Preparation and shape memory properties of rigid-flexible integrated epoxy resins via tunable micro-phase separation structures

摘要

In this work, two types of rigid-flexible integrated epoxy resins, diglycidyl ether of eugenol-2-mercaptoethanol (DGEEM) and diglycidyl ether of vanillic alcohol (DGEVA), which possess similar rigid methoxy-substituted aromatic structures and different soft aliphatic chains in length, were prepared. Micro-morphology structures were tested by AFM, AFM nanomechanical mapping, and AFM-IR. Macro-properties were respectively characterized by tensile test and shape memory test. Results showed that a series of tunable micro-morphology structures including hard-phase-rich sea-island structure, bi-continuous structure, and soft-phase-rich sea-island structure were explored after cured with 4,4-methylenedianiline. Moreover, the shape memory mechanism for these SMEPs was concluded: phase separation structures are the base of these SMEPs, and soft phase acts as switching segments, which contributes to shape memory strain of the SMEPs. The optimal designed SMEPs with bi-continuous phase structure was prepared from this mechanism, which exhibit good mechanical properties and excellent shape memory performance.