Solution cation-binding properties of segmented polyethylene oxide-A13C NMR spectroscopic study

Jayakannan, M.; Ramakrishnan, S.

doi:10.1002/1099-0518(20000801)38:15<2635::aid-pola20>3.0.co;2-6

Cited by 6 publications

(6 citation statements)

References 20 publications

(17 reference statements)

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“…For instance, by the use of poly(ethylene glycol)s (PEG) of varying molecular weights a series of segmented poly(ethylene oxide)s (SPEO) were readily prepared. [50] Glass transition temperatures and crystallization propensities of these types of SPEOs are determined by the PEG segment length, and therefore make them potentially useful for solid-polymer electrolyte applications. Furthermore, the modification of the pendant groups using phenolic-type monomers can lead to other interesting structures, such as branched PEO equivalents 54.…”

Section: Hyperbranched Poly(aryl Ether)smentioning

confidence: 99%

Recent Developments in Polyether Synthesis

Jayakannan

Ramakrishnan

2001

Macromol. Rapid Commun.

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Section: Hyperbranched Poly(aryl Ether)smentioning

confidence: 99%

Recent Developments in Polyether Synthesis

Jayakannan

Ramakrishnan

2001

Macromol. Rapid Commun.

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“…A bis‐benzyl methyl ether monomer, bis 1,4‐(methoxymethyl)‐2,3,5,6‐tetramethylbenzene, which is readily prepared from durene, is condensed with polyethylene glycols (PEGs) of different molecular weights (di‐, tri‐, and tetraethylene glycol and PEGs with molecular weights 300, 600, 1000, 1500, and 3400). The resultant polymers have oligoethylene oxide segments that are separated at regular intervals by xylylene units, hence the term “segmented polyethylene oxide” (SPEO) 20. Further, to study the effect of molecular kinks on the thermal properties of SPEO, another series of polyethers was prepared by using 1,3‐bis(methoxymethyl)‐2,4,5,6‐tetramethylbenzene (prepared from isodurene) and the same PEGs.…”

Section: Introductionmentioning

confidence: 99%

Segmented polyethylene oxides: A new class of polyethers prepared via melt transetherification

Jayakannan¹,

Ramakrishnan²

2001

J. Polym. Sci. A Polym. Chem.

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Several segmented polyethylene oxides (SPEOs) were prepared by a melttransetherification process using 1,4-bis(methoxymethyl)-2,3,5,6-tetramethylbenzene and polyethylene glycols (PEGs) of different molecular weights (di-, tri-, and tetraethylene glycols and PEGs of molecular weights 300, 600, 1000, 1500, and 3400) as the monomers. The effect of polymerization temperature (185 and 150°C) on the molecular weight of SPEOs was studied, and it was shown that the molecular weight is larger at a higher polymerization temperature. The reversal of the polycondensation (transetherification) equilibrium by treatment of the polyethers with excess methanol transformed them completely into the starting monomers. The analysis of the degraded products by mass and NMR spectroscopies revealed that side reactions, such as the self-condensation of diols, are insignificant. The polymers containing shorter PEG spacers are amorphous, whereas the ones with longer PEG spacers are semicrystalline. The glass-transition temperature (T g ) of the SPEOs decreased with increases in the spacer length and attained the value of PEO at PEG-600, whereas the melting transition (T m ), crystallization temperature (T c ), and their enthalpies of transition, (⌬H m ) and (⌬H c ), increased with increases in the spacer length. The introduction of "molecular kinks" into SPEOs by the use of another monomer, 1,3-bis(methoxymethyl)-2,4,5,6tetramethylbenzene, surprisingly, showed little effect on their thermal properties. A "branched-PEO" analogue, containing pendant oligoethyleneoxy units, was also prepared, and its thermal properties were compared with its linear analogue. Preliminary ionic conductance measurements showed that some of these SPEOs could serve as potential candidates for solid polymer-electrolyte applications.

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“…NMR titration experiment is a very useful means of analyzing the hydrogen‐bonding interactions in solution. Unlike IR techniques, the association constants for the hydrogen bonding can also be determined from the chemical shift values 32. To investigate the effect of various structural subunits on the hydrogen‐bonding nature and its strength, 1 H NMR titration experiments were carried out in CDCl 3 (same solvent used for morphology studies), and association constants ( K ) were determined.…”

Section: Resultsmentioning

confidence: 99%

Microporous polyurethanes: Synthesis and investigation of the mechanism of the pore formation

Deepa

Jayakannan

2006

J Polym Sci B Polym Phys

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A new approach for microporous polymeric material is developed utilizing the secondary interactions such as hydrogen bonding in the polymer chains in polyurethane systems at ambient conditions. A new series of highly rigid, thermally stable, and readily soluble cycloaliphatic polyurethanes were designed and synthesized for this purpose, based on new tricyclodecanedimethanol and 1,4‐cyclohexanedimethanol. The hydrogen‐bonding interactions induce phase separation in solution, which leads to polymer‐rich and solvent‐rich domains; subsequent evaporation of the solvent molecules results in micropores. The phase‐separation process in the polyurethane is found to be highly dependent on the chemical structures of the polymer chain backbone. 1H NMR titration experiments were carried out to understand the mechanism of the micropore formation and its dependence on different structural subunits. The hydrogen‐bonding association constant (K) obtained from the titration experiments revealed that higher the K‐value more the tendency to form micropores. A fully cycloaliphatic polyurethane produces micropores of sizes ranging from 1 to 8 μm, and each pore is separated by 10−20 μm, whereas the replacement of one of the cyclic unit in the backbone disturbs the entire phase‐separation process and results in nonporous morphology. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1296–1308, 2006

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Solution cation-binding properties of segmented polyethylene oxide-A13C NMR spectroscopic study

Cited by 6 publications

References 20 publications

Recent Developments in Polyether Synthesis

Recent Developments in Polyether Synthesis

Segmented polyethylene oxides: A new class of polyethers prepared via melt transetherification

Microporous polyurethanes: Synthesis and investigation of the mechanism of the pore formation

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