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Article
Effect of water absorption on impact strength for epoxy-glass fibers composite
تأثیر امتصاصیة الماء على قوة الصدمة لمت ا ركب الایبوكسي المدعم بالالیاف الزجاجیة

Author: Qayes Abdullah Abbas قیس عبد الله عباس
Journal: Journal of university of Anbar for Pure science مجلة جامعة الانبار للعلوم الصرفة ISSN: 19918941 Year: 2011 Volume: 5 Issue: 2 Pages: 67-72
Publisher: University of Anbar جامعة الانبار

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Abstract

Hand lay-up method was used to prepare sheets of epoxy (EP) reinforced with 12 layers of(0 -90 ) glass fiber mat with volume fraction equal to 30%. The sheets of Ep- glass fiber composite werecut to samples with standard dimensions for charpy impact test. The main objective of this research was tostudy the effect of water absorption on impact strength for epoxy-12 glass fiber composite. Diffusivitybehavior and diffusion coefficient were investigated. The samples were dividing to three groups immersedin distilled water for different time, the first group 15 days ,the second group 27 days and the last 39 days atconstant temperature(±20)C the mass gain recorded every 3 days till saturation (M  ) after that the massgain decreased .the results showed that the maximum diffusion coefficient (minimum absorption resistance) was for sample (A),while the minimum diffusion coefficient (maximum absorption resistance) was forsample (C). The impact strength has been investigated for samples before and after the immersion indistilled water for different time. The results show that the impact strength decreased with increasing thetime of immersion for samples

الخلاصة:تم استخدام طریقة التصنیع الیدوي لتحضیر طبقات من الایبوكسي) ٩٠ )والمحاكة بشكل حصیرة وبكسر حجمي مقداره ٣٠ % من ألیاف التسلیح . قطعت هذه الطبقات من مت ا ركب الایبوكسي  - ٠ والألیاف الزجاجیة بالأبعاد القیاسیة لاختبار تأثیر الصدمة لشاربي .ویهدف البحث الى د ا رسة تأثیر امتصاص الماء على قوة الصدمةلمت ا ركب الایبوكسي المدعم - ١٢ طبقة من الالیاف الزجاجیة ، وقد تم د ا رسة سلوك الانتشاریة ومعامل الانتشار. وزعت العینات إلى ثلاثمجامیع وغمرت في الماء المقطر لفت ا رت زمنیة مختلفة .المجموعة الأولى غمرت لمدة ١٥ یوما، والمجموعة الثانیة ٢٧ یوما والأخیرة ٣٩بعد ذلك (M∞) یوما عند درجة ح ا ررة ثابتة (± ٢٠ ).تم حساب الزیادة بالكتلة حیث سجلت كل ٣ أیام حتى الوصول إلى حالة التشبعفي حین ، (A) لوحظ إن الربح بالكتلة انخفض. أظهرت النتائج أن قیمة معامل الانتشار القصوى (مقاومة الامتصاص الدنیا)كانت للعینةتم د ا رسة قوة الصدمة للعینات قبل وبعد الغمر بالماء المقطر .(C) أن الحد الأدنى لمعامل الانتشار (مقاومة الامتصاص القصوى) للنموذجولفت ا رت زمنیة مختلفة.وقد أظهرت النتائج ان قوة الصدمة تقل بزیادة زمن الغمر للعینات.


Article
Studying the Impact Strength of (Epoxy with TiO2 and MgO) Composite

Authors: Balkees M.Deya’a --- Fawziea M. Hussien --- Intihah Gatia Dway
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2011 Volume: 29 Issue: 10 Pages: 1971-1978
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

This work has been done with using of epoxy resin mixed with polystyrene(90/10) % to compose binary blend. Two types of powder (TiO2, MgO) in two volume fractions of (10, 15) % were used as reinforcement materials to the prepared polymer (B).Hand lay-up technique is used in fabrication of the composite samples. Impact test was carried out for the proper samples in both normal condition and after immersion in water, KOH (0.5 N), HCL (0.5 N) solutions for periods ranging up to 8 weeks. After comparing the results between the polymer blend and their composite, it was found that Impact Strength were greater for the matrix (B) after immersion compared with their values beforeimmersion while the results of the composite before immersion show that(B+10%MgO) has higher impact strength (11.333) KJ/m2


