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Interfacial entanglement and co-crystallization are identified to cause adhesion. Adhesion between polyethylene and different types of polypropylenes (PPs), including impact-modified PP isotactic PP and ethylene-propylene random copolymers, was increased with concentration of ethylene or ethylene–propylene rubber and faster cooling in co-extrusion. A more miscible interface is the key for improved adhesion.
Particle formation in an initial stage of emulsifier-free organotellurium-mediated living radical emulsion polymerization (emulsion TERP) of styrene at 60°C was investigated at two stirring rates (220 and 1000 r.p.m.), at which styrene phase floated as a layer on an aqueous phase at 220 r.p.m. or dispersed as droplets at 1000 r.p.m. Because percentage of PMAA30-TeMe consumed in the initial stage was much higher at 1000 r.p.m. than 220 r.p.m., self-assembly nucleation preferentially occurred at 1000 r.p.m., resulting in nanometer-sized particles and good control/livingness.
The solubility and phase behavior of five polyethers in 14 different room-temperature ionic liquids (ILs) were studied by changing the structures of polyethers and the cations and anions in the ILs. Certain combinations of a polyether and an IL binary mixture exhibited lower critical solution temperature (LCST) phase behavior. The phase separation temperature (cloud point) was revealed to be sensitive to the aromaticity and alkyl chain length of the IL cations, the anionic Lewis basicities of the ILs and the polarity of the polyethers. PEGE, poly(ethyl glycidyl ether).
Polyelectrolyte multilayers-modified membrane filter, leading to achieve rapid immunoassay as compared with the conventional enzyme-linked immunosorbent assay (ELISA) system. The antigen–antibody reaction was carried out by the centrifugal permeation of antigen solution allowing the local condensation of the antigen molecules in the proximity of the primary antibody. Hence, the incubation time for the antigen–antibody reaction was just permeation time, 3 min, which overcomes the molecular diffusion as rate-limiting factor compared with conventional ELISA method.
1-Adamantyl methacrylate (AdMA) was polymerized using atom transfer radical polymerization (ATRP), producing the well-defined poly(1-adamantyl methacrylate) (PAdMA). Simultaneous control of the molecular weight and tacticity of PAdMA was achieved by ATRP in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). Block copolymerization of AdMA and methyl methacrylate (MMA) was achieved by activators generated by electron transfer (AGET) ATRP method. Differential scanning calorimetry (DSC) measurement revealed the relationship among the glass transition temperature, molecular weight and tacticity of PAdMA.
The molecular dynamics and orientation of vulcanized natural rubber stretched at low extension ratio were studied by solid-state 13C NMR and density functional theory (DFT) calculations. Isoprene units of the oriented rubber chains in stretched NR rotate rapidly around an axis that almost aligned with C=C bond direction of polyisoprene.
Two neutral ligands, carbonyl and phosphine, were cooperatively incorporated into half-metallocene iron(II) complexes [CpFeBr(CO)(PR3)] for more active and versatile systems in transition metal-catalyzed living radical polymerization. Among the CpFeBr(CO)(PR3) complexes examined, CpFeBr(CO)(PMePh2) showed the highest activity and the best controllability, and the ‘living’ character of the polymerizations therewith was proved by sequential monomer-addition experiments. In spite of the high activity, the Fe(II) complex is stable and robust enough to be handled under air, rendering it suitable for practical use.
Novel amylose ester derivatives were synthesized and their chiral recognition abilities as chiral stationary phases for high-performance liquid chromatography were evaluated. Among the prepared derivatives, the nonsubstituted cinnamate derivative showed a relatively high chiral recognition, and interestingly, its ability was influenced by the preparation conditions of packing materials using silica gel as a support.
Chiral rod-coil type-organoboron polymers, S-poly and R-poly, have been prepared from Sonogashira coupling reaction of BODIPY-based monomer bearing bis-iodophenyl and decyl groups with S- or R-binaphthyl derivatives. The SEM analysis of each chiral polymer revealed μm-sized fiber-like structures formed by aggregation of each particle, however, the mixed polymer (S-poly/R-poly = 30/70) showed complete particle structures from nm to μm sizes, and the ΦF of the mixed polymer was significantly high (0.98).
Well-defined aniline-chain-end-functionalized regioregular poly(3–hexylthiophene)s (P3HT-NH2) have been synthesized on the basis of Grignard metathesis polymerization. The selectivity of monofunctionalization and the high degree of amine functionality (85–92%) were confirmed by MALDI-TOF mass spectroscopy. A block copolymer through ionic interaction was successfully synthesized simply by blending P3HT-NH2 with carboxy chain-end-functionalized polystyrene. Thermal and optical properties of the block copolymer are investigated by DSC, TGA and UV-vis spectroscopy. The self-assembly behavior of the polymer was observed by AFM showing nanofibril structures with 12–15 nm width.
The thermal relaxation of a monolayer of PMMA deposited on a thick film was discussed by the direct observation of single chains using scanning near-field optical microscopy (SNOM). The polymer chain of the monolayer penetrated into the bulk substrate with a diffusion rate much faster than that of the translational diffusion of the entire chain. Conversely, the radius of gyration in the lateral direction was maintained throughout the relaxation process.
Multihybrid particles having a gold core, silica as an inital shell and polymethylmethacrylate (pMMA) as a second shell (Au@SiO2@pMMA) were synthesized and assembled in two to three dimensions using the Langmuir–Blodgett technique.
Interaction between a chiral polymer obtained by cyclopolymerization of a bisacrylamide [poly(1)] and aromatic aldehydes was investigated by CD, NMR and IR measurements. The observed induced CD demonstrated that the chiral frameworks of poly(1) forced aldehydes to remain in a chiral environment. NMR and IR measurements on the mixtures of poly(1) and aromatic aldehydes suggested that carbonyl groups interacted with the polymer.
When methanol, a non-solvent, was added to dilute THF solutions of an optically active polyfluorene derivative, the liquid–liquid phase separation took place, and circular dichroism (CD) was induced at a low temperature. The CD induction upon cooling was a rather slow process, according to the first-order reaction kinetics. The intermolecular chiral interaction in the concentrated phase may be responsible for the CD induction or nonracemization of this helical polyfluorene derivative in phase-separating solutions.
