合物材料的机械完整性尤为关键。在这项研究中,开发了一种在热塑性共聚物中获得自修复性能的方法,该方法依赖于所有大分子中存在的非共价偶极力,尤其是含氟共聚物。C─F 和 C═O 键之间以及 CH/CH 实体之间的偶极力的组合促进了无需外部干预的自修复。偶极-偶极、偶极诱导偶极和诱导偶极诱导偶极相互作用的存在导致粘弹性响应,从而控制含氟共聚物在环境条件下的宏观自主多循环自修复。归因于单体序列和单体摩尔比的有利偶极力引起所需的共聚物立构规整性,从而使机械损伤过程中储存的熵能得以恢复。使用偶极力代替化学或物理修饰不仅消除了额外的改变,从而实现了多次损伤修复循环,而且还为设计可自修复的商品热塑性塑料提供了更多机会。这些材料可能有许多应用,从电子产品、离子电池、H 燃料分配软管到自修复宠物玩具、包装、油漆和涂料等。