Original Article

The introduction of imide groups into reactive oligomers containing long-chain aliphatic structures improved their compatibility with biphenyl-type epoxy resins. UV‒vis spectroscopy revealed the presence of intermolecular charge-transfer interactions between the biphenyl and imide groups. Cured epoxy blends containing the imide-based reactive oligomer exhibited smaller phase-separated structures than blends containing the imide-free reactive oligomer. It was found that the compatibility of the reactive oligomers influences the size of the phase-separated structures in the cured epoxy resins.

A decomposable and recyclable polymer consisting of polystyrene and trithiocarbonates was synthesized. The synthesized polymer decomposed by mixing with allylamine. The decomposition was due to the reaction between trithiocarbonate in the polymer and allylamine. The decomposition was evaluated by the indentation test and the spectroscopies (e.g., ¹H NMR). Following the decomposition, the recycling of the decomposed polymer was conducted via a thiol-ene reaction by shining UV light (λ =365 nm). The resultant recycled polymer showed as high mechanical strength as the original polymer before decomposition.

We report controllable protein adsorption onto crystalline assemblies of carboxylated cello-oligosaccharides synthesized via enzyme-catalyzed oligomerization. Under various pH and ionic strength conditions, significant adsorption of basic proteins onto negatively charged cello-oligosaccharide assemblies was observed. Notably, we found that acidic proteins were adsorbed onto the cello-oligosaccharide assemblies at an acidic pH, which was significantly enhanced under low ionic strength conditions. Our findings demonstrate the electrostatic control of protein adsorption onto cello-oligosaccharide assemblies through adjustments to their surface properties and solution parameters.

This study presented a noval material derived from poly(vinyl alcohol) (PVA), which was crosslinked with L-glutamic acid to improve the poor stability of PVA in water and modified with surface porosity introduced by poly(ethylene glycol) (PEG). The research primarily focused on elucidating the influence of PEG on the physicochemical properties of the material, which were governed by phase separation and hydrogen bonding interactions with PVA. The presence of porous structures significantly altered the material’s properties and enhanced its adsorption capacity toward copper(II) ions.

Substituting hydroquinone into polyallylamine allows the resulting organic redox polymer to achieve 99% of its theoretical capacity in aqueous electrolytes. A polymer-air secondary battery fabricated with this redox polymer as the electrode-active material exhibited a constant discharge voltage, high cyclability, and high rate capability. In addition, facile acid treatment decomposes the redox polymer into its raw materials. This work demonstrates a polymer design strategy for integrating typically hydrophobic organic redox molecules into recyclable aqueous batteries.

Cellulose acetate sponges were fabricated by cryo-templating, without chemical crosslinking, from cellulose acetate nanofilms produced using a nonsolvent-induced phase separation (NIPS)-jet spinning technique. X-ray computed tomography (X-CT) revealed their open-cell, continuous microstructure. The sponges exhibited resilience, stability, and mechanical tunability via microstructural tailoring. Their viscoelasticity was attributed to the bending of the cell structure and the delamination and slippage of the uncrosslinked nanofilms.

Mucin is a biological compound that consists of high-molecular-weight glycoproteins and plays an important role in the evaporation of water from respiratory droplets. The detailed structure of mucin has been clarified by static light scattering and the Fujita plot. The molecular weight is 2.92 × 10⁷, and the radius of gyration is 289 nm. The hydrodynamic radius is 198 nm, which was determined from multiangle dynamic light scattering. The scattering function reveals that mucin has a chain-like, elongated structure.

The crystal structure of the nylon-6 α form has been established on the basis of wide-angle X-ray diffraction data analysis. We have believed it for the past 70 years. However, the combination of X-ray and neutron diffraction data has required us to introduce the statistical disorderliness to the chain-packing mode as well as revise the space group to that of a higher symmetry. The refined crystal structure makes it possible to perform a more reliable quantitative analysis of the structure‒property relationship of the α form.

This study aimed to elucidate the mechanism underlying the release of micrometer-scale particles from transient networks using a systematically controlled model system composed of tetra-armed polyethylene glycol (Tetra-PEG slime). The system features a well-defined structure with uniform strand lengths and functionalities. Our results demonstrate that particle release is governed by the dissolution of the matrix and that the release barrier depends on the surrounding network topology. This release behavior is primarily determined by network connectivity and is independent of polymer concentration and strand length.

Biomass-derived tricomponent polymers were synthesized consisting of Levoglucosenone, aliphatic dithiol, and dicarboxylic dihydrazide. Sequential treatment of LGO with 1,4-butanedithiol followed by polycondensation with several dicarboxylic dihydrazides resulted in the formation of the corresponding polyhydrazones. All the C-S and C = N bonds were formed stereoselectively, which provided us their optical properties. In addition, these polymers also formed organogels with DMF after further heating. The degree of swelling varied between 170% and 469% depending on the carbon number of the dicarboxylic dihydrazide.

Graft copolymerization of a bifunctional monomer, triethylene glycol dimethacrylate (TEGDMA), onto deproteinized natural rubber (DPNR) was performed in latex stage using a redox initiator. It was found that TEGDMA could be grafted onto NR chain with low conversion and grafting efficiency. TEM revealed the formation of a continuous nanomatrix of poly(TEGDMA) surrounding the rubber particles. This nanomatrix enhanced structural integrity, gel content and slightly shifted the glass transition temperature. Thermal and mechanical properties, assessed by DSC, TGA, DMA, and swelling tests, demonstrated that polyTEGDMA significantly influenced the graft copolymer’s performance.

