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A new manipulation technique of polyurethane materials via electrophoretic deposition (EPD) is proposed. Polyurethanes with sulfonyl groups are synthesized for the EPD coatings on a stainless-steel electrode plate at the anode side selectively. The coating properties, including peeling resistance, scratch resistance, and transparency, are improved by optimizing soft segment fraction and also by reducing aromaticity of the polyurethanes.

Relationship between the primary structures and their properties is recognized as an important research subject for polymer chemists. To make progress in this academic field, innovative synthetic procedures of cyclic polymers are essential. The synthetic strategy has two typical pathways: one is the ring closure of functional linear polymers and the other is ring expansion polymerization using cyclic monomers, an initiator, or a catalyst. This focus review deals with the recent synthetic evolution of cyclic polymers, focusing on our new strategy: ring closing without highly dilute conditions.

A preparation of polyacrylate-based vitrimer-like elastomers with dynamic bond-exchangeable cross-links is demonstrated. The component polymer is a poly(ethyl acrylate)-based copolymer bearing pyridine groups randomly, which was cross-linked by a quaternization reaction of pyridine groups with dibromo cross-linkers (dibromo hexane). The bond exchange is induced via trans-N-alkylation of quaternized pyridines at high temperatures, which is revealed by temperature-ramp FT-IR, elongational creep, and stress-relaxation tests. Some useful functions of the present material, such as reprocessability, thermal and chemical recyclability, are provided due to the bond exchange nature.

Direct Observation of Cyclic Poly(N-substituted maleimide)s with Broad Size Distributions Synthesized by Anionic Polymerization using an N-Heterocyclic Carbene and Successive Ring Closure Without High Dilutions.

We chose an autoinduction (IPTG-independent) system for overexpression of recombinant proteins using E. coli as the expression host. In autoinduction, glucose and lactose are used as main carbon sources for cell growth. When the glucose is almost completely consumed as the first growth of E. coli., the carbon source turns to lactose, accompanied by regioselective chemical transformation of lactose to allolactose, which acts as the trigger for activation of transcription by releasing the repressor. Using this system, we achieved marked overexpression of the biosynthesized GFP and aECM-CS5-ELF.

Dehydration polycondensation of bromoadipic acid and methylsuccinic acid with 1,4-butanediol was performed at 80 °C to synthesize aliphatic polyesters containing pendent bromo groups without dehydrobromination using scandium trifluoromethanesulfonate as the catalyst. Azidation of poly(butylene bromoadipate-co-butylene methylsuccinate) also proceeded to generate poly(butylene azidoadipate-co-butylene methylsuccinate) (M_n=10.4 × 10³). We successively photo-crosslinked the resultant azidopolyesters by UV irradiation. We also described azidation of polyesters having pendent hydroxyl groups by using the ‘diphenylphosphoryl azide-1,8-diazabicyclo[5.4.0]undec-7-ene substitution strategy’ to produce water-soluble polyesters containing pendent azido groups (M_n=7.5 × 10³).

We performed the ternary ‘click’ copolymerization (gelation) of bis(butynyl) methylsuccinate, bis(butenyl) methylsuccinate and 3,6-dioxa-1,8-octanedithiol to synthesize a poly(ester-sulfide) gel, which after oxidation using Oxone afforded the poly(ester-sulfone) gel. The synthesized poly(ester-sulfone) gel was anode-selectively deposited on a stainless-steel electrode by electrophoretic deposition although the parent poly(ester-sulfide) gel was not.

The pH-sensitive peptide-grafted PNIPAm was successfully synthesized. The grafted PNIPAm shows different structures according to pH and temperature. Only above transition temperature and under basic conditions did the grafted peptide chains form a stable β-sheet structure and act as bridging points between the (Leu-Lys)₈-grafted poly(N-isopropylacrylamide) globules, resulting in the formation of a large aggregated body. This multi-stimuli-responsive polymer has a wide range of applications in nanotechnology.

The thiol-Michael polyaddition of three dialkynyl monomers with several dithiols proceeded using triethylamine as the catalyst to give unsaturated poly(ester-thioether)s with the expected structures (M_n, 2.4 × 10³ to 22.6 × 10³; molecular dispersity index [M_w/M_n], 1.26–2.00). All of the poly(ester-thioester)s had single glass-transition temperature values between −27 and 49 °C. While the rigid main chains improved the glass transition temperature, all of the poly(ester-thioester)s showed apparent enzymatic hydrolysis by lipase but low biodegradability in biodegradation tests using activated sludge.

We here demonstrate the importance of ligand–ligand distance on physical property tuning of metallosupramolecular materials by utilizing model-like polyesters bearing pyridine ligands at the side groups with a controlled ligand-distance. The ligand distance is treated as the pyridine group equivalent molecular weight (M_Py) and takes values of 900, 750, 550, and 420. The metal salt ZnCl₂ forms coordination bonds with the pyridine ligands, generating a metallosupramolecular network. DSC and rheological measurements revealed that the glass transition temperatures and apparent activation energy (E_a) of segmental motion changes in a close correlation with 1/M_Py.

The functionalization methods of polymeric materials using various types of cross-links, such as supramolecular cross-links, photo cross-links, and associative dynamic covalent bonded cross-links, were described. First, the enhancement and precise tuning of the thermal and mechanical properties are demonstrated in the supramolecular cross-link-based and photo cross-link-based designs. In the latter section, the design and physical property tuning of functional materials based on a special type of cross-linked materials with associative dynamic covalent bonded cross-links, known as vitrimers, are demonstrated.

Our recent studies on the zincate complex dilithium tetra-tert-butylzincate-catalyzed transesterification and polymerization are reviewed. In the first part of this report, the ROP of ε-caprolactone catalyzed by TBZL is described. In the second part of this report, the acylation and transesterification of alcohols with vinyl acetate and carboxylic esters catalyzed by TBZL are summarized. Next, TBZL-catalyzed polycondensations of diphenyl carbonate (DPC) with diols are discussed. In the last part of this report, the transesterifications of poly(phenyl methacrylate) (PPhMA) side chains with alcohols catalyzed by TBZL are described.