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Article
The Rheological Properties of Isothermal Curing of DGEBA/ TETA Epoxy System
دراسة الخواص الريولوجية بثبوت درجة الحرارة لعملية تقسية راتنج الايبوكسي بأستخدم مادة تراي اثلين تترا امين

Authors: Adnan A. Abdul Razak --- Najat j. Saleh --- Maryem Emad
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2015 Volume: 33 Issue: 5 Part (A) Engineering Pages: 1095-1112
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this study viscosity (η) of diglycidyl ether of bisphenol A / triethylenetetramine (DGEBA/TETA) system were measured through curing using a Brookfield viscometer at four different temperatures (30, 45, 60 and 80) °C. The measurements were carried out for two hardener/resin ratios (13 and 20) phr. The gel time was calculated for each hardener/resin ratio formulation; from the viscosity experimental data. The results showed that the gel time decrease with increasing curing temperature for each hardener/resin ratio formulation. Viscosity profiles were described by a model based on the Boltzmann function. The fitted results agreed well with the experimental values.

في هذا البحث تم قياس اللزوجة لنظام مكون من (DGEBA/TETA ) خلال عملية الانضاج بأستخدام مقياس اللزوجة من نوع Brookfieldفي اربع درجات مختلفة (30,45,60,80) م0 . تم أخذ القياسات باستخدام نسبتين للراتنج / المصلد وهما (13) و(20) جزء من المائة .تم حساب زمن التصلب gel time)) لكل نسبة من الراتنج/ المصلد من قياسات اللزوجة . أظهرت النتائج بان زمن التصلد يزداد مع زيادة درجة الانضاج لكل نسبة من نسب الراتنج/ المصلد . تم وصف منحنى اللزوجة بموديل يعتمد على موديل (Boltzman) وتم مطابقة النتائج المستخلصة من الموديل مع النتائج المختبرية وظهر تطابق كبير بينهما .

Keywords

Epoxy Resin --- Curing --- Rheology --- Hardener


Article
A Study Mechanical Properties of Epoxy Resin Cured at Constant Curing Time and Temperature with Different Hardeners

Authors: Najat j. Saleh --- Adnan A. Abdul Razak --- Manal A. Tooma --- Mariam E.Aziz
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2011 Volume: 29 Issue: 9 Pages: 1804-1819
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this study, a low molecular weight epoxy resin diglycidyl ether of bisphenol A (DGEBA) is cured isothermally with an aliphatic and aromatic amine hardeners separately. (1) Triethylenetetramine (TETA), (2) diamino diphenylmethane (DDM). The samples were prepared for different hardener/resin ratios, (under stoichiometry, stoichiometry and above stoichimetry). The mechanical Properties impact strength, tensile strength, hardness, flexural strength, compression strength and bending strength of an epoxy system has been investigated in this work. For DGEBA/TETA system the tests were done on four hardener/resin ratios (10, 13, 15 and 20) phr and for DGEBA/DDM system the hardener/resin ratios were four also; (24, 27, 30 and 34) phr. The results showedthat the above stoichiometry ratio formulation (15 phr for DGEBA/TETA system and 30 phr for DGEBA/DDM system) gave the best mechanical properties, while the DGEBA/DDM system showed better mechanical properties than the DGEBA/TETA system.


Article
Composite Resin Coating for The Protection of Surfaces and Metals
استخدام المتراكبات الراتينج في الطلاء لحماية الاسطح والمعادن

Authors: Nessrain A. Hussain نسرين علي حسين --- Nadia Abraheem Fakry نادية ابراهيم فخري --- Huda Ali Al Pana هدى علي البنا
Journal: Iraqi Journal of Science المجلة العراقية للعلوم ISSN: 00672904/23121637 Year: 2013 Volume: 54 Issue: 1 Pages: 110-114
Publisher: Baghdad University جامعة بغداد

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Abstract

The curing process of epoxy resin was investigated with some additives and fillers such as nano fumed silica with primary particle diameter of 56–58 nanometers, fine ferric oxide with an average particle diameter of 0.4 micrometer, fine calcium carbonate with an average particle diameter of 0.58 micrometer, and plasticizer, a new composite resin has been obtained. Based on present experimental results, the new composite resin shows high impact strength and hardness as well as the ability of the composite withstand to degradation from water way in. Additionally, curing time of composite was reduced to the minimum set time than epoxy resin at different temperature. This new composite resin was used appropriately for coating to protect surfaces and metals in marine ships from corrosion which meet the requirements for certain applications such vehicles body, crude oil tankers, petroleum pipelines services, and other applications.

تم في هذا البحث تحوير و معالجة راتنج الايبوكسي مع بعض المواد المضافة والحشوات مثل السيليكا المتطايرة حيث يتراوح قطر الدقائق ما بين 56-58 نانوميتر , دقائق اوكسيد الحديديك بمعدل قطر 0.4 مايكروميتر , ملدن , دقائق كاربونات الكالسيوم بمعدل قطر 0.58 مايكروميتر لغرض الحصول على مادة مركبة راتنجية . ولقد أظهرت النتائج المختبرية ان المادة المركبة ذات قوة صدم و قوة صلادة عالية اضافة الى امكانيتها على مقاومة أنحلالها في الماء وكذلك تم تقليص زمن تصلب وتقسية المادة المركبة الراتنجية بمقدار زمني اقل بكثير من تقسية راتنج الايبوكسي بمختلف درجات الحرارة. وأعتمادا" للمواصفات التي تم الحصول عليها فان المادة المركبة الجديدة تم تطبيقها لاغراض طلاء الاسطح والقطع المعدنية المستخدمة في صناعة الزوارق والقطع البحرية لغرض حمايتها من التآكل , كذالك تنوع استخداماتها بما يتلائم مع بعض التطبيقات التي تدخل في طلاء الناقلات والانابيب النفطيه


Article
Evaluation of the Effect of Microwave Irradiation and Die Hardener Application on Surface Hardness of Type IV Dental Stone

Authors: Suha Fadhil Dulaimi سهى فاضل دليمي --- Lateef E. A. Al-Jorani لطيف عيسى الجوراني
Journal: Tikrit Journal for Dental Sciences مجلة تكريت لعلوم طب الاسنان ISSN: 20731213 Year: 2016 Volume: 4 Issue: 2 Pages: 128-135
Publisher: Tikrit University جامعة تكريت

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Abstract

Type IV dental stone play an important role during fabrication ofindirect dental restoration. It should be accurate in every respect,dimensionally stable over time, hard enough to with standfabrication process resistant to the inadvertent abrasions caused byfabrication. The aim of present study was to evaluate the effect ofmicrowave irradiation and die hardener application on surfacehardness of type IV dental stone. Two commercial brands of typeIV dental stone (Spofadental/ Czech, Zhermack/ Italy) wereevaluated. 30 samples were prepared from each brand and left todry for 24hr. After that divided into three groups, control group(10 samples without treatment), 10 samples subjected tomicrowave irradiation at 650 watt output power and 2450 MHZfor 10 mint. And 10 samples painted with die hardener. Surfacehardness measured with Shore C (Durometer, Digital hardnesstester). The die hardener application not affect surface hardness ofboth brands (P>0.05). However microwave irradiation increasesurface hardness of Spofadental Type IV dental stone. But reducesurface hardness of Zhermack Type IV dental stone. After 24hr. ofpouring Type IV dental stone (Spofadental / Czech, Zhermack /Italy) die hardener application not affect surface hardness.However surface hardness of Spofadental Type IV dental stonemay be improved with microwave irradiation. But Zhermack TypeIV dental stone showed reduction in surface hardness aftermicrowave irradiation.

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