Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
POLYURETHANES - EFFECT OF CHEMICAL-COMPOSITION ON MECHANICAL-PROPERTIES AND OXYGEN PERMEABILITY
Date
1992-01-01
Author
ULUBAYRAM, K
Hasırcı, Nesrin
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
104
views
0
downloads
Cite This
A series of polyether urethane films with varying hard/soft segment ratio were synthesized using toluene-2,4-diisocyanate (TDI) and polypropylene glycol (PPG) in order to evaluate them as biomaterials. In order to obtain medical purity the polymerization reactions were carried out in bulk without using any other ingredients such as solvent, catalyst, u.v. absorber, etc. The effects of chemical composition and the presence of the chain extender on some properties were examined. For the samples with higher TDI to PPG ratio, a decrease in ultimate elongation and an increase in tensile strength were observed. Addition of chain extender caused an increase in both. On the other hand, the ultimate elongation increased and tensile strength decreased with an increase in molecular weight of the PPG used. As the chemical compositions are changed by increasing the polyol content, an increase in oxygen permeability is also observed.
Subject Keywords
Polyether polyurethane
,
Mechanical properties
,
Oxygen permeability
,
Biomaterials
URI
https://hdl.handle.net/11511/29947
Journal
POLYMER
DOI
https://doi.org/10.1016/0032-3861(92)90874-v
Collections
Graduate School of Natural and Applied Sciences, Article
Suggestions
OpenMETU
Core
Highly Crystalline Poly(L-lactic acid) Porous Films Prepared with CO2-philic, Hybrid, Liquid Cell Nucleators
Culhacioglu, Yagmur; Hasırcı, Nesrin; Dilek Hacıhabiboğlu, Çerağ (2019-12-18)
Supercritical CO2 (scCO(2)) foaming of poly(L-lactic acid) composite films with liquid polyhedral oligomeric silsesquioxanes (PLLA-POSS) was carried out to obtain polymer matrices for drug delivery applications. Highly crystalline (>45%) PLLA generally requires high supercritical processing (saturation) temperatures close to its melting temperature (similar to 450 K) and pressures about or over 20 MPa for foaming with scCO(2). To decrease the saturation temperature and obtain ductile PLLA films with uniform...
Immobilization of Invertase in a Novel Proton Conducting Poly(vinylphosphonic acid) - poly(1-vinylimidazole) Network
Isikli, Suheda; Tuncagil, Sevinc; Bozkurt, Ayhan; Toppare, Levent Kamil (Informa UK Limited, 2010-01-01)
A novel proton conducting polymer blend was prepared by mixing poly(vinylphosphonic acid) (PVPA) with poly(1-vinylimidazole) (PVI) at various stoichiometric ratios via changing molar ratio of monomer repeating unit to achieve the highest protonation. The polymer network having the most suitable stoichiometric ratio for substantial proton conductivity was prepared and characterized by FT-IR spectroscopy and proton conductivity measurements. The network was used for immobilization of invertase and some import...
Photoconductivity of P3HT films measured by time-resolved THz spectroscopy
Esentürk, Okan; Heilweil, Edwin J. (Optical Society of America (OSA); 2007-01-01)
Photoconductivities of P3HT polymer films varying in molecular weight were directly measured and compared using optical pump-THz probe spectroscopy. Conductivities of P3HT polymers depend on the polymer length, ring orientation regularity and film morphology. © 2007 Optical Society of America.
Indium tin oxide nanoparticles as anode for light-emitting diodes
Çırpan, Ali (Wiley, 2006-02-15)
Thin films of indium tin oxide (ITO) nanoparticles have been investigated as anode materials for polymer light-emitting diodes. A luminance efficiency (0.13 cd/ A), higher than that (0.09 cd/A) obtained in a control devices fabricated on conventional commercial ITO anodes were found. The thin films were made by spin coating of a suspension followed by annealing. The ITO nartoparticle films have a stable sheet resistance of 200 ohm/sq, and an optical transmittance greater than 86% over the range of 400-1000 ...
Thermal Properties of Polyurethane Films Prepared from Mixed Cellulose, Hemicelluloses and Lignin
SHAO, Meng; LIU, Zhu-qing; Lİ, Dong; ZHAO, Yang; Özkan, Necati; CHEN, Xiao Dong (2012-01-01)
Polyurethane (PU) films were prepared from liquefied cellulose, hemicelluloses and lignin in different proportions. The simplex-lattice design method was employed to investigate the effects of each component and their associated interactive effects on the properties of the liquefied products and the PU films. Thermal properties were studied by means of Dynamic Mechanical Analyzer (DMA) and Thermal Gravimetry Analyzer (TGA). Results showed that the contents of cellulose, hemicelluloses and lignin significant...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
K. ULUBAYRAM and N. Hasırcı, “POLYURETHANES - EFFECT OF CHEMICAL-COMPOSITION ON MECHANICAL-PROPERTIES AND OXYGEN PERMEABILITY,”
POLYMER
, pp. 2084–2088, 1992, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/29947.