Department of Synthesis and Characterization of Polymers

The aim of the department is to cover completely the expertise in synthesis of polymers using various polymerization techniques including free radical, reversible-deactivation radical and anionic polymerizations. The second object of synthesis represents preparation, spectral characterization and mainly utilization of different fluorescence probes for characterization of polymer microstructure and for polymerization study mechanism. Modification of polymers by grafting, crosslinking and functionalizations and preparation of polymeric and inorganic nanoparticles and hybrids represents another part of synthetic direction. Prepared as well as comercial polymers are characterised by spectral methods (UV-VIS, FTIR, Fluorescence and Raman spectroscopy), thermal analysis (DSC, TGA, chemiluminescence, thermal and photo stability, flammability) and their molar characteristics by advanced HPLC techniques. Electron spin resonance (ESR) and positron annihilation lifetime spectroscopy (PALS) techniques are used for the microscopic structural-dynamic characterization of various pure and composed organic materials.

Research Topics:

1. Study and development of reversible-deactivation radical polymerizations and synthesis of functional polymers
2. Inorganic and carbon (nano)particles and hybrids
3. Polymeric (nano)particles, (hydro)gels and (nano)fibres
4. Synthesis and properties of photoactive compounds
5. Synthesis of polymers and polymeric materials from renewable monomers
6. Degradation, stabilization and flammability of polymers
7. Liquid chromatography research for effective separation of macromolecules
8. Structure and physico - chemical properties of polymers

5. Synthesis of polymers and polymeric materials from renewable monomers

New functional polymers from a renewable γ-butyrolactone monomers

Wide range of compounds containing γ‒lactone ring can be found or obtained after some process from various types of plants, while many of them are also biologically active. Our attention is paid to use some of that compounds, such as α‒methylene‒γ‒butyrolactone (MBL), γ‒methyl‒α‒methylene‒γ‒butyrolactone (MMBL), α-angelica lactone and β‒angelica lactone in synthesis new types of functional polymers. α-Methylene-γ-butyrolactone (MBL), known also as a Tulipalin A, is present in the form of glycoside (Tuliposide A) in tulips in relatively high concentrations (0.2–2 wt.% of the glycoside in fresh weight of various parts of tulips). In addition, MBL can be produced also from biomass sugar-based itaconic anhydride or by biosynthesis from pyruvate and acetyl coenzyme A. picture
MBL consists of five-member lactone ring and exocyclic carbon-carbon double bond and therefore it can serve as dual monomer enabling both the radical polymerizations and ring opening copolymerizations.

Ring opening copolymerizations of angelica lactones and MBL with other lactones such as ε-caprolactone and L,L-dilactide are intensively studied under various polymerization conditions and using various catalysts. Final functional polyesters contain a double bonds along the chain, which can be further available for different types of post-functionalization.

Synthesis of MBL-based star-like block copolymers with properties of thermoplastic elastomers
Reversible-deactivation radical polymerizations are used to functional (co)polymers with pendant butyrolactone ring for further functionalization. Block copolymers of MBL and butyl acrylate show properties of thermoplastic elastomers with high thermal stability and elastic properties remaining even at temperatures up to 350 °C.

Tulipalin A – monomer for the preparation of superabsorbent hydrogels. Polymers derived from nature were synthesized as a promising material with superabsorbent properties. α-Methylene-γ-butyrolactone (MBL), also known as Tulipalin A, is fungitoxic substance isolated mainly from tulips. In our research we focused on synthesis and properties of new superabsorbent polymers derived from hydrolyzed MBL - 4-hydroxy-2-methylenebutanoate (SHMB). Copolymerization of SHMB with acrylamide (AM) at various ratios in the presence of crosslinker yielded hydrogels with superior degree of swelling and comfortable handling. The effect of chemical composition (AM : SHMB ratio), the concentration of monomers in water and amounts of crosslinker were investigated. Hydrogels showed equilibrium degree of swelling in the range of 13,000 – 82,000%. Swelling capacity significantly increased with increased amount of SHMB. The viscoelastic characteristics of the hydrogels were significantly influenced by both the monomers ratio and crosslinker content.

SEM analysis of PMBL nanoparticles prepared via batch polymerization
From tulips to polymeric nanoparticles. MBL was used as a monomer for the preparation of nanoparticles via heterogeneous polymerization process. The results are presented for the surfactant as well as surfactant-free polymerization of MBL with ionic, water soluble initiator potassium persulfate. The influence of polymerization technique (batch or semibatch), type of surfactant, surfactant concentration and ionic strength of the aqueous phase on molar mass and size of nanoparticles was studied. As a surfactant, sodium dodecyl sulphate, Tween 80 and monomer SHMB prepared by saponification of MBL were examined. The ionic strength was generated by addition of NaCl electrolyte. The size of the particles increases gradually with increasing ionic strength of the aqueous phase. The weight average molecular weights and molecular weight distributions were determined by size exclusion chromatography (SEC). Dynamic light scattering (DLS) was used to evaluate the size distribution profile and size of PMBL particles. According to experimental conditions nearly monodisperse polymer particles of 0.15 to 0.60 µm were produced.

Related recent publications:

  • J. Kollár, M. Mrlík, D. Moravčíková, Z. Kroneková, T. Liptaj, I. Lacík, J. Mosnáček „Tulips: A Renewable Source of Monomer for Superabsorbent Hydrogels”, Macromolecules, 2016, 49 (11), 4047-4056.
  • A. Juhari, J. Mosnacek, J. A. Yoon, A. Nese, Koynov, T. Kowalewski, K. Matyjaszewski „Star-like Poly(n-butyl acrylate)-b-poly(alpha-methylene-gamma-butyrolactone) Block Copolymers for High Temperature Thermoplastic Elastomers Applications”, Polymer, Vol. 51 (21), p. 4806–4813 (2010).