scholarly journals Reactions of N,N′-bis(2-hydroxyethyl)oxalamide with Ethylene Carbonate and Use of the Obtained Products as Components of Polyurethanes Foams

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Iwona Zarzyka-Niemiec
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Physical Properties ◽  
Ethylene Carbonate ◽  
Polyurethane Foams ◽  
Reaction Conditions ◽  
Good Thermal Stability ◽  
Molar Excess ◽  
Instrumental Methods ◽  
Derivatives Of

-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.

scholarly journals Hardly Flammable Polyurethane Foams with 1,3-Pyrimidine Ring and Boron Atoms

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1603
Author(s):  
Elżbieta Chmiel-Szukiewicz
Keyword(s):  
Thermal Stability ◽  
Water Absorption ◽  
Ethylene Carbonate ◽  
Pyrimidine Ring ◽  
Polyurethane Foams ◽  
Good Thermal Stability ◽  
Negative Effect ◽  
Instrumental Methods ◽  
Foam Production

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.

Polyhydroxyalkylation of urea with ethylene carbonate and application of obtained products as components of polyurethane foams

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Iwona Zarzyka-Niemiec
Keyword(s):  
Thermal Stability ◽  
Compressive Strength ◽  
Ethylene Carbonate ◽  
Polyurethane Foams ◽  
Urea Derivatives ◽  
Good Thermal Stability ◽  
Low Mass ◽  
Products Of Reaction ◽  
Derivatives Of ◽  
Partial Release

AbstractThe reaction between urea and ethylene carbonate occur with partial release of CO2 and partial incorporation of carbonate groups into products. The carbonate groups were found to be attached both to nitrogen of urea and to oxyethylene chain. The most effective catalyst of the synthesis was potassium carbonate. The hydroxyethyl and hydroxyethoxy groups of urea derivatives undergo partial dimerization to form carbamate groups in the products. The products of reaction between urea and ethylene carbonate have good thermal stability, they start to decompose at 200°C. The obtained products can be used as polyol components for polyurethane foams. Polyurethane foams obtained from hydroxyethoxy derivatives of urea (EC8) are rigid products of low water uptake, good stability of dimensions, low mass loss on 30 days heating at 150°C, enhanced thermal stability and good compressive strength.

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
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Boric Acid ◽  
Ethylene Carbonate ◽  
Pyrimidine Ring ◽  
Polyurethane Foams ◽  
High Thermal Stability ◽  
H Nmr ◽  
Maldi Tof ◽  
Instrumental Methods

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.

Preparation and properties of polyurethane foams from hydroxypropoxy derivatives of urea and isocyanates

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Iwona Zarzyka-Niemiec ◽  
Katarzyna Rydel
Keyword(s):  
Thermal Stability ◽  
Propylene Carbonate ◽  
Water Uptake ◽  
Polyurethane Foams ◽  
High Thermal Stability ◽  
Diphenylmethane Diisocyanate ◽  
Rigid Polyurethane Foams ◽  
Molar Excess ◽  
Derivatives Of

AbstractThe products of hydroxyalkylation of N,N’-bis(2-hydroxypropyl)urea (BHPU) with large molar excess of propylene carbonate (PC) posses enhanced thermal stability. These products and 4,4’-diphenylmethane diisocyanate were used as substrates for obtaining rigid polyurethane foams, which had high thermal stability and low water uptake.

Obtaining of polyurethane foams with contribution of hydroxyalkylation products of oxalamide with alkylene carbonates and their properties

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Iwona Zarzyka-Niemiec
Keyword(s):  
Thermal Stability ◽  
Propylene Carbonate ◽  
Water Uptake ◽  
Ethylene Carbonate ◽  
Polyurethane Foams ◽  
Good Stability ◽  
Reaction Products ◽  
Molar Excess

AbstractReaction products of Oxalamide (OD) with a 8- and 12-molar excess of ethylene carbonate (EC) and propylene carbonate (PC), characterized by an enhanced thermal stability due to the presence of Oxalamide arrangement, were used as polyol components for obtaining foamed polyurethane plastics. As an isocyanate agent diphenylmethane-4,4’-diisocyanate was used. The obtained new foamed polyurethane plastics are characterized by a slight water uptake, good stability of dimensions and an enhanced thermal stability.

Effect of Heat Treatment on Mechanical Properties of ECAPed 7075 Aluminum Alloy

2013 ◽  
Vol 829 ◽  
pp. 62-66 ◽  
Author(s):  
Alireza Fallahi ◽  
Hossein Hosseini-Toudeshky ◽  
Seyed Mahmoud Ghalehbandi
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Thermal Stability ◽  
Aluminum Alloy ◽  
Solution Treatment ◽  
7075 Aluminum Alloy ◽  
Ecap Processing ◽  
Good Thermal Stability ◽  
7075 Alloy

It is the objective of this study to investigate the effect of ECAP processing and heat treatment on the mechanical properties of the UFG 7075 alloy. Also the effect of post ECAP heat treatment is investigated. The alloy is processed by ECAP after annealing as well as solution treatment to produce an UFG structure. Furthermore mechanical properties and their variations during annealing and aging are investigated. The hardness of the pre-ECAP annealed and the pre-ECAP solutionised 7075 aluminum alloy has increased significantly compared with that of the CG sample. Also hardness of ECAPed specimen has not experienced significant changes in post-ECAP heat treatment and indicated that the alloy had approximately good thermal stability.

