Nonisocyanate polyurethane (NIPU) has been extensively studied because of its sustainability potential. However, the low reactivity of five-membered cyclocarbonates with amines and the side reactions at higher temperatures always sacrifice the performance of NIPUs. In this work, a bisphenol-S cyclic thiocarbonate and different amino-terminated dimer-acid polyamides (DAPAs) were used to prepare nonisocyanate polythiourethanes (SPTU-DAs). Wherein bisphenol-S acts as a hard segment due to a π−π package, plentiful hydrogen bonds introduced by DAPA units induce crystallization and nanophase separation. They both endow the NIPUs with high mechanical performance. Meanwhile, active cyclic thiocarbonate, instead of cyclic carbonate, ensures rapid synthesis under mild conditions without side reactions. The experimental results of DSC, WAXD, and DMA confirmed the existence of crystallization of SPTU-DAs. The as-prepared thermoplastic polythiourethane has a maximum strength of more than 10 MPa, which is stronger than those of the cross-linked nonisocyanate polythiourethanes reported. It is of key significance to obtain the high performance of nonisocyanate polythiourethanes.

Construction of 2D materials into a hierarchical structure cannot only effectively avoid restacking of individual nanosheets but also endows them with improved catalytic efficiency, which have generated extensive interest in recent years. Nevertheless, the scalable and effective preparation of 2D materials constructed hierarchical structures, such as unique 2D/1D structure, is rarely achieved. Herein, we report a facile alkali-soaking strategy for the preparation of 2D transition metal hydroxide/oxide nanosheets-assembled hierarchical structures, in which the rational designed bimetallic metal–organic frameworks (MOFs) are annealed followed by a simple alkali soaking. Our method is capable of preparing various hierarchical structures based on 2D materials, including Co­(OH)2, Ni­(OH)2, and Mn3O4 nanosheets. Moreover, a high yield of ∼2.2 g was achieved for a batch of Co­(OH)2 nanosheet-assembled structure. Impressively, the as-synthesized Co­(OH)2 hierarchical structure shows excellent electrocatalytic performances toward the oxygen evolution reaction (OER), which achieves a current density of 10 mA cm–2 at a low overpotential of 267 mV with a small Tafel slope of 62.0 mV dec–1. Furthermore, it delivers a small charging/discharging voltage gap of 1.2 V at 75 mA cm–2 and high stability for over 240 h, when used as an air cathode for rechargeable Zn-air batteries.

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Diglycerol and dimer acid (DA) are used as precursors for the solvent-and catalyst-free synthesis of fully biobased non-isocyanate polyurethanes to replace toxic isocyanates and petroleum-based reactants. Linear polyhydroxy(amide-urethane)s (L-NIPHAUs) were synthesized via the melt aminolysis copolymerization between diglycerol dicarbonate (DGDC) and diamino-telechelicoligoamides (DAPAhs) from DA and hexamethylenediamine (HDA). By changing the DA/HDA molar ratios, the structures of DAPAhs and L-NIPHAUs were regulated in a simple and straightforward manner. Atomic force microscopy (AFM) and dynamic mechanical analysis (DMA) of the L-NIPHAUs reveal that the huge polarity difference between the hard segments (HSs) and soft segments (SSs) leads to nanophase separation. The N-amidohexylene-diglycerolbis(hydroxyurethane)-N′-amidohexylene and N-amido-hexylene-N′-amido segments form double HSs, while the bulky nonpolar DA residues serve as SSs. L-NIPHAUs also exhibit semicrystalline structures with good thermal stability evidenced by wide-angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), and thermogravimetry analysis (TGA). They possess T m ranging from 94 to 110 °C and tunable mechanical properties with a tensile strength of 7.3−12.1 MPa and strain at break of 311−858%. Introducing DA segments increases the hydrophobicity of L-NIPHAUs and the water contact angle and decreases the surface energy. L-NIPHAUs also show excellent solvent resistance in organic solvents, thanks to their intramolecular hydroxyurethane hydrogen bonding, three-dimensional inherent intermolecular hydrogen bonding networks, and the modification of bulky nonpolar DA SSs.

Understanding the dynamical behaviors of two-dimensional (2D) macromolecules is of fundamental importance for the precise modulation of their assembled structures and material performances. However, considerably less is known about how discrete macromolecular sheets aggregate into extended macroscopic assemblies in solutions. The absence of a quantitative description of the assembly process limits the precise structural control of assemblies. Here, we investigated the aggregation thermodynamic transition and kinetic behavior of 2D macromolecules in the model of single layer graphene oxide (GO). Combining Flory−Huggins theory with experimental observations, we unveiled the critical thermodynamic transition of GO to correlate with the solvent property. We proposed a theoretical falling-leaf model to quantitatively describe the kinetic aggregation process of 2D GO sheets. Experimental analysis validated the theoretical prediction that the thickness of GO aggregates has a power law relation with the poor solvent content. Our work provides a fundamental understanding of phase separation of 2D macromolecules and offers an insight into modulating the aggregated structures of their assembled materials.