Fawzia F. Abdel‐Mohsen and Mohamed A. Radwan
Fire retardant alkyd resins modified with dehydrated caster oil were prepared directly without going though the alcoholysis step. The method is based upon dehydrating castor oil…
Abstract
Fire retardant alkyd resins modified with dehydrated caster oil were prepared directly without going though the alcoholysis step. The method is based upon dehydrating castor oil with trimellitic anhydride. The oil thus produced contains sufficient combined carboxyl groups capable of polyesterifications with triols and glycerol or chlorinated monocyclic acetal and glycerol, and the macro‐structure is completed by further reaction with PA or chlorendic anhydride to obtain flame retardant resins. Melamine formaldhyde resin have been used in combination with the previous alkyd resins to improve hardness and also fire retardancy.
Fawzia F. Abdel‐Mohsen and Mohamed A. Radwan
Fire retardant oil‐modified alkyd resin based on chlorendic ahnydride (1,4,5,6,7 7‐hexachlorobicyclo‐(2,2,1) hept‐5‐ene‐2,3‐dicarboxylic anhydride) have been synthesized using…
Abstract
Fire retardant oil‐modified alkyd resin based on chlorendic ahnydride (1,4,5,6,7 7‐hexachlorobicyclo‐(2,2,1) hept‐5‐ene‐2,3‐dicarboxylic anhydride) have been synthesized using linseed oil, phthalic anhydride and glycerol. Several paint formulations were designed to study the effect of pigment/binder ratio, antimony trioxide and chlorinated thermosetting and thermoplastic polymers on fire retardancy. Oxygen index method was used to evaluate the fire retardancy of paints. The chlorinated alkyd resin was used as a plasticizer for laroflex MP 35 to improve the fire retardancy of the thermoplastic chlorinated polymer.
Saad Amin Fam and Fawzia F. Abdel‐Mohsen
A petroleum fraction having a boiling range 200–250°C (kerosene), free from aromatic and n‐paraffin hydrocarbons was oxidised by bubbling air at 130–150°C, at normal pressure, in…
Abstract
A petroleum fraction having a boiling range 200–250°C (kerosene), free from aromatic and n‐paraffin hydrocarbons was oxidised by bubbling air at 130–150°C, at normal pressure, in the presence of cobalt naphthenate as a catalyst. Optimum yield of oxynaphthenic acid was obtained after sixteen hours and thirty minutes oxidation at 140°C. Two layers were formed, the bottom product was a viscous liquid insoluble in petroleum ether and alcohols. Oxyacids, mainly hydroxy naphthenic acids, were obtained after treatment and purification of the viscous liquid.
Fawzia Fahim Abdel-Mohsen and Hassan Salah Aly Emira
– The purpose of this study was to prepare colour pigments for use as spectrally selective coatings for solar absorbers.
Abstract
Purpose
The purpose of this study was to prepare colour pigments for use as spectrally selective coatings for solar absorbers.
Design/methodology/approach
Nano-particles cobalt and nickel oxides were prepared by sol–gel techniques. These oxides were prepared with its molar ratios and annealed at 200, 400, 600 and 800°C. The structure of the pigments was characterized by infrared spectrometer, differential scanning calorimetry analysis, X-ray diffraction, transmission electron microscope and scanning electron microscope.
Findings
Encapsulated cobalt and nickel oxides were completely formed at 800 and 600°C, and its colour was black and dark green, respectively. The results confirmed that black and green pigments combined selectivity with colour. Optical properties such as absorption and reflection were affected by the firing temperatures on cobalt and nickel oxides–gel polymers. All synthesized pigments consisted of nano-particles.
Research limitations/implications
The prepared samples used in the present work were synthesized from cobalt chloride and nickel acetate. The salts were dispersed in polyacrylamide as a precursor.
Practical implications
The prepared metal oxides had good solar properties.
Originality/value
Colour becomes more important for thermal solar collectors, and it has attracted interest. This might be related to a generally growing attention towards architectural integration of solar energy systems into building. Architects would prefer different colours besides black, even if lower efficiency would have to be accepted.
Details
Keywords
Fawzia Fahim Abdel‐Mohsen and Hassan Salah Aly Emira
This work aimed to prepare black transition metal oxide pigments to be used as solar absorbers in the solar selective and other industrial paints.
Abstract
Purpose
This work aimed to prepare black transition metal oxide pigments to be used as solar absorbers in the solar selective and other industrial paints.
Design/methodology/approach
Mixed metal oxide CoCuMnOx spinel pigments were synthesised via the sol‐gel route. These oxides, namely (I‐Co0.50Cu0.25Mn0.25)Ox, (II‐Co0.25Cu0.50Mn0.25)Ox and (III‐Co0.25Cu0.25Mn0.50)Ox, were prepared with different molar ratios and annealed at 600, 800 and 900°C, respectively. The prepared oxides were characterised by infrared spectrometer (IS), differential scanning calorimetry analysis (DSC), X‐ray diffraction (XRD) and transmission electron microscope (TEM).
Findings
The prepared pigments have a spinel structure with the composition CoCuMnOx. All synthesised pigments consisted of nano particles ranged from 10 to 80 nm. The optical properties showed high absorption and moderately low reflectance in the solar wavelength range.
Research limitations/implications
The prepared samples, used in the present work, were synthesized from cobalt sulphate, copper chloride and manganese chloride. The salts were dispersed in polyacrylamide as a precursor.
Practical implications
The prepared samples were thermally stable and had good optical properties. They could be used as absorber materials in the painting of solar collectors.
Originality/value
These thermally stable mixed metal oxides could be used in the painting of solar collectors. The three mixed metal oxides could be used as absorber materials for heating solar collectors due to their high absorption and moderately low reflectance in the solar wavelength range.