Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Epoxy

Flexural Properties of Functionally Graded Polymer Alumina Nanoparticles

Mahdi M. S. Shareef; Ahmed N. Al-Khazraji; Samir A. Amin

Engineering and Technology Journal, 2021, Volume 39, Issue 5A, Pages 821-835
DOI: 10.30684/etj.v39i5A.1949

In this paper, a functionally graded polymer nanocomposite (FGPNC) was arranged via mixing the Alumina (Al2O3) nanoparticles (50 – 100 nm) with an epoxy matrix through five layers of 1.2 mm thickness for each layer using hand lay–up technique. Different volume fractions were taken (0, 1, 2, 3 and 4) % of the used nanoparticles and were cast in molds made from acrylic for creating the graded composite sheet in the thickness direction. The prepared isotropic specimen was tested by tensile and compressive test. The results showed that the (4% Vf of Al2O3) has the best enhancement of the ultimate tensile strength (85.25% from neat epoxy) and decreased thereafter. Flexural properties of three different types of functionally graded materials (FGMs), including FGM1, FGM2 and FGM3, isotropic nanocomposite (2% Al2O3) and pristine epoxy were obtained. Flexural strength and flexural modulus of the functionally graded polymer nanocomposite for each type of FGMs enhanced by (51.7%) and (67%), respectively for the FGM1 loaded from the neat epoxy side, whereas for the FGM1 loaded from the (4%) side, the improvement in these properties was (17.8%) and (29.4%), correspondingly over those for the neat epoxy. For FGM2, the improvement in the flexural strength was (27%) and (71.8%) for the flexural modulus as compared with pristine epoxy. The enhancement in the flexural strength of FGM3 was (27%) and flexural modulus (57.7%). Design Modeler (ANSYS Workbench) was used to verify the experimental flexural test results. A very good agreement was found between the experimental and numerical results with a maximum error of (3.92%) in the flexural modulus for FGM1 loaded from the composite side.

Flexural and Impact Properties of Epoxy Composites Reinforced with Peanut Shell Particles

Hwazen Fadhil

Engineering and Technology Journal, 2020, Volume 38, Issue 7, Pages 1026-1033
DOI: 10.30684/etj.v38i7A.584

Natural materials have been extensively used as reinforcements in polymer matrices instead of non-degradable synthetic reinforcement such as carbon, glass or aramid. The use is because of their low density, good mechanical properties, availability, and biodegradability. Peanut shell is one such natural waste filler used, and it contains cellulose, hemicellulose, and lignin. Natural fiber/particle sources are not only strong and lightweight but are relatively very cheap. This paper offers the comparison of the flexural, and impact energy test properties of the peanut shell reinforced with the epoxy resin matrix. Peanut shells add into the epoxy resin matrix with various weight fractions (2%, 4%, 6%, and 8%) and have been fabricated by hand lay-up procedure. Flexural strength and flexural modulus changed from (140MPa) to (160 MPa), and from (2 GPa) to (7.79 GPa) respectively, impact strength, and fracture toughness changed from (2.5 KJ/m2) to (7 KJ/m2), and from (2.23 MPa.m1/2) to (7.07 MPa.m1/2), respectively as a function of the particle weight fraction. The highest flexural strength and modulus obtained samples (reinforced 4% wt. peanut shell), while samples (reinforced +8% wt. peanut shell) provided the highest impact strength and fracture toughness.

Effect of Natural Fibers on Mechanical Properties of Polymer Composites

Ruaa H. AbdulRaheem

Engineering and Technology Journal, 2018, Volume 36, Issue 10A, Pages 1059-1067
DOI: 10.30684/etj.36.10A.6

The mechanical behavior of coconut shell (CS) particulate epoxy composites was concentrated on keeping in mind the end goal to create designing materials for modern application. Minute of the support with various weight portions (5, 10, 15, 20 and 25) wt%. Epoxy and composite materials were prepared by hand lay-up molding. The physical properties are thermal conductivity while the mechanical properties were hardness, tensile properties, impact properties, and flexural strength. The resulting composites of thermal conductivity 0.1005 W∕ m.c° that is lower than pure epoxy and commonplace materials utilized for home-structures. As for the mechanical properties, composite materials with (Epoxy+25%CS) has the maximum hardness of (76.6) shore D, The ultimate tensile strength of 33.42MPa was obtained from (Epoxy+25%CS), while the elongation at fracture with addition in filler concentration of 1.50 % was obtained from (Epoxy+25%CS) is lower than other composites. The highest impact strength, fracture toughness was 80J∕m2, 12.87 MPa.m-1/2 respectively. Flexural strength & shear stress of the composite materials with addition in reinforcement content at 5wt % &10wt% (39, 40.5)Mpa & (1.95,2.03)Mpa respectively while is other composites.

Study On the Flexural and Impact Properties of Short Okra Natural Fiber Reinforced Epoxy Matrix Composites

Aseel Mahmood Abdullah; Ahmed Mudhafar Hashim

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1696-1706

The okra natural fiber reinforced epoxy matrix composites were prepared by
hand-lay-up. The weight fractions of okra fiber are (1, 3, 6, 9, and 12% by weight
wt). The flexural properties and impact resistance of composites were determined
by the flexural and impact tests. The maximum modulus of elasticity is (844.93
MPa) at the weight fraction of (12 % wt) of okra fiber, comparison with (91.25
MPa) for virgin epoxy material. The maximum impact energy is (0.75 J) at the
weight fraction of I(12 % wt) of okra fiber, comparison with (0.05 J) for virgin
epoxy material.

