Polyethylene oxide-hydroxyapatite composite and microporous polyethylene oxide-polymethacrylic acid polymer complex preparation and characterization

Banat, Raid M I
The first part of this study covers the crosslinking of polyethylene oxide (PEO) and its composite with calcium hydroxyapatite (HA) and their mechanical, swelling and morphological properties. Sheets of neat PEO (two different molecular weights) and composites of PEO-HA were prepared by compression molding. The composites and PEO thick sheets were crosslinked with exposure of UV- irradiation in presence of acetophenone (AP) for different periods of time. This simple method of crosslinking, UV-irradiation induced crosslinking in the presence of acetophenone, yielded PEO with gel content up to 90%. Gel content, equilibrium swelling ratio, mechanical and morphological properties of the low molecular weight polyethylene oxide LMPEO-HA composites of crosslinked and uncrosslinked were evaluated. Although the inclusion of HA into LMPEO inhibited the extent of crosslinking, LMPEO- III(20%)HA composite showed the highest gel content with appreciable equilibrium swelling and mechanical strength. The growth of HA from simulated body fluid solutions on fractured surfaces of LMPEO and LMPEO-HA was found to be very favourable in short times. The dimensional stability of these samples is found to be good enough after swelling and deposition experiments. Good compatibility between the hydroxyapatite and PEO can be regarded to be useful tissue-adhesive material. In the second part of this study a microporous polymer complex of polymethacrylic acid (PMAA)-polyethylene oxide was prepared and characterized. Microporous polymer complex of PMAA-PEO was obtained by solution polymerization using benzoyl peroxide as the initiator. PEO (Mv; 200,000) and methacrylic acid monomer mixture produced a microporous polymer complex with a scaffold strength. The polymer complex of PMAA- PEO was partially water soluble. To overcome the solubility of the water- soluble microporous polymer complex; chemical crosslinking was carried out by using ethlyleneglycol dimethacrylate monomer (EGDMA) as the crosslinking agent. Depending upon the extent of crosslinking process PMAA-PEO became water insoluble but it could swell in aqueous solution without any rupture. Thermal stability of the prepared crosslinked and uncrosslinked microporous polymer complex of PMAA-PEO was examined by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Compressive mechanical properties were also examined.


Study on the properties of crosslinking of poly(ethylene oxide) and hydroxyapatite-poly(ethylene oxide) composite
Banat, R; Tincer, T (2003-10-10)
This study covers the crosslinking of poly-(ethylene oxide) (PEO) and its composite with calcium hydroxyapatite (HA), their mechanical and swelling properties, and morphology. Sheets of the composites of PEO (two different grades with M-v: 5x10(6) and 2x10(5)) and HA and neat PEO were prepared by compression molding. The prepared composite. and. PEO (0.1-mm-thick) sheets were crosslinked with exposure of UV-irradiation in the presence of a photoinitiator, acetophenone (AP). This simple method for crosslinki...
Pyrolysis mass spectrometric analysis of copolymer of polyacrylonitrile and polythiophene
Oğuz, Gülcan; Hacaloğlu, Jale; Department of Polymer Science and Technology (2004)
In the first part of this work, the structural and thermal characteristics of polyacrylonitrile, polyacrylonitrile films treated under the electrolysis conditions in the absence of thiophene, polythiophene and the mechanical mixture and a conducting copolymer of polyacrylonitrile/polythiophene have been studied by pyrolysis mass spectrometry technique. The thermal degradation of polyacrylonitrile occurs in three steps; evolution of HCN, monomer, low molecular weight oligomers due to random chain cleavages a...
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Surfaces of multiwalled carbon nanotubes (CNT) were functionalized by treatment with strong acid mixture (purification) followed by modification with sodium dodecyl sulfate, poly(ethylene glycol) (PEG), and diglycidyl ether of Bisphenol A (DGEBA). Poly(ethylene terephthalate) (PET)-based conductive polymer composites were prepared by using these CNT by means of melt mixing with a twin screw extruder. Amount of carboxylic acid groups on the CNT surface increased after acid treatment but decreased with surfac...
Poly(epsilon-caprolactone) Composite Scaffolds Loaded with Gentamicin-Containing beta-Tricalcium Phosphate/Gelatin Microspheres for Bone Tissue Engineering Applications
Sezer, Umran Aydemir; Arslantunalı Şahin, Damla; Aksoy, Eda Ayse; Hasırcı, Vasıf Nejat; Hasırcı, Nesrin (2014-04-15)
In this study, novel poly(epsilon-caprolactone) (PCL) composite scaffolds were prepared for bone tissue engineering applications, where gentamicin-loaded -tricalcium phosphate (-TCP)/gelatin microspheres were added to PCL. The effects of the amount of -TCP/gelatin microspheres added to the PCL scaffold on various properties, such as the gentamicin release rate, biodegradability, morphology, mechanical strength, and pore size distribution, were investigated. A higher amount of filler caused a reduction in th...
Ni and cu incorporated mesoporous nanocomposite catalytic materials
Nalbant, Asli; Doğu, Timur; Balci, Suna (2008-02-01)
Nickel and copper incorporated MCM-41-like mesoporous nanocomposite materials prepared by the direct hydrothermal synthesis and the impregnation procedures showed highly attractive pore structure and surface area results for catalytic applications. The XRD patterns showed that characteristic MCM-41 structure was preserved for the materials synthesized following an impregnation procedure before the calcination step. The surface area of the Cu impregnated material with a quite high Cu/Si atomic ratio (0.19) w...
Citation Formats
R. M. I. Banat, “Polyethylene oxide-hydroxyapatite composite and microporous polyethylene oxide-polymethacrylic acid polymer complex preparation and characterization,” Ph.D. - Doctoral Program, Middle East Technical University, 2002.