Multiscale Modeling of the Morphology and Properties of Segmented Silicone-Urea Copolymers

Date

2011-9-9

Author

Yıldırım, Erol
Yurtsever, Ersin
Yilgor, Iskender
Yilgor, Emel

Metadata

Show full item record

Item Usage Stats

271
views

0
downloads

Molecular dynamics and mesoscale dynamics simulation techniques were used to investigate the effect of hydrogen bonding on the microphase separation, morphology and various physicochemical properties of segmented silicone-urea copolymers. Model silicone-urea copolymers investigated were based on the stoichiometric combinations of alpha,omega-aminopropyl terminated polydimethylsiloxane (PDMS) oligomers with number average molecular weights ranging from 700 to 15,000 g/mole and bis(4-isocyanatocyclohexyl)methane (HMDI). Urea hard segment contents of the copolymers, which were determined by the PDMS molecular weight, were in 1.7-34% by weight range. Since no chain extenders were used, urea hard segments in all copolymers were of uniform length. Simulation results clearly demonstrated the presence of very good microphase separation in all silicone-urea copolymers, even for the copolymer with 1.7% by weight hard segment content. Experimentally reported enhanced properties of these materials were shown to stem from strong hydrogen bond interactions which leads to the aggregation of urea hard segments and reinforcement of the PDMS.

Subject Keywords

Modeling, Silicone elastomer, Hydrogen bonding, Morphology

URI

https://hdl.handle.net/11511/28598

Journal

Journal of Inorganic and Organometallic Polymers and Materials

DOI

https://doi.org/10.1007/s10904-011-9588-1

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

Hydrogen bonding in polyanilines Bahçeci, S.; Toppare, Levent Kamil; Yurtsever, E. (Elsevier BV, 1994-12) Hydrogen bonding between poly(bisphenol A carbonate) (PC) and polyaniline (PAn) is analyzed using semi-empirical quantum methodology. Fully optimized AM1 molecular orbital calculations are reported for various aniline structures (monomer, dimer and trimer), the monomer of the PC and the hydrogen-bonded model of PAn-PC oligomer.
In situ DRIFTS characterization of wet-impregnated and sol-gel Pd/TiO 2 for NO reduction with CH4 Karakaş, Gürkan; Ozkan, Umit S. (Elsevier BV, 2002-05-01) The adsorption/desorption behavior of 2%Pd/TiO2 catalysts synthesized by wet-impregnation and modified sol–gel techniques were examined in NO–CH4–O2 reaction using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The catalyst prepared by the modified sol–gel method showed significantly higher resistance toward oxygen while maintaining a 100% NO conversion. Under NO+CH4+O2 flow, the main adsorbed NO species was identified as the linearly adsorbed NO on metallic palladium (Pd0–NO)...
Multiscale Modeling of Thin-Wire Coupling Problems Using Hybridization of Finite Element and Dipole Moment Methods and GPU Acceleration ÖZGÜN, ÖZLEM; Mittra, Raj; Kuzuoğlu, Mustafa (2020-01-01) In this article, a hybrid numerical method, called finite element method (FEM) + dipole moment (DM), is presented for efficient solution of multiscale electromagnetic radiation and scattering problems that involve structures with fine features, such as thin-wire antennas or objects. In this method, the FEM is hybridized with the DM approach to help ease certain computational burdens, such as mesh refinement, ill-conditioning, memory overload, and long computation times, when solving multiscale problems with...
Multicomponent ion exchange on synthetic zeolites Beşel Düzgün, Elif; Yücel, Hayrettin; Department of Chemical Engineering (2014) Zeolites are natural and synthetic microporous crystalline aluminosilicates with ion-exchange and molecular sieve properties. Zeolites consist of a three-dimensional framework of (SiO4)4- and (AlO4)5- tetrahedras, connected by a shared oxygen atom. The presence of aluminum in the aluminosilicate framework introduces a net negative charge. Zeolites are mostly used in ion exchange, adsorption processes and catalytic applications. The objective of the study was to determine and model the multicomponent ion exc...
Direct synthesis of hydrogen storage alloys from their oxides Tan, Serdar; Öztürk, Tayfur; Aydınol, Mehmet Kadri; Department of Metallurgical and Materials Engineering (2011) The aim of this study is the synthesis of hydrogen storage compounds by electrodeoxidation technique which offers an inexpensive and rapid route to synthesize compounds from oxide mixtures. Within the scope of this study, two hydrogen storage compounds, FeTi and Mg2Ni, are aimed to be produced by this technique. In the first part, effect of sintering conditions on synthesis of FeTi was studied. For this purpose, oxide pellets made out of Fe2O3-TiO2 powders were sintered at temperatures between 900 °C – 1300...

Citation Formats

E. Yıldırım, E. Yurtsever, I. Yilgor, and E. Yilgor, “Multiscale Modeling of the Morphology and Properties of Segmented Silicone-Urea Copolymers,” Journal of Inorganic and Organometallic Polymers and Materials, pp. 604–616, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/28598.