Article
Impact Strength of Maxillary Complete Dentures Fabricated From Different Heat Cured Acrylic Resin Denture Base Materials

Author: Mohammed A. Abdulla
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2012 Volume: 12 Issue: 19 Pages: 24-31
Publisher: Mosul University جامعة الموصل

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Abstract

AIMS: Evaluation of the impact strength of maxillary complete dentures fabricated from new type high impact heat-cured acrylic denture base material and comparison with other types of acrylic resin denture base materials. MATERIALS AND METHODS: Three types of materials were used in this study, high impact heat-cured acrylic resin; cross-linked acrylic resin (no cadmium); and conventional heat-cured acrylic resin. Twenty four maxillary complete dentures were fabricated to be tested and divided into three groups. Group 1, Group 2, and Group3 for high impact acrylic resin, cross-linked acrylic resin, and conventional heat- cured resin, respectively. Before testing, all specimens were stored in distilled water at 37ºC for 2 months. The impact strengths (J) of the dentures were measured with a falling-weight impact test. The impact strengths of both groups were compared by a repeated measures analysis of variance (ANOVA) and Duncan's Multiple Analysis Range Test to determine the signifi-cant difference among the tested groups at (p<0.001) level of significance. RESULTS: There is a sig-nificant difference of the mean values of impact strengths for high impact acrylic resin, cross linked acrylic resin and conventional acrylic resin denture base materials at crack initiation and complete frac-ture. The impact strength between crack initiation and complete fracture within each group was signifi-cantly different (p<0.001) for all the groups, and more energy was needed for complete fracture than that for crack initiation for the high impact strength acrylic resin. CONCLUSIONS: Maxillary com-plete dentures made from high impact acrylic resin denture base material have significantly higher im-pact strength than that of maxillary complete denture made from cross-linked and conventional acrylic resin denture base materials. Maxillary complete dentures made from cross-linked acrylic resin denture base material have significantly higher impact strength than that made from conventional acrylic resin denture base materials.


Article
IMPACT MODIFIER OF EPOXY RESIN WITH CITRACONICIATED POLYBUTADIENE AS TOUGHENING AGENT

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Abstract

The impact strength of epoxy resin based on diglycidyl ether of bis phenol-A- with citraconiciated polybutadiene were investigated. The polybutadiene citraconiciated by reaction with citraconic anhydride and benzoyl peroxide as initiator. The percent citraconiciation was 10%.In the present work citraconiciated polybutadiene was used as impact modifier for epoxy resin. The percentage of the blend between citraconiciated polybutadiene and epoxy resin was (5, 7.5, 12.5, and 20%) while the amine hardener of the epoxy resin was added at a ratio of 1 part amine to 3 part epoxy.

تم في هذا البحث تحضير بولي بيوتاداين بمجاميع من الستراكونيك بنسبة 10% وذلك بمفاعلة البولي بيوتاداين مع الستراكونيك اللامائي بوجود بيروكسيد البنزويل كبادئ للتفاعل. تم أستخدام البولي بيوتاداين المطعم بالستراكونيك كمحسن لقوة الصدم للأيبوكسي بعد أن مزج مع اللأيبوكسي بالنسب ( 5 , 7.5 , 12.5 , 20 % ) بينما كانت نسبة المصلب الأميني الى اللأيبوكسي هي جزء واحد من الأمين وثلاثة أجزاء من الأيبوكسي.أظهرت النتائج تحسنا" واضحا" في قوة الصدم للأيبوكسي بزيادة نسب البولي بيوتاداين المطعم بالستراكونيك بسبب زيادة التوافقية بين الراتنج الأيبوكسي و البولي بيوتاداين المطعم بمجاميع الستراكونيك الفعالة.


