Effects of regular networks composed of rigid and flexible segments on the shape memory performance of epoxies

A series of regular rigid-flexible crosslinking epoxy networks were prepared from dithiol allyl glycidyl ethers (DTAGEs) and 4,4’-diaminodiphenylmethane (DDM). In these networks, the chemical structure of DTAGEs was tidily flexible and that of DDM was simply rigid, which ensured the flexible segments more distinguishable from the rigid units. The effects of regularity and rigid-flexible character of the networks on shape memory properties, especially shape recovery speed, were investigated detailly. It was found shape recovery speed was reversely proportional to the flexibility of the regular crosslinking networks. Compared with flexibility, regularity had a greater impact on the recovery speed. In addition, regularity had a significant influence on the recovery speed of the rigid units while had little influence on that of the flexible segments. The well-designed regular rigid-flexible crosslinking networks exhibited excellent shape memory performance with high shape memory fixity (≥ 98.4%) and shape mem...