Filtreler
DNA adsorption and dynamic mechanical analysis of polymeric oil/oil acid copolymers

Çakmaklı, Birten | Hazer, Baki | Erdoğan, Taner | Mutlu, Ayşe Gül

Article | 2013 | Journal of Polymer Research20 ( 3 )

A variety of new polymeric materials [Polylinseed oil-g-PMMA (PLO-g-PMMA), Polylinseed oil-g-PS (PLO-g-PS), Polysoybean oil-g-PMMA (PSB-g-PMMA), Polylinoleic acid-g-PMMA (PLina-g-PMMA), Polylinoleic acid-g-PS (PLina-g-PS), Polylinoleic acid-g-PnBMA (PLina-g-PnBMA), Polyhydroxy alkanoate-sy-g- Polysoybean oil-g-PMMA (PHA-PSB-PMMA) and Polyhydroxy alkanoate-sy-g- Polylinoleic acid-g-PMMA (PHA-PLina-PMMA)] were prepared from soluble polymeric oil/oily acid peroxides initiating the co-polymerization of Poly(methyl methacrylate) (PMMA), Polystyrene (PS) and Poly(n-butyl methacrylate) (PnBMA). Pure PMMA, PS, PnBMA and these copolymers con . . .tain different polymeric oil/oil acid initiators were investigated as to the relationship between their dynamic mechanical properties. The DMA results show that the transition from glassy to rubbery behavior is broad for these polymers due to the presence of the triglyceride/oil acid molecules acting like plasticizers in the system. Furthermore, they were compared with dynamic mechanical analysis (DMA) and differential scanning calorimeter (DSC) analysis results. The mechanical properties of these homopolymer and copolymers were also assessed by tensile tests of the polymers in terms of the stress and strain values at the break point. When these results were compared with those for PMMA and PnBMA, it is worth noting that copolymer samples containing PLO, PSB, or PLina in its structure showed changed stress at their break point or in the strain value at its break point. The contact angle testing and DNA adsorption of oil/oil acid copolymers were also studied. Compared with homopolymers, the hydrophilicity and DNA adsorption of the copolymer samples improved because of the presence of PLO, PSB, or PLina blocks. Considering all these results, it is recommended that the copolymers used as candidate biomaterials. © 2013 Springer Science+Business Media Dordrecht Daha fazlası Daha az

Synthesis of microbial elastomers based on soybean oil. Autoxidation kinetics, thermal and mechanical properties

Hazer, Baki | Hazer, Derya Burcu | Çoban, Burak

Article | 2010 | Journal of Polymer Research17 ( 4 ) , pp.567 - 577

Microbial bioelastomers prepared by the autoxidation of the unsaturated medium-long chain length copoly- 3-hydroxyalkanoate's (mlcl-PHAs) based on soybean oily acids (Sy) have been reported. Pseudomonas oleovorans were grown on a series of the mixture of octanoic acid (OA) and Sy with the weight ratio of 20:80, 28:72 and 50:50 in order to obtain unsaturated mlcl-copolyesters coded PHO-Sy-2080, PHO-Sy-2872, and PHO-Sy-5050, respectively. The microorganism was also grown on the mixture of Sy and 10-undecenoic acid (UA) with the weight ratio of 50:50 to obtain unsaturated copolyester coded PHU-Sy-5050. The PHAs obtained were characteri . . .zed by 1H NMR and GC-MS techniques. Double bond contents of the unsaturated PHAs obtained were varying between 0.8 to 20 mol %. Autoxidation of the unsaturated copolyesters were carried out on exposure to air at room temperature in order to obtain new biomaterials whose mechanical strength was improved. Autoxidation kinetics, shelf life, mechanical and thermal properties of these biomaterials were evaluated Daha fazlası Daha az

Synthesis and properties of chitosan-modified poly(vinyl butyrate)

Akgün, Sibel | Ekici, Gülsüm | Mutlu, Nilüfer | Beşirli, Necati | Hazer, Baki

Article | 2007 | Journal of Polymer Research14 ( 3 ) , pp.215 - 221

Modification of chitosan by grafting of vinyl butyrate was carried out in homogeneous phase using potassium persulfate as redox initator and 1.5% acetic acid as solvent. The percent grafting and grafting efficiency were analysed and the high grafting efficiency up to 94% was observed. The effects of reaction variables such as monomer concentration, initiator concentration, temperature and reaction time were investigated. It was observed that the solubility of chitosan was markedly reduced after grafting with vinyl butyrate. The grafted product is insoluble in common organic solvents as well in dilute organic and inorganic acids. Cha . . .racterization of the graft copolymers were carried out by using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM) technics. Characteristic signal of carbonyl group was observed at 1,731 cm-1 which belongs to the poly vinyl butyrate segments in the graft copolymer. The melting transition of the chitosan main chain in the copolymer shifted to 124°C from its original value 101°C. In addition to these, we have also studied topology of the graft copolymer and the SEM micrograph showed continuous homogenous matrix which means there is no phase separation. © Springer Science+Business Media B.V. 2007 Daha fazlası Daha az

Synthesis of block/graft copolymers based on vinyl benzyl chloride via reversible addition fragmentation chain transfer (RAFT) polymerization using the carboxylic acid functionalized Trithiocarbonate

Hazer, Baki | Arslan, Hülya | Senemoğlu, Yetkin | Şen, Şadi

Article | 2019 | Journal of Polymer Research26 ( 5 ) , pp.215 - 221

Reversible Addition-Fragmentation Chain-Transfer (RAFT) polymerization of styrene (St), vinyl benzyl chloride (vbc), tert-butyl methacrylate (tertBMA) and n-butyl methacrylate (nBMA) was investigated using carboxylic acid functionalized trithiocarbonate (R2). A series of random copolymer of styrene and vinyl benzyl chloride was prepared in order to control chloromethyl functionality in the copolymer, via RAFT polymerization. Addition to this, first-order kinetic behavior of the RAFT polymerization of vbc using R2 was also evaluated. A novel series of amphiphilic copolymers based on polyethylene glycol (PEG) with molar masses of 500 . . .and 2000 g/mol, functionalized polyvinyl benzyl chloride (Pvbc) were obtained via the Williamson-ether-synthesis. As chloromethyl functionality increases, the introduced PEG increases. Fractional precipitation, thermal properties and water uptakes of the amphiphilic polymer samples were evaluated. The new polymers can be the promising materials with high aqueous solubility capacity. © 2019, The Polymer Society, Taipei Daha fazlası Daha az

The effect of gold clusters on the autoxidation of poly(3-hydroxy 10-undecenoate-co-3-hydroxy octanoate) and tissue response evaluation

Hazer, Derya Burcu | Hazer, Baki

Article | 2011 | Journal of Polymer Research18 ( 2 ) , pp.251 - 262

We describe the synthesis and characterization of gold clusters embedded into poly (3-hydroxy octanoate-co-3-hydroxy-10-undecenoate) (PHOU), and evaluated the tissue response of the material upon implantation onto muscle tissue (rat). For this aim, PHOU was obtained by Pseudomonas oleovorans from octanoic acid (OA) and 10-undecenoic acid (UA) with a weight ratio of 50:50. The unsaturated co-polyester film in which HAuCl4 was dispersed was exposed to air at room temperature to produce gold clusters embedded into cross-linked PHOU. The cross-linking kinetics of the gold catalyzed PHOU autoxidation was followed by sol-gel analysis. In . . .vivo tissue reactions of the cross-linked PHOU embedded gold clusters were evaluated by subcutaneous implantation in rats. The rats appeared to be healthy throughout the implantation period. No symptom such as necrosis, abscess or tumor genesis was observed in the vicinity of the implants. Retrieved materials varied in their physical appearance after 6 weeks of implantation. AFM and SEM micrographs of the PHOU containing gold clusters were also taken. © 2010 Springer Science+Business Media B.V Daha fazlası Daha az

Synthesis and characterization of novel rod-coil (tadpole) poly(linoleic acid) based graft copolymers

İnce, Özge | Akyol, Elvan | Sulu, Elvan | Şanal, Timur | Hazer, Baki

Article | 2016 | Journal of Polymer Research23 ( 1 ) , pp.1 - 10

Synthesis of novel poly (styrene)-g-poly(linoleic acid)-g-poly(ethylene glycol) amphiphilic rod-coil tadpole and poly (styrene)-g-poly(linoleic acid)-g-poly (dimethyl siloxane) double hydrophobic rod-coil tadpole graft copolymers have been reported. In the first step, poly(linoleic acid) peroxide macro initiator (PLina) was prepared by exposing linoleic acid to air at room temperature for three weeks, in view of the autoxidation process. In the second step, poly styrene-g-poly linoleic acid graft copolymer (PLinaS) was prepared by the polymerization of styrene initiated by PLina. In the third step, PS-g-PLina-g-PEG rod-coil tadpole . . .amphiphilic graft copolymer and PS-g-PLina-g-PolyPDMS rod-coil tadpole double hydrophobic graft copolymers were obtained by the reaction of carboxylic ends of PLinaS with polyethylene glycol (PEG) with primary amine terminal and poly (dimethyl siloxane) (PDMS) with primary amine terminals. The target copolymers and all intermediates were well characterized by GPC, FTIR, 1H NMR, DSC, and TGA in detail. © 2015, Springer Science+Business Media Dordrecht Daha fazlası Daha az

6698 sayılı Kişisel Verilerin Korunması Kanunu kapsamında yükümlülüklerimiz ve çerez politikamız hakkında bilgi sahibi olmak için alttaki bağlantıyı kullanabilirsiniz.

creativecommons
Bu site altında yer alan tüm kaynaklar Creative Commons Alıntı-GayriTicari-Türetilemez 4.0 Uluslararası Lisansı ile lisanslanmıştır.
Platforms