Dihydrazone-based dynamic covalent epoxy networks with high creep resistance, controlled degradability, and intrinsic antibacterial properties from bioresources

Abstract

This work highlights the exploitation of the dihydrazone motif to build antibacterial covalent adaptable networks with no creep at ∼105 °C.

Mechanically robust, creep-resistant, intrinsic antibacterial and reprocessable dynamic polyurethane networks based on azine moieties

“…The high performance of ACPCNs could be ascribed to the rigid conjugated azine structure and Schiff base-related hydrogen bonds. [42][43][44] Although ACPCN45121 showed the highest data except for the breaking stress, the film contracted severely, which led to an uneven structure exhibiting higher standard deviation.…”

“…The dynamic exchange mechanism of small compounds had been studied by Ma's group. 42 Two small molecules reacted to produce a new compound through a metathesis mechanism at 150 1C for 6 h (Scheme 1b).…”

“…40,41 Ma's group have synthesized an epoxy monomer containing azine moiety and prepared dihydrazone CANs with excellent mechanical properties, creep resistance, controlled degradability, and inherent antibacterial properties. 42 However, the azine groups have not been applied in dynamic crosslinked polyurethane networks to the best of our knowledge. The relatively high exchange temperature of azine groups is expected to solve the heat-resistant problem of dynamic covalent crosslinked polyurethane networks.…”

Photo- and Acid-Degradable Polyacylhydrazone–Doxorubicin Conjugates

“…As discussed above, poly(acyl)hydrazones have been studied in the literature as dynamic covalent polymers, and have been proposed for the development of self-healing materials and adaptable networks due to the reversible nature of the (acyl)hydrazone bonds, which can be cleaved and reformed upon the application of a stimulus, such as acidic media or temperature [ 34 , 43 , 44 ]. In order to investigate the dynamic nature of the acylhydrazone bonds of the PEG- alt -AA copolymer prepared in this work, a solution of the polymer in H 2 O was first irradiated for 2 h at 254 nm to cleave the acylhydrazone bonds, and was afterwards left under stirring for 24 h in the dark.…”

Study on the Thermal and Impact Resistance Properties of Micro PA66/PU Synergistically Reinforced Multi-Layered Biaxial Weft Knitted Fabric Composites

“…Epoxy is the common matrix in fi ber-reinforced composites. Its highly cross-linked structure [24] has many useful properties, such as high modulus of elasticity [25], high failure strength [25], high creep resistance [26], and etc. However, most of the epoxy is brittle, which will lead to the impact resistance of the…”