scholarly journals Improved thermally stable oligoetherols from 6-aminouracil, ethylene carbonate and boric acid

2019 ◽  
Vol 17 (1) ◽  
pp. 1080-1086
Author(s):  
Elżbieta Chmiel-Szukiewicz

AbstractSyntheses of oligoetherols with a 1,3-pyrimidine ring and boron atoms using 6-aminouracil, ethylene carbonate and boric acid has been proposed. The structure of the obtained products were determined by instrumental methods (IR, 1H-NMR and MALDI-ToF spectra). The physicochemical and thermal properties of oligoetherols were examined. The products were characterized by high thermal stability. Based on the tests performed, it was found that oligoetherols obtained from 6-aminouracil, boric acid and ethylene carbonate are suitable for the manufacturing of polyurethane foams with improved thermal stability and reduced flammability.

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1603
Author(s):  
Elżbieta Chmiel-Szukiewicz

This work presents the results of research related to the determination of application possibilities of new oligoetherols with 1,3-pyrimidine rings and boron atoms in rigid polyurethane foam production. Oligoetherols were obtained from 1,3-bis(2-hydroxyethyl)uracil, boric acid, and ethylene carbonate. Their structure was determined by instrumental methods (IR, 1H-NMR and MALDI-ToF spectra) and the physicochemical and thermal properties were examined. Obtained oligoetherols were used for synthesis of polyurethane foams. Some properties of the foams, such as apparent density, water uptake, dimensions stability, thermal stability, compression strength, thermal conductivity, oxygen index, and horizontal burning were investigated. The introduction of boron atoms into the foam structure reduced their flammability, but unfortunately it had a negative effect on the water absorption of the obtained materials—the water absorption was higher compared to the boron-free foams. The obtained foams showed good thermal stability compared to classic, rigid polyurethane foams.


2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Iwona Zarzyka-Niemiec

-bis(2-hydroxyethyl)oxalamide (BHEOA) was subject to hydroxyalkylation with ethylene carbonate (EC). By means of instrumental methods (IR, -NMR, MALDI ToF, GC, and GC-MS), an influence of the reaction conditions on structure and compositions of the obtained products was investigated. The hydroxyalkyl and hydroxyalkoxy derivatives of oxalamide (OA) were obtained by reaction of BHEOA with 2–10-molar excess of ethylene carbonate (EC, 1,3-dioxolane-2-one). The products have a good thermal stability and possess suitable physical properties as substrates for foamed polyurethanes. The obtained products were used in manufacturing the rigid polyurethane foams which possess enhanced thermal stability and good mechanical properties.


2011 ◽  
Vol 239-242 ◽  
pp. 2905-2908 ◽  
Author(s):  
Jun Gang Gao ◽  
Wei Hong Wu ◽  
Xing Li

Boron-containing bisphenol-S formaldehyde resin (BBPSFR) was synthesized by formalin method. The structure and thermal properties of BBPSFR were characterized by 1H NMR, FTIR, torsional braid analysis (TBA) and thermogravimetric analysis (TGA), respectively. The results showed that the borate had formed, and the six-member ring containing boron-oxygen coordinate structure also formed during the curing process. The glass transition temperature (Tg) of BBPSFR is higher 104°C than that of bisphenol-S formaldehyde resins (BPSFR); the initial degradation temperature (Ti ) increases about 43°C; thermal degradation rate decrease and thermal stability increase significantly.


2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Iwona Zarzyka

The work focuses on research related to determination of application possibility of new, ecofriendly boroorganic polyols in rigid polyurethane foams production. Polyols were obtained from hydroxypropyl urea derivatives esterified with boric acid and propylene carbonate. The influence of esterification type on properties of polyols and next on polyurethane foams properties was determined. Nitrogen and boron impacts on the foams’ properties were discussed, for instance, on their physical, mechanical, and electric properties. Boron presence causes improvement of dimensional stability and thermal stability of polyurethane foams. They can be applied even at temperature 150°C. Unfortunately, introducing boron in polyurethanes foams affects deterioration of their water absorption, which increases as compared to the foams that do not contain boron. However, presence of both boron and nitrogen determines the decrease of the foams combustibility. Main impact on the decrease combustibility of the obtained foams has nitrogen presence, but in case of proper boron and nitrogen ratio their synergic activity on the combustibility decrease can be easily seen.


2013 ◽  
Vol 690-693 ◽  
pp. 619-622
Author(s):  
Hai Jun Lv ◽  
Yi Feng Yu ◽  
Lei Liu ◽  
Ai Bing Chen ◽  
Zhi Chao Hu ◽  
...  

Novel hole-transporting materials (M1, M2) containing triphenylamine and dipyridine units have been synthesized and characterized. Two compounds have excellent solubility in common solvents. The optical, electrochemical and thermal properties of the materials were studied in detail. The results show that two compounds have green emission in dichloromethane, high thermal stability and proper HOMO levels. The properties of compounds M1 and M2 indicate that two compounds are candidates for the application in Organic light-emitting devices as hole-transporting materials.


