On the validity of a commonly employed infrared procedure used to determine thermodynamic parameters associated with hydrogen bonding in polymers

Coleman, Michael M.; Skrovanek, Daniel J.; Howe, Stephen E.; Painter, Paul C.

doi:10.1021/ma00144a033

Cited by 57 publications

(29 citation statements)

References 3 publications

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“…Such a competition of Li + ‐ion coordination with hydrogen bonding was reported earlier by Ferry et al37 Our results for the area percentage (Table III) indicate the presence of such competition, which results in more free NH groups from the hydrogen‐bonded ones with an increase in the salt concentration. However, a quantitative estimation of free and hydrogen‐bonded NH groups from band areas may lead to erroneous results, as the absorptivity coefficient for the hydrogen‐bonded NH bands is a function of the strength of the hydrogen bond and the band frequency 38, 39…”

Section: Resultsmentioning

confidence: 99%

Morphology and ionic conductivity of thermoplastic polyurethane electrolytes

Chen

Wen

et al. 2003

J of Applied Polymer Sci

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Thermoplastic polyurethane (TPU) with a mixture of soft segments [poly(ethylene glycol) (PEG) and poly(tetramethylene glycol) (PTMG)], denoted TPU-M, was prepared as an ion-conducting polymer electrolyte. TPUs with PEG and PTMG as soft segments were also synthesized individually as polymer electrolytes. The changes in the morphology and ion conductivity of the phase-segregated TPU-based polymer electrolytes as a function of the lithium perchlorate concentration were determined with differential scanning calorimetry, Fourier transform infrared spectroscopy, alternating-current impedance, and linear sweep voltammetry measurements. Both solid and gelatinous polymer electrolytes were characterized in this study. The effect of temperature on conductivity was studied. The conductivity changes revealed the combined influence of PTMG and PEG units in TPU-M. The swelling characteristics in a liquid electrolyte and the dimensional stability were evaluated for the three TPUs. Because of its dimensional stability and ionic conductivity, the TPU system containing both PEG and PTMG as soft segments was found to be more suitable for electrolyte applications. A room-temperature conductivity of approximately 1 ϫ 10 Ϫ4 was found for TPU-M containing 50 wt % liquid electrolyte.

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Section: Resultsmentioning

confidence: 99%

Morphology and ionic conductivity of thermoplastic polyurethane electrolytes

Chen

Wen

et al. 2003

J of Applied Polymer Sci

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“…The above results suggest that poly(LA-co-DHHDA)s with up to 1.2 mol% of DHHDA are crystalline or have crystalline regions, but become amorphous when the crosslink density is too high (> 2%). 83 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 characteristic amide bond signals, as present in nylon 6,6 , [86][87][88] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60...…”

Section: Application Of the Building Blocks In Polymer Synthesismentioning

confidence: 99%

Synthesis of Novel Renewable Polyesters and Polyamides with Olefin Metathesis

Dewaele¹,

Meerten²,

Verbelen³

et al. 2016

ACS Sustainable Chem. Eng.

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Unsaturated and hydroxyl-functionalized C6-dicarboxylic acids were successfully synthesized via olefin metathesis from methyl vinyl glycolate (MVG), a renewable α-hydroxy C4-ester product from Lewisacid carbohydrate conversion. Addition of a second-generation Hoveyda-Grubbs catalyst to neat MVG leads to a near quantitative yield of dimethyl-2,5-dihydroxy-3-hexenedioate (DMDHHD). Additional hydrolysis and hydrogenation steps form interesting polymer building blocks like 2,5-dihydroxy-3hexenedioic acid (DHHDA) and 2,5-dihydroxyadipic acid (DHAA). Their use in polyester and polyamide synthesis is demonstrated after determination of their physical and spectroscopic characteristics. Copolymerization of DHHDA with L-lactic acid for instance produces a crosslinked poly(L-lactic acid-co-DHHDA) polyester. Proof of crosslinks is ascertained by NMR and FT-IR. Substantial impact on the melting, thermal and polar properties of PLA are observed already at low amounts of DHHDA (0.1 mol%) in accord with the presence of crosslinks in the polymer. Bio-based polyamides were also synthesized by equimolar reaction of DHHDA with hexamethylenediamine, producing a renewable polyamide analogue of the petroleum-based nylon 6,6. Interestingly, the assynthesized polyamide (α-bishydroxylated unsaturated polyamide, HUPA) possesses similar thermal stability as nylon 6,6 but shows different chemical properties as a result of the double bond and αhydroxy functionality.