Semi-bio-based aromatic polyamides from 2,5-furandicarboxylic acid: toward high-performance polymers from renewable resources

RSC Advances ◽  
2016 ◽  
Vol 6 (90) ◽  
pp. 87013-87020 ◽  
Author(s):  
Kaiju Luo ◽  
Yan Wang ◽  
Junrong Yu ◽  
Jing Zhu ◽  
Zuming Hu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Renewable Resources ◽  
High Performance ◽  
Good Thermal Stability ◽  
Aromatic Polyamides ◽  
High Performance Polymers ◽  
Furandicarboxylic Acid

Aromatic furanic polyamides with relatively high molecular weight were synthesized, and good thermal stability and mechanical properties were demonstrated.

Cryogenic thermal insulating and mechanical properties of rigid polyurethane foams blown with hydrofluoroolefin: Effect of perfluoroalkane

2021 ◽  
pp. 0021955X2110626
Author(s):  
Tae Seok Kim ◽  
Yeongbeom Lee ◽  
Chul Hyun Hwang ◽  
Kwang Ho Song ◽  
Woo Nyon Kim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Cell Size ◽  
Thermal Insulation ◽  
Coefficient Of Thermal Expansion ◽  
Lower Surface ◽  
Polyurethane Foams ◽  
Insulation Material ◽  
Pu Foams

The effect of perfluoroalkane (PFA) on the morphology, thermal conductivity, mechanical properties and thermal stability of rigid polyurethane (PU) foams was investigated under ambient and cryogenic conditions. The PU foams were blown with hydrofluorolefin. Morphological results showed that the minimum cell size (153 μm) was observed when the PFA content was 1.0 part per hundred polyols by weight (php). This was due to the lower surface tension of the mixed polyol solution when the PFA content was 1.0 php. The thermal conductivity of PU foams measured under ambient (0.0215 W/mK) and cryogenic (0.0179 W/mK at −100°C) conditions reached a minimum when the PFA content was 1.0 php. The low value of thermal conductivity was a result of the small cell size of the foams. The above results suggest that PFA acted as a nucleating agent to enhanced the thermal insulation properties of PU foams. The compressive and shear strengths of the PU foams did not appreciably change with PFA content at either −170°C or 20°C. However, it shows that the mechanical strengths at −170°C and 20°C for the PU foams meet the specification. Coefficient of thermal expansion, and thermal shock tests of the PU foams showed enough thermal stability for the LNG carrier’s operation temperature. Therefore, it is suggested that the PU foams blown by HFO with the PFA addition can be used as a thermal insulation material for a conventional LNG carrier.

Bulk Fe-Al-C Nanoalloys Made by Mechanically Alloying with Subsequent Spark Plasma Sintering and Their Mechanical Properties

2005 ◽  
Vol 101-102 ◽  
pp. 103-110 ◽  
Author(s):  
Yoritoshi Minamino ◽  
Yuichiro Koizumi ◽  
Nobuhiro Tsuji ◽  
Naoko Hirohata ◽  
Kiyoshi Mizuuchi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Compression Tests ◽  
Good Thermal Stability ◽  
Environmental Embrittlement ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Superior Mechanical Properties ◽  
Bulk Nanocrystalline ◽  
Rupture Strain

Three kinds of bulk nanocrystalline Fe-24at%Al-Xat%C (X=1,2,4) alloy were produced from Fe and Al powders with addition of methanol by MA with subsequent SPS at 1273K under 64MPa. Their microstructure and mechanical properties were investigated. The compacts have the relative densities of 99.97% (1at%C) to 99.6% (4at%C). The structure of compacts with 1at%C is composed of Fe3Al grains of 1.5µm in diameter and nano k-carbides (Fe3AlC0.5) precipitates, while those of compacts with 2 and 4at%C are composed of nanocrystalline Fe3Al of about 80nm in diameter, nano k-carbides and a-grains of about 1µm in diameter. These structures have the good thermal stability, maintaining the nanostructure even at 973K. The mechanical properties of these compacts were measured by compression tests at R.T. to 973K. The compacts with 1at%C and 2at%C of this work perform the superior mechanical properties (e.g. yield strength of 2.15GPa and rupture strain of 0.14 for compact with 2at%C at R.T.) when compared with the ordinary Fe3Al casting (e.g. 380MPa and 0.12). They also exhibit no environmental embrittlement, which is one of fatal problems for the ordinary Fe3Al mateials.

Effect of Long-Term Aging on Microstructure and Mechanical Properties of a Wrought Ni-Base Superalloy

2015 ◽  
Vol 816 ◽  
pp. 546-550
Author(s):  
Chao Yuan ◽  
Huan Wang ◽  
Jian Ting Guo ◽  
He Yong Qin
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Room Temperature ◽  
Excellent Thermal Stability ◽  
Good Thermal Stability ◽  
Increasing Trend ◽  
Size And Morphology ◽  
Strength And Plasticity ◽  
Base Superalloy

During long-term and high temperature service, microstructures of superalloys may change and then have an adverse impact on mechanical properties, so the stabilities of a wrought Ni-base superalloy aging without stress at 650°C were investigated in this paper. The results showed that the size and morphology of γ' precipitates in the alloy were not obviously influenced with the increase of exposure time, and primary MC carbides present excellent thermal stability. Moreover, almost no detrimental phase was found. Tensile strength and plasticity at room temperature after aging remained steady. Under the condition of 650°C/823MPa, the stress ruptures life presented increasing trend overall and plasticity decreases slightly. In conclusion, the experiment alloy presents a good thermal stability at 650°C.

Sign in / Sign up

Export Citation Format

Share Document