Hydrogen bonding and polyurethane morphology. II. Spectroscopic, thermal and crystallization behavior of polyether blends with 1,3-dimethylurea and a model urethane compound

Yılgör, Emel; Yurtsever, E.

doi:10.1016/s0032-3861(02)00566-9

Cited by 108 publications

(68 citation statements)

References 20 publications

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“…Polyurethanes are versatile polymers that have been employed in the development of many materials which can be found as elastomers, fibers, thermorigid and thermoplastic materials [1][2][3][4].…”

Section: Introductionmentioning

confidence: 99%

“…A wide range of physical properties and morphologies can be achieved depending on the composition and the chemical architecture of the hard and soft segments. The primary driving force for domain formation is the strong intermolecular interaction by hydrogen bonds, that urethane and urea units are capable of forming [3,8,13,14]. Some properties of polyurethanes are directly related to the amount of the hard-segment domains, which are extensively hydrogen-bonded with the neighboring chains [8,[10][11][12].…”

Section: Introductionmentioning

confidence: 99%

“…Some properties of polyurethanes are directly related to the amount of the hard-segment domains, which are extensively hydrogen-bonded with the neighboring chains [8,[10][11][12]. In polyether-based polyurethanes and poly(urethane-urea)s, some of the N-H groups will also associate with the oxygen of the ether linkage due to partial phase mixing [2,3,8,15]. The Fourier transform infrared spectrometry (FTIR) is a powerful technique for the investigation of the hydrogen bonding behavior in polyurethanes [14,16] specially the absorption region of carbonyl groups is concerned.…”

Section: Introductionmentioning

confidence: 99%

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Waterborne polyurethanes: influence of chain extender in ftir spectra profiles

Delpech

Miranda

2012

Open Engineering

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Non-polluting systems based on waterborne polyurethanes (wPU) and poly(urethane-urea)s (wPUU) were synthesized employing poly(propylene glycol) (PPG), dimethylolpropionic acid (DMPA) and 4,4'-dicyclohexylmethane diisocyanate (HMDI) as monomers. In the formulations, the length and the proportion of the soft segments were varied. Three types of chain extenders were employed: ethylene glycol (EG), producing urethane linkages; and ethylenediamine (EDA) and hydrazine (HYD), forming urea linkages. Cast films obtained from wPU and wPUU, monomers and prepolymers were analyzed by Fourier transform infrared spectrometry (FTIR). The profile of carbonyl absorption bands obtained for the films showed some remarkable differences depending on the formulation. The bands were split into two parts, which were directly related to the tendency of hydrogen bond formation. The length of soft segment, the amount of rigid portions and the presence of urea linkages showed a marked influence in both intensity and frequency absorption of the bands.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Waterborne polyurethanes: influence of chain extender in ftir spectra profiles

Delpech

Miranda

2012

Open Engineering

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“…The formation of urea linkages was not seen. The bands characteristic of urea were not observed: 1650 cm -1 to 1620 cm -1 (amide I), 1580 cm -1 to 1550 cm -1 (amide II), and 1240 to 1220 cm -1 (amide III) (Hummel et al 1979;Yilgör et al 2002). The absorption band at 3450 cm -1 could be assigned to hydroxyl groups in the cured films, and, as already mentioned, the films' poor resistance to polar liquids could be connected to the presence of these groups.…”

Section: Pu Films Prepared From Lw and Lwbmentioning

confidence: 95%

Preparation of Two-Component Polyurethane Coatings from Bleached Liquefied Wood

Cheumani-Yona

Budija²,

Hrastnik

et al. 2015

BioResources

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Liquefied wood-based polyurethane wood coatings of an aesthetically acceptable light colour were prepared and characterised. Liquefied black poplar wood was obtained by solvolysis in a polyethylene glycol/glycerol mixture, and it was bleached with hydrogen peroxide. The bleaching treatment converted liquefied wood from a dark brown to a yellowish product. Polyurethane films were prepared by the curing of liquefied wood with polymeric diphenylmethane diisocyanate or trimethylolpropane toluene diisocyanate prepolymer (TMP/TDI) isocyanate-type hardeners. It was found that the selected properties of the films prepared from the bleached liquefied wood were, in general, equivalent to those prepared from unbleached liquefied wood. The mechanical properties of the films obtained with the TMP/TDI curing agent were acceptable for wood coating applications. The initial poor resistance of the films to water and ethanol was substantially improved by the addition of n-octyltriethoxysilane to the liquefied wood prior to the preparation of the polyurethane coatings; the hardness of the films also increased.

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“…[48][49][50] As shown in Figure 9(a), there are some differences in the region of 3000-3600 cm −1 corresponding to N-H stretching vibration of PAs. For RPA as seen in Figure 9(a), the bands at 3344 and 3268 cm −1 may be assigned to the free N-H groups and the hydrogen bonded N-H groups, respectively.…”

Section: Hydrogen Bond Analysismentioning

confidence: 97%

Synthesis, helicity, thermal stability, and low infrared emissivity of optically active polyacetylenes carrying tyrosine pendants

Chen

Zhou

et al. 2014

Designed Monomers and Polymers

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Optically active polyacetylenes (LPA and DPA) and racemic polyacetylenes (RPA) were prepared by the polymerization of N-propioloyl-tyrosine methyl esters that derived from chiral and racemic tyrosine. All the polymers were characterized by Fourier transform infrared spectroscopy, 1 H NMR, 13 C NMR, gel permeation chromatography, thermogravimetric analysis, UV-vis spectroscopy, and circular dichroism spectroscopy; furthermore, the infrared emissivity values were also investigated. Both LPA and DPA possessed the helical conformations and a higher degree of intra-and interchain hydrogen bonds compared with RPA, which presented irregular polymer chain. The thermal stability of LPA and DPA was higher than that of RPA due to the helical conformations, which could be easy to form a high degree of intra-and interchain hydrogen bonds in the structure. Therefore, LPA and DPA exhibited lower infrared emissivity values (8-14 μm) than that of RPA, which resulted from the helical conformations and a higher degree of intra-and interchain hydrogen bonds.

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Hydrogen bonding and polyurethane morphology. II. Spectroscopic, thermal and crystallization behavior of polyether blends with 1,3-dimethylurea and a model urethane compound

Cited by 108 publications

References 20 publications

Waterborne polyurethanes: influence of chain extender in ftir spectra profiles

Waterborne polyurethanes: influence of chain extender in ftir spectra profiles

Preparation of Two-Component Polyurethane Coatings from Bleached Liquefied Wood

Synthesis, helicity, thermal stability, and low infrared emissivity of optically active polyacetylenes carrying tyrosine pendants

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