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“…It is well-known that polyamide vibrations found in the infrared spectral region are sensitive to the strength of hydrogen bonds (32)(33)(34)(35), to local conformations (36), and to the type of packing that the chains adopt (37). Comparison with infrared spectra reported in the literature should therefore give information on these specific aspects of model compounds.…”

Section: The Amide I and Ii Infrared Spectral Regionmentioning

confidence: 99%

“…The position and intensity of ν(NH) and amide I bands are sensitive to the strength of hydrogen bonds and have been used to quantify the proportion of free and hydrogen-bonded amide groups in polyamides (32)(33)(34)(35). The amide I band is attributed mostly to C=O stretching, but C-N stretching and C-C-N deformation also contributes to this band (38).…”

Section: The Amide I and Ii Infrared Spectral Regionmentioning

confidence: 99%

Effect of chain ends on the structure of aramid oligomers

Mehenni¹,

Guillou²,

Tessier³

et al. 2008

Can. J. Chem.

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Synthesis, X-ray diffraction, and Fourier transform infrared spectroscopy of aliphatic-aromatic aramid oligomers are reported with the aim of shedding light on the effect of end-chain substituent on the morphology and structure of poly(para-phenylene terephthalamide) or PPTA. Three types of X-ray powder diffraction patterns were observed: one similar to that of PPTA form I, one similar to that of PPTA form II, and an additional form never reported. Some compounds, differing by their internal distribution of amide-aromatic rings, adopt two different crystal structures, whereas compounds having the same internal amide-aromatic arrangements, but differing by the nature of the end-groups, can adopt the same crystal structure. This clearly shows that both factors influence the packing adopted by the chains. Single-crystal structures of two polymorphs of a nitro-terminated model compound were resolved; both forms incorporate dimethyl formamide, and both show completely different packing. Infrared amide I and II band positions of most studied compounds match those observed for PPTA forms I or II, indicating that they exhibit planar hydrogen bonded sheets of molecules.Résumé : La synthèse et des études de diffraction des rayons X, et de spectroscopie infrarouge à transformée de Fourier ont été effectués sur des oligomères aramides, dans le but de fournir des informations sur l'effet de substituants en bout de chaîne sur la morphologie et la structure du poly(para-phénylene téréphthalamide), ou PPTA. Trois types de clichés de diffraction de poudre ont été observés: un similaire à celui de la forme I du PPTA, un similaire à celui de la forme II, et une forme additionnelle jamais rapportée auparavant. Certains composés modèles qui diffèrent de par leur distribution interne de cycles aromatiques et de groupements amides adoptent des structures cristallines différentes, alors que certains composes modèles ayant le même arrangement interne de cycles aromatiques, adoptent la même structure cristalline. Ceci démontre clairement que ces deux facteurs influencent l'arrangement moléculaire adopté par les chaînes. Les structures cristallines de monocristaux de deux polymorphes d'un composé modèle ayant un substituant nitro en bout de chaîne ont été résolues, les deux incluent des molécules de diméthylformamide, et les deux adoptent des types d'empilement moléculaire complètement différents. En spectroscopie infrarouge, les positions des bandes amide I et II de la plupart des composes étudiés correspondent à celles observées pour les formes I et II du PPTA, indiquant que ces composés possèdent probablement des feuillets de molécules assemblées par liaison hydrogène.Mots-clés : aramide, structure cristalline, poly(para-phénylène téréphtalamide).

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On the validity of a commonly employed infrared procedure used to determine thermodynamic parameters associated with hydrogen bonding in polymers

Cited by 57 publications

References 3 publications

Morphology and ionic conductivity of thermoplastic polyurethane electrolytes

Morphology and ionic conductivity of thermoplastic polyurethane electrolytes

Synthesis of Novel Renewable Polyesters and Polyamides with Olefin Metathesis

Effect of chain ends on the structure of aramid oligomers

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