Mechanical Properties For Pipes Made From Composite Materials (Glass/ Epoxy And Carbon/ Epoxy) Subjected To Internal Pressure

Zainab K. Hantoosh; Hatam Kareem Kadhom; Aseel Jasim Mohammed

Engineering and Technology Journal, 2012, Volume 30, Issue 6, Pages 117-134

Composite Materials have been used extensively in application such as pipes and pressure vessels. Therefore it is important for further studies on the properties of these materials. This paper presents the results from a series of tensile tests on the mechanical properties of composite materials. Specimens cut from pipes made from composite materials were tested under internal pressure loadings have been tested by using a series of ASTM Standards test methods for mechanical properties. Based on the results obtained, the longitudinal E11,
transverse E22 and shear modulus G12 of 101.2 GPa, 5.718 GPa, 4.346 GPa and 36.6, 5.4 GPa, 4.085 GPa for carbon and glass fiber/ epoxy composites, respectively, while the ultimate longitudinal XL, transverse XT and shear tensile τ0 strengths of 1475.4 MPa, 20 MPa, 36 MPa and 618.9 MPa, 14 MPa, 28 MPa for carbon and glass fiber/epoxy composites, respectively. The results from this series of tests have been presented and compared with results from analytical equations. Good agreement was achieved between the experimental results and
analytical results.

Studying the Effect of Water on Electrical Conductivity of Cu Powder Reinforced Epoxy Composite Material

Nirvana A. Abd Alameer

Engineering and Technology Journal, 2012, Volume 30, Issue 2, Pages 197-202

We study electrical conductivity behavior of Cu-powder reinforced epoxy
composite material in different solutions (distilled water, tap water &3.5%NaCl)
with a weight fraction (5, 15, 30 &45) was investigated for (7) weeks immersion
time. The results exhibit that electrical conductivity increases as increasing
immersion time due to the specimen was absorbed the solutions. The maximum
values were reached with 3.5% NaCl solution because of Cl ions whereas electrical
conductivity not apparent in distilled water was attributed to pure water containing
no ions is an excellent insulator.

Studying the Effect of Chemical Solutions on Bending Behavior of Epoxy Reinforced With CDs Waste

Nervana A. Abd Alameer

Engineering and Technology Journal, 2011, Volume 29, Issue 14, Pages 2926-2932

The aim of this study is the effect of salt, acid and base solutions on bending behavior of CDs reinforced epoxy. Epoxy resin matrix is reinforced with weight fraction 15, 30&45 % chopped chips CDs waste. The experimental results indicate that the composites materials have higher flexural stiffness than the matrix material where the young modulus of epoxy is improved from 2.6GPa for matrix to 3.936 GPa
reinforced with 45% CDs that is 60% increasing, due to CDs were more contact which have high flexural stiffness. The test solutions chosen were 10 % NaCl, NaOH & H2SO4. The results indicate that the 45% CDs reinforced epoxy chosen is good chemical resistant to NaCl and NaOH whereas flexural stiffness changes are relatively for each examination time, while the maximum flexural stiffness occurred in H2SO4 solution was approximately -10% for 8 week due to epoxy is less resistant
to sulfuric acid.

Preparation Of High Efficient (Epoxy/Plants Coal/Alumina) Primers Applied To Concrete Petroleum Tanks

Nagham H.Abood; Alyaa E; Raghad O. Abas; Falak O.Abas

Engineering and Technology Journal, 2010, Volume 28, Issue 22, Pages 6546-6556

Very little work has been reported on the influence of exposure to
petroleum products on the chemical resistance of concrete. The work presented in this paper deals with the fundamental aspects of this problem. Therefore different chemical solutions are used to study the chemical effect on this type of tanks that used in petroleum storage.
The effect of different additive fillers are used in prepared primer and are studied for different exposure media (moisture, 10% H2SO4, Oil) during 28 day residue time at 50 oc, and measure the penetration and chemical resistance of these samples. Two types of filler are used organic (charcoal 30 m particle size), and in organic (alumina 100 m particle size) to improve the chemical resistance of the prepared epoxy primer at different mixing ratio (st.s, Ch 1.2, 2.4, 3.6, A 1.2, 2.4, 3.6) respectively. A comparative analysis shows that high chemical resistance appeared for alumina samples than charcoal especially for optimum mixing ratio (2.4 Ep. / additives). Less effect of thickness on chemical properties appeared for standard sample and large effect of thickness for charcoal and alumina samples with preference for
alumina especially at optimum thickness ( 2mm ) for alumina and ( 3 mm) for charcoal samples with 2% comparison effect of thickness.
Also less effect of both moisture and oil compared to high effect of acidic solution (10% H2SO4 ) on the prepared samples with clear appearance to charcoal at 3 mm thickness and 1 mm for alumina.

Electrical And Thermal Properties Of Epoxy Resin Filled With Carbon Black

Waffa Abdul Kazem; Najat j. Salah; Adnan A. Abdul Razak

Engineering and Technology Journal, 2009, Volume 27, Issue 11, Pages 2223-2232

Thermal and electrical conductivity of an insulating polymer can be achieved by
dispersing conducting particles (e.g., metal, carbon black) in the polymer. The resulting materials
are referred to as conducting polymer composites. Electrical and thermal properties of epoxycarbon
black composites were studied in this work. The weight fraction of the carbon blacks
ranged from 0.0 up to 20 wt % with the epoxy resin. By discharging a high voltage through the
composite it was found that the resistivity of the composite decreased. Epoxy-carbon black
composites show significant differences from the neat epoxy resin measured in the frequency
range. Conductivity percolation threshold was found when carbon blacks is added in the range of
1 and 2 wt%. It was found that the epoxy/ carbon black composites have better thermal properties
than the neat epoxy.