Article
The effect of adding single walled carbon nanotube with different concentrations on mechanical properties of heat cure acrylic denture base material

Author: Rafah Adil Ibrahim رفاه عادل ابراهيم
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2015 Volume: 27 Issue: 3 Pages: 28-32
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The most widely used material for fabrication of denture base is poly methyl methacrylate, despite itspopularity, the main problems associated with it as a denture base material are poor strength particularly underfatigue failure inside the patient mouth, impact failure outside the patient mouth, which are the main causes forfracture of denture, several studies was done to increase mechanical properties of denture base. The present studywas conducted to evaluate and compare the effect of addition single walled carbon nanotubes in differentconcentrations to polymethyl methacrylate on some mechanical properties (surface hardness, surface roughness,impact strength and transverse strength).Materials and methods: Forty eight samples were prepared for pilot study divided into four groups according to theconcentrations of singled walled carbon nanotubes ( 0%, 0.5%, 1% & 1.5%) added to heat cure acrylic resin , eachgroup was divided into four subgroups according to the tests conducted (Surface hardness , surface roughness,impact strength and transverse strength) and the results obtained were evaluated to determine the concentrationof singled walled carbon nanotubes (SWCNTS) that improve the mechanical properties of heat cure acrylic resin tobe used to complete our study, so another 80 samples were made divided into two main groups (0% SWCNTS ascontrol group) and (1.5% SWCNTS test group) and all the tests were done again.Results: Impact strength and transverse strength were significantly increased after adding 1.5% SWCNTS While surfacehardness was significantly decreased and surface roughness was non-significantly affected when compared withcontrol group.Conclusions: Impact strength and transverse strength of hot cure acrylic resin reinforced with 1.5% SWCNTS weregreatly increased


Article
Study Some of Mechanical Properties and Effects of Immersion in Solution of (Epoxy /Unsaturated Polyester) Blend Which Reinforced with Glass Fiber
دراسة بعض الخواص الميكانيكية وتأثير الغمر بالمحاليل لخليط ( اليبوكسي والبولي أستر غير المشبع) المدعم بالياف الزجاج

Author: بشرى حسني موسى
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2011 Volume: 29 Issue: 10 Pages: 464-473
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this research, polymer blend was prepared from Epoxy resin and unsaturated polyester resin as matrix material (EP/UPE) with weight ratio (90/10) %. E-glass fibers type (woven roven) was used as a reinforcement material with volume fraction for fibers (Vf =30 %) by using hand lay-up method. Some mechanical properties were studied on the specimens of the above mentioned materials and then the results of the blend (EP/UPE) compared with its composite which was reinforced with glass fibers. The samples were immersed in (H2SO4) and (NaOH) solutions with normality (0.1 N) at room temperature for (7,14, 21, 28) days. The effects of the immersion were noticed on the hardness and impact strength values. It was found that the reinforcement with glass fiber leads to the increasing of both impact strength and shore hardness of the composite before theimmersion. The effects of immersion showed decreasing of hardness values after immersion samples in to both above solutions while the results of impact strength showed an increasing after the immersion in to the acidic solution and decreasing of the pure blend and its composite after the immersion in to the basic solution.


Article
The Effect of the Poly Vinyl Chloride (PVC) Addition on Surface Hardness and Impact Strength Properties of Heat-Cured Acrylic Resin Denture Base Material
تأثیر إضافة بولي فنیل كلورید على خواص الصلادة وقوة التصادم لمادة طقم الاسنان المبلمرة ح ا رریا

Author: Ehsan Ali Abed احسان علي عبد
Journal: Journal of university of Anbar for Pure science مجلة جامعة الانبار للعلوم الصرفة ISSN: 19918941 Year: 2010 Volume: 4 Issue: 3 Pages: 50-53
Publisher: University of Anbar جامعة الانبار

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Abstract

Abstract:The most common materials used for fabrication of denture base are poly methylmethacrylate (PMMA) and methyl methacrylate (MMA). Preparation of heat cured, ultered ormodified, denture base acrylic resin was carried out by preparing of poly (methyl methacrylate)Polymer, - PMMA- (75%) and poly vinyl chloride -PVC - (25%), and the liquid part composed ofmethyl methacrylate -MMA- monomer. All the specimens were cured by using short curing cycle (90min. at 74ºC followed by 30 min. at 100º C). Some mechanical properties of the prepared materialwere evaluated in comparison with the control denture base acrylic resin. The polymer was prepared bygraft copolymerization method. The total 40 specimens, 20 specimens for each experimental or controlmaterial were tested.The results showed that the experimental polymer has hardness and impactstrength higher than that of control polymer

