Calculation of the force field for several trihalides of group V atoms from raman spectra

Karmanov, V. I.; Kozulin, A. T.

doi:10.1007/bf00624120

Cited by 4 publications

(6 citation statements)

References 5 publications

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“…Notice the appearance of another peak at 3170-3275 cm −1 , which corresponds to the overtone of the deformation vibration of the N-H group increased by Fermi resonance. 32 However, the N-H bands at 3330 cm −1 are shifted to lower regions with increasing SiO 2 concentration confirming that the N-H group and Si-O-Si are connected by hydrogen bonding.…”

Section: Ftir Analysismentioning

confidence: 90%

Novel hyperbranched waterborne polyurethane‐urea/silica hybrid coatings and their characterizations

Jena

Sahoo

Narayan

et al. 2011

Polymer International

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Thermally resistant and mechanically stable novel hyperbranched waterborne polyurethane‐urea/silica hybrid coatings were prepared by using 3‐aminopropyltriethoxysilane as a coupling agent with SiO2 as a crosslinker. The extent of hydrogen bonding was investigated to show a dependence on SiO2 concentration, which increased the glass transition temperature of the polymers with increasing SiO2 concentration. Thermal decomposition profiles and the corresponding stability data suggest two‐step decomposition for the hybrids; further, their stability increased with increasing concentration of SiO2.Copyright © 2011 Society of Chemical Industry

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Section: Ftir Analysismentioning

confidence: 90%

Novel hyperbranched waterborne polyurethane‐urea/silica hybrid coatings and their characterizations

Jena

Sahoo

Narayan

et al. 2011

Polymer International

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“…From Raman microscopy, complementary information was obtained concerning the molecular structure of the PUR. Tentative band assignments are made from reference to earlier Raman studies on model PURs [22][23][24][53][54][55] and citations therein. As expected, the most intense bands from the Raman spectra are assigned to C-C, C=C, C-N and N-H groups (Fig.…”

Section: Polyurethane Reference Characterisationmentioning

confidence: 99%

“…Regarding the assignment of these variations, several authors have attributed them to hydrogen-bonding interactions on the PUR segregated structure. [24,53] The intensity variation at 1660 cm À1 may be related to the formation of new H bonds on C=O groups from urea linkages and the successive loss of intensity at 1712 cm À1 to the loss of H bonds on urethane linkages.…”

Section: Dark Ageing Experimentstorage Conditionsmentioning

confidence: 99%

“…[23] Furthermore, different hydrogen-bonding interactions were confirmed for TPU films (prepared with and without solvents) based on the analysis of the amide I region. [24] This approach has also been applied by Weakley et al for the study of hydrogen-bonding interactions on different hard-to-soft segment mole fractions for a TPU. [25] From these and previous studies concerning hydrogenbonding on proteins and amide solutions, [26,27] it can be concluded that Raman microscopy is highly sensitive to hydrogen-bonding interactions, which are particularly important in the design of PUR chemical and physical properties.…”

Section: Introductionmentioning

confidence: 99%

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A new insight into polyurethane foam deterioration – the use of Raman microscopy for the evaluation of long‐term storage conditions

Sá

Ferreira

Matos

et al. 2016

J Raman Spectroscopy

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This research aims at bringing new contributions for lowering the polyether‐based polyurethane (PUR) flexible foam high deterioration rate by studying selected storage conditions. With a life expectancy of 20–50 years, many PUR objects show severe deterioration signs that, so far, cannot be prevented. To establish a preservation strategy, a natural ageing experiment in the dark (12 months, 45–55% relative humidity) has been carried out for the study of four storage conditions: open air at room temperature (T) and sealed enclosures at room T (with/without oxygen) and low T (11–13 °C). For this research, unaged (model PUR) and naturally pre‐aged (commercial PUR) references were included. The samples were analysed every 3 months by colourimetry, optical microscopy (visible and UV light), infrared and Raman microspectroscopies. Further statistical data treatment was carried out in order to identify significant spectral variations (ANOVA) and to uncover correlations between molecular spectral lines and physical aspects. Raman proved to be a powerful tool in the detection of early stage PUR molecular deterioration. For both model and commercial samples, open‐air storage proved to be the most harmful condition, while anoxic storage showed the best results. In general, this experiment has enabled new contributions for lowering PUR high deterioration rate. Copyright © 2016 John Wiley & Sons, Ltd.

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“…Amide III is highly diverse by coupling with -NH deformation modes between 1252 and 1256 cm À1 . [31] The band at 1446 cm À1 is attributed to CH 2 scissoring and CH 3 deformation. The amide IV, V and VI bands are designed by highly mixed modes comprising a significant contribution from the -NH out-of-plane deformation mode, assumed to be in the 800-400 cm À1.…”

Section: Effect Of Organoclay On Hydrogen Bonding Interaction Of Copumentioning

confidence: 99%

The influence of reactive organoclay on a biorenewable castor oil-based polyurethane prepolymers toughened polylactide nanocomposites

Gurunathan

Nayak

2016

Polym. Adv. Technol.

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Polylactide (PLA) is the most extensively reviewed and utilized biodegradable and renewable thermoplastic polyester, with potential to replace conventional petroleum-based polymeric materials. To improve the toughness of PLA, castor oil-based polyurethane prepolymer (COPUP) toughened PLA nanocomposites were prepared via the melt mixing process and investigated for its mechanical, thermal and morphological properties. X-ray diffraction and transmission electron microscopy studies revealed the formation of polymer blend nanocomposites. Mechanical tests revealed optimum performance characteristics at PLA/COPUP ratio of 70:30. Further, loading of the organoclay showed higher tensile strength and modulus of the blend nanocomposites as compared to optimized blend. The morphological results indicated that the surface roughness increases as a function of the organoclay incorporation. Thermogravimetric measurements reveal that the thermal stability of the blend increases with the incorporation of organoclay. The improved mechanical properties along with its biodegradability might lead to new industrial and biomedical applications.

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Calculation of the force field for several trihalides of group V atoms from raman spectra

Cited by 4 publications

References 5 publications

Novel hyperbranched waterborne polyurethane‐urea/silica hybrid coatings and their characterizations

Novel hyperbranched waterborne polyurethane‐urea/silica hybrid coatings and their characterizations

A new insight into polyurethane foam deterioration – the use of Raman microscopy for the evaluation of long‐term storage conditions

The influence of reactive organoclay on a biorenewable castor oil-based polyurethane prepolymers toughened polylactide nanocomposites

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