Properties and phase segregation of crosslinked PCL‐based polyurethanes

Güney, Aysun; Hasırcı, Nesrin

doi:10.1002/app.39758

Cited by 31 publications

(20 citation statements)

References 47 publications

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“…In the PU IR spectra, one can observe the absorption bands associated with a urethane group, such as the stretching vibrations of an amine group -NH at 3300 cm −1 [20]. The position of bands suggests that -NH groups are engaged in the formation of hydrogen bonds [21]. The double peak appearing at ca.…”

Section: Resultsmentioning

confidence: 99%

Thermal properties of polyurethane-based composites modified with chitosan for biomedical applications

Szlachta

Ordon

Nowicka

et al. 2020

J Therm Anal Calorim

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The thermal properties of chitosan and hydroxyapatite (HAp)-crosslinked polyurethanes (PU) prepared in a two-step bulk polymerization were investigated. Synthesis of PU was carried out using 1,6-hexamethylene diisocyanate, poly(ethylene glycol) 2000 and dibutyltin dilaurate as a catalyst. Various molar ratios of chitosan and 1,4-butanediol were applied, and the effects of incorporating different HAp amounts and the chitosan-to-BDO ratio were studied. It was found that the thermal properties of PU materials depend on polysaccharides and bioceramics load, which was confirmed by differential scanning calorimetry and thermogravimetry. The glass transition temperature increases with increasing chitosan fraction. Similarly, the onset temperature of degradation increased with chitosan addition. On the other hand, the presence of ceramics did not show a significant impact on the thermal properties of PU composites. Successful polymerization and chain extension of the isocyanate groups with hydroxyl moieties from chitosan and HAp were confirmed by Fourier transform infrared spectroscopy, and the morphology was examined using scanning electron microscopy.

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Section: Resultsmentioning

confidence: 99%

Thermal properties of polyurethane-based composites modified with chitosan for biomedical applications

Szlachta

Ordon

Nowicka

et al. 2020

J Therm Anal Calorim

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“…e absorption bands at 1725 and 1630 cm −1 are due to the vibration of C=O (carbonyl) groups in urethane bonds (I amide absorption band). e band at around 1585 cm −1 corresponds with N-H stretching vibration [31,32]. e bands in the 1150-950 cm −1 range from the ether C-O-C groups from PEG [33] are covered with bands related to PO 3− 4 groups from HA [34], but the bands in this range are broader than for pristine HA.…”

Section: Ftir and Xrd Analysis Of Ha-g-pegmentioning

confidence: 96%

Thermal Stabilization of Polyoxymethylene by PEG-Functionalized Hydroxyapatite: Examining the Effects of Reduced Formaldehyde Release and Enhanced Bioactivity

Król-Morkisz

Karaś

Majka

et al. 2019

Advances in Polymer Technology

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Nanostructured hydroxyapatite (HA) functionalized with poly(ethylene glycol) (HA-g-PEG) of different molar mass was used as a thermal stabilizer to prepare polyoxymethylene (POM) composites by a melt processing method. The chemical and crystalline structure of (HA-g-PEG) and POM/HA-g-PEG composites was investigated by means of FTIR and XRD. The thermal properties, degree of crystallinity, and melting behaviour of POM-based composites were analysed with TG, DSC, and TOPEM DSC methods. The tensile strength, Young’s modulus, toughness, and wettability of POM were investigated as well. A preliminary assessment of bioactivity, in vitro chemical stability, and formaldehyde release from POM/HA-g-PEG composites by Schiff’s test was also performed. An SEM/EDX method was used to observe the morphology of POM/HA-g-PEG composites. The results indicate that the addition of 1% HA-g-PEG slightly increases the melting temperature and degree of crystallinity. In small amounts, HA-g-PEG particles probably act as nucleating agents for the POM crystallization process. Incorporation of 5% HA-g-PEG to POM caused a decrease in the crystallinity of the polymer matrix, as a result, some mechanical properties of POM/HA-g-PEG composites also decreased. The thermal stability of POM/HA-g-PEG composites improved significantly from 309°C for unmodified POM to 342°C for POM/10.0% HA-g-PEG 600. The most effective thermal stabilizer was synthesized with the lowest mass-average molar mass PEG. The in vitro bioactivity test confirmed that, as the average molar mass of PEG in HA-g-PEG hybrids increased, POM-based composites indicated higher bioactivity. The in vitro chemical stability analysis results showed that both the POM matrix and the HA-g-PEG additive remain stable during the whole incubation time. Importantly, after seven days of dynamic incubation, no formaldehyde was detected in all filtrates, which is crucial in biomedical applications, among others.

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“…The bands at 1532 cm −1 was attributed to the bending vibration of NH and the stretching vibration of CN which confirmed that urethane linkages were formed between OH in the HTWT and NCO. The band at 1710 to 1725 cm −1 which was observed in PUF1‐PUF4 was assigned to the carbonyl stretching of CO that was hydrogen bonded with the N‐H group of polyurethane . The bands at 1510 and 1596 cm −1 were derived from the aromatic rings of PMDI .…”

Section: Resultsmentioning

confidence: 99%

“…The first stage of degradation at 330 to 346 °C corresponded to breakage of the urethane bond. The second stage at 367 to 432 °C corresponded to the decomposition of the HTWT, and the third stage at 451 to 466 °C corresponded to the decomposition of the PCL diols …”

Section: Resultsmentioning

confidence: 99%

Polyurethane foams from oligomers derived from waste tire crumbs and polycaprolactone diols

Rattanapan

Pasetto

Pilard

et al. 2016

J of Applied Polymer Sci

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This work was an initial study on the synthesis of polyurethane foams (PUF) by using diols obtained from the controlled degradation of waste tire crumbs and from polycaprolactone (PCL) followed by examination of their biodegradability. Natural rubber (NR, cis−1,4 polyisoprene) and butadiene rubber (BR) chains contained in waste tire crumbs were chemically modified into carbonyl telechelic (CTWT) and successively into hydroxyl telechelic oligomers (HTWT). Four types of PUF were prepared with different molar ratios between the HTWT and the PCL diols. CTWT and HTWT were analyzed by 1H‐NMR, SEC, and FT‐IR to confirm their chemical structure. Formation of the urethane bond was demonstrated by FT‐IR spectra. The addition of the PCL diol increased the thermal degradation temperature of the PUF based on thermogravimetric analysis. According to scanning electron microscopy, polyhedral closed cells were obtained. The molar ratio of HTWT/PCL diols strongly affected the kinetic rate of foam formation and foam morphology. A low kinetic rate provided PUF with a high density, small cell size, and a broad cell size distribution. In order to assess biodegradation of PUF, the modified Sturm test was carried out for 60 days at ambient temperature (27–30 °C). The biodegradation of PUF containing only HTWT was 31.2% and 51.3% at 28 days and 60 days of testing, respectively whereas the PUF containing 1/0.5 HTWT/PCL diols (by mole) showed a higher biodegradation: 39.1% and 64.3% at 28 days and 60 days of testing respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44251.

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Properties and phase segregation of crosslinked PCL‐based polyurethanes

Cited by 31 publications

References 47 publications

Thermal properties of polyurethane-based composites modified with chitosan for biomedical applications

Thermal properties of polyurethane-based composites modified with chitosan for biomedical applications

Thermal Stabilization of Polyoxymethylene by PEG-Functionalized Hydroxyapatite: Examining the Effects of Reduced Formaldehyde Release and Enhanced Bioactivity

Polyurethane foams from oligomers derived from waste tire crumbs and polycaprolactone diols

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