Conformational structure of bisphenol A polycarbonate studied by infra-red spectroscopy

Schmidt, Pavel; Dybal, Jiřı́; Turska, E.; Kulczycki, A.

doi:10.1016/0032-3861(91)90377-u

Cited by 38 publications

(37 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results are in good agreement with the measured infrared spectra. 37 On the basis of symmetry we find that Raman activity is allowed for modes localized on the carbonate group, the isopropylidene unit (1217 and 3078 cm -1 ), and on the phenylene groups (1471 and 1586 cm -1 ).…”

Section: A Geometrical Structures 1 Single Moleculementioning

confidence: 98%

Density Functional Study of Crystalline Analogs of Polycarbonates

1998

View full text Add to dashboard Cite

Density functional studies have been performed for two crystalline analogs of Bisphenol A polycarbonate (BPA-PC) and for the isolated structural unit. The calculations are free of adjustable parameters and yield equilibrium structures that agree well with available data. Vibrational frequencies have been calculated for the molecular unit. For all structures we have calculated the energy barriers for rotation of segments of the molecule, and we have compared the results with experiment. All phenylene groups rotate freely in the isolated molecular unit, but the corresponding π-flips in the crystalline phases are hindered by the neighboring molecules and reflect the chain packing. The minimum energy barrier for the rotation in the crystal (7.7 kcal/mol) is associated with the rotation of the inner phenylene ring in the molecular unit. The activation energy for the rotation of the methyl groups is 3.4 kcal/mol, independent of the chain packing, and the barriers for rotation of the carbonyl group are 8.7 and 19 kcal/mol in the molecule and crystal phase, respectively.

show abstract

Section: A Geometrical Structures 1 Single Moleculementioning

confidence: 98%

Density Functional Study of Crystalline Analogs of Polycarbonates

1998

View full text Add to dashboard Cite

show abstract

“…[24] In a previously reported study, conformational changes were monitored by the C2O stretching absorption at 1 775 cm -1 which was identified as a doublet containing contributions at 1 767 and 1 785 cm -1 from t-t and c-t conformers. [25] In a later study, the conformationally sensitive band at 1 600 cm -1 which is due to the in-plane stretching of the phenyl groups was used. [26] This band contains contributions from t-t and c-t conformers at 1 594 and 1 604 cm -1 .…”

Section: Ris Models and Single-chain Conformational Propertiesmentioning

confidence: 99%

Conformational Analysis, RIS Models and Single-Chain Properties of Structurally Modified Polycarbonates, 1. Effect of Cyclohexyl and Phenyl Ring Substitutions

Sulatha¹,

Natarajan²,

Sivaram³

2002

Macromol. Theory Simul.

View full text Add to dashboard Cite

“…Analysis of polycarbonate Schmidt et al (1991) had suggested that polycarbonate contained conformationally sensitive infrared bands namely carbonate carbonyl, phenyl (C=C) stretching, and C-O-C skeletal vibrations that change during degradation, while Gagnadre et al (1993) observed that aromatic bending vibration at 1,508 cm -1 was not affected significantly even under strong ionic irradiation. The methyl index decreased from 0.28 (for control polycarbonate) to 0.11 for in vitro sample, indicating possible oxidation of tertiary methyl group.…”

Section: Resultsmentioning

confidence: 98%

Bisphenol A and metabolites released by biodegradation of polycarbonate in seawater

Artham

Doble

2011

Environ Chem Lett

View full text Add to dashboard Cite

This is the first report of bisphenol A release from polycarbonate during biodegradation by marine microorganisms. Bisphenol A is a monomer in polycarbonate and an endocrine disruptor toxic for marine organisms. Biodegradation of polycarbonate is poorly documented. Here, we have tested the possible release of bisphenol A and metabolites during biodegradation of polycarbonate by marine microorganisms. Polycarbonate degradation was carried out in vitro using a mixed marine microbial consortium isolated from the Bay of Bengal, India, 1 year under controlled laboratory conditions. The degradation was monitored by elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and gas chromatography-mass spectrometry (GC-MS). The organic soluble metabolites were analyzed by high-performance liquid chromatography (HPLC). We found that bisphenol A was released. The amount of bisphenol A released during 1 year is higher than the half-maximal effective concentration (EC 50 ) values reported for marine organisms. We also identified the following bisphenol A metabolites: 4-hydroxyacetophenone, 4-hydroxybenzaldehyde, and 4-hydroxybenzoic acid. Polycarbonate biodegradation was evidenced by gravimetric weight loss and Fourier transform infrared spectroscopy. The reduction of methyl and carbonyl indices suggests oxidation and hydrolysis of the polymer, respectively. 2D NMR showed an aromatic C-C cleavage.

show abstract

Conformational structure of bisphenol A polycarbonate studied by infra-red spectroscopy

Cited by 38 publications

References 14 publications

Density Functional Study of Crystalline Analogs of Polycarbonates

Density Functional Study of Crystalline Analogs of Polycarbonates

Conformational Analysis, RIS Models and Single-Chain Properties of Structurally Modified Polycarbonates, 1. Effect of Cyclohexyl and Phenyl Ring Substitutions

Bisphenol A and metabolites released by biodegradation of polycarbonate in seawater

Contact Info

Product

Resources

About