Volume 48 Issue 6, June 2016

Polymers that contain arylene groups in their main chain are of significant importance because of their applications to semiconducting materials or engineering plastics. Therefore, controlled methods for the synthesis of arylene-containing polymers based on chain-growth polymerization have been intensively developed in polymer chemistry. This review focuses on the advances in chain-growth polymerization accompanied by formation/introduction of arylene groups into polymer main chains.

Our recent results in the concurrent cationic vinyl-addition and ring-opening copolymerization of vinyl ethers (VEs) and oxiranes are summarized with particular emphasis on the strategies required to generate crossover reactions between different types of monomers. Most importantly, carbocation generation via the ring-opening reaction of the oxonium ion is indispensable for the crossover reaction from oxirane to VE. This article also summarizes concurrent cationic vinyl-addition, ring-opening and carbonyl-addition terpolymerization, the copolymerization using an alkoxyoxirane through the alkoxy group transfer mechanism and the long-lived species-mediated polymerization using cyclic formals.

Various stimuli-responsive materials consisting of the rigid rod-like polyelectrolyte ‘imogolite’ have been prepared. The combination of imogolite and dicarboxylic acids yields hydrogels that exhibit thixotropy (upper photographs) and physical anisotropy via the orientation of the imogolite. Robust hydrogels have also been obtained by polymerization of vinyl monomers in aqueous imogolite dispersions that show reversible isotropic–anisotropic structural transitions in response to strain (middle photographs). Furthermore, an electrorheological effect of the aqueous imogolite dispersions at low voltage has been discovered that should permit the design of imogolite-based electro-stimulus-responsive materials (lower photographs).

Thermal reaction mechanism of γ-irradiated polytetrafluoroethylene (PTFE) is elucidated at the molecular level by kinetic analysis, where a new multichannel Fourier-transform chemiluminescence spectrometer was used.

In this study, we were synthesized novel biomass network polymer containing silsesquioxane as inorganic moiety. First, novel network polymer precursors were synthesized with castor oil or branched poly(l-lactic acid) (PLLA) and 3- (triethoxysilyl) propyl isocyanate. Precursors were carried out to cross-link reaction at 120 °C for 24 h, and obtained network polymer films. Furthermore, we were synthesized cross-linked film, which was increased inorganic moiety using tetraethyl orthosilicate.

Magnetic-field-induced alignment of low-molecular-weight syndiotactic polystyrene (sPS) has achieved. Isothermal crystallization from the melting state containing local ordered domains under the 2 or 10 T of the magnetic-field-induced alignment of sPS crystals. The crystalized sPS samples formed the β phase, and the b-axis was aligned parallel to the magnetic field. Low molecular weight of sPS and high magnetic field were effective for high alignment degree. A stepwise crystallization attained higher alignment of sPS compared with an isothermal crystallization.

We measured the single-molecule interaction force between various hydroxybenzoic acids and a Si₃N₄ cantilever by atomic force microscopy in force curve mode. The adhesion properties of hydroxybenzoic acids with different numbers of hydroxyl groups in various positions on the aromatic ring were compared to determine the effect of the hydroxyl groups on single-molecule interactions. It was found that as the number of hydroxyl group increases, the number of single-molecule interactions increases and the interaction force also increases. A catecholic system with two hydroxyl groups on the aromatic ring, similar to that found in mussel adhesive, has been well studied. Here we demonstrate that gallic acid with three hydroxyl groups on the aromatic ring showed good adhesion and a large number of single-molecule interactions. We synthesized gallic acid adhesives that exhibited sufficiently strong adhesion (10 MPa) to be of practical use.

1,1-Bis(4′-N,N-dimethylaniline)-tetraphenylsilole (APh-TPS) and APh-TPS containing polymers (PF-APh-TPS) were successfully synthesized and characterized. Compared with the 1,1-dimethyl-2,3,4,5-tetraphenylsilole analogs, superior PLED performances were achieved based on PF-APh-TPS with 1,3,5-tris (2-N-phenylbenzimidazolyl) benzene (TPBI) as the hole-blocking layer.

A number of amphiphilic N-isopropylacrylamide (NIPAAm) oligomers and polymers with a S-1-dodecyl-S′-trithiocarbonate (DTC) and an amino terminal group has been designed. The electrostatic interactions between the amine segments and the anionic metal cyanide complexes have a significant role in the morphology and thermoresponsiveness of the hybrids. The hybrids of PNIPAAms and metal complexes can lead not only to nanostructures in water but also to cylindrical aggregates (or spherical aggregates) assembled in rod, square and sheet structures.

Model calculation results for the coefficient of performance c (solid) of a gel actuator driven by the shrinking transition and the increment of the transition temperature (ΔT/T₀) (broken) of the gel plotted against applied force. The shape of these curves depends on the ratio α/β (see text), but the real gels seem to hold α/β >1. In this figure α=3 and β=2 are used for calculation. A reduced form is employed for these variables.

Glycopolymers bearing oligosaccharides with narrow polydispersity indexes (<1.4) were synthesized using a ‘post- click’ chemistry method. A polymer backbone was synthesized by reversible addition-fragmentation chain transfer polymerization with acrylamide derivatives. Maltose, lactose, 3′-sialyllactose and 6′-sialyllactose were added to the polymer backbone and corresponding glycopolymers were obtained. The interactions between the glycopolymers and lectins were evaluated by a quartz crystal microbalance measurement. The interactions between the glycopolymers and influenza viruses were evaluated by hemagglutination inhibition assay.