Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Silica


Effect of Silica Powder Addition on Mechanical Properties of Polymer Laminate Composite

F.A. Hashim; M.S. Hamza; R.R. Abdullah

Engineering and Technology Journal, 2017, Volume 35, Issue 7, Pages 737-740

In this study laminate composites were prepared, one was reinforced with three layers of kevlar fibers at (Vf = 17.89%) and the second was reinforced with hybrid laminate with sequence of layers (Kevlar-Glass-kevlar (KGK)) at (Vf = 15.3%), samples were tested before and after silica addition at volume fraction (3%). Tests were (tensile, flexural, impact, hardness, and optical microscope), hand lay-up technique used to prepare samples. Matrix was unsaturated polyester resin. Results showed that mechanical properties (tensile strength, flexural strength, and fracture toughness) decreased after silica addition from (190 MPa, 610 MPa, 35.6 MPa.m1/2 ) to (100.5 MPa, 212MPa, 27.7 MPa.m1/2 ) respectively for composite reinforced with three layers of Kevlar fibers at (Vf = 17.89%) and from (175.5 MPa, 387 MPa, 32.36 MPa.m1/2 ) to (67.6 MPa, 210 MPa, 23 MPa.m1/2 ) respectively for laminate composite with layers (Kevlar-Glass-Kevlar (KGK)) at (Vf = 15.3%). Hardness increased after addition of silica from (79.25 to 81.2) for composite with three layers of Kevlar fibers at (Vf = 17.89%) and from (80 to 82.3) for composite with layers (Kevlar-Glass-Kevlar (KGK)). Optical microscope showed that layers were distributed in matrix and addition of silica leads to delamination of composite after using flexural test.

Study some thermal properties for hybrid composite reinforced with particales

Ali Hassan R.Al-Azzawi; Balkees M. D.AL-Dabbagh; Sana Ali .j

Engineering and Technology Journal, 2015, Volume 33, Issue 7, Pages 1330-1336

In this work a hybrid composite materials were prepared containing matrix of polymer blend (Novolac 80% + Epoxy 20%) reinforced by different reinforcing materials (Alumina Powder (type α) + Silica Powder + Asbestos short fiber) with two values of volume fraction (30, 40) %.

The hybrid composite materials prepared are:
• H1 = Blend + Al2O3(α ) + AS (30) %
• H2 = Blend + SiO2 + AS (30) %
• H3 = Blend + Al2O3 (α ) + SiO2+ AS (30) %
• H4 = Blend + Al2O3(α ) + AS (40) %
• H5 = Blend + SiO2 + AS (40) %
• H6 = Blend + Al2O3(α ) + SiO2+ AS (40) %
All samples related to mechanical, thermal, electrical and physical tests were prepar by hand lay up process. The tests can be classifi into four groups: For the (H1) samples, there was high tendency to loose weight with high temperature and less as to the samples (H6).

A Study of Mechanical Properties of Polymethl Methacrylate Polymer Reinforced by Silica Particles (Sio2)

Jawad Kadhim Oleiwi; Farhad Mohammad O.Kushnaw; Israa Faisal qhaze

Engineering and Technology Journal, 2013, Volume 31, Issue 15, Pages 2925-2940

In this research the mechanical properties of PMMA polymer reinforced by
ceramic particles (silica) has been investigated. Many tests are performed on these
composites. The effects of the particles size and volume fraction on the mechanical
properties which include: ultimate tensile strength, elongation percentage, modulus
of elasticity, bending modulus, flexural strength, max. shear stress, impact strength
and fracture toughness were studied.
Statistical and mathematical analyses were used to the processing of the
experimental data. Mathematical models were done which show the mechanical
properties of composite materials as a function of particles size and volume
fraction.
The results had revealed that the values of modulus of elasticity, elongation
percentage, tensile strength, bending modulus and max. shear stress increase with
the addition of SiO2 particles and with the increase of the volume fraction of them
and its reach the maximum value at (12% vol.) and (25 mm) particles size. The
values of fracture toughness and impact energy decrease with increase of volume
fraction. Silica particles with small particles size improved these properties more
than that of large particles size.

Adsorption of Direct Yellow 4 Dye on the Silica Prepared from Locally Available Sodium Silicate

Sameer Hakeem Kareem; Manal Obeid Hamza

Engineering and Technology Journal, 2012, Volume 30, Issue 15, Pages 2609-2625

In this study the ability of removing direct yellow 4 dye (DY4) from aqueous solutions using silica as adsorbent was examined. The silica was prepared from locally available sodium silicate. The effect of various experimental parameters contact time, amount of silica used, pH, ionic strength and temperature were investigated in a batch adsorption technique. The obtained experimental data shows that, the adsorption of direct yellow 4 dye was increased directly with increasing concentration, amount of silica, added sodium chloride and temperature in optimum pH (7) and equilibrium time of 45 min. The kinetic data were analyzed through pseudo first-order, pseudo second-order and intraparticle diffusion models. The pseudo second-order model best represented adsorption kinetics. Additionally, this study used the Langmuir, Freundlich and Temkin isotherms to describe equilibrium adsorption and calculating thermodynamic values. The equilibrium adsorption of direct yellow 4 on silica is best fitted in the Langmuir isotherm (R2 =0.981).