论文标题
连接器介导的玻璃二聚体中的熵控制的交联
Entropy-Controlled Cross-Linking in Linker-Mediated Vitrimers
论文作者
论文摘要
最近开发的连接器介导的玻璃体基于对各种市售聚合物的二Xborolanes的分解，既表现出良好的加工性和出色的性能，例如机械，热和化学耐药性，这表明了工业中加工的交联聚合物的新方法，其中设计原理仍然未知[M. M. [M. M. M. [M. M.）[M. M. [M. M. [M. M.）[M. Rottger等人，Science 356，62（2017）]。在这里，我们制定了一个理论框架，以阐明接头介导的玻璃体的相位行为，其中熵起着控制作用。我们发现，随着接头浓度的增加，玻璃二聚体会经历重进入凝胶溶剂的转变，这解释了最近的实验[S. S. Wu，H。Yang，S。Huang，Q.Chen，Macromolecules 53，1180（2020）]。更有趣的是，在低温极限下，接头浓度仍然决定了玻璃二聚体的交联度，这源自聚合物的构象熵与接头的转换熵之间的竞争。我们的理论预测与计算机模拟定量一致，并提供了理解和控制该新开发的玻璃二聚体系统的性质的指南。
Recently developed linker-mediated vitrimers based on metathesis of dioxaborolanes with various commercially available polymers have shown both good processability and outstanding performance, such as mechanical, thermal, and chemical resistance, suggesting new ways of processing cross-linked polymers in industry, of which the design principle remains unknown [M. Rottger, et al., Science 356, 62 (2017)]. Here we formulate a theoretical framework to elucidate the phase behaviour of the linker-mediated vitrimers, in which entropy plays a governing role. We find that with increasing the linker concentration, vitrimers undergo a reentrant gel-sol transition, which explains a recent experiment [S. Wu, H. Yang, S. Huang, Q. Chen, Macromolecules 53, 1180 (2020)]. More intriguingly, at the low temperature limit, the linker concentration still determines the cross-linking degree of the vitrimers, which originates from the competition between the conformational entropy of polymers and the translational entropy of linkers. Our theoretical predictions agree quantitatively with computer simulations, and offer guidelines in understanding and controlling the properties of this newly developed vitrimer system.
