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A more efficient route for the synthesis of phosphonated dimethyl isophthalate, disodium salt is shown to provide a significantly higher yield (42%), in contrast to a previously reported yield (15%). This higher yield enabled the synthesis of phosphonated poly(ethylene terephthalate) (PPET) ionomers using conventional melt polycondensation with ethylene glycol and dimethyl terephthalate. The physical...
The phase diagram for the thermoreversible gelation of poly(ether ether ketone) (PEEK) in dichloroacetic acid (DCA) was constructed over broad temperature and concentration ranges, revealing that PEEK is capable of dissolving and forming gels in DCA up to a weight fraction of 25 wt%. For PEEK solutions within this concentration range, the time required for gelation decreased with increasing temperature...
Tris- and tetra-(β-alanine)-grafted polyisobutylenes (A3 and A4) with the same grafting density have been synthesized and studied. IR, DSC, SAXS, and WAXD show that the β-alanine tetramer segments in A4 form β-sheet crystals similar to those in A3. A3 and A4 are melt-processable TPEs. The less than 5% by volume of β-sheet crystals in A3 and A4 bring about mechanical properties significantly better...
Multiblock copolymers of poly(arylene ether sulfones) (PAESs) and poly(1,4-cyclohexylenedimethylene terephthalate) (PCT) were synthesized via melt-phase polymerization. PAES oligomers (Mn = 2000 g/mol) were synthesized with hydroxyethoxyl end groups, and then reacted with dimethyl terephthalate (DMT) and 1,4-cyclohexanedimethanol (CHDM) to obtain segmented copolymers with the goal of introducing semi-crystallinity...
Polymer tubes with control on tube thickness and surface morphology are highly desirable for a wide range of applications in energy storage and transport as well as in tissue engineering and drug delivery. In this work, using the non-electrospinning Spinneret based Tunable Engineered Parameters (STEP) platform, we demonstrate fabrication of long (mm-cm) aligned polystyrene (PS) nano and microscale...
Segmented polyurethanes based on polytetramethylene glycol (PTMG) of 1000 g/mol were synthesized using a two-step polymerization procedure. Various hard segments were obtained using hexamethylene diisocyanate (HDI) or 4,4′-methylenebis(phenyl isocyanate) (MDI) as the diisocyanates and hydroquinone bis(2-hydroxyethyl)ether (HQEE) or triptycene-1,4-hydroquinone bis(2-hydroxyethyl)ether (TD) as the chain...
A series of multiblock copolymers based upon alternating segments of a hydrophilic disulfonated poly(arylene ether sulfone) and a hydrophobic fluorine-terminated poly(arylene ether benzonitrile) (6FPAEB) were synthesized and characterized for use as proton exchange membranes (PEM). The ion-exchange capacity of the block copolymers were varied by utilizing 4,4′-biphenol or hydroquinone in combination...
An unprecedented family of segmented polydimethylsiloxane poly(urea oxamide) (PDMS-UOx) copolymers displayed thermoplastic elastomeric behavior with improved thermomechanical properties compared to PDMS polyurea (PDMS-U) analogs. A two-step, PDMS end-capping sequence using diethyl oxalate and hydrazine generated difunctional oxamic hydrazide capped oligomers. Polymerization with HMDI provided high...
A new synthetic strategy using melt transesterification enabled selective control of ionic charge placement into the hard segment or soft segment block of segmented copolyesters. Dynamic mechanical analysis of sulfonated soft segment copolyesters revealed an increase in the low-T g transition and rubbery plateau storage modulus as a function of sulfonation level. Sulfonated hard segment copolyesters...
Adenine-functionalized ionenes (ionene-A) and thymine-functionalized ionenes (ionene-T) were synthesized from novel nucleobase-containing monomers from an efficient aza-Michael addition to an acrylate precursor. Complexes of ionenes with nucleobase-containing guest molecules (n-butyl thymine, nBT and n-butyl adenine, nBA) exhibited well-defined complementary hydrogen bonding interactions. Job’s analysis...
Poly(ethylene glycol) (PEG)-based sulfonated polyurethanes bearing either sulfonated soft segments (SSSPU) or sulfonated hard segments (SHSPU) were synthesized using sulfonated monomers. Differential scanning calorimetry (DSC) revealed that sulfonate anions either in the soft segments or hard segments both increased the glass transition temperatures (T g ’s) of the soft segments and suppressed...
A semi-continuous process using scCO 2 is reported for processing polymer–clay composites with high clay loading (i.e. 10wt %) by reducing the collapse of the exfoliated clays. Two major modifications are involved in the new procedure: exfoliating the nano-clay directly into the hopper filed with pellets followed by processing the composite immediately and sequentially mixing the clay into...
A series of sulfonated poly(arylene ether sulfone) (BPSH-BPS) multiblock copolymer (MBC) ionomers were studied with respect to structure and physical properties. Ion exchange capacity (IEC w ) on a weight basis was constant for all MBC ionomers with controlled ionic and nonionic block lengths of 5k:5k, 10k:10k and 15k:15k. Viscoelastic properties were investigated as a function of block length,...
Lightly sulfonated syndiotactic polystyrene (sPS) nanocomposites were prepared using a solution intercalation technique, and the effect of montmorillonite clay on the crystallization kinetics of sulfonated sPS ionomer nanocomposites was systematically studied. Wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM) were used to evaluate the dispersion of clay platelets within...
The effects of block length and solution-casting conditions on the final microstructures and properties of disulfonated poly(arylene ether sulfone) multiblock copolymer (BPSH100–BPS0) films for proton exchange membranes were investigated based on the basic principles of microstructure formation of block copolymers. Morphological studies using transmission electron microscopy and small angle X-ray...
Perfluorosulfonate ionomers (PFSIs) neutralized by tetraalkylammonium ions have been investigated using variable temperature 1 H and 13 C solid-state NMR (ssNMR) spectroscopy to probe the thermally induced properties of tetraalkylammonium ions at temperatures near the α-relaxations. Tetramethylammonium (TMA + ), tetraethylammonium (TEA + ), tetrapropylammonium (TPA...
Blends of poly(vinylidene fluoride) (PVDF) with a perfluorosulfonate ionomer, Nafion ® , have been prepared and examined in terms of the crystallization kinetics of the PVDF component. In blends of PVDF with Na + -form Nafion ® , the rates of bulk crystallization, as observed by DSC, and the spherulitic growth rates of the PVDF component, as observed using optical microscopy,...
Sulfonated ethylene vinyl alcohol copolymers have been synthesized and artificial muscles have been produced from this new class of ionomeric membrane materials. FTIR spectroscopy confirmed the modification through introduction of peaks characteristic of ester linkages between sulfosuccinic acid and vinyl alcohol. Solid-state 23 Na NMR showed the ionic functionalities aggregate during membrane...
Poly(ethylene terephthalate) ionomer (PETI)/organically-modified montmorillonite clay (OMC) nanocomposites were prepared via melt extrusion. Sulfonated PET containing various incorporations of ionic comonomer and clay modifications were investigated. The random incorporation of ionic functionalities along the PET backbone enhances interactions between the matrix polymer and montmorillonite clay resulting...
The influence of ionic comonomer units and ionic aggregation on the crystallization behavior and crystallite surface energies of poly(butylene terephthalate-co-5-sodiosulfoisophthalate) (PBTi) ionomers containing 3 and 5mol% dimethyl-5-sodiosulfoisophthalate monomer units is compared to that of pure poly(butylene terephthalate). The rate of crystallization of the ionomers, as determined from an Avrami...
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