Determination of the diffusion constants of liquids in polymers by sorption and by internal reflection spectroscopy

Remizov, N.A.; Chalykh, A.Ye.; Popov, V.Ya.; Lavrent'ev, V. V.

doi:10.1016/0032-3950(82)90139-3

Cited by 4 publications

(2 citation statements)

References 2 publications

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“…Its historical development can be found in the literature [19]. The first attempts [115,116] were made in the early 1980's, but they were not conclusive because valid equations were not incorporated into the model for analysis. In 1984, an article was published by Brandth et al [117] about an ATR experiment done in situ concerning the diffusion of small molecules in polyethylene.…”

Section: By Atr Spectroscopymentioning

confidence: 99%

Spectroscopic characterization of molecular interdiffusion at a poly(vinyl pyrrolidone)/vinyl ester interface

Laot

Marand

Oyama

1999

Polymer

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Mechanical properties of (woven carbon fiber / vinyl ester matrix) composites can be greatly improved if the interphase between the reinforcing high-strength low-weight fiber and the thermoset resin is made more compliant. In order to improve the adhesion of the vinyl ester matrix to the carbon fiber, a thermoplastic coating such as poly(vinyl pyrrolidone) (PVP) can be used as an intermediate between the matrix and the fiber. The extent of mutual diffusion at the (sizing material / polymer matrix) interphase plays a critical role in determining the mechanical properties of the composite.In this research, the molecular interdiffusion across a poly(vinyl pyrrolidone))/vinyl ester monomer (PVP/VE) interface is being investigated by Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR) spectroscopy. The ATR method which can be used to characterize the transport phenomena, offers several advantages, such as the ability to monitor the diffusion in situ or to observe chemical reactions. In order to separate the effects of the vinyl ester monomer diffusion and the crosslinking reaction, ATR experiments were carried out at temperatures below the normal curing temperature. Diffusion coefficients were determined by following variations in infrared bands as a function of time, and fitting this data to a Fickian model. The values of the diffusion coefficients calculated were consistent with values found in the literature for diffusion of small molecules in polymers. The dependence of diffusion coefficients on temperature followed the Arrhenius equation. Hydrogen bonding interactions were also characterized. The diffusion model used in this study, however, does not seem to be appropriate for the particular (PVP/VE) system.Because the glass transition temperature of the PVP changed as diffusion proceeded, one would expect that the mutual diffusion coefficient did not stay constant. In fact, it was shown that the T g can drop by 140 o C during the diffusion process. A more suitable model of the (PVP/VE) system should take into account plasticization, hydrogen bonding, and especially a concentration dependent diffusion coefficient. Further analysis is therefore needed.iv ACKNOWLEDGMENTS

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Section: By Atr Spectroscopymentioning

confidence: 99%

Spectroscopic characterization of molecular interdiffusion at a poly(vinyl pyrrolidone)/vinyl ester interface

Laot

Marand

Oyama

1999

Polymer

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show abstract

“…Additionally, IR spectroscopy was employed to monitor the diffusion and transport low molecular weight compounds and to provide the predictive thermodynamic description of sorption processes in polymers. 18 Examples include exploration of structure and dynamics of H 2 O molecules in polymeric matrices, 364 as well as diffusion of acetone, methyl ethyl ketone and benzene polyethylene, 365 which aims to demonstrate the feasibility and accuracy of the ATR measurement of diffusion coefficients.…”

Section: Diffusionmentioning

confidence: 99%