Thermodynamic characterization of miscible blends from very similar polymers by inverse gas chromatography. The poly(ethyl acrylate)-poly(vinyl propionate) system

Deanin

2003

The inverse gas chromatography method was extended to study the concentration dependent FloryHuggins interaction parameter between poly(vinyl chloride) (PVC) and plasticizers using literature data. For both PVC/ polyadipate and PVC/epoxidized soybean oil (ESO) systems, the miscibility was better at the high PVC end. The specific interaction between PVC and plasticizers was estimated from the difference between the experimental results and the enthalpies of mixing predicted by the solubility parameter model. The interaction was negative and skewed toward the high PVC end, and rendered the overall interaction parameter negative at high PVC compositions. Chemical potential was used to determine the phase composition of PVC/plasticizer mixtures.

Section: Interaction Parameters Of Polymer Blends By Igc Methodsmentioning

confidence: 94%

Concentration dependency of interaction parameter between PVC and plasticizers using inverse gas chromatography

Deanin

2003

“…Etxeberria et al29 reached the following two conditions in discussing the plotting method of Farooque and Deshpande27: first, reject the probes that had similar interaction parameters with both pure polymers, because this implied similar specific retention volumes; second, the probes were selected in order to try to cover all possible chemical structures and polarities. The first condition was also suggested by Mandal et al4, 38 because a similar retention volume led to a higher error in the calculation. The second condition intended to find a probe with a large |χ 12 − χ 13 | value to facilitate plotting of eq.…”

Section: Resultsmentioning

confidence: 79%

“…If the trend continued, a lower critical solution temperature could occur 39. This is common to many polymer systems, but the differential scanning calorimetry study by Mandal et al38 indicated that there was no phase separation below the decomposition temperature (about 300°C). This may be the result of the relatively low molecular weight of PVPr (49,000).…”

Section: Resultsmentioning

confidence: 98%

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Determination of polymer–polymer interaction parameters using inverse gas chromatography

2003

ABSTRACT:A modified method is discussed that is based on Farooque and Deshpande's method to obtain polymerpolymer interaction parameters using inverse gas chromatography (IGC) data. In the Farooque and Deshpande method, the ratio of the difference of probe-polymer interaction parameters between two polymers and the probe volume [( 12 Ϫ 13 )/V 1 ] is used as the abscissa. In the modified method, the ratio [( 2 12 ϩ 3 13 )/V 1 ] is used as the abscissa. Experimental data previously reported for a poly(⑀-caprolactone)-polyepichlorohydrin (PCL/PECH) blend and a poly(ethyl acrylate)-poly(vinyl propionate) (PEA/PVPr) blend are analyzed. It is found that the slopes obtained by the new method had smaller deviations from the theoretical values than the Farooque and Deshpande method. The standard deviations of both slopes and intercepts obtained from the new method are also smaller. Using the new method, the polymer-polymer interaction parameters obtained from the intercept are negative numbers for the PCL/PECH system and very small positive numbers for PEA/PVPr. Explanations are given for the probe and concentration dependency of the polymer-polymer interaction parameters that are generally observed in IGC studies. A new method for selecting the best probe for calculating the interaction parameter is discussed.

“…Second, the probes were selected in an attempt to cover all possible chemical structures and polarities. The first condition was also suggested by Mandal and coworkers4, 45 because a similar retention volume led to an error in the calculation. The second approach was intended to find a probe with a large value of |χ 12 − χ 13 |.…”

Section: Resultsmentioning

confidence: 99%

Analysis of the thermodynamic compatibility of poly(vinyl chloride) and nitrile rubbers from inverse gas chromatography

2003

ABSTRACT:The solubility parameter method was applied to an analysis of the solution thermodynamic data of several solutes (probes) in polymers obtained by inverse gas chromatography. Experimental data previously reported by different authors were analyzed. The polymers used as the stationary phases were poly(vinyl chloride) (PVC), two nitrile rubbers (NBRs), and PVC/NBR blends. From the retention volumes of the probes, the Flory-Huggins interaction parameters at infinite dilution were calculated. The interaction parameters, in turn, were related to the solubility parameters of the solutes and stationary phases. With a series of probes, the solubility parameters of PVC and NBRs were determined. Differences existed between the experimental values of the size-corrected free energies of solutions and the values calculated with solubility parameters. The differences were generally negative values. When these differences obtained from two NBR rubbers were plotted versus PVC, a correlation was found. Methods for obtaining the interaction parameters of polymer blends were examined. A modified plotting method gave a linear line and an interaction parameter between two polymers consistent with the results of the solubility parameters.