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Article
Synthesis , Characterization And Mesomorphic Properties Of New Liquid Crystalline Compounds Involving Ester – Schiff – Chalcone Linkages

Authors: Uhood J. AL-Hamdani --- Roza A.Salman
Journal: JOURNAL OF THI-QAR SCIENCE مجلة علوم ذي قار ISSN: 19918690 Year: 2014 Volume: 5 Issue: 1 Pages: 38-42
Publisher: Thi-Qar University جامعة ذي قار

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Abstract

In order to investigate the influence of the terminal substitution on mesomorphism five compounds containing ester – Schiff base – chalcone as a central linkage and different terminal substitutions in one side of the molecules , were synthesized and their mesomorphic properties were studied . The mesomorphic properties of all the synthesized compounds have been characterized by differential scanning calorimetry ( DSC ) and polarizing optical microscopy (POM) attached with a Mettler hot stage .All compounds have been characterized by FTIR,1H-NMR, MS-Spectra spectroscopy .


Article
Study of Thermal Stability of Tetraphenanthroporphyrazine and SomeMetal Complexes By Thermogravimetric Analysis .
دراسة الاستقرارية الحرارية للتترافينانثروبورفرازين وبعض معقداتها الفلزية بواسطة التحليل الحراري الوزني

Authors: Ahlam J. Abdul- ghani احلام جميل عبد الغني --- Asmaa M- N. Khaleel اسماء محمد نوري خليل
Journal: Iraqi Journal of Science المجلة العراقية للعلوم ISSN: 00672904/23121637 Year: 2015 Volume: 56 Issue: 1B Pages: 316-328
Publisher: Baghdad University جامعة بغداد

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Abstract

The thermal stability of previously prepared tetraphenanthroporphyrazine (TPPH2) and its complexes with VO(IV) , Co(II) , Cu(II) , Zn(II) , Mg(II) , Ca (II) ions were studied by thermogravimetric analysis (TG & DTG) at temperature range (20-1000oC). The results indicated that these compounds have a high thermal stability comparable to those of phthalocyanine compounds (PC) and higher than those of hemiporphyrazine compounds (HP) . In general metal complexes were more stable than parent ligand . Data of magnetic susceptibility and electrical conductivity were also obtained as further support for the studied compoundes .

شخصت الاستقرارية الحرارية لحلقة التترافينانثروبورفرازين (TPPH2) ومعقداتها الفلزية مع الايوناتCu(II) ,Co(II), VO(IV) Mg(II) ,Ca (II), Zn(II) المحضرة سابقا من خلال دراسة التحليل الحراري الوزني (TG & DTG) في مدى درجات الحرارة (20-1000oم) بينت النتائج ان هذه المركبات تمتلك استقرارية حرارية عالية مقاربة لمركبات الفثالوسيانين (PC) واكثر استقرارية من مركبات الهيميبورفرازين (HP) بصورة عامة كانت المعقدات الفلزية اكثر استقرارية من الليكاند.اجريت قياسات الحساسية المغناطيسية والتوصيلية الكهربائية وكانت النتائج متفقة مع الصيغ التركيبية المقترحة للمركبات المدروسة .


Article
تحسين الاستقرارية الحرارية لسبائك

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Abstract

It is well established that Aluminum and its alloys are widely used in aerospace industries, for their good mechanical and physical properties. In addition, to reliable toughness and low density which is the prime importance factor in selecting materials for aerospace industries.Duralumin (Al-4% Cu) is one of these important alloys and it is one of (2XXX) series where Copper is the major alloying element. However, in spite of its high strength, it has low thermal stability, which imposes limitations on Airplanes speeds, from which Air frame is made. This work represents an attempt to improve thermal stability.Several techniques were adopted to evaluate the role of thermo-mechanical treatments and alloying elements. Results show an interesting behaviour and significant improvement in properties.

