Multicomponent Quantitative Analysis

Brown, C. W.; Obremski, Robert J.

doi:10.1080/05704928408060424

Cited by 25 publications

(12 citation statements)

References 12 publications

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“…Specific intermolecular interactions, such as hydrogen bonding (Brown and Obremski, 1984;Coleman and Painter, 1984;Coleman et al, 1991) and donor-acceptor complex formation, can lead to the negative enthalpy of mixing necessary to obtain miscible homopolymer blends (Olabisi at al., 1979). However, in copolymer-containing blends a different situation exists; miscible blends can be obtained without specific intermolecular interactions.…”

Section: Introductionmentioning

confidence: 99%

Vapor-liquid equilibria for copolymer/solvent systems: Effect of “intramolecular repulsion”

Gupta¹,

Prausnitz²

1996

Fluid Phase Equilibria

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The role of intramolecular interactions in blend miscibility is well documented for polymer+copolymer mixtures (ten Brinke et al., 1983;Paul and Barlow, 1984). Some copolymer+polymer mixtures are miscible although their corresponding homopolymers are not miscible; for example, over a range of acrylonitrile content, styrene/acrylonitrile copolymers are miscible with poly(methy1 methacrylate) but neither polystyrene nor polyacrylonitrile is miscible with poly(methy1 methacrylate). Similarly, over a composition range, butadiendacrylonitrile copolymers are miscible with poly(viny1 chloride) while none of the binary combinations of the homopolymers [polybutadiene, polyacrylonitrile, and poly(viny1 chloride)] are miscible. This behavior has been attributed to "intramolecular repulsion" between unlike copolymer segments.We have observed similar behavior in vapor-liquid equilibria (VLE) of copolymer+solvent systems. We find that acrylonitrile/butadiene copolymers have higher affmity for acetonitrile solvent than do polyacrylonitrile or polybutadiene. We attribute this non-intuitive behavior to "intramolecular repulsion" between unlike segments of the copolymer. This repulsive interaction is weakened when acetonitrile molecules are in the vicinity of unlike copolymer segments, favoring copolymer+solvent miscibility. We find similar behavior when acetonitrile is replaced by methyl ethyl ketone. To our best knowledge, this effect has not been reported previously for VLE. We have obtained VLE data for mixtures containing a solvent and a copolymer as a function of copolymer composition. It appears that, at a given solvent partial pressure, there may be copolymer composition that yields maximum absorption of the solvent. This highly non-ideal VLE phase behavior may be useful for optimum design of a membrane for a separation process.

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Section: Introductionmentioning

confidence: 99%

Vapor-liquid equilibria for copolymer/solvent systems: Effect of “intramolecular repulsion”

Gupta¹,

Prausnitz²

1996

Fluid Phase Equilibria

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“…MLR is an inverse method that uses the multiple linear regression model that was discussed earlier [1,46] : where X sel contains the responses of the x variables to be used in the MLR model. If the total number of available x variables ( M ) is less than the number of samples used to build the model ( N ), then X sel can contain all of the x variables.…”

Section: Multiple Linear Regression ( Mlr )mentioning

confidence: 99%

“…where X contains the spectra of N samples, C contains the pure concentrations of P chemical components for the N samples, K contains the pure component spectra of the P components, and E contains the model error [1,46] . This model indicates that any sample ' s spectrum is simply a linear combination of the spectra of the pure components (in K ).…”

Section: Classical Least Squares ( Cls )mentioning

confidence: 99%

Chemometrics in Process Analytical Technology (PAT)

Miller

2010

Process Analytical Technology

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“…Multivariate Calibration for the Analysis of a Sample with Undetermined Path Length. Assuming a generalized Beer-Lambert law, 23,24 the spectrum of a mixture of m constituents is the result of a linear combination of their respective m pure spectral profiles. For a set of n different mixtures, this gives in matrix notation, for a fixed reference path length:…”

Section: Theoretical Backgroundmentioning

confidence: 99%

Fast and Robust Method for the Determination of Microstructure and Composition in Butadiene, Styrene-Butadiene, and Isoprene Rubber by Near-Infrared Spectroscopy

2006

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In the tire industry, synthetic styrene-butadiene rubber (SBR), butadiene rubber (BR), and isoprene rubber (IR) elastomers are essential for conferring to the product its properties of grip and rolling resistance. Their physical properties depend on their chemical composition, i. e., their microstructure and styrene content, which must be accurately controlled. This paper describes a fast, robust, and highly reproducible near-infrared analytical method for the quantitative determination of the microstructure and styrene content. The quantitative models are calculated with the help of pure spectral profiles estimated from a partial least squares (PLS) regression, using (13)C nuclear magnetic resonance (NMR) as the reference method. This versatile approach allows the models to be applied over a large range of compositions, from a single BR to an SBR-IR blend. The resulting quantitative predictions are independent of the sample path length. As a consequence, the sample preparation is solvent free and simplified with a very fast (five minutes) hot filming step of a bulk polymer piece. No precise thickness control is required. Thus, the operator effect becomes negligible and the method is easily transferable. The root mean square error of prediction, depending on the rubber composition, is between 0.7% and 1.3%. The reproducibility standard error is less than 0.2% in every case.

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Multicomponent Quantitative Analysis

Cited by 25 publications

References 12 publications

Vapor-liquid equilibria for copolymer/solvent systems: Effect of “intramolecular repulsion”

Vapor-liquid equilibria for copolymer/solvent systems: Effect of “intramolecular repulsion”

Chemometrics in Process Analytical Technology (PAT)

Fast and Robust Method for the Determination of Microstructure and Composition in Butadiene, Styrene-Butadiene, and Isoprene Rubber by Near-Infrared Spectroscopy

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