The entanglement dynamics of salt-free aqueous solutions of poly(sodium styrenesulfonate) was investigated using conventional bulk shear rheometry and diffusing wave spectroscopy microrheometry. Our scaling analysis of the entanglement concentration, plateau modulus, and relaxation time revealed a clear crossover from polyelectrolyte-like to neutral polymer-like behavior at a critical monomer concentration c_D ~ 0.3 M and a critical degree of polymerization N^* ~ 6000. We also found that the polymer concentration and molecular weight dependence of the tested entanglement parameters showed good agreement with the Dobrynin model.

A well-controlled ring-opening alternating copolymerization (ROAC) of cyclic anhydrides and isobutylene oxide (IBO) using organobase catalysts was developed. Using t-BuP₂ as a catalyst, the ROAC of phthalic anhydride (PA) and IBO proceeds smoothly, yielding crystalline P(PA-alt-IBO) with narrow molecular weight distribution (Đ ≤ 1.1). This method was extended to other cyclic anhydrides and initiators. Additionally, this ROAC system was applied to the synthesis of copolymers, including statistical copolymer and block copolymer. This study provides a straightforward and precise strategy for synthesizing crystalline polyesters and further macromolecular designs.

In this study, we used coarse-grained molecular dynamics simulations with iterative defect removal algorithm to investigate structure-properties relationship of star polymer networks (SPNs) and telechelic polymer networks (TPNs). SPNs possess a mechanism that eliminates loop defects during network formation, resulting in a greater number of elastically effective junctions than in TPNs. Despite the differences in cross-linking mechanisms, both network types exhibit shear moduli approximately twice the value predicted by the phantom network model using the effective closed cycle density, independently on the number of branches or the binding ratios.

Optical microscopy combined with a stretching stage allows the comparison of stress‒strain curves and real-time visualization of microscale structural changes in a microparticle-based polymer film under tensile testing. In films composed of inter-crosslinked microparticles, particle deformation deviated from affine behavior due to limited deformability. Local clusters of microparticles exhibited more location-dependent deformation, suggesting that the separation of neighboring particles contribute to film fracture.

A double-layer-coated slow-release fertilizer (DCSRF) was prepared with urea as the core, citric acid-modified starch and polyvinyl alcohol as the inner coating, and sodium alginate as the outer coating. Compared with the single-layer coated fertilizer (SCSRF), the DCSRF demonstrated superior slow-release effects, releasing 69.2% of the nutrients within 38 days in water. Additionally, adding 2% DCSRF to soil increased its maximum water-holding capacity by 8%. Pot trials revealed that the DCSRF considerably improved target crop growth, including tiller number, plant height, root depth, and leaf width, outperforming the other methods.

A π-conjugated Lewis acid dopant, branched octyloxy borane (BOB), was designed to modulate the solid-state microstructure of DPP-based polymers. BOB suppresses long-range crystallinity and promotes short-range aggregation via non-covalent interactions. At 1 wt%, it improves the crack onset strain from 20 to 100%, while retaining high carrier mobility over 1.0 cm² V^–1 s^–1. This strategy enables simultaneous enhancement of mechanical and electronic performance through dopant-induced morphology tuning.

Poly(ether ether ketone) (PEEK), a high-performance engineering plastic, was investigated to evaluate how its aggregation structure is influenced by crystallization pathway, cold crystallization and melt crystallization, and temperature affect. The degree of crystallinity increased with increasing crystallization temperature, while crystallographic lattice distortion decreased, regardless of the crystallization pathway. These results indicate that crystallization temperature plays a more dominant role than the pathway in determining the structure. The findings highlight the importance of thermal molecular motion during crystallization and provide valuable insights for optimizing the processing and design of semicrystalline engineering plastics.

Ring-opening copolymerization using the cyclic comonomer 3,7-bis(methylene)-1,5-dithiacyclooctane (BMDTO) introduces cleavable C–S bonds for chemical recyclability; however, it suffers from low molar mass via bulk free radical polymerization due to undesired radical transfer. To this end, this study leverages emulsion polymerization to produce polystyrene-BMDTO copolymers (1–7 mol% BMDTO), achieving higher molar mass (81 vs. 17 kg/mol) at 2.4 mol% BMDTO. Nuclear magnetic resonance spectroscopy and size exclusion chromatography confirm the incorporation and cleavability of BMDTO, establishing emulsion polymerization as a viable method for producing recyclable, high-performance vinyl copolymers.

A trifunctional five-membered cyclic carbonate resin synthesized from resveratrol (Res-TC) was thermally cured with diamines: trioxyethylene diamine (TODA), dioxyethylene diamine (DODA), m-xylene diamine (mXDA), pentamethylene diamine (PMDA), and Jeffamine ED-600. An adhesion test of the metal substrates revealed that cured Res-TC/TODA adhered strongly to metal substrates. After treatment with enzymes such as lipase and protease, some cured resins exhibited greater water uptake than did those treated with pure water, indicating that the enzymes cleaved the network of the cured resins and gradually decomposed the materials.