Articles in 2017

The 1,1,3,3,5,5,7,7-octamethyltetrasiloxane-containing gelator, (R, R )-g/Si, was synthesized by a hydrosilylation with a gelation-driving segment based on trans-(1R, 2R)- 1,2-diaminocyclohexane. Gelation abilities were investigated in the mixed solvents of HDEH, liquid paraffin, and D5. (R, R )-g/Si could form stable and transparent gels due to the flexible octamethyltetrasiloxane segment.

Poly(L-lactide-co-glycolide)-b-poly(ɛ-caprolactone) multiblock copolymers (PLGA-PCL MBCs) were synthesized by the self-polycondensation of PLGA-PCL diblock copolymers (PLGA-PCL DBCs) in the presence of condensation agents. The phase-segregated PLGA domains acted as hard domains, improving the tensile properties. The hydrolytic degradation of PLGA-PCL MBC films in phosphate-buffered saline (PBS: pH=7.4) proceeded much faster than that of poly(L-lactide) (PLLA)-PCL MBC.

New organically bridged trialkoxysilanes containing 1,2,3-triazole moieties were synthesized. They were polymerized by sol–gel reactions, giving bridged silica membranes. Water separation properties of the membrane were investigated using a 2000 p.p.m. NaCl aqueous solution, as being 3.7–5.4 × 10⁻¹³ m³/m²·Pa· s of water permeance and 95–96% of NaCl rejection. Separation of neutral solutes such as 2-propanol, glucose and maltose from water by the membrane was also examined. The cutoff molecular weight (solute molecular weight on 90% rejection) was estimated to be 165.

The small-angle X-ray scattering intensity from the coexisting concentrated phase was measured in a phase-separated aqueous solution of the thermosensitive block copolymer poly(2-isopropyl-2-oxazoline)-b-poly(2-ethyl-2-oxazoline) under amphiphilic conditions (50 °C). The concentrated phase was disordered with no sign of micro phase separation. In addition, the scattering from individual copolymer chains and their aggregates existing in the concentrated phase hardly contributed to the total scattering intensity of the phase-separated colloidal solution of the block copolymer.

We synthesized difunctional and trifunctional vinyloxiranes and investigated the synthesis of networked polymers via the radical ring-opening homopolymerization or copolymerization of these monomers. The obtained networked polymers contained vinyl ether structures in the main chain, as confirmed by infrared analysis. In addition, we investigated the radical ring-opening copolymerization of monofunctional vinyloxirane or adamantane-substituted vinylcyclopropane. Networked polymers with various crosslinking densities were obtained, and the heat resistance and volume change of these polymers were evaluated before and after curing.

The author has recently focused on exploring novel possibilities of cellulose and amylose, which exist in great abundance on earth. In this review, the author describes the functionalization of cellulose and amylose to give novel chiral functions other than that as chiral stationary phases and their use in applications, such as asymmetric organocatalysts, chiral auxiliaries and chiral fluorescent sensors. Furthermore, the application of a saccharide-containing helical polymer, which can be prepared through polymerization of a glucose-based monomer, to a circularly polarized luminescence material is also described.

Stereocomplexes of polylactide with both terminals conjugated to bio-based aromatic compounds, with benzyl alcohol (b1) as an initiator and 3,4-diacetoxycinnamic acid (DACA) as a protection group, were easily formed via inkjet printing techniques based on even layer-by-layer assembly (DACA-SCb1-LbL) and solution mixing (DACA-SCb1-mix). The thermal properties of the stereocomplexes were superior to those of the original PLAs. Inkjet printing is a powerful method of forming functional, thermally stable PLA stereocomplexes with both terminals conjugated.

Both experimental measurements and molecular simulations were applied to probe the strain-induced crystallization (SIC) of natural rubber in real time, and some interesting results have been found. A very large fraction of unoriented amorphous phase remains, even at high strains. The onset strain of SIC in peroxide-cured NR decreases with increasing crosslinking density, while that in sulfur-cured NR is independent of crosslinking density. This difference may be caused by different network structures. Nanofillers, entanglements, non-rubber components and pseudoend-linked networks also result in abnormal SIC phenomena.

A new type of porous crystal, metal–organic framework (MOF), has been recently utilized for the preparation of network polymers. The obtained network polymers possess highly controlled structures derived from the molecular organization of MOF crystal. This focus review emphasizes the significance of integration of flexible organic polymers and rigid MOFs to attain shaped network polymers and organic–inorganic hybrid networks.

Schematic representation depicts the synthesis, microstructure and EMI shielding properties of functional cotton and nylon fabrics based on polyaniline nanofibers.