تهدف هذه الد ا رسة إلى إضافة مادة بولیمر فنیل كلورید الى مادة بولیمر مثیل میثااكریلات التي تعتبر أكثر المواد شیوعا فيعمل طقوم الأسنان البلمرة ح ا رریاً ود ا رسة بعض الخواص المیكانیكیة مثل الصلادة وقوة التصادم بالمقارنة مع مادة بولیمر مثیلمیثااكریلات( المادة القیاسیة). في هذه الد ا رسه تم تحضیر بولیمر مثیل میثااكریلات ( ٧٥ % ) وبولیمر فنیل كلورید ( ٢٥ %) وتمخلطهما مع سائل مثیل میثااكریلات باستخدام طریقة البلمرة المشتركة المطعمة. تم تحضیر ٤٠ عینه بمعدل ٢٠ عینه لكل اختبار منكل ماده.أظهر النتائج ان الصلادة وقوة التصادم لعینات المادة التجریبیة أكبر منه في عینات المادة القیاسیة وكان هذا الاختلاف غیرمعنوي إحصائیا. وهذا یعود لوجود مادة البولیمر فنیل كلورید الذي أعطى المادة التجریبیة أكثر تماسكا من المادة القیاسیة


Article
Evaluation Study of Glass Fiber Reinforced Polyester and Kevlar Reinforced Polyester by Taguchi Method
دراسة تقييم ما بين البولي استر المقوى بالياف الزجاج والبولي استر المقوى بالياف الكفلر بواسطة طريقة تاكوجي

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Abstract

In the present investigation two different types of fiber reinforced polymer composites were prepared by hand lay-up method using three different parameters (curing temperature, pressing load and fiber volume fraction). These composites were prepared from the polyester resin as the matrix material reinforced with glass fibers as first group of samples and mat Kevlar fibers as the second group, both with different volume fractions (4%, 8%, and 12%) of fibers. They were then tested by tensile strength and impact strength. The main objective in this study is to use Taguchi method for predicting the better parameters that give the better tensile and impact strength to the composites, and then preparing composites at these parameters and comparing them with the randomly used once. The experimental and analytical results showed that the Taguchi method was successful in optimizing the parameters that give the highest properties and it can find the most influential parameter regardless of the material used. Also it showed that the volume fraction was the most influential parameter on the tensile and impact strength. The difference between these composites was in the properties values and that the Kevlar composites have higher tensile and impact strength.

تم في هذا البحث تحضير مادتين متراكبتين مختلفتين من البوليمر المقوى بالالياف بواسطة طريقة التحضير اليدوي وباستخدام ثلاثة متغيرات هي (درجة حرارة المعالجة، حمل الكبس و الكسر الحجمي للالياف). تم تحضير المواد المتراكبة من راتنج البولي استر كمادة اساس مقوى بالياف الزجاج كمجموعة اولى من العينات والياف الكفلر كمجموعة ثانية من العينات وبكسور حجمية مختلفة لكل نوع من الالياف هي (4%، 8%، 12%). تم بعدها اجراء اختباري مقاومة الشد ومقاومة الصدمة على العينات. ان الهدف الاساسي من البحث هو استخدام طريقة تاكوجي للتكهن بافضل المتغيرات التي تعطي افضل مقاومة شد وصدمة للمواد المتراكبة ومن ثم تحضير مواد متراكبة عند هذه المتغيرات ومقارنتها مع المتغيرات المستخدمة المختارة عشوائيا. اظهرت النتائج التجريبية والتحليلية بان طريقة تاكوجي كانت ناجحة في التكهن وايجاد المتغيرات التي تعطي اعلى الخواص وكذلك يمكنها ايجاد المتغير الاكثر تاثيرا على الخواص بغض النظر عن المادة المستخدمة. اظهرت النتائج كذلك بان الكسر الحجمي كان المتغير الاكثر تاثيرا على مقاومة الشد والصدمة. كذلك ان الفرق بين المادتين المحضرتين كان في قيم الخواص وان المادة المتراكبة ذات الياف الكفلر اعطت مقاومة شد وصدمة اعلى.


