Pyrolysis and thermal degradation studies of non-isocyanate polyurethanes modified by polyhedral oligomeric silsesquioxanes
Authors:
- Artur Bukowczan,
- Piotr Stachak,
- Izabela Łukaszewska,
- Tomasz M. Majka,
- Edyta Hebda,
- Krzysztof Pielichowski
Abstract
This work reports on the thermal properties of non-isocyanate polyurethanes (NIPUs) obtained via the polyaddition reaction of polyether diamine with five membered tri(cyclic carbonate) by using a prepolymerization method. The non-isocyanate polyurethanes were further chemically modified by trifunctional polyhedral oligomeric silsesquioxane (POSS) - triglycidylisobutyl POSS (3epPOSS), resulting in hybrid composite materials containing 5 to 15 wt% POSS. Thermal properties of the obtained materials were studied by various methods, such as Thermogravimetric analysis (TGA), Pyrolysis with gas chromatography and mass spectrometry (Py-GC/MS), and Microscale Combustion Calorimetry (MCC), and were later discussed in dependence of their composition and structure assessed by Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) techniques. FTIR spectra confirm the successful synthesis of NIPUs and their hybrids with POSS. The results of XRD and SEM revealed homogeneous distribution of silsesquioxane in the bulk of the NIPU matrix. Depending on the POSS concentration in the PU hybrids, various self-assembling structures were formed. TGA analysis indicated a two- and three-step degradation process of NIPU materials in inert and oxidative atmospheres, respectively. Significantly higher degradation temperatures and a remarkably reduced degradation rate for composite materials compared to unmodified NIPU matrix were observed during the second degradation step under an oxidative atmosphere. Based on the overall stabilization effect (OSE), hybrids containing 10 and 15 wt% of 3epPOSS were more thermally stable than the unmodified NIPU matrix. Py-GC/MS demonstrated that the products of NIPU thermal decomposition originate from hydroxyurethane moieties, main substrate core structures, and others, such as catalysts. Incorporation of 3epPOSS into the NIPU matrix decreases its flammability, as evidenced by the results of the MCC, with a nearly 20 % reduction effect noted for the composite with of 15 wt% of POSS, compared to the unmodified NIPU matrix. Importantly, chemical modification of NIPU by POSS caused a reduction of the heat of combustion in the final stage of degradation by ca. 30 %.
- Record ID
- CUTee19dbc1be5a47188fcaf8a520005782
- Publication categories
- ;
- Author
- Journal series
- Thermochimica Acta, ISSN 0040-6031, e-ISSN 1872-762X
- Issue year
- 2023
- Vol
- 723
- Pages
- [1-12]
- Article number
- 179484
- Other elements of collation
- fot.; rys.; tab.; wykr.; Bibliografia (na s.) - 11-12; Bibliografia (liczba pozycji) - 71; Oznaczenie streszczenia - Abstr.; Numeracja w czasopiśmie - Vol. 723
- Keywords in English
- NIPU, thermal degradation, POSS, pyrolysis, nanomaterials
- ASJC Classification
- ; ;
- DOI
- DOI:10.1016/j.tca.2023.179484 Opening in a new tab
- URL
- https://www.sciencedirect.com/science/article/abs/pii/S0040603123000539 Opening in a new tab
- Related project
- Nowe nanostrukturalne kompozyty hybrydowe poliuretan bezizocyjanianowy / funkcjonalizowany POSS. . Project leader at PK: , ,
- Language
- eng (en) English
- Score (nominal)
- 100
- Score source
- journalList
- Score
- Publication indicators
- Uniform Resource Identifier
- https://cris.pk.edu.pl/info/article/CUTee19dbc1be5a47188fcaf8a520005782/
- URN
urn:pkr-prod:CUTee19dbc1be5a47188fcaf8a520005782
* presented citation count is obtained through Internet information analysis, and it is close to the number calculated by the Publish or PerishOpening in a new tab system.