Effects of Ligands in Rare Earth Complex on Properties, Functions, and Intelligent Behaviors of Polyurea–Urethane Composites

Abstract

There is a need to create next-generation polymer composites having high property, unique function, and intelligent behaviors, such as shape memory effect (SME) and self-healing (SH) capability. Rare earth complexes can provide luminescence for polymers, and their dispersion is highly affected by ligand structures. Here, we created three different REOCs with different ligands before studying the effects of ligands on REOC dispersion in polyurea–urethane (PUU) with disulfide bonds in main chains. In addition, the effects of different REOCs on mechanical properties, luminescent functions, and intelligent behaviors of PUU composites were studied. The results showed that REOC I (Sm(TTA)3phen: TTA, thenoyltrifluoroacetone; phen, 1,10-phenanthroline) has incompatible ligands with the PUU matrix. REOC I and REOC III (Sm(BUBA)3phen: BUBA, 4-benzylurea-benzoic acid) with amine and urea groups facilitate their dispersion. It was REOC III that helped the maintenance of mechanical properties of PUU composites due to the good dispersion and the needle-like morphologies. Due to more organic ligands of REOC III, the fluorescence intensity of composite materials is reduced. The shape recovery ratio of the composite was not as good as that of pure PUU when a large amount of fillers was added. Besides, REOC I reduced the self-healing efficiency of PUU composites due to poor dispersion, and the other two REOCs increased the self-healing efficiency. The results showed that ligands in REOCs are important for their dispersion in the PUU matrix. The poor dispersion of REOC I is unbeneficial for mechanical properties and intelligent behavior. The high miscibility of REOC II (Sm(PABA)3phen: PABA, 4-aminobenzoic acid) decreases mechanical properties as well but ensures the good shape recovery ratio and self-healing efficiency. The mediate miscibility and needle-like morphology of REOC III are good for mechanical properties. The shape recovery ratio, however, was decreased.

Multifunctional properties optimization and stimuli‐responsivity of shape memory polymeric nanoarchitectures and applications

“…These SMPNs are sensitive to UV, Vis, and NIR light. [90,91] A study fabricated a thermoplastic polyurethane (PU)-oriented photomechanical elastomer (PME) possessing light-responsivity as well as self-mending properties. [92] PME underwent synthesization through reacting toluene-2,4-diisocyanate (TDI) with poly (propylene glycol) to fabricate a PU prepolymeric matrix, subsequented by reaction with PU prepolymer with 4,4-methylenedianiline (MDA) as well as DAB.…”

Constructing Self-Healing Polydimethylsiloxane through Molecular Structure Design and Metal Ion Bonding

“…Rare earth metals, as important strategic resources, find extensive applications in the metallurgy and petrochemical industries due to their unique properties [24]. Rare earth ions possess distinctive 4f electron orbitals, exhibiting outstanding optical and electromagnetic characteristics, and have been widely applied in the field of polymer materials science [25]. Moreover, rare earth ions can form metal coordination bonds with organic ligands, offering potential for constructing self-healing polymer materials.…”