Laser Raman Studies of Poly(vinyl chloride)

Liebman, Shirley A.; Foltz, Carl R.; Reuwer, J. F.; Obremski, Robert J.

doi:10.1021/ma60019a029

Cited by 33 publications

(7 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many efforts have been done to simulate the dependence of both the macrocosmic and microcosmic structure of PVC molecular chains on aging conditions in the accelerating aging process 4–10. It is convinced that the photo‐dehydrochlorination of PVC is dominated in the initial aging step.…”

Section: Introductionmentioning

confidence: 99%

Formation mechanism of microvoids and microcracks of poly(vinyl chloride) under an artificial aging environment

Xiang

Wang

Chen

et al. 2011

J of Applied Polymer Sci

View full text Add to dashboard Cite

Degradation behaviors of both the unplasticized and plasticized poly(vinyl chloride) (UPVC and PPVC) under an artificial accelerating aging condition were extensively studied. The dependence of mechanical properties, average molecular weight (MW), and surface morphology of the earlier PVC on aging time was investigated by tensile tests, gel penetrate chromatogram (GPC), and scanning electron microscope (SEM), respectively. Fourier transform infrared and ultraviolet (UV)–visible spectroscopy were used to evaluate the probable formation of both the oxygen‐containing groups and the conjugated sequences during aging. The results reveal that UPVC is much easier to be degraded than PPVC under the same testing conditions. The irradiated surface is detected to change from an even topology into a rough topology initially, and then follows the appearance of many voids even cracks in the SEM morphology. During the aging process, oxygen‐containing groups and conjugation of PVC molecular chains around the cracks are observed, and noticeably increase with aging time. However, visible difference of the corresponding MWs of PVC before and after aging is not detected. Moreover, a novel degradation mechanism nearly related to the formation of microvoids and microcracks based on the cohesion energy of groups along PVC molecular chains is developed and semiquantitatively discussed. It is detected that the formation of microvoids and microcracks is attributed to both the thermodynamic changes of PVC backbone during the aging and the aggregation of oxygen‐containing groups with relatively large volumes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

show abstract

Section: Introductionmentioning

confidence: 99%

Formation mechanism of microvoids and microcracks of poly(vinyl chloride) under an artificial aging environment

Xiang

Wang

Chen

et al. 2011

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…Raman bands observed in VCM and MMA spectra (Bodoc et al, 2012;Gulari et al, 1984;Edwards et al, 2006;Willis et al, 1969;Liebman et al, 1971;Maddans, 1977;Bowden et al, 1991). Fig.…”

Section: Tablementioning

confidence: 99%

“…The vibrational assignments for methyl methacrylate and vinyl chloride spectra are reported in Table 4. These vibrational bands were identified with the aid of various published works (Bodoc et al, 2012;Gulari et al, 1984;Edwards et al, 2006;Willis et al, 1969;Liebman et al, 1971;Maddans, 1977;Bowden et al, 1991). Particular attention must be observed to the peaks located at 1640 cm À1 and 1604 cm À1 .…”

Section: Raman Monitoring Proceduresmentioning

confidence: 99%

Real time monitoring of the quiescent suspension copolymerization of vinyl chloride with methyl methacrylate in microreactors – Part 3. A kinetic study by raman spectroscopy and evolution of droplet size

Castor

Pontier

Durand

et al. 2017

Chemical Engineering Science

View full text Add to dashboard Cite

h i g h l i g h t s Experimental work on the suspension copolymerization of VCM with MMA by using microreactors. The reaction kinetics was monitored by Raman spectroscopy. Evolution of the particle volumes was monitored and correlated to monomer conversion. Performances between bifunctional and monofunctional initiators were compared. A new mechanism based on the results from both video camera and Raman spectroscopy is proposed.

show abstract

“…Thermal degradation of PVC has been shown to significantly alter − the Raman spectrum; new Raman bands appeared at about ∼1100 and ∼1500 cm -1 and were attributed to resonance Raman vibrations of conjugated polyene sequences, (−CHCH−) n , formed by the dehydrochlorination of PVC. The position of the peak at about 1500 cm -1 is directly related 41 to the length of the conjugated sequences, n , whereas the intensity of the resonance Raman band around 1100 cm -1 is related to the degree of degradation and the exciting radiation wavelength.…”

Section: Introductionmentioning

confidence: 99%

“…The position of the peak at about 1500 cm -1 is directly related 41 to the length of the conjugated sequences, n , whereas the intensity of the resonance Raman band around 1100 cm -1 is related to the degree of degradation and the exciting radiation wavelength. It was found that it is possible to detect conjugated polyenes down to levels of 0.003%. , …”

Section: Introductionmentioning

confidence: 99%

Polarized Resonance Raman and FTIR Reflectance Spectroscopic Investigation of the Molecular Orientation in Industrial Poly(vinyl chloride) Specimens

Voyiatzis¹,

Andrikopoulos²,

Papatheodorou³

et al. 2000

Macromolecules

View full text Add to dashboard Cite

The molecular orientation of uniaxially drawn commercial poly(vinyl chloride), PVC, specimens has been investigated by polarized Fourier transform infrared (FTIR) in the specular reflectance mode and by resonance Raman scattering in various combinations of sample orientation, scattering configuration and polarization geometry. The orientation was examined as a function of the specimen draw ratio. The Kramers-Kronig transformation has been used to obtain infrared absorption spectra from the FTIR reflectance data; the orientation was determined by the dichroic ratio of the C-Cl stretching and CH 2 rocking modes of PVC. The resonance Raman spectra of polyene segments that result from partial thermal degradation/dehydrochlorination of PVC during processing have been utilized in order to determine the parameters of the orientation distribution function. The all-trans conjugated polyene sequences formed during degradation are considered as rodlike segments in the polymer backbone and are used as indicators of orientation within the amorphous-like polymer phase. As far as the trends are concerned, data analysis showed good agreement between FTIR and Raman results regarding the induced molecular orientation in industrial PVC specimens.

show abstract

Laser Raman Studies of Poly(vinyl chloride)

Cited by 33 publications

References 1 publication

Formation mechanism of microvoids and microcracks of poly(vinyl chloride) under an artificial aging environment

Formation mechanism of microvoids and microcracks of poly(vinyl chloride) under an artificial aging environment

Real time monitoring of the quiescent suspension copolymerization of vinyl chloride with methyl methacrylate in microreactors – Part 3. A kinetic study by raman spectroscopy and evolution of droplet size

Polarized Resonance Raman and FTIR Reflectance Spectroscopic Investigation of the Molecular Orientation in Industrial Poly(vinyl chloride) Specimens

Contact Info

Product

Resources

About