Article
Assessment of zirconium oxide nano-fillers incorporation and silanation on impact, tensile strength and color alteration of heat polymerized acrylic resin

Authors: Ihab N.S ايهاب نبيل --- Hassanen K.A. --- Ali N.A. علي نعمة
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: special issue 2 Pages: 36-42
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The mechanical strength and color stability of poly methylmethacrylate (PMMA) remains far from idealfor maintaining the longevity of denture. The purpose of this study was to assess impact, tensile strength and colorstability of heat polymerized denture base after addition of salinated and non-salinated zirconium oxide (ZrO2) nanofillers.Materials and methods: zirconium oxide nanofillers were incorporated into (PMMA) denture base by free radical bulkpolymerization. The nano-particales were Silanated by coating with a layer of trimethoxysilypropylmethacrylate(TMSPM) before dispersed and sonicated in monomer (MMA) in two percentages of 3% and 5% by weight. Then itwas mixed with acrylic powder as general conventional method. One hundred and seventy five specimens wereprepared for this study. fifty bar shapes specimens (80mm x 10mm X 4mm) for impact strength test, another fiftydumbbell shaped specimens (75mm × 12.75mm × 2.5mm ) were prepared for tensile strength test. On the otherhand, seventy five disc shaped specimens (50mm diameter and 0.5mm thickness) were prepared for color stabilitytest. They were divided into two groups according to the nanofillers used ; silanated and non-silanated ZrO2nanofillers, for each group Three subgroups were prepared (one control and two(3% and 5%) for the silanated andnon-silanated ZrO2 nano-fillers. Impact strength test was carried out with charpy type impact testing instrument. Whiletensile strength test were done by using Jain Qiao equipment system. . On the other hand, color stability wasobjectively assessed by using a spectrophotometer device after 48 hours immersion in three different solutions(distilled water, cola and tea) and the amount of light absorption was calculated. Impact and tensile strengthmeans (in MPa) and color stability means (in nm) were analyzed statistically by analysis of variance and thecomparative T-test and least significance test (LSD).Result: Significant increase in impact strength occur in acrylic reinforced with 5% wt silanated (ZrO2) nanofillers , butnon significant increase was observed at 5% wt non-silanated (ZrO2) nanofillers when compared with control group.On the other hand, there were non-significant improvements in the tensile strength for all groups of (ZrO2)reinforcements. While for the color stability test data showed significant increase in the light absorptions forspecimens reinforced with (ZrO2) nanofillers when compared with control group. on the other hand, there were nosignificant difference observed between specimens reinforced with non-silanated and silanated (ZrO2) nanofillers.Conclusion: the findings of this study showed that Silanaized ZrO2 nano-fillers is effective in improving impact strengthwhile it was not effective in improving the tensile strength, the maximum increase in impact strength was observed indenture base nano composite containing 5% wt of silanated ZrO2 nano-fillers. On the other hand, significant colordifferences were detected between control group and specimens incorporated with zirconium oxide nano-fillers atdifferent immersion solutions


Article
The effect of thermocycling and different pH of artificial saliva on the impact and transverse strength of heat cure resin reinforced with silanated ZrO2 nano-fillers

Author: Rola W. Abdul-Razaq رولا وليد عبد الرزاق
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2013 Volume: 25 Issue: special issue 1 Pages: 12-17
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The aim of this study was to evaluate the effect of thermo cycling and different pH of artificial saliva(neutral, acidic, basic) on impact and transverse strength of heat cure acrylic resin reinforced of with 5% silanatedZrO2 nano fillers.Materials and methods: 120 samples were prepared, 60 samples for impact strength test and another 60 samples fortransverse strength test, for each test, samples were divided into two major groups (before and after thermo cycling),then each of these major groups were further subdivided into 3 subgroups according to the pH of prepared artificialsaliva (neutral, acidic, basic). Charpy impact device was used for impact strength test and Flexural device was usedfor transverse strength test.Result: There was a non-significant difference between the two major groups (before and after thermo cycling). Alsoresults showed that there was a non-significant difference between the subgroups for each major group in referenceto pH of artificial saliva. These results were found in both impact and transverse strength.Conclusion Transverse strength and impact strength of heat cure acrylic resin reinforced with silanated ZrO2nanofillers was not affected by thermocycling and different PH of artificial saliva suggesting improvement in themechanical properties

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