Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Rheology

The Rheological Properties of Isothermal Curing of DGEBA/ TETA Epoxy System

Adnan A. Abdul Razak; Najat j. Saleh; Maryem Emad

Engineering and Technology Journal, 2015, Volume 33, Issue 5, Pages 1095-1112

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.

Study the Influence of Poly Vinyl Acetate on Flow Behavior of Bentonite Dispersions in Water

Saad R. Sultan

Engineering and Technology Journal, 2009, Volume 27, Issue 4, Pages 799-808

The present investigation is concerned to study the influence of poly vinyl
acetate (PVAc.) on flow behavior of bentonite dispersions in water, poly vinyl acetate
was added to the bentonite dispersion in different concentration (5, 7.5, 10, 12.5, 15, 17.5
and 20) gm/l. after that, the flow properties of these samples was measured and that
included (viscosity, shear stress, shear rate and Bingham yield value), The results show
thixotropy flow by a hysteresis loop of the flow curves for bentonite dispersion with and
without poly vinyl acetate, but with (PVAc.) give higher fluidity flow.
Also the morphology of bentonite dispersions was analyzed before and after adding
poly vinyl acetate by scanning electron micrograph (SEM), it is show that a weak
association between (PVAc.) and bentonite dispersions.