احتل الالمنيوم وسبائكه مكانة واسعة في مجال صناعات الفضاء ويعود ذلك بالاساس الى خواصه الميكانيكية والفيزياوية الجيد، وامتلاكه قيمة عالية من (المقاومة/ الوزن) هذا المعيار يعتبر مقياساً لاختيار المواد المناسبة لصناعات الفضاء.تعد سبيكة الديورالومين (Duralumin) (Al-4%Cu) احدى السبائك المهمة التي تعود الى سلسلة (2xxx) حيث النحاس عنصر السبك الاساسي فيها. وتمتاز هذه السبيكة بمقاومة عالية (High Strength) الا ان استقراريتها الحرارية (Thermal Stability) محدود مما تضع محدداً لسرعة الطائرات التي تصنع ابدانها (Air Frame) من هذه السبائك وبذا فقد جرت هذه الدراسة كمساهمة لتحسين الاستقرارية الحرارية لها. تبنى البحث بعض التقنيات لتقييم دور المعاملات الحرارية- الميكانيكية المزدوجة وعناصر السبك. واظهرت النتائج اهمية كبيرة في تطوير سلوك وخواص السبائك المستخدمة.


Article
Evaluation of Mechanical and Thermal properties for Polymer blends based on Epoxy and some Organophosphorus Resins containing Silicon.
تقييم بعض الخواص الميكانيكية والحرارية لمخاليط بوليمرية معتمدة على الايبوكسي و بعض راتنجات السليكون العضوية

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Abstract

Abstract; In this paper we prepared a number of polymer blends between organophosphous resins contain silicon (p-si-resins) namely polytris((dimethyl ethoxy silyl)phosphate and polytris(dimethyl phenyloxy silyl)phosphate separately and epoxy resin by weight percentages (5-25)%. Some mechanical properties such as impact strength and hardness of the prepared polymer blend were studied, it was observed that the impact strength increases with increasing the proportion of p-si-resins. The hardness has been decreased in values when compared with the epoxy resin alone. This is due to the flexibility provided by the p-si-resins. Thermal stability of the prepared polymer blends were studied by thermo gravimetric analysis technique TGA with measuring some functions such as decomposition temperature, activation energy, rate of decomposition and char content. The results showed that thermal stability of the polymer blends increase with increasing the proportion of p-si-resins. In addition the flame resistance of prepared polymer blends according to standard specifications (ASTM D 568)was evaluated. The results showed an improvement in flame resistance and that by observing the decrease in the rate of burning and weight loss with the increase in the proportion of p-si- resins.

الملخص:تم تحضير عدد من الامزجة البوليمرية بين راتنجات الفسفور العضوية المحتوية على السليكون وهي polytris((dimethyl ethoxy silyl)phosphate, polytris(dimethyl phenyloxy silyl)phosphate والايبوكسي( epoxy) وبنسب وزنية 5-25)%). تم دراسة بعض الخواص الميكانيكية مثل مقاومة الصدم والصلادة للامزجة البوليمرية المحضرة وقد وجد ان مقاومة الصدم تزداد مع زيادة محتوى راتنجات (p-si-resin) بينما لوحظ ان قيم الصلادة تقل عند مقارنتها مع راتنج الايبوكسي لوحدة ويعود ذلك الى خواص المرونه التي توفرها راتنجات العضوية المحتوية على سليكون .بالاضافة الى ذلك تم دراسة الثبات الحراري للامزجة البوليمرية المحضرة بواسطة التحليل الحراري الوزني TGA وقد حسبت بعض الدوال الحرارية مثل درجات التفكك وطاقة التنشيط ومعدل سرعة التفكك ومحتوى التفحم وقد بينت النتائج بأن الثبات الحراري للامزجة البوليمرية يزداد مع زيادة محتوى راتنجات الفسفور العضوية المحتوية على السليكون .كما تم ايضا دراسة مقاومة الاحتراق للامزجة البوليمرية المحضرة بموجب المواصفات القياسية ASTM D568 وقد اشارت النتائج الى تحسن مقاومة الاحتراق للامزجة وذلك من خلال النقصان الملاحظ في معدل سرعة الاحتراق والفقدان بالوزن عند زيادة محتوى راتنجات الفسفور العضوية المحتوية على السليكون في شبكة الايبوكسي.


