ALBERT

Notizen: Purpose - To develop a method for the preparation of micaceous zinc ferrite (MZF), anticorrosive pigment having desirable chemical and physical properties. Design/methodology/approach - MZF pigment was prepared after firing the oxidised solid molten salts without washing. The MZF pigment obtained was characterised using X-ray diffraction analysis, crystal size analysis, scanning electron microscope and energy dispersive X-ray analysis. The pigment obtained was also evaluated chemically with respect to moisture content, content of water-soluble salts, hydrogen ion concentration (pH) and weight loss; and physically with respect to particle shape, colour, specific gravity and oil absorption. Commercially available micaceous iron oxide and zinc ferrite pigments were also characterised in comparison. Findings - A spinel, MZF pigment was prepared using relevant oxidised solid molten salts. The preparation produced a lamellar structure with a basic nature giving not only barrier protection but also chemical passivation of the substrate. Research limitations/implications - The anticorrosive properties of the pigments obtained could be evaluated using more conventional methods such as salt-spray test. Practical implications - The pigment prepared could be used as a highly efficient pigment for anticorrosion coating for steel. Originality/value - The method for the preparation of MZF pigment was novel. The pigment obtained could be used in various resin systems to produce anticorrosive paints for steel protection.

Notizen: Purpose - To evaluate the efficiency of complex esters as plasticizers in polyvinyl chloride plastisols and plasticates. Design/methodology/approach - Several poly(vinyl chloride) plastisols and plasticates were prepared with standard phthalate plasticizers and complex esters and were characterised using standard and laboratory methods. Findings - The use of mixtures of three new CE with standard phthalate plasticizers increased the physical, mechanical and electric characteristics of the resulting PVCPs and PVCPl. Research limitations/implications - The use of three new CE, obtained by esterification of dicarboxylic acids (adipic, sebacic, pelargonic), poly(ethylene glycol) and i-octanole, as plasticizers of poly(vinyl chloride) plastisols and plasticates was investigated. The use of CE based on other organic acids could be explored. Practical implications - The results confirmed the efficiency of plasticization of PVC by CE. Such a finding has significant industrial implication. Originality/value - Several findings are original and are of importance to relevant industry. The new CE with high molecular weights were effective plasticizers of PVC. The efficiency of the plasticizers depended on their chemical structure. The molecular weight of the CE had no influence on the compatibility of plasticizers and other components of the PVC plastisols and plasticates.

Notizen: Purpose - To prepare and characterise organotin polymers via a new synthetic route by exchange reactions of poly-N-acryloyloxy- and poly-N-methacryloyloxy-tetrabromophthalimide with hydroxy- and aminotri-n-butyltin benzoates. Design/methodology/approach - Preparation of N-acryloyloxytetrabromophthalimide (NATP) and N-methacryloyloxytetrabromophthalimide (NMTP) by the reaction of N-hydroxytetrabromo-phthalimide with acryloyl or methacryloyl chloride. The exchange reactions of the resulting polymers with amino and hydroxytri-n-butyltin benzoate were carried out. The structure of the resulting compounds was characterised. Findings - NATP and NMTP were prepared by the reaction of N-hydroxy-tetrabromophthalimide with acryloyl or methacryloyl chloride in the presence of TEA. The monomers prepared were easily polymerised. The exchange reactions of poly-NATP and poly-NMTP with amino and hydroxytri-n-butyltin benzoate were studied. The structure of the polymers and copolymers prepared was confirmed by tin analysis, IR and 1HNR spectroscopy. Research limitations/implications - The new monomer described in the present investigation may be useful for the preparation of organotin polymers by a new synthetic route. Also, the organotin polymers prepared had good film properties and were suitable for film formation. Practical implications - The method for the preparation of monomer is simple and the exchange reactions provide a simple and practical solution for preparation of some classes of organotin polymers and copolymers. Originality/value - The method of preparation of organotin polymers was novel and may be useful for preparation of other organotin polymers and copolymers.

