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001-es BibID:BIBFORM113662
035-os BibID:(cikkazonosító)2937 (Scopus)85164750542 (WoS)001028649300001
Első szerző:Czifrák Katalin (vegyész)
Cím:Bisphenol A Diglycidyl Ether-Primary Amine Cooligomer-poly (epszilon-caprolactone) Networks: Synthesis and Characterization / Katalin Czifrák, Csilla Lakatos, Gabriella Szabó, Bence Vadkerti, Lajos Daróczi, Miklós Zsuga, Sándor Kéki
Dátum:2023
ISSN:2073-4360
Megjegyzések:In this work, the preparation and systematic investigation of cross-linked polyurethane-epoxy (PU-EP) polymer systems are reported. The PU-EP polymers were prepared using a reaction of isocyanate (NCO)-terminated PU-prepolymer with diglycidyl ether of bisphenol A (DGEBA)-amine cooligomer. The oligomerization of DGEBA was carried out by adding furfurylamine (FA) or ethanolamine (EA), resulting in DGEBA-amine cooligomers. For the synthesis of NCO-terminated PU-prepolymer, poly(?-caprolactone)diol (PCD) (Mn = 2 kg/mol) and 1,6-hexamethylene diisocyanate (HDI) were used. The cross-linking was achieved by adding DGEBA-amine cooligomer to PU-prepolymer, in which the obtained urethane bonds, due to the presence of free hydroxil groups in the activated DGEBA, served as netpoints. During cross-linking, ethanolamine provides an additional free hy- droxyl group for the formation of a new urethane bond, while furfurylamine can serve as a thermoreversible coupling element (e.g., Diels?Alder adduct). The PU-EP networks were characterized using attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA) and scanning electron microscopy (SEM). The DMA curves of some PU-EPs (depending on the compositions and the synthetic method) revealed a plateau-like region above the melting temperature (Tm) of PCD, confirming the presence of a cross-linked structure. This property resulted in a shape memory (SM) behavior for these samples, which can be fine-tuned in the presence of furfurylamine through the formation of additional thermoreversible bonds (e.g., Diels-Alder adduct).
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
DGEBA-amine cooligomer
polyurethane
DGEBA-polyurethane
characterization
shape memory
Megjelenés:Polymers. - 15 : 13 (2023), p. 1-15. -
További szerzők:Lakatos Csilla (1990-) (környezetmérnök) Szabó Gabriella Vadkerti Bence (1994-) (okleveles vegyészmérnök) Daróczi Lajos (1965-) (fizikus) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:GINOP-2.3.3-15-2016-00021
GINOP
TKP2021-EGA-20
Egyéb
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Intézményi repozitóriumban (DEA) tárolt változat
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2.

001-es BibID:BIBFORM104056
035-os BibID:(WoS)000480531700080 (Scopus)85066821056 (cikkazonosító)825
Első szerző:Nagy Lajos (vegyész)
Cím:Designed Polyurethanes for Potential Biomedical and Pharmaceutical Applications : Novel Synthetic Strategy for Preparing Sucrose Containing Biocompatible and Biodegradable Polyurethane Networks / Lajos Nagy, Miklós Nagy, Bence Vadkerti, Lajos Daróczi, György Deák, Miklós Zsuga, Sándor Kéki
Dátum:2019
ISSN:2073-4360
Megjegyzések:In this paper the preparation and detailed characterization of designed polyurethanes (SPURs) are reported for potential biological, biomedical and/or pharmaceutical applications. Importantly, in order to fulfill these goals all reactants and solvents used were selected according to the proposal of EUR-8 Pharmacopoeia. For the synthesis, a novel strategy was introduced and elaborated. A series of SPUR samples was prepared from poly(-caprolactone)-diol, 1,6-hexamethylene diisocyanate and sucrose as a chain extender/crosslinking agent to obtain sucrose containing polyurethanes. In addition, the mol ratios of the sucrose were varied within an order of magnitude. The prepolymers and the products of the syntheses were investigated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and infrared spectroscopy (IR), respectively. It was found that the reactivity of the eight free hydroxyl groups of sucrose are different, and after curing the SPUR samples at 60 C no free isocyanate groups can be observed. Furthermore, swelling experiments performed with various solvents of different polarities revealed that the highest degree of swelling took place in dimethyl-sulfoxide. However, low degrees of swelling were recognized in water and hexane. It is important to note that the gel contents were around 90% in all cases, which demonstrate that the crosslinking was almost complete. In addition, the kinetics of swelling were also evaluated and successfully modeled. The crosslink densities were calculated from the data of the swelling experiments by means of the Flory-Rehner equation. Unexpectedly, it was found that the crosslink density decreased with the increasing sucrose content also in line with the results obtained by relaxation modulus experiments and dynamic mechanical analysis (DMA). The Tg and Tm of SPUR samples, determined from DSC and DMA measurements, were around 57 C and 27 C, respectively. According to the mechanical tests the SPUR samples showed high elongation at break values, i.e., high flexibilities. Furthermore, the stress-strain curves were also modeled and discussed.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
poly(epsilon-caprolactone)
1,6-hexamethylene-diisocyanate
sucrose
polyurethane
swelling
mechanical testing
Megjelenés:Polymers. - 11 : 5 (2019), p. 1-19. -
További szerzők:Nagy Miklós (1976-) (vegyész) Vadkerti Bence (1994-) (okleveles vegyészmérnök) Daróczi Lajos (1965-) (fizikus) Deák György (1954-) (polimer kémikus) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:GINOP-2.3.3-15-2016-00021
GINOP
FK-128783
Egyéb
Internet cím:Szerző által megadott URL
DOI
Intézményi repozitóriumban (DEA) tárolt változat
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