Sulfonation degree determination by adiabatic bomb calorimetry of polystyrene ionomers

Dumanlı, Ahu Gümrah
In this study, the sulfonation degree of sulfonated polystyrene is determined by adiabatic bomb calorimeter, which is a novel analysis method for this determination. The theoretical combustion enthalpy calculations are compared with the experimental results and a correlation factor is found between these values. The effect of neutralization on the calorific values is also examined. The sulfonation reaction and the degree of sulfonation are determined by analytical titration method and elemental sulfur analysis and these results are supported by the Tg values obtained from DSC. The molecular weight of polystyrene is determined in order to see the relationship between the experimental calorific value and molecular weight. Atomic Absorption Spectroscopy (AAS) is used to evaluate neutralization of sulfonated polystyrene samples. For this purpose, sulfonated polystyrene (SPS) samples with varying percentage of sulfonation are prepared. These SPS samples are used in the preparation of; 3.28 mol% Zn neutralized polystyrene (3.28% Zn-SPS), 4.38 % Zn- SPS, 6.51% Zn-SPS, 7.29 Zn-SPS and corresponding Magnesium and Aluminum ionomers. Na ionomers; 1.7 %Na-SPS, 2.6% Na*SPS, 4.2% Na-SPS are provided from Exxon laboratories are used also in the adiabatic bomb calorimeter and AAS analysis. The increasing sulfonation degree yields a decrease in both the experimental and the theoretical combustion enthalpy values. Metal ion incorporation i.e. Ai3+ to the structure alters the experimental combustion enthalpy values comparing with the corresponding sulfonated polystyrene. Higher sulfonation degree ionomers i.e. 7.29% Zn-SPS, deviates positively from the decreasing behavior of the combustion enthalpy, due to formation of higher degree of aggregation.


Sulfonation degree determination of polystyrene ionomers by using adiabatic bomb calorimeter
Alkan, C; Dumanli, AG; Aras, L (Wiley, 2006-06-15)
Sulfonation degree determination of sulfonated polystyrene and the corresponding ionomers are performed by adiabatic bomb calorimeter. The theoretical calculations from the band energies for the combustion enthalpy values (calorific values) and the experimental values are compared, and a linear relation between the values is found. Sulfonation and neutralization processes are examined by elemental Sulfur analysis and atomic absorption spectroscopy (AAS). It was obvious that increasing sulfonation degree yie...
Temperature dependence of the damping constant and the order parameter close to the lambda phase transitions in ammonium halides
Yurtseven, Hasan Hamit (Elsevier BV, 2006-10-01)
This study gives our calculation for the damping constant, using the expressions derived for an Ising pseudospin-phonon coupled system in the ammonium halides (NH4Cl and NH4Br). For this calculation of the damping constant, we use the temperature dependence of the order parameter calculated from the molecular field theory. We predict here the damping constants for the v(5) (174 cm(-1)) and v(5) (177 cm(-1)) Raman modes of NH4Cl and NH4Br, respectively, below T-lambda and compare them with our observed bandw...
Pressure dependence of the Raman frequencies for the translational mode in ammonia solid II
Yurtseven, Hasan Hamit (Elsevier BV, 2006-12-01)
We study here the translational mode of the ammonia solid II near the melting point by calculating its Raman frequencies as a function of pressure for the fixed temperatures of 230.4, 263.4 and 297.5 K. We perform this calculation of the Raman frequencies using the volume data by means of our Gruneisen relation. The Raman frequency shifts as the volume changes with the pressure, exhibit an anomalous behaviour near the melting point in the ammonia solid II.
Viscosity measurement and modeling of lipid supercritical carbon dioxide mixtures
Yener, Meryem Esra; Rizvi, SSH; Harriott, P (1998-01-31)
The viscosities of supercritical carbon dioxide (SC-CO2) containing different levels of methyl oleate and oleic acid were measured with a high pressure capillary viscometer. The SC-CO2-methyl oleate system was evaluated at 313.15, 323.15 and 333.15 K and 11.5, 13.7 and 15.5 MPa, respectively. The SC-CO2-oleic acid system was evaluated at 313.15 K and 20.5 and 30.0 MPa and 333.15 K and 30.0 MPa. The increase in SC-CO2 viscosity was as high as 15-20% at the maximum methyl oleate concentrations (4-5 wt%) and 6...
Oxidative coupling of methane over NbO (p-type) and Nb2O5 (n-type) semiconductor materials
Erarslanoglu, Y; Onal, I; Doğu, Timur; Senkan, S (Springer Science and Business Media LLC, 1996-01-01)
Oxidative coupling of methane to higher hydrocarbons was investigated using two types of semiconductor catalysts, NbO (p-type) and Nb2O5 (n-type) at 1 atm pressure. The ratio of methane partial pressure to oxygen partial pressure was changed from 2 to 112 and the temperature was kept at 1023 K in the experiments conducted in a cofeed mode. The results indicated a strong correlation between C-2+ selectivity performance and the electronic properties of the catalyst in terms of p- vs. n-type conductivity. The ...
Citation Formats
A. G. Dumanlı, “Sulfonation degree determination by adiabatic bomb calorimetry of polystyrene ionomers ,” M.S. - Master of Science, Middle East Technical University, 2003.