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001-es BibID:BIBFORM084572
Első szerző:Todea, Anamaria
Cím:Biocatalytic synthesis of delta-gluconolactone and epsilon-caprolactone copolymers / Anamaria Todea, Valentin Badea, Nagy Lajos, Kéki Sándor, Carmen G. Boeriu, Francisc Péter
Dátum:2014
ISSN:0001-527X 1734-154X
Megjegyzések:The biodegradability and biocompatibility properties of epsilon-caprolactone homopolymers place it as a valuable raw material, particularly for controlled drug delivery and tissue engineering applications. However, the usefulness of such materials is limited by their low hydrophilicity and slow biodegradation rate. In order to improve polycaprolactone properties and functionalities, copolymerization of epsilon-caprolactone with delta-gluconolactone was investigated. Since enzymatic reactions involving sugars are usually hindered by the low solubility of these compounds in common organic solvents, finding the best reaction medium was a major objective of this research. The optimal copolymerization conditions were set up by using different organic media (solvent and solvents mixtures), as well as solvent free systems that are able to dissolve (completely or partially) sugars, and are nontoxic for enzymes. Native and immobilized lipases by different immobilization techniques from Candida antarctica B and Thermomyces lanuginosus have been used as biocatalyst at 80 degrees C. Although the main copolymer amount was synthesized in DMSO:t-BuOH (20:80) medium, the highest polymerization degrees, up to 16 for the copolymer product, were achieved in solventless conditions. The products, cyclic and linear polyesters, have been characterized by FT-IR and MALDI-TOF MS analysis. The reaction product analysis revealed the formation of cyclic products that could be the major impediment of further increase of the chain length
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
?-caprolactone
d-gluconolactone
lipases
biopolymers
Megjelenés:Acta Biochimica Polonica. - 61 : 2 (2014), p. 205-2010. -
További szerzők:Badea, Valentin Nagy Lajos (1979-) (vegyész) Kéki Sándor (1964-) (polimer kémikus) Boeriu, Carmen G. Francisc Péter
Pályázati támogatás:POSDRU/159/1.5/S/137070
Egyéb
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2.

001-es BibID:BIBFORM104069
035-os BibID:(WoS)000489104300028 (Scopus)85071906261 (cikkazonosító)1402
Első szerző:Todea, Annamaria
Cím:Biodegradable Oligoesters of epsilon-Caprolactone and 5-Hydroxymethyl-2-Furancarboxylic Acid Synthesized by Immobilized Lipases / Anamaria Todea, Ioan Bîtcan, Diana Aparaschivei, Iulia Păuşescu, Valentin Badea, Francisc Péter, Vasile Daniel Gherman, Gerlinde Rusu, Lajos Nagy, Sándor Kéki
Dátum:2019
ISSN:2073-4360
Megjegyzések:Following the latest developments, bio-based polyesters, obtained from renewable raw materials, mainly carbohydrates, can be competitive for the fossil-based equivalents in various industries. In particular, the furan containing monomers are valuable alternatives for the synthesis of various new biomaterials, applicable in food additive, pharmaceutical and medical field. The utilization of lipases as biocatalysts for the synthesis of such polymeric compounds can overcome the disadvantages of high temperatures and metal catalysts, used by the chemical route. In this work, the enzymatic synthesis of new copolymers of ?-caprolactone and 5-hydroxymethyl-2-furancarboxylic acid has been investigated, using commercially available immobilized lipases from Candida antarctica B. The reactions were carried out in solvent-less systems, at temperatures up to 80 C. The structural analysis by MALDI TOF-MS, NMR, and FT-IR spectroscopy confirmed the formation of cyclic and linear oligoesters, with maximal polymerization degree of 24 and narrow molecular weight distribution (dispersity about 1.1). The operational stability of the biocatalyst was explored during several reuses, while thermal analysis (TG and DSC) indicated a lower thermal stability and higher melting point of the new products, compared to the poly(epsilon-caprolactone) homopolymer. The presence of the heterocyclic structure in the polymeric chain has promoted both the lipase-catalyzed degradation and the microbial degradation. Although, poly(epsilon-caprolactone) is a valuable biocompatible polymer with important therapeutic applications, some drawbacks such as low hydrophilicity, low melting point, and relatively slow biodegradability impeded its extensive utilization. In this regard the newly synthesized furan-based oligoesters could represent a "green" improvement route.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
copolymerization
renewable
oligoester
lipase
furan-based
epsilon-caprolactone
Megjelenés:Polymers. - 11 : 9 (2019), p. 1-17. -
További szerzők:Bîtcan, Ioan Aparaschivei, Diana Pausescu, Iulia Badea, Valentin Francisc Péter Gherman, Vasile Daniel Rusu, Gerlinde Nagy Lajos (1979-) (vegyész) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:GINOP-2.3.3-15-2016-00021
GINOP
Internet cím:DOI
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