Polymer Thermodynamics

In KosekGroup we have a great experience in the experimental investigation of:

  • Thermodynamic properties such as sorption, diffusion, swelling, softening.
  • Morphology of complex heterophase polymers.
  • Development and characterization of polymeric foams.

We investigate the whole polymerization via sub-processes and related phenomena. For this purpose we employ many different methods, such as:

  • gravimetric sorption balances for solubility measurements
  • video-microscopic apparatus swelling measurements
  • pressure decay apparatus for diffusion measurements
  • TD-NMR for both morphology and transport insight through chain relaxation
  • laser-dilatometry apparatus for softening measurements
  • AFM, micro-CT and SEM for morphology investigations

We have a broad base of experimental data, advanced tools and unique equipment tailored for special needs. Experimental section of KosekGroup closely cooperates with mathematical modelling. Experiments can provide a background for validation or deeper understanding of the physics in the system.

During all types of catalytic polymerization, transport processes in the reaction mixture significantly influence the reaction kinetics, which is influenced by monomer concentration at active catalyst sites. This concentration is given by the solubility and diffusivity of the monomer(s) in the nascent polymer. On the other hand, the solvent sorbed in the polymer affects its mechanical properties (e.g., softening) and can even cause the adhesion of the polymer to reactor wall.

Our research is focused on all of the above mentioned phenomena connected to transport processes. We have the broadest database of thermodynamic data relevant to catalytic polymerization [1-8]. Resulting data help us to provide better understanding of thermodynamic behavior in PE and also can serve for the optimization of industrial processes.

Thermodynamic behavior affects not only the reaction kinetics but also the morphology development of growing polymer. Our research provides an insight into all stages of polymer evolution [9-12]. Thanks to our unique instrumentation we can take a look on the morphology from the different views, from macroscale up to nanoscale, in both 2D or 3D.

 

 

References:

[1] Chmelař J., Smolná K., Haškovcová K., Podivinská M., Maršálek J., Kosek J.: Equilibrium sorption of ethylene in polyethylene: Experimental study and PC-SAFT simulations, Polymer, 2015, 59: 270-277.

[2] Chmelař, J.; Haškovcová, K.; Podivinská, M. & Kosek, J. Equilibrium Sorption of Propane and 1-Hexene in Polyethylene: Experiments and Perturbed-Chain Statistical Associating Fluid Theory Simulations Industrial & Engineering Chemistry Research, 2017, 56, 6820-682.

[3] Podivinská M., Jindrová K., Chmelař J., Kosek J.: Swelling of polyethylene particles and its relation to sorption equilibria under gas-phase polymerization conditions, Journal of Applied Polymer Science, 2017, 45035: 1-7.

[4] Hajova H., Chmelar J., Nistor A., Gregor T., Kosek J.: Experimental study of sorption and diffusion of n-pentane in polystyrene. Journal of Chemical Engineering Data, 2013, 58(4): 851–865.

[5] Chmelar J., Matuska P., Gregor T., Bobak M., Fantinel F., Kosek J. Softening of polyethylene powders at reactor conditions, Chemical Engineering Journal, 2013, 228: 907-916.

[6] Chmelař, J.; Gregor, T.; Hajová, H.; Nistor, A.; Kosek, J. Experimental study and PC-SAFT simulations of sorption equilibria in polystyrene. Polymer, 2011, 52: 3082–3091.

[7] Hajová H., Pokorný R., Kosek J. Diffusion Transport in Reconstructed Semi-Crystalline Structure of Polyolefins. Polymer Reaction Engineering – 10th International Workshop, 2011, 302: 121–128.

[8] Novák A., Bobák M., Kosek J., Banaszak B.J., Lo D., Widya T., Ray W.H., de Pablo J.J.: Ethylene and 1-hexene sorption in LLDPE under typical gas-phase reactor conditions: Experiments. Journal of Applied Polymer Science, 2006, 100 (2), 1124–1136.

[9] Smolná K., Gregor T., Buráň Z., Kosek J.: Formation and distribution of rubbery phase in high impact poly(propylene) particles, Macromolecular Materials and Engineering, 2016, 301 (4): 390-400.

[10] Chmelař J., Pokorný R., Schneider P., Smolná K., Bělský P., Kosek J.: Free and constrained amorphous phases in polyethylene: Interpretation of 1H NMR and SAXS data over a broad range of crystallinity, Polymer, 2015, 58: 189-198.

[11] Smolná K., Gregor T., Kosek J.: Morphological analysis of high-impact polypropylene using X-ray microCT and AFM, European Polymer Journal, 2013, 43(12): 3966-3976.

[12] Meisterová L., Zubov A., Smolná K., Štěpánek F., Kosek J. X-ray Tomography Imaging of Porous Polyolefin Particles in Electron Microscope, Macromolecular Reaction Engineering, 2013, 7(6): 277-288.