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A novel hyperbranched polymer endcapped with 4-methylcoumarin group (MCTH40) was prepared via thiol–ene addition reaction of thiol-modified hyperbranched polyester (fully thioglycolic acetate of Boltorn™ H40, TAH40) with a vinyl monomer (7-(4-vinyl-benzyloxyl)-4-methylcoumarin, VBMC), and characterized with 1 H NMR and FT-IR spectroscopies. Its reversible photo-crosslinking/photo-cleavage...
There has been growing evidence, both experimental and theoretical, that block copolymer systems with well-defined sulfonated regions may provide enhanced proton transport, especially at low relative humidity. We have recently demonstrated a novel way to make hydrocarbon hydrophobic–hydrophilic block copolymers. While the chemical structure and chemical compositions are very similar to random copolymers,...
A kind of β-nucleating agent, namely a stearic acid and stearate lanthanum complex (NAβ), was introduced into isotactic polypropylene (i-PP) via an in situ polymerization method for the first time. A dynamic adhesion model was constructed for interpreting the β-nucleating agent dispersion process. The effects of a polymerized dispersion of the β-nucleating agent on the content of β-crystal and crystallization...
A series of novel fluorinated poly(aryl ether)s containing phthalazinone moieties (FPPEs) have been prepared by a modified synthetic procedure for optical waveguide applications. The obtained random copolymers exhibited excellent solubility in polar organic solvents, high glass transition temperatures (T g s: 185–269°C), good thermal stabilities (the temperatures of 1% weight loss: 487–510°C)...
A series of high molecular weight, sulfonated polyimide copolymers (8a–f) with controlled acid contents have been obtained using 2,2′-bis(4-sulfobenzyloxy)benzidine (14) prepared via a flexible synthetic route. This series of novel sulfonated polyimide membranes were found to possess higher hydrolytic stability than polyimides in which the sulfonic acid groups are bound directly to the polymer main...
Bimodal elastomer networks, so called due to their nominal bimodal molecular weight distribution of starting oligomers, are of continued interest due to the enhanced strength and toughness seen in certain mixtures. Researchers have suggested that the enhanced properties stem from the particular micromechanics of the networks formed by these systems at these optimal compositions. This work extends...
The morphology of a synthesized poly[(tert-butyl acrylate)-b-styrene-b-isobutylene-b-styrene-(tert-butyl acrylate)] pentablock terpolymer was determined using transmission electron microscopy, atomic force microscopy and small angle X-ray scattering methods. The outer blocks of this material were converted to the acrylic acid form by a thermal process that caused a beta-scission reaction in a simple...
Preparation of core–shell particles consisting of polystyrene–poly(ethylene glycol) monomethacrylate (PS–PEGMA) core covered with polypyrrole (PPy) shell is described. The thickness of PPy shell, which strongly influences electrical properties of the films prepared from the particles, can be varied by changing pyrrole load, controlling the overall template surface area in the system and by influencing...
Phase transitional behavior has been investigated for a series of ethylene (E) and tetrafluoroethylene (TFE) two-component copolymers on the basis of the temperature dependent measurement of X-ray fiber diagrams taken for the uniaxially-oriented samples. The usage of such uniaxially-oriented samples has allowed us to clarify the structural changes more definitely than before. So far, the crystalline...
Thermosensitive triblock copolymers with two hydrophilic poly(N-isopropylacrylamide) blocks flanking a central hydrophobic poly(ɛ-caprolactone) block were synthesized by atom transfer radical polymerization. Core-shell micellization of the triblock copolymers was inferred from the 1 H NMR spectra derived in two different solvent environments (CDCl 3 and D 2 O). The micellar...
Impact strength and tensile energy absorption of polymer–clay nanocomposites were measured using polymers that are glassy or rubbery at ambient temperatures. The results highlight the apparent contradictions that arise in these tests. Polystyrene, with initially low toughness, suffered a decrease in impact strength of 3% (notched) and 23% (un-notched) but the tensile energy at break increased by 120%...
This article reviews recent studies on the polymerization of 1,6-heptadienes and 2-aryl- and 2-alkoxy-1-methylenecyclopropanes catalyzed by Co, Fe, and Pd complexes. Co and Fe complexes with bis(imino)pyridine ligands catalyze the cyclopolymerization of 1,6-heptadiene in the presence of MMAO to produce the polymer, which contains five-membered rings in the monomer units. The polymers with cis- or...
The rheological characterization for a set of structurally diverse core cross-linked star (CCS) polymers is presented. The influence of arm molecular weight (M w(arm) ) and CCS polymer molecular weight (M w(CCSP) ) on the steady- and dynamic-shear properties determined by plate rheometry will be discussed. Both these parameters dramatically affect the CCS polymer solution properties...
The effect of nanoclay concentration on the molecular orientation and drawability of poly(ethylene terephthalate) PET was examined using thermal and vibrational spectroscopic analysis. Although drawability at 83°C in hot air increased by the addition of nanoclay, the maximum draw ratio was independent of nanoclay concentration. The average molecular orientation of the PET chain was found to mimic...
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