Showing 4 results for R. Bagheri
M. A. Golozar and R. Bagheri,
Volume 19, Issue 1 (7-2000)
Abstract
In this paper
, the effect of curing time and temperature as well as various primers on durability of high density polyethylene on plain carbon steel have been investigated. The aim is to increase adhesion, improve durability and also to produce a defect-free in order to improve the corrosion resistance of steel substrate. For this purpose, after surface preparation and applying a primer (zinc phosphate, polyvinylalcohol, resol, stearic acid, and polyurethane) polymer coating was applied using electrostatic powder coating system. Coatings having 300 µ thickness were produced and then subjected to primary and secondary curing treatments. In addition to adhesion, ductility, and corrosion tests, quality of coatings were studied using scanning electron microscopy. The results obtained revealed that, surface porosity and uniformity of metal/coating interface is a function of curing time and temperature, as well as of the primers used. The best results obtained after curing for 45 min at 230˚C. The effects of primers were as following: no primers
R. Bagheri and M.a. Golozar,
Volume 25, Issue 2 (1-2007)
Abstract
Using Electrostatic Spray Coating Technique, Polypropylene Powder (EPD 60R) was applied on carbon steel substrates at room temperature. In order to obtain a uniform coating, steel substrates with powder coatings were heated in a vacuum oven at various temperatures up to 250° C for various periods of time up to 45 min and a pressure of 200 mb. The coatings produced had thicknesses of around 470 microns. In order to modify the chemical structure of this polymer, the powder coatings containing various weight percentages of maleic (anhydride (MA) and a peroxide (TBHP or DCP) were also applied onto the steel substrates under the above conditions. Adhesion strength, wear resistance, and ductility of polymer coatings produced were assessed using ASTM standard methods. Results obtained revealed that the polymer coating containing 5 wt%. MA and 0.1 wt% TBHP had the best mechanical properties. Adhesive strength and wear resistance of this coating were 14.3 kgf and 250.3 cm, at 6 kgf, respectively, under the applied load of 6kg. Results obtained from DSC thermographs and IR Spectroscopy also proved the chemical bond formation (grafting) between the polymer and MA. The mechanical properties of coatings on steel substrate stem from such graftings.
H. Khabbazi, R. Bagheri, and M.a Golozar,
Volume 26, Issue 1 (7-2007)
Abstract
Polypropylene (PP) has poor adhesion to metals and other surfaces for its chemical structure. Hence, chemical modification of PP is necessary for metal surface coating application. In this research, grafting of maleic anhydride (MA) onto co(propylene-b-ethylene) in the presence of a dicumyl peroxide (DCP) was accomplished in a single screw extruder. Characteristics of the modified polymer were determined by Infra-red Spectroscopy (IR), Scanning Electron Microscopy (SEM), and adhesion test. Maximum grafting of MA was found to be 1.2832% for 1.5 pph of MA. Adhesion test showed that the samples containing 1 pph of MA (degree of grafting is 0.5816%) had better adhesion to steel surface (17.25 kgf).
A.r. Bagheri and S. Hashemi,
Volume 26, Issue 2 (1-2008)
Abstract
