writer：Qiong Li, Songqi Ma*, Jingjing Wei, Sheng Wang, Xiwei Xu, Kaifeng Huang, Binbo Wang, Wang
keywords：Epoxy resins; Shape memory polymers; Structure-property relationships; Non-planar ring; Computational simulation
source：期刊
specific source：Macromoleclar Research
Issue time：2019年

Non-planar-ring epoxies together with non-planar-ring hardeners could achieve thermosets combining ultra-high shape recovery speed and excellent thermal properties. High shape recovery speed reflected high efficiency, and could decrease the energy consumption and the harmful effect of external stimuli on the materials, while it often conflicts with the thermal properties of shape memory polymers. In this paper, for the first time, epoxy resins with the super-short shape recovery time within 3s were developed from non-planar-ring epoxies and hardeners, and their glass transition temperature (Tg) were ~127 °C much higher than their benzene ring analogues. The effects of non-planar-ring structures of the epoxies and hardeners on the curing behavior, thermal properties as well as the shape memory properties of the thermosets were systematically investigated; the structure-property relationships were disclosed with the help of computational simulation of structure parameters and ESP maps. The faster shape recovery speed of the non-planar-ring epoxy thermosets is from their higher molecular mobility contributed by the conformational transition of non-planar-rings as well as their higher recovery force compared with benzene ring analogs. Their higher Tgs are from the steric hindrance by the larger molecular volume of the non-planar-rings than benzene ring. This work will provide an effective method to produce shape memory polymers with excellent shape memory effects and high performance.