Synthesis of comb-type amphiphilic graft copolymers derived from chlorinated poly(?-caprolactone) via click reaction

This work refers to the synthesis of a series of novel chlorinated poly(?-caprolactone) (PCL) for further functionalization of PCL. For this aim, chlorine gas was passed through into the chloroform solution to obtain chlorinated polycaprolactone. The chlorine contents in chlorinated PCL were between 0.9 and 1.6 mol%. The molecular weights of the polymers (Mn) changed from 4853 to 9497 g/mol. As the amount of passing chlorine gas increases, the molecular weight of the chlorinated PCL was found to decrease. Pendant chloride groups of PCL were reacted with sodium azide to prepare PCL with pendant azide groups (PCL-N3). Poly-(ethylene glycol) methyl ether (mPEG) was reacted with propargyl chloride to achieve alkynyl mPEG (mPEG-alkyn). Click reaction was then carried out by the reaction between PCL-N3 and mPEG-alkyn to obtain PCL-g-PEG comb-type amphiphilic graft copolymer. Interestingly, SEM images of the PCL-g-PEG comb-type amphiphilic graft copolymers showed the highly microporous structure. The resulting products were characterized by 1H NMR, FT-IR, gel-permeation chromatography, SEM, surface tension, contact angle and water uptake measurements, differential scanning calorimeter and thermogravimetric analyses techniques. © 2016, Springer-Verlag Berlin Heidelberg.-2012-10-03-13 2211??? 211T016This work was supported by B??lent Ecevit University Research Fund (#BEU-2012-10-03-13), TUBITAK (Grant # 211T016) and TUBITAK 2211???A National Scholarship Programme for Timur ?anal (PhD Student)

Redox polymerization of N-isopropylacrylamide by using hydroxylated soya oil polymer

Water soluble hydroxylated soya oil polymer was used in the redox polymerization of N-isopropylacrylamide (NIPAM) in order to obtain water-based hydroxylated-soya oil polymer-g-PNIPAM graft copolymer. For this purpose, soya oil was exposed to air under sunlight to obtain autoxidized soya oil polymer (PSy-ox). PSy-ox was allowed to react with diethanol amine to obtain hydroxylated soya oil polymer (hydroxylated-PSy). An ammonium persulfate with hydroxylated-PSy redox initiating system was used in the polymerization of NIPAM in order to obtain thermoresponsive hydroxylated-PSy-g-PNIPAM water-based graft copolymers. The graft copolymers were characterized using proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, gel permeation chromatography, thermal gravimetric analysis, and differential scanning calorimetry techniques. The effects of hydroxylated-PSy on the thermal response rate of PNIPAM and the percentage of transmittance in the water of graft copolymers were studied by means of observing UV transmittance behaviors in response to changing temperature. This showed the temperature-responsive property, and exhibited a volume phase transition from 22 °C to 29 °C, while that of PNIPAM was 32 °C. © TÜBİTAK

Permeation studies of indomethacin from different emulsions for nasal delivery and their possible anti-inflammatory effects

PubMed ID: 18431669The purpose of this research was to develop an emulsion formulation of indomethacin (IND) suitable for nasal delivery. IND was incorporated into the oil phases of oil in water (O/W) and water in oil (W/O) emulsions. For this purpose, different emulsifying agents (Tween 80, Span 80 and Brij 58) were used in two emulsion formulations. When the effects of several synthetic membranes (nylon, cellulose, cellulose nitrate) were compared with the sheep nasal mucosa, the cellulose membrane and sheep nasal mucosa showed similar permeation properties for O/W emulsion (P > 0.05). To examine the absorption characteristics of IND, the anti-inflammatory properties of intravenous solution of IND, intranasal O/W emulsions of IND (with or without enhancers) and intranasal solution of IND (IND-Sol) were investigated in rats with carrageenan-induced paw edema. When citric acid was added to the nasal emulsion, the anti-inflammatory activity was similar to that of intravenous solution (P > 0.05). Finally, it was concluded that, intranasal administration of IND emulsion with citric acid may be considered as an alternative to intravenous and per oral administrations of IND to overcome their adverse effects. © American Association of Pharmaceutical Scientists 2008.This study was supported by Research Foundation of Ege University. The authors would like to thank Pınar Integrated Meat and Flour Inc. for providing the sheep nasal mucosa in performing the ex vivo studies. -