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Christian Sánchez ◽  
Carlos Bustos ◽  
Fabiola Alvarado ◽  
Eduardo Schott ◽  
Nicolas Gatica ◽  
...  

Abstract We present the synthesis of polymers by means of self-condensation of ethyl 3-aminophenyl acetate, using HCl as catalyst at high temperature and reduced pressure. This polymer was fractionated by successive precipitation from mixtures of methanol/diethylether of different polarity, yielding three polymeric fractions: Poly A, Poly B and Poly C. Likewise, under the same conditions, 3- aminophenyl acetic acid yields only one polymeric fraction, Poly D. These polymers were characterized by elemental analysis, IR and, in some cases, by 1H-NMR and X-Ray Photoelectron Spectroscopy (XPS). The obtained results show that polymers can be classified as hybrid materials, because in the backbone, they contain simultaneously the amide and imine groups and, at the end of the chain, they have amine and carboxylic acid functions. High solubility of some of these polymers in DMF or methanol has permitted the determination of viscosities and the preparation of films. Poly B and Poly C films exhibit amorphous morphology; and Poly D display spherullitic-type semi-crystallization pattern. The polymers can absorb solvents and they can swell up forming large-sized gels in DMF and methanol. Besides these polymers have high thermal stability that reaches a weight loss of 11.60% at 353 °C.


2018 ◽  
Vol 54 (4) ◽  
pp. 719-741 ◽  
Author(s):  
Iwona Zarzyka ◽  
Anita Bialkowska ◽  
Tomasz Paczesniak ◽  
Wieslaw Fracz ◽  
Dorota Majda

In this work, the research results of the synthesis and properties of the polyols with the oxamidoester group, obtained in the reaction of N-substituted morpholine-2,3-dione derivatives with excess of alkylene carbonates have been presented. Using these derivatives as polyol components, rigid foamed polyurethane materials of high thermal stability and mechanical strength have been obtained. New polyurethane foams obtained using hydroxypropyl morpholine-2,3-dione derivatives can be used as heat-insulating materials of operating temperature as high as 150°C.


e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Elżbieta Chmiel-Szukiewicz

AbstractNew method of synthesis of polyetherols with 1,3-pyrimidine ring by reactions of 6-aminouracil with ethylene carbonate and propylene oxide was described. The structure of products was analyzed using the IR, 1H-NMR and MALDI-TOF spectroscopies. Some physical properties and thermal stability of polyetherols were investigated. Initial tests on the foaming of polyurethanes obtained from the polyetherols were performed. Some properties of the foams such as apparent density, absorption of water, linear dimensions stability, thermal resistance and compression strength were investigated. Obtained foams show an improved thermal stability.


2011 ◽  
Vol 284-286 ◽  
pp. 1863-1866 ◽  
Author(s):  
Wen Wen Shan ◽  
Guan Jun Chang ◽  
Fang Hua Zhu ◽  
Lin Zhang

The carbazoled poly(arylene imino)s (c-PAI) have been synthesized via palladium-catalyzed polycondensation of 3,6-diamino-N-(2-ethylhexyl)carbazole with different aromatic dibromides. The structure of c-PAI were characterized by means of FT-IR, 1H NMR spectroscopy and elemental analysis, the results show an agreement with the proposed structure. The thermal properties of c-PAI were detected by DSC and TG. The result show that the polymers possess high glass transition temperature (Tg>250°C ), good thermal stability with high decomposition temperatures (TD>410°C), In addition to the thermal properties, the optical properties were studied, including Uv-vis absorption, photoluminescence and time of flight (TOF).


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1352 ◽  
Author(s):  
Minghui Zhang ◽  
Haiqin Wen ◽  
Xiuhong Pan ◽  
Jianding Yu ◽  
Hui Shao ◽  
...  

The effect of Yb3+ ions on upconversion luminescence and thermal properties of Tm3+/Yb3+ co-doped La2O3-Nb2O5-Ta2O5 glasses has been studied. Glass transition temperature is around 740 °C, indicating high thermal stability. The effect of Yb3+ ions on the thermal stability is not obvious. Both the glass forming ability and the upconversion luminescence first increase and then decrease with the increase of Yb3+ ions. The glasses perform low glass forming ability with ΔT around 55 °C. Blue and red emissions centered around 477, 651, and 706 nm are obtained at the excitation of 976 nm laser. The upconversion luminescence mechanism is energy transfer from Yb3+ to Tm3+ mixed with two- and three- photon processes. The thermal kinetic Differential Thermal Analysis (DTA)-analysis indicates that the average activation energy first increases and then decreases with the increase of Yb3+ ions. This result can be introduced in order to improve upconversion luminescence of glasses by crystallization in the future. Tm3+/Yb3+ co-doped La2O3-Nb2O5-Ta2O5 glasses with good upconversion and thermal properties show promising applications in solid-state laser, optical temperature sensing.


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