Search results

1 – 10 of 28
To view the access options for this content please click here
Article
Publication date: 30 August 2013

Hassan Salah Aly Emira, Yosreya Mostafa Abu‐Ayana and Sanaa Mohammad El‐Sawy

The purpose of this paper is to study the corrosion protective properties of modified urea and/or thiourea formaldehyde resins for steel surface.

Abstract

Purpose

The purpose of this paper is to study the corrosion protective properties of modified urea and/or thiourea formaldehyde resins for steel surface.

Design/methodology/approach

Three butyl alcohol modified amino resins were laboratory prepared. The three modified resins were characterized using thermal gravimetric analysis and infrared; the solid content and refractive index of each were also measured.

Findings

The resins that contain both nitrogen and sulphur have excellent corrosion inhibitive activity compared with that containing nitrogen only.

Research limitations/implications

The modified resins were based on urea formaldehyde resin, mixed urea and thiourea formaldehyde resin and thiourea formaldehyde resin, respectively.

Practical implications

The prepared resins were introduced in different coating formulations based on short‐oil alkyd resin, medium‐oil alkyd resin and plasticized chlorinated rubber. They were then tested and evaluated for corrosion protection of steel surfaces.

Originality/value

All the prepared resins show promising results for corrosion protection of steel surfaces.

Details

Pigment & Resin Technology, vol. 42 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

To view the access options for this content please click here
Article
Publication date: 1 May 1978

R.A. Ellis

The interaction between formaldehyde and urea or thiourea has been reported by Richard and Gourdenne who used G.P.C. columns packed with reticular polystyrene gel of pore…

Abstract

The interaction between formaldehyde and urea or thiourea has been reported by Richard and Gourdenne who used G.P.C. columns packed with reticular polystyrene gel of pore sizes 3×104, 3×103, 103, 500, 200, 100, 60 and 60 A and which were eluted with N, N‐dimethylformamide at 50°C. These authors prepared precursors such as monomethylolurea and N, N‐dimethylolurea in aqueous base at 4°C which prevented their autocondensation. These materials were positively identified by proton nuclear magnetic resonance spectroscopy, but they were not resolved from one another nor from urea itself on the G.P.C. columns on account of the fact that the strong solvation by the eluent dimethyl‐formamide was not affected by the substitution of one or two methylol groups into the urea molecule. Using an acid solution at room temperature, it was found that the reaction between formaldehyde and urea or disubstituted urea produced substances such as methylene diurea and methylene di (N, N‐dimethylurea) which, respectively, eluted before and after urea itself. When urea or thiourea was reacted with formaldehyde at a molar ratio of 1:1.8 in a 30% aqueous solution of pH 8 at 95°C, it was shown by nuclear magnetic resonance spectroscopy that the individual urea residues were linked by ether bridges only and that methylenic linkages were totally absent. The degree of cross‐linking of the products was expressed in terms of the ratio of the number of protons included in these bridges to the total number of protons in the various methylene groups as determined by nuclear magnetic resonance spectroscopy. Five samples were taken from such a reaction between urea and formaldehyde. Their G.P.C. curves were obtained and they were shown to display a wider molecular size distribution as the calculated degree of cross‐linking increased. The initial sample was found to be comprised of a mixture of mono‐ and dimethylolurea, but the samples taken later on during the reaction were more highly polymerised and could not be assigned individual molecular structures. A similar conclusion was reached using a mixture of thiourea and formaldehyde in the preparation of a resin.

Details

Pigment & Resin Technology, vol. 7 no. 5
Type: Research Article
ISSN: 0369-9420

To view the access options for this content please click here
Article
Publication date: 1 October 1970

M.E. Roper

For many years zinc has been used for the protection and decoration of iron and steel sheet and manufactured goods; with the method of application taking into account such…

Abstract

For many years zinc has been used for the protection and decoration of iron and steel sheet and manufactured goods; with the method of application taking into account such factors as service requirements, economics, and convenience of application. Among the most widely adopted methods have been galvanizing (immersion in molten zinc or zinc alloys), zinc spraying, peen plating, vapour diffusion (Sheradizing), and electroplating.

Details

Anti-Corrosion Methods and Materials, vol. 17 no. 10
Type: Research Article
ISSN: 0003-5599

To view the access options for this content please click here
Article
Publication date: 1 February 2003

A.A. Mahmoud, A.M.F. Eissa, M.S. Omar, A.A. El‐Sawy and A.F. Shaaban

White pine wood was impregnated with a mixture of methyl methacrylate (MMA) and N‐methacryloyloxyphthalimide and by other three mixtures prepared by mixing MMA and N

Abstract

White pine wood was impregnated with a mixture of methyl methacrylate (MMA) and N‐methacryloyloxyphthalimide and by other three mixtures prepared by mixing MMA and N‐methacryloyloxytetrabromo‐phthalimide. Water uptake of treated wood was found to be 54 per cent after water‐soaking test of 168 h and maximum antiswell efficiency was found to be 48 per cent for treated wood samples with non‐brominated comonomer mixture.

Details

Pigment & Resin Technology, vol. 32 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

To view the access options for this content please click here
Article
Publication date: 1 July 1968

M.N. Desai, G.H. Thanki and M.H. Gandhi

Organic compounds containing sulphur, nitrogen and oxygen atoms are capable of retarding metallic corrosion. As the thiourea molecule contains one sulphur and two nitrogen…

Abstract

Organic compounds containing sulphur, nitrogen and oxygen atoms are capable of retarding metallic corrosion. As the thiourea molecule contains one sulphur and two nitrogen atoms, thiourea and its derivatives are potential corrosion inhibitors. While extensive investigations have been carried out on inhibitor properties of thiourea, due attention has not yet been paid to a systematic study of inhibitor action of thiourea derivatives. However, several substituted thioureas have been investigated as corrosion inhibitors. The applications of thiourea and its derivatives as corrosion inhibitors reported in literature up to 1967 are narrated in this article.

Details

Anti-Corrosion Methods and Materials, vol. 15 no. 7
Type: Research Article
ISSN: 0003-5599

To view the access options for this content please click here
Article
Publication date: 1 May 2007

M.K. Zahran, R.I. Mahmoud and M.H. El Rafie

Polyacrylamid-guar gum composite has been prepared via graft copolymerization of acrylamide onto guar gum using the KBrO3/ thiourea redox system. The amide groups (40%) in…

Abstract

Polyacrylamid-guar gum composite has been prepared via graft copolymerization of acrylamide onto guar gum using the KBrO3/ thiourea redox system. The amide groups (40%) in the composite are converted to reactive groups through methylolation with formaldehyde, with a view to obtaining reactive composite. The composite and the reactive composite were used as pastes for printing cotton fabrics with pigment dyes. The prints were assessed for color strength (K/S) and overall fastness properties.

Printing was carried out under different conditions, including the amount of composite used as a substitute for kerosene emulsion, the amount of binder incorporated into the printing paste and the types of catalysts. The printed samples were evaluated by monitoring the color strength (K/S) and fastness properties such as washing, rubbing and light. Based on the results obtained, it is concluded that a partial substitution ratio of 20/75 (composite/kerosene emulsion), 8gm binder/100gm printing paste and 1% of catalyst (NH4Cl, DAP, Citric acid or [NH4]2SO4) represent the proper formulation for gaining good dye fixation and excellent fastness properties. The results indicate that the reactive composite prepared is the most suitable thickener for printing cellulosic fabrics with pigment dyes.

Details

Research Journal of Textile and Apparel, vol. 11 no. 2
Type: Research Article
ISSN: 1560-6074

Keywords

To view the access options for this content please click here
Article
Publication date: 1 May 1971

M.N. Desai, S.M. Desai, M.H. Gandhi and C.B. Shah

This concluding part reviews the actions of inhibitors to acidic, ammonical, organic, atmospheric and miscellaneous product corrosion on aluminium. The comprehensive…

Abstract

This concluding part reviews the actions of inhibitors to acidic, ammonical, organic, atmospheric and miscellaneous product corrosion on aluminium. The comprehensive reference list is also concluded.

Details

Anti-Corrosion Methods and Materials, vol. 18 no. 5
Type: Research Article
ISSN: 0003-5599

To view the access options for this content please click here
Article
Publication date: 1 January 1996

F.F. Abd El Mohsen, R.M. Mohsen and Y.M. Abu Ayana

Modern glues are manufactured with high moisture and water resistance; urea‐formaldehyde resins for gluing purposes are based on the fact that excellent control of the…

Abstract

Modern glues are manufactured with high moisture and water resistance; urea‐formaldehyde resins for gluing purposes are based on the fact that excellent control of the condensation reaction is possible by variation of pH, which can be applied easily at the production process. Among conclusions is that the shear stress of these resins is twice that of the unmodified type.

Details

Pigment & Resin Technology, vol. 25 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

To view the access options for this content please click here
Article
Publication date: 1 December 1973

M.N. Desai, S.S. Rana and M.H. Gandhi

Zinc is one of the most important nonferrous metals and finds extensive use in metallic coatings. It is resistant to atmospheric attack and corrodes rapidly only in highly…

Abstract

Zinc is one of the most important nonferrous metals and finds extensive use in metallic coatings. It is resistant to atmospheric attack and corrodes rapidly only in highly polluted air. It is resistant to most fresh waters but its resistance to sea water and to very soft water is lower. In many aerated hot waters, reversal of polarity between zinc and iron occurs at temperatures of 60°C or above. The corrosion products of zinc are readily soluble both in alkalis and acids and protect the metal surface only in neutral media. In neutral solutions, zinc is corroded mainly by oxygen depolarisation. The dissolution rate of zinc in acids is greatly affected by the over‐potential of hydrogen evolution at cathodic inclusions.

Details

Anti-Corrosion Methods and Materials, vol. 20 no. 12
Type: Research Article
ISSN: 0003-5599

To view the access options for this content please click here
Article
Publication date: 14 March 2016

Rabab Amin and Amal El-Ebissy

The purpose of this study was to prepare partially methylolated polyacrylamide-guar gum via graft copolymerization of acryalmide and guar gum using the potassium bromate…

Abstract

Purpose

The purpose of this study was to prepare partially methylolated polyacrylamide-guar gum via graft copolymerization of acryalmide and guar gum using the potassium bromate/thiourea redox system.

Design/methodology/approach

Using HCHO (40 per cent), amide groups in the composite are converted to reactive composite. The reactive composites (N-methylolated [PAam-GG]) were used as pastes for printing cotton fabrics with pigment dye, under a variety of conditions. Variables studied include the amount of binder incorporated into the printing paste and different catalysts incorporated into the printing paste.

Originality/value

Characterization of printing samples under different conditions, including amount of the beneficial effects of varying conditions of printing on the color strength (K/S); the color parameters L, a, b, h and c; and the change in color difference (ΔE) were also investigated. The Fourier transforms infrared spectra of printed cotton fabrics has followed each condition of printing. The obtained results indicate that the improvement in the printing process may be due to change in molecular configuration as a result of the variation in chemical bond.

Details

Research Journal of Textile and Apparel, vol. 20 no. 1
Type: Research Article
ISSN: 1560-6074

Keywords

1 – 10 of 28