Article
Synthesis, Characterization of New Polyamides Bearing Triarylamine for Lightemitting Diodes

Journal: Ibn Al-Haitham Journal For Pure And Applied Science مجلة ابن الهيثم للعلوم الصرفة والتطبيقية ISSN: 16094042 Year: 2019 Volume: 32 Issue: 1 Pages: 80-100
Publisher: Baghdad University جامعة بغداد

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Abstract

In this work, new di-acid monomers 4, 4’-di-carboxillic-4”-bromo-2”, 6”-dimethyl triphenylamine (Ma),4, 4’- di-carboxylic -4”-chloro-2”, 6”-dimethyl triphenylamine (Mb) and 4, 4’- di-carboxylic -2”,4”-dichloro-6”-methyl triphenylamine (Mc) were synthesized by reaction of p-cyanobenzofluride with threedifferent aromatic amines (4-bromo,2,6-dimethyl aniline, 4-chloro,2,6-dimethyl aniline and 2,4 dichloro,6- methyl aniline ) via aromatic nucleophilc substitution method to form three di cyano intermediates 4,4’-Dicyano-4”-bromo-2”, 6”-dimethyl triphenylamine (Da), 4, 4’-dicyano-4”-chloro-2”, 6”-dimethyltriphenylamine (Db) and 4, 4’-dicyano-2”,4”-dichloro-6”-methyl triphenylamine (Dc) which form final dicarboxylicmonomers after alkaline hydrolysis. Finally, these monomers react with two different aromaticdi amines, phenylene diamins and benzidine respectively via polycondensation reaction to form finalpolyamides 4"-bromo-2", 6"-dimethyl-triphenylamine-4, 4'-polyphenylbenzamide (Pa), 4”-chloro-2”,6”-dimethyl- triphenylamine-4,4'-polyphenylbenzamide (Pb), 2”,4”-dichloro-6”-methyl-triphenylamine 4,4'-polyphenylbenzamide (Pc),4"-bromo-2",6"-dimethyl triphenylamine-4,4'- polyphenylbiphenylamide (Pd),2”,4”-dichloro-6”-methyl-triphenylamine-4,4’-polyphenylamide (Pf). The chemical structure of thesepolymers characterized by FTIR and NMR techniques. All the results of polyamides showed excellentsolubility in most polar solvents to form strong thin films. The polyamides possess a good thermalstability with height glass transition temperatures (Tg). Polyamides in DMSO solvent gave strongphotoluminescence PL. Thin casting films of these polyamides in cyclic voltammetry (C.V) onglass base of iridium-tin oxide (ITO) as working electrode in dry CH3CN solvent contains 0.1 Mof tetrabutylantimoneperchlorate (TBAP) as an Electrolyte gave one redox wave


Article
The Effect of Cesium Chloride on Thermal Properties of Poly (Vinyl Alcohol)

Author: Nadia Azeez Betti
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 12 Part (A) Engineering Pages: 2193-2206
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Poly (vinyl alcohol), PVA for short, films doped with different concentrations of cesium chloride(CsCl) (0% , 2% , 4% , 6% , 8% , 10% , 12% , 14% ,16% ) were prepared by solution casting method to study the effect of this salt on thermal properties of PVA by using thermogravimetric analysis (TGA) .It was found that the dopedPVA films with concentrations(14% and 16%) of CsCl aremore thermal stable than PVA while doped PVAfilms with concentrations ( 4% and 6%) of CsCl are less thermal stable than PVA and the dopedPVA films with concentration of ( 2% , 8% , 10% and 12%) are almost as thermal stable as PVA. Fourier transform infrared spectroscopy (FTIR) was also used to investigate complexation between CsCl and PVA and was foundthat the doped PVA films with concentration (2% , 4% , 6% and 8%) of CsClshowno significant shifts in wave numbers of the characteristic bands of PVA while doped PVA films with concentrations (10%, 12% ,14% and 16% ) of CsClshow a significant shifts to a higher values in wave number of stretching vibration of (-OH) comparing to PVA indicating well complexation between CsCl and PVA.


