Infrared spectra of high polymers

Krimm, Samuel

doi:10.1007/bf02283926

Cited by 74 publications

(92 citation statements)

References 215 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The ATR-FTIR spectra of PLA and PET films displayed the typical vibrations bands of these materials in accordance with other studies (Figure 5 and 6) [25,26,43,44]. For PLA, -C=O stretching (1720 cm -1 ), -CH 3 bending (1452 cm -1 ), -C=O bending (1270 cm -1 ), -C-O-C stretching (1185 cm -1 ), -C-Ostretching (1130 and 1088 cm -1 ), -OH bending (1046 cm -1 ) and -C-C-stretching attributed to amorphous and crystalline phases (863 and 758 cm -1 , respectively) [25,44].…”

Section: Chemical Modificationssupporting

confidence: 90%

“…For PLA, -C=O stretching (1720 cm -1 ), -CH 3 bending (1452 cm -1 ), -C=O bending (1270 cm -1 ), -C-O-C stretching (1185 cm -1 ), -C-Ostretching (1130 and 1088 cm -1 ), -OH bending (1046 cm -1 ) and -C-C-stretching attributed to amorphous and crystalline phases (863 and 758 cm -1 , respectively) [25,44]. For PET, -C=O stretching (1752 cm -1 ), -CH 2 bending (1452 cm -1 ), -C=O bending (1260 and 1246 cm -1 ), O-C stretching (1118 and 1098 cm -1 ) and the vibration modes associated to the aromatic ring (1578, 1506, 1018, 874 and 726 cm -1 ) [26,43]. When the properties of polymer materials are modified by chemical reactions such as degradation, polymerization or chemical bonds creation, formation of new bands or chemical shifts are expected in the ATRspectra.…”

Section: Chemical Modificationsmentioning

confidence: 99%

See 1 more Smart Citation

How high pressure CO2 impacts PLA film properties

Rocca-Smith¹,

Lagorce-Tachon²,

Iaconelli³

et al. 2017

Express Polym. Lett.

View full text Add to dashboard Cite

Abstract. This work investigated the sorption and the diffusion properties of CO 2 under high pressure and the further modifications induced in Poly(lactic acid) (PLA) thin layers. Poly(ethylene terephtalate) (PET) was also considered for comparative purposes. Firstly, from thermodynamic equilibrium, the CO 2 sorption isotherm (two sorption-desorption cycles, up to 25 bar, at 25°C) gave strong evidence of a physisorption mechanism and of a hysteresis phenomenon. Infrared spectroscopy analysis confirmed that no chemical reaction occurred. Secondly, from the kinetics aspect, the CO 2 diffusion coefficient was found around 10 -13 m 2 ·s -1 and was slightly faster for sorption compared to desorption. Additionally, when CO 2 sorption occurred, the PLA structure and its functional properties were modified due to plasticization and swelling. CO 2 plasticization reduced the glass transition temperature of PLA and accelerated the physical ageing of the polymer. These results are therefore of significant importance in industrial processing and applications which involve close contact between CO 2 and PLA.

show abstract

Section: Chemical Modificationssupporting

confidence: 90%

Section: Chemical Modificationsmentioning

confidence: 99%

How high pressure CO2 impacts PLA film properties

Rocca-Smith¹,

Lagorce-Tachon²,

Iaconelli³

et al. 2017

Express Polym. Lett.

View full text Add to dashboard Cite

show abstract

“…According to our previous estimation of CH 3 -stretching IR absorptions, the first CH 3 stretching overtone vibration occurs in this region. 21 To assign NIR bands to PE, we measured NIR spectra of various linear alkane solvents from hexane to tetradecane, along with molten HDPE. These spectra were measured using optical path lengths of 2 and 0.65 mm, respectively.…”

Section: Resultsmentioning

confidence: 99%

In situ near-infrared spectroscopic studies of the structural changes of polyethylene during melting

Mizushima

Kawamura

Takahashi

et al. 2011

Polym J

View full text Add to dashboard Cite

Conformational changes occurring during the melting of various polyethylene (PE) materials, including high-density PE (HDPE), linear low-density PE (LLDPE) and low-density polyethylene (LDPE), were investigated using near-infrared spectroscopy. The assignment of PE to the 1650-1900 nm spectral region was suggested, on the basis of computational and experimental data for normal alkanes. The present results suggested that the 1690 and 1710 nm bands should be assigned to the CH 3 groups in branched chains and chain ends, respectively. The HDPE and LDPE crystal lattices have very few defects, in contrast to LLDPE, which has more crystal lattice defects. The chain ends and junctions of LDPE are excluded from the crystal lattice and exist in a thick amorphous layer, whereas LLDPE includes comonomers in its crystalline lattice.

show abstract

“…Investigations on crystalline polymorphs, especially the field of polymer science, are based on the careful assignment of IR features. 4,6,[10][11][12][13][14][15][16][17] A comprehensive interpretation of the vibrational spectra of semi-crystalline polymers is a very intriguing and nontrivial topic, because in this case several different concurrent structural effects determine the spectral pattern of the material:…”

Section: Introductionmentioning

confidence: 99%

Intermolecular modulation of IR intensities in the solid state. The role of weak interactions in polyethylene crystal: A computational DFT study

Galimberti

Milani

Maschio

et al. 2016

The Journal of Chemical Physics

View full text Add to dashboard Cite

Density functional crystal orbital study on the normal vibrations and phonon dispersion curves of all-trans polyethylene J. Chem. Phys. 108, 7901 (1998) Density functional theory calculations with periodic boundary conditions are exploited to study the infrared spectrum of crystalline polyethylene. Spectral changes lead by the intermolecular packing in the orthorhombic three-dimensional crystal are discussed by means of a careful comparison with calculations carried out for an isolated polymer chain in the all-trans conformation, described as an ideal one-dimensional crystal. The results are analyzed in the framework of the "oligomer approach" through the modelling of the IR spectrum of n-alkanes of different lengths. The study demonstrates that a relevant absorption intensity modulation of CH 2 deformation transitions takes place in the solid state. This finding suggests a new interpretation for the experimental evidences collected in the past by means of IR intensity measurement during thermal treatment. Moreover, the comparison between calculations for 3-D crystal and for the isolated polyethylene chain (1-D crystal) allows to put in evidence the effect of the local electric field on the computed infrared intensities. This observation provides guidelines for the comparison between infrared absorption intensities predicted for an isolated unit and for a molecule belonging to a crystal, through the introduction of suitable correction factors based on the refraction index of the material and depending on the dimensionality of such units (0D-molecule; 1D-polymer; 2D-slab). Published by AIP Publishing.[http://dx

show abstract

Infrared spectra of high polymers

Cited by 74 publications

References 215 publications

How high pressure CO2 impacts PLA film properties

How high pressure CO2 impacts PLA film properties

In situ near-infrared spectroscopic studies of the structural changes of polyethylene during melting

Intermolecular modulation of IR intensities in the solid state. The role of weak interactions in polyethylene crystal: A computational DFT study

Contact Info

Product

Resources

About