摘要
离子作用的可逆性赋予了含离子聚合物丰富的力学和电学性能,使其广泛应用在高抗冲材料、记忆材料、自修复材料和智能响应材料等新兴领域.本专论结合作者近年的研究工作,介绍了含离子聚合物体系的构效关系和分子流变学,从3个方面展开:第1部分介绍了对于含离子聚合物的离子聚集状态的调控,和离聚物与聚电解质的相互转化;第2部分介绍了离子高度聚集的无规离聚物丰富的线性黏弹性,重点介绍了非缠结体系在链均一个离子浓度附近区域的溶胶凝胶转变以及缠结体系在平均每个缠结链段一个离子浓度附近区域的单平台到双平台模量的转变;第3部分介绍了如何进行分子设计,使得含离子聚合物成为有效的离子传输介质.最后总结了该研究领域的科学问题和面临的挑战.
Ion-containing polymers refer to polymers with covalently bonded ionic groups. The strength of ionic interaction relies on the ionic species as well as the polarity of their surrounding medium, and thus can be tuned in a wide range. When the energy approaches the thermal energy, association and dissociation of the ionic interaction would enter a time window of our observation and thus the interaction becomes reversible. The reversibility enables the ion-containing polymers to exhibit rich rheological and dielectric properties, so as to be applied in varied novel materials including impact-resistant, shape-memory, self-healing and intelligent materials. This review highlights recent progresses on understanding the structure-property relationship and molecular rheology of the ion-containing polymers. Part I summarizes a relationship between the association status and interaction energy of ions and/or ionic dipoles. In particular, definitions of ionomer and polyelectrolyte have been given on a basis of relative strength of the electrostatic interaction and thermal energy. Morphological and dynamic changes have been explained along with an ionomer-to-polyelectrolyte transition though introducing polar solvent into an ionomer. Part II summarizes evolution of linear viscoelasticity of random ionomers（in which the ionic groups are randomly distributed） with the ion content. Particular interests have been placed on a sol-gel transition that occurs at averagely ~ one ion per chain and completed at averagely ~ two ions per chain for non-entangled random ionomers, and a single-to-double plateau transition that occurs at averagely ~ one ion per entanglement for entangled random ionomers. Both the theoretical and experimental developments have been summarized with respect to the improved understanding of the two transitions. Part III summarizes the ion transportation within the ion-containing polymers, in particular molecular design to soften the ionic interaction as well as to increase the ion mobility, both should enhan
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2017年第8期1220-1233,共14页
Acta Polymerica Sinica
关键词
离聚物
聚电解质
单离子导体
结合能
可逆性
线性黏弹性
Ionomer
Polyelectrolyte
Single-ion conductor
Association energy
Reversibility
Linear viscoelasticity
