Real-time monitoring of diffusion between laminated polymer films

Krongauz, Vadim V.; Mooney, William F.; Schmelzer, Eva

doi:10.1016/0032-3861(94)90935-0

Cited by 9 publications

(5 citation statements)

References 7 publications

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“…16, 18, 222-230), 33,41,42,47,49]. The values of water diffusivities obtained in the present work, and a few other studies [16,17,22,36,37,[50][51][52][53], were based on a coincidence of a broadest region Fig. 4 Kinetics of water absorption in bromobutyl rubber.…”

Section: Calculations and Data Reductionmentioning

confidence: 95%

Kinetics of water vapor diffusion in resins

Krongauz

Bennett

Ling

2016

J Therm Anal Calorim

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The water vapor sorption and desorption kinetics were monitored in methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS), bromobutyl, ethylenepropylene-butadiene monomer (EPDM) rubber, and butyl rubber at various temperatures by gravimetric method. Modified thermogravimetric analysis system was built and used. The geometry of the samples was approximating that of the infinite two-sided plane sheet of certain thickness. The coefficients of water vapor diffusion in polymers were deduced by comparing the experimentally monitored kinetics and kinetics computed using diffusion coefficients as adjustable parameters. The activation energies of water vapor diffusion in these polymers were deduced in the temperature range from 30 to 75°C. The activation energy of diffusion was 45.9 kJ mol -1 in bromobutyl rubber, 46.4 kJ mol -1 in butyl rubber, 60.3 kJ mol -1 in EPDM rubber, and 43.5 kJ mol -1 in MABS. Compensation effect was observed for water vapor diffusion in this series of polymers. Compensation effect parameters were determined to be, a = -23.9/ln(cm 2 s -1 ) and b = 0.49/(mol kJ -1 ) 9 ln(cm 2 s -1 ), in fair agreement with published data for water diffusion in polymers.

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Section: Calculations and Data Reductionmentioning

confidence: 95%

Kinetics of water vapor diffusion in resins

Krongauz

Bennett

Ling

2016

J Therm Anal Calorim

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“…Scientifically, there is interest in understanding how small molecule motions, including rotational reorientation 2 and translational diffusion, may be coupled to or decoupled from various polymer relaxation processes, such as the α-relaxation associated with cooperative segmental motions occurring near the glass transition temperature, T g . Numerous techniques, including fluorescence quenching, , fluorescence recovery after photobleaching, , UV/vis and infrared spectroscopy, − mass uptake, , charge transfer techniques, and capillary column inverse gas chromatography, , have been employed to measure translational small molecule diffusion coefficients on the order of 10 -10 cm 2 /s. To date, two techniques reported in the literature, forced Rayleigh scattering (FRS) ,− and holographic recovery after photobleaching (HFRAP), have been used to measure significantly lower diffusion coefficients, 10 -12 −10 -16 cm 2 /s, for molecules exhibiting Fickian diffusion and some degree of coupling to the polymer α-relaxation process near T g .…”

Section: Introductionmentioning

confidence: 99%

Small Molecule Probe Diffusion in Thin Polymer Films Near the Glass Transition: A Novel Approach Using Fluorescence Nonradiative Energy Transfer

1996

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A novel experimental approach involving fluorescence nonradiative energy transfer (NRET) is employed to study the Fickian diffusion of small molecules in rubbery polymer films near the glass transition. A theoretical formalism has been developed which directly relates the small molecule translational diffusion coefficient, 𝒟, to changes in the energy transfer efficiency, E. Values of 𝒟 as low as 5 × 10-16 cm/s have been measured. In this approach, two thin polymer films are sandwiched together, one labeled with either NRET donor or acceptor chromophores and the second doped with the complementary chromophore. Upon annealing for a time t, dopant chromophore diffusion occurs in which E is proportional to (𝒟t)1/2/w, where w is the donor film thickness. Values of 𝒟 for pyrene, N-(2-hydroxyethyl)-N-ethyl-4-(tricyanovinyl)aniline (TC1), bis(phenylethynylanthracene) (BPEA), and decacyclene in poly(isobutyl methacrylate) (PiBMA) and for BPEA in poly(ethyl methacrylate) (PEMA) have been measured over temperatures ranging from ca. T g to T g + 20 °C. Among these chromophores, significant differences in both the magnitude and temperature dependence of 𝒟 were observed and are attributed to differences in molecule size, shape, and flexibility. Two anomalous effects are observed from a comparison of translational diffusion and rotational reorientation dynamics of TC1 in PiBMA near T g. The first is an apparent enhancement in translational diffusion relative to rotational reorientation dynamics, with the average translational displacement of a chromophore during an average rotational relaxation time, 〈τrot〉, being a couple orders of magnitude larger than the length of the molecule. This behavior may be explained by significant local-scale heterogeneity in the polymer, i.e., the broad distribution of polymer α-relaxation times. The second regards the different temperature dependencies of 〈τrot〉 and 𝒟 near T g. This may be explained qualitatively by a strong temperature dependence of the breadth of the distribution of α-relaxation times, an effect known to be present in the TC1−PiBMA system employed in this comparison as well as a variety of other polymer systems near T g.

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“…Diffusion of solvent and plasticizer molecules in solid polymers is slow, with diffusion coefficients of the order of 10 −8 to 10 −9 cm 2 /s . As a consequence of slow molecular diffusion in polymers, extraction of plasticizers and additives from the polymer solids is a slow process that may take days.…”

Section: Introductionmentioning

confidence: 99%

Revisiting analysis of phthalate plasticizers concentration in poly(vinyl chloride)

Krongauz

Ling

O’Connell

2014

Vinyl Additive Technology

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The method of the efficient analysis of di(2-diethylhexyl) phthalate, tri(2-ethylhexyl) trimellitate, di(2-ethylhexyl) terephthalate, and other phthalate plasticizers concentrations in plasticized poly(vinyl chloride) (PVC) was developed. The method is based on quantitative dissolution of the PVC sample in methyl ethyl ketone with the consequent precipitation of PVC with hexane and concentration of phthalate in an organic layer. A capillary column-based gas chromatographic technique for phthalates separation and quantification was developed and used in conjunction with the PVC and phthalates dissolution technique. The developed method of phthalate plasticizers analysis proved to be relatively fast, reproducible, and straightforward. J.

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Real-time monitoring of diffusion between laminated polymer films

Cited by 9 publications

References 7 publications

Kinetics of water vapor diffusion in resins

Kinetics of water vapor diffusion in resins

Small Molecule Probe Diffusion in Thin Polymer Films Near the Glass Transition: A Novel Approach Using Fluorescence Nonradiative Energy Transfer

Revisiting analysis of phthalate plasticizers concentration in poly(vinyl chloride)

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