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Ion-conductive behavior of a novel polymer electrolyte without oxyethylene units, poly(ethylene carbonate) (PEC)-Li salt system, was reported. Salt-concentration dependence revealed that the LiCF3SO3 and LiClO4 electrolytes exhibit typical polyether-like conduction behavior. However, the LiBETI, LiBF4 and LiTFSI electrolytes were much different, and the conductivity increased and Tg decreased with increasing salt concentration. This behavior of salt-rich PEC electrolytes relates to the ‘polymer-in-salt’ system. Li+ transference number of PEC-LiBF4 (44.4 wt%) electrolyte was measured, and the value was estimated to be ∼0.5 at 100 oC.
Based on the systematic classification and on the isomeric properties of polymer chain topologies, a variety of novel multicyclic macromolecular constructions has now been rationally designed and subsequently realized. In particular, an electrostatic self-assembly and covalent fixation process, optionally in conjunction with effective covalent linking chemistry, has been demonstrated as a new synthetic protocol for unprecedented polymers possessing multicyclic topologies.
We have proposed the concept and significance of nano-alloyed polymer, which includes nano-dispersed domains, and have developed the biaxially stretched film with higher glass transition temperature and improved dimensional stability as compared with regular poly(ethylene terephthalate) film (Figures 1 and 2). Highly concentrated polyimide master batches are made at much lower temperature compared with regular processing temperature. The nano-alloyed film is obtained by film-making process having biaxial stretching and heat treatment. The nano-sized domains have an important role as pseudo-cross-linkage points, for demonstrating good drawing process ability and high orientation.
Poly (butylene succinate)(PBS) nanocomposites and PBS ionomer were prepared by in situ polymerization. This review focused on the effect of the modified clay, TS-1 zeolite and ionic group in PBS matrix on physical properties, rheological properties, crystallization behavior and biodegradability control.
This article reviews recent findings on the optical, electro-optic, and optoelectronic properties of natural and chemically modified DNAs. This review specifically deals with photoluminescence and ET, lasing, NLO, organic light-emitting diode, and photovoltaic characteristics of various compositions based on natural and modified DNAs. Replacement of the Na+ counter-ions of natural DNA with functionalized cationic moieties is rapidly broadening the possible utilizations of DNA-based novel materials.
π-Conjugated polymers are synthesized by C–H and C–X polycondensation of 2-(4-haloaryl)thiophene monomers with a nickel catalyst and Knochel–Hauser base (TMPMgCl·LiCl (chloromagnesium 2,2,6,6-tetramethylpiperidide lithium chloride salt)). The C–H functionalization polycondensation reaction of a monobrominated monomer undergoes dehydrobrominative polymerization with an equimolar amount of TMPMgCl·LiCl and a catalytic amount of NiCl2dppp to afford poly(2,5-thienylene-1,4-phenylene) and poly(2,5-thienylenepyridine-2,5-diyl) in reasonable yields. Polycondensation with triflate as a leaving group proceeds under similar conditions to afford poly(thienylenephenylene) with excellent yield. Poly(benzodithiophene) is also found to be obtained by the reaction of the corresponding monobrominated benzodithiophene in the presence of a nickel-catalyst-bearing N-heterocyclic carbene as a ligand.
The polysilsesquioxane (PSQ) containing ethylxanthate groups was used for the graft polymerization of several acrylamide monomers by MADIX process. The controlled graft polymerization gave the PSQs containing the polymeric components as the graft chains. The introduction of the polymers provided an amphiphilic property to the polysilsesquioxaneane. In addition, the grafted PSQ containing poly(acryloyl morpholine) showed a thermoresponsive property in an aqueous solution. The reversible hydrophobic aggregation of the polysilsesquioanes was observed at ca. 80°C.
The endo-structure tetracarboxylic dianhydride was a crystal and could be divided into meso and racemic isomers. However, the exo-structure tetracarboxylic dianhydride was a highly viscous liquid. Polyimides derived from these tetracarboxylic dianhydrides and 4,4′-oxydianiline were colorless and organosoluble. The exo-structure polyimides had better mechanical properties and higher glass transition temperatures than the endo-structure polyimides.
Monodispersed spherical silver nanoparticles with 35±5 nm diameter were prepared by microwave irradiation of an AgNO3 aqueous solution in poly(ethylene glycol) (PEG). Thanks to the hydroxyl groups at the chain-ends of the PEG, the matrix of the Ag nanoparticles suspension was well incorporated into a polyurethane backbone, allowing a good distribution of the metal particles inside the final nanocomposite without aggregation. An optimal antibacterial activity was observed for a 35 p.p.m. Ag concentration against P. aeruginosa and E. faecalis without significant variation of the intrinsic physicochemical properties of polyurethane material.
Poly(3,4-ethylenedioxythiophene) is electropolymerized on a single-walled carbon nanotube film to reduce sheet resistance without causing loss in transparency.