Article
Improvement, the Performance of Polyurethane (PUR), Y-290 Resin as Coating of Oil Pipeline by Using Multi-Walled Carbon Nanotubes (MWCNTs)

Authors: S.A. Awad --- E.M. Khalaf
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 8 Part (A) Engineering Pages: 845-848
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this study, polyurethane epoxy-Y290 (PUR-Y290) as a matrix material was reinforced by 1%MWCNTs. Polyurethane is a thermoset polymer and using for several applications particularly as coatings of gas and oil pipeline. Polyurethane uses as a liquid coating against the corrosion, and that is caused by the direct exposure for long periods of UV irradiation and humidity. The nanocomposites were prepared by adding 1wt% MWCNTs to polyurethane and mixed by using an ultrasound mixer. Polyueethane-1%MWCNTs composite sample was exposed to accelerate weathering (UV irradiation coming from sunlight, moisture, and salt water spray) during the exposure to different durations 6 months, 12 months and 24 months. Exposed and unexposed samples were investigated and evaluated by thermal and mechanical tests.It was found that the incorporation 1.0%wt of MWCNTs filler, enhanced the thermal stability and improved the mechanical properties during the exposure for long-term life to accelerated weathering conditions, compared with polyurethane coating without MWCNTs filler. These results indicated that polyurethane (liquid coating) nanocomposites have a higher resistance to environmental condition and give more protective against corrosion of oil pipelines and applied as coatings by spray method to protect the oil pipeline surfaces from environmental conditions.


Article
Impact of Intermediate and Terminal Groups on the Thermal Stability of Bent-Core Liquid Crystals
تأثير المجاميع الوسطية والطرفية على الاستقرار الحراري للبلورات السائلة المنحنية

Author: Mohammed M. Aftan محمد مزهر عفتان
Journal: Tikrit Journal of Pure Science مجلة تكريت للعلوم الصرفة ISSN: 18131662 Year: 2018 Volume: 23 Issue: 1 Pages: 83-91
Publisher: Tikrit University جامعة تكريت

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Abstract

A series of new mesogenic chalcone, azomethine and azo compounds were successfully synthesized. A chalcone was prepared via condensation of isophthaldehyde with a p-hydroxyacetophenone in a basic medium, Schiff bases was prepared by condensation isophthaldehyde with a p-hydroxyaniline in acidic medium. While azo compound was obtained by a reaction of m-diaminobenzen with NaNO2 and phenol, and the generated compound was reacted with alkyl bromide. The structures of such compounds were confirmed by FT-IR and 1H-NMR spectrometer. The liquid crystal phases were studied by Differential Scanning Calorimeter (DSC) and polarizing optical microscope with heating. A thermal stability of liquid crystal phases were increased by increasing the length of aliphatic chain to smectic phases and decreasing in the thermal stability of nematic phase. It has been observed that the thermal stability of liquid crystal in chalcone compounds were higher than others, azo and azomethine compound.

حضرت سلسلة ميزوجينية جديدة لمركبات الجالكون وقواعد شف ومركبات الازو، تم تحضير الجالكونات بتكاثف 1مول من ايزوفثالديهايد مع مولين من بارا-هيدروكسي اسيتوفينون بوسط قاعدي، حضرت قواعد شف بتفاعل 1مول من ايزوفثالديهايد مع مولين من بارا-هايدروكسي انلين بوسط حامضي، تم الحصول على مركبات الازو بتفاعل ميتا ثنائي-امينوبنزين مع NaNO2 والفينول، واخيراً فوعلت المركبات المحضرة مع بروميد الالكيل. شخصت المركبات المحضرة بجهاز طيف الاشعة تحت الحمراء IR وطيف الرنين النووي المغناطيسي 1HNMR-d. تمت دراسة الاطوار البلورية السائلة بجهاز مسعر المسح التفاضلي DSC ومجهر الضوء المستقطب. اظهرت الاطوار البلورية السائلة استقراراً حرارياً يزداد بزيادة طول السلسلة الاليفاتية للاطوار السمكتية يصاحبه انخفاض بالاستقرار الحراري للطور النيماتي. لوحظ ان الاستقرار الحراري للاطوار البلورية السائلة لمركبات الجالكون اعلى من مركبات الازو وقواعد شف المناظرة


Article
The Preparation, Characterization and the Study of Thermal Properties to Some Co-Phthalocyanine Polymers Derivative from Epichlorohydrine and Dichlorodimethyl Silane
تحضير وتشخيص ودراسة الخواص الحرارية لبعض بوليمرات الكوبلت (II) فثالوسيانين المشتقة من الايبي كلوروهايدرين وثنائي مثيل سلين

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Abstract

A novel class of polymer containing the metallophthalocyanine ring [MPc, M= Co(II)] in the chain was synthesized by polycondensation of 4.4',4'',4'''-tetraminophthalocyanato cobalt (II) with epichlorohydrine and dichlorodimethyl silane by [1:2] mole ratio (MPc: Epichlorohydrine or dichlorodimethyl silane). The structures of the polymers were characterized by FTIR, U.V-Visible spectrophotometry, and X-ray diffraction. The thermal stabilities of the polymers were evaluated by dynamic thermo gravimetric analysis (TG) and diffraction scanning calorimetric (DSC).

تم خلال الدراسة الحالية تحضير نوعين من البوليمرات الفلزية لفلز الكوبلت الثنائي باستخدام البلمرة التكثيفية وذلك بتفاعل 4، 4"،4""،4"""- رباعي امينو فثالوسياناتو الكوبلت (II) مع كلاً من ثنائي كلورو ثنائي مثيل سلين وايبي كلوروهايدرين بنسبة مولية (2:1)، شخصت البوليمرات المحضرة بثلاث تقنيات اساسية (مطيافية الاشعة تحت الحمراء، مطيافية الاشعة المرئية وفوق البنفسجية و حيود الاشعة السينية). كما تم دراسة الثبات الحراري للبوليمرات المحضرة باستخدام التحليل الحراري الوزني والتحليل الحراري المسعري، واظهرت النتائج التحليل الحراري للبوليمرات المحضرة وبنسبة (1:2) اعلى ثبات حراري بالمقارنة مع مركبات الامينو فثالوسانين بسبب زيادة الوزن الجزيئي والاواصر الكيميائية المتكونه، وكذلك بالنسبة لقياسات الاشعة السنية كانت البوليمرات اكثر انتظاماً بلورياً بسبب وجود بعض المجاميع المعوضة التي تزيد من ترابط جزيئات البوليمر مع بعضها لذا تكون اكثر انتظام بلوري.


Article
Thermogravimetric Analysis on PVA / PVP Blend Under Air Atmosphere

Author: Nadia Azeez Betti
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 13 Part (A) Engineering Pages: 2433-2442
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Films of poly vinyl alcohol (PVA) /poly vinyl pyrrolidone (PVP) blends have been prepared by solution casting method with different ratios of each other (100/0 , 80/20 , 60/40 , 50/50 , 40/60 , 20/80 , 0/100) to investigate their thermal stability comparing to correspondent pure polymers by using thermogravimetric analysis (TGA) under air atmosphere. It was found that PVA and PVP films show two decomposition steps while PVA/PVP blend films show three decomposition steps except the film of the ratio (20/80) that shows four decomposition steps .It was also found that blending decreases the temperature ranges at which the first and the second decomposition steps of PVA and PVP occur. It was found that blending PVA with PVP has significant effect on weight loss at first decomposition step of PVA by increasing it as the ratio of PVP increases. It was also found that blending PVA with PVP has significant effect on weight loss at second decomposition step of PVA by decreasing it as the ratio of PVP increases. It was found that the weight loss at third decomposition step of PVA/PVP blend films increases as the ratio of PVP increases . According to TGA thermograms under air atmosphere, PVA , PVP and PVA/PVP blend films show almost the same total weight loss which means of same thermal stability.

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