Investigating the measurement structure of the Turkish version of the Dysfunctional Attitudes Scale-9

The Turkish version of the Dysfunctional Attitudes Scale-9 (DAS-9) items assesses an individual’s level of endorsement of dysfunctional attitudes associated with depression. The purpose of this study was to evaluate factorial reliability and validity of the Turkish version of the DAS-9. Exploratory and confirmatory factor analyses and the MIMIC model were used to investigate the psychometric properties of the DAS-9. The exploratory factor analysis results indicated a two-factor structure: (a) personal/internal rigid thoughts, and (b) dysfunctional thoughts involving other people and the external world. Participants at a high risk for depression endorsed the factor scores significantly higher than participants at a lower risk. Overall, the results suggest that the scale is a reliable and valid measure that can be used by clinicians and researchers to measure level of dysfunctional attitudes. © 2019, Springer Science+Business Media, LLC, part of Springer Nature

Sustainable Concretes for Structural Applications

For the production of a high-performance concrete (HPC) matrix, a large amount of binder is normally used. The production of ordinary Portland cement (OPC) as the binder of concrete accounts for 7% of CO2 emission, which has notable environmental impacts, and subsequently results in unsustainable concrete. The aim of the present study was to investigate the effect of replacing OPC with calcium sulfoaluminate cement (CSA) or ground granulated blast-furnace slag (GGBS) as sustainable binders on the engineering properties of HPC. Additionally, the effect of introducing double hooked-end (DHE) steel fibers at a fiber volume fraction of 1% on the properties of HPC was assessed. The compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity of HPC were evaluated. Moreover, a scanning electron microscopy (SEM) method was used to study the microstructure of the concretes. The results indicate that the replacement of OPC with CSA cement results in an improvement in the mechanical properties of HPC particularly at later ages of curing, while combination CSA cement with OPC and GGBS in the binary and ternary systems degrades the concrete’s strengths. The addition of 1% DHE steel fibers significantly increased the engineering properties of concrete. The results show that the bond between a cement matrix and steel fibers has been enhanced due to the expansive behavior of CSA cement. The SEM observation also shows the significant influence of CSA cement on the microstructure of concrete by forming a rich amount of ettringite which subsequently results in an improvement in the properties of concrete

Synthesis and characterization of amphiphilic triblock copolymers including -alanine/-methyl--alanine and ethylene glycol by "click" chemistry

WOS: 000460703600029Terminally azide poly--alanine (PBA-Az) was directly obtained by hydrogen transfer polymerization of acrylamide in the presence of sodium azide as an initiator. However, terminally azide poly(-methyl -alanine) (PmBA-Az) was synthesized by the reaction between terminally bromo poly(-methyl -alanine) and sodium azide. Dipropargyllated polyethylene glycol (PEG-di-Pr) was synthesized by using the reaction of PEGs with different molecular weights and propargyl bromide. Synthesis of poly(-alanine-b-ethylene glycol-b--alanine) and poly(-methyl -alanine-b-ethylene glycol-b--methyl -alanine) amphiphilic ABA triblock copolymers was achieved via click chemistry of PBA-Az or PmBA-Az and PEG-di-Pr with different molecular weight. Click reaction parameters such as concentration and time were assessed. Macromonomers and the amphiphilic triblock copolymers were characterized by using H-1-NMR, FT-IR, MALDI-MS, TGA, and elemental analysis techniques. The multi-instruments studies of the obtained amphiphilic triblock copolymers reveal that the copolymers easily formed as a result of click chemistry