A novel dynamic network was successfully prepared via self-complementary quadruple hydrogen bonding through Upy-telechelic poly(tetremethylene ether) glycol (PTMEG) and four-arm star-shaped poly(ε-caprolactone) ((4)PCL) precursors. The structure and the dynamic feature were identified by FT-IR and (1)H NMR. The differential scanning calorimetry (DSC) analysis indicated that the crystalline PCL and PTMEG segments show a separated melting peak, and the aggregation of Upy dimer was also observed. The dynamic mechanical analyzer (DMA) test reveals that the storage modulus of the network drops evidently across the thermal transition. These characteristics of the network ensure that it exhibits a triple-shape effect, and the composition of the network influences the performance of shape memory effect. The variation of the fixing ratio of the network in each deformation step is quite according to the crystallinity of the dominant segment. The reversibility of the quadruple hydrogen bonding between Upy dimer endues the network with self-healing capacity, and the damage and healing test of the network revealed that increasing the content of the PTMEG segment will be of benefit to self-healing performance.

A novel light-induced shape-memory material based on poly(l-lactide)-poly(ethylene glycol) copolymer is developed successfully by dangling the photoresponsive anthracene group on the PEG soft segment selectively. For synthesis strategy, the preprepared photoresponsive monomer N,N-bis(2-hydroxyethyl)-9-anthracene-methanamine (BHEAA) is first embedded into PEG chains; then, we couple this anthracene-functionalized PEG precursor with PLA precursor to result in PLA-PEG-A copolymer. The composition of target product can be well-defined by simply adjusting the feed ratio. The chemical structures of intermediate and final products are confirmed by (1)H NMR. Differential scanning calorimetry analysis of material reveals that the PEG soft segment became noncrystallizable when 4% or more BHEAA is introduced, and this feature is beneficial to the mobility of anthracene groups in polymer matrix. The static tensile tests show that the samples exhibit rubberlike mechanical properties except for the PLA-dominant one. The reversibility of [4 + 4] cycloaddition reaction between pendant anthracene groups in PLA-PEG-A film is demonstrated by UV-vis. Eventually, the light-induced shape-memory effect (LSME) is successfully realized in PLA-PEG-A. The results of cyclic photomechanical tests also reveal that the content of PLA hard segment as well as photosensitive anthracene moieties plays a crucial role in LSME.

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A multi-stimuli-responsive shape-memory ternary nanocomposites with selective dispersion of MWCNTs was developed by introducing MWCNTs into a PBS-PCL multiblock copolymer matrix (PBSPCL) by a facile approach.