Notizen: Purpose - Several solid solution combinations of aluminium oxide and iron oxide, for the preparation of a new pigment, were investigated to study the effect of aluminium oxide to iron oxide ratio on various properties of the resulting pigments. Design/methodology/approach - The conditions for the preparation of the pigments via solid solution interaction at 1,000°C had been estimated. Characterisation of three different combinations of aluminium oxide and iron oxide were carried out using spectroscopic methods of analysis via X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM and SEM). Also, evaluation of the pigments prepared, in terms of oil absorption, specific gravity, water-soluble matter, and pH, using international standard testing methods was performed. The pigments prepared were incorporated in anticorrosive paint formulations based on medium oil alkyd resin as a binder. The physico-mechanical properties of the relevant paint films were obtained, while their anticorrosive properties were assessed by tests in 3.5 per cent NaCl solution for 28 days. Findings - The results showed that the anticorrosive protection properties of the pigment prepared were better than their aluminium and iron counterparts. Research limitations/implications - The pigments prepared may be used in different applications other than paint formulations. As the concentration of iron oxide increases, the hardness and the anticorrosive protection performance of the paint film increase. As the concentration of aluminium increases, elasticity, impact resistance and ductility also increase. Application of different combinations of these pigments in paint films had been studied. However, investigation of the application of these pigments in other systems such as plastics could also be interesting. Practical implications - The pigments prepared can be used as reinforcing filler in different rubber and plastic composites, beside its ferro-magnetic properties. As the concentration of alumina increased, the reinforcing and magnetic effects decreased and vice versa. Originality/value - Iron oxide is an abundant ore in several world countries; it is an inorganic, environmentally friendly material, which exhibits good Moh's hardness. Adding aluminium oxide which is a very light element having a unique flaky structure to iron oxide gave a new pigment that can be used not only in paint formulations, but also in rubber and plastic composites as reinforcing fillers.

Notizen: Purpose - To evaluate the competing reaction of isocyanate with cellulose and water which can provide direction for further studies on bonding and curing reactions of isocyanate with wood. Design/methodology/approach - Two modern analytical techniques, Fourier transform infra-red (FTIR) and X-ray photoelectron spectroscopy (XPS), were used. The FTIR was used to identify the products of the reaction of phenyl isocyanate (PI) with alcohol, water, and cellulose; while the XPS was used to evaluate the proportions of isocyanate that reacted with water or cellulose when PI reacted with cellulose at different moisture contents (MCs), respectively. Findings - Methods for the IR identifications of reaction results of PI with n-propanol, water, and cellulose, in which the reactions of PI with water and PI with cellulose resulted in N,N'-diphenylurea and carbamate, respectively, were developed. It was discovered that the extent of reaction of isocyanate and cellulose decreased with increasing cellulose MC, and 92.98 per cent isocyanate reacted with water when 9.78 per cent MC was reached. It was confirmed that the products of the PI reaction were distributed mainly on the surface of the cellulose particles. Research limitations/implications - The study only focused on the reaction of PI. However, the industrial isocyanates, e.g. methylene diphenyl diisocyanate (MDI), polymerized methylene diphenyl diisocyanate (p-MDI) that have complexities in chemical structures and components, make analyses with FTIR and XPS impossible. Practical implications - The paper provides some instructive information about the isocyanate reaction that will help understanding the characteristics of isocyanate and guiding the design of technology bonding isocyanate to fibre, wood, etc. Originality/value - The application of FTIR and XPS for evaluating the reaction of isocyanate with cellulose having different MCs was novel and may be used as a reference for other relevant studies.

Notizen: Purpose - Preparation of new organotin polymers via a new synthetic route based on the exchange reactions of pentachlorophenyl acrylate or methacrylate with amino-tri-phenyltin benzoates or hydroxyl-tri-phenyltin benzoates. Design/methodology/approach - The pentachlorophenyl acrylate or methacrylate was prepared by polymerisation in solution with azobisisobutyrontrile as a free radical initiator. The polymers obtained were allowed to undergo exchange reactions with amino-tri-phenyltin benzoates or hydroxyl-tri-phenyltin benzoates. The structure of the polymers prepared was confirmed by IR spectroscopy. Films were prepared from purified organotin polymers solution on glass, PVC and tin plates. The release of tin compound from the films, when immersed in aqueous media, was assessed. The concentration of the released tin (ppm) was measured by atomic adsorption spectrophotometer. Findings - The new synthetic route was effective, the organotin polymers prepared had good film properties and the release of tin compounds increased with the content of tin in the organotin polymers. Research limitations/implications - The alkaline resistance of the polymeric films prepared needs improvement. Practical implications - The polymers prepared provide a family of effective polymeric fungicide useful for a number of applications including water sterilisation. Originality/value - The polymers prepared contained pendent triphenyltin moieties which slowly hydrolysed to give fungicidal and antifouling effects.

Notizen: Purpose - To evaluate the effects of different levels of quaternised pyrodextrin as wet-end and filler retention aid additives in papermaking. Design/methodology/approach - The pulp furnishes used in this study were a mixture of bleached rice straw pulp with bleached sulphite softwood pulp at a ratio of 60:40. The beaten pulps (never dried) were treated with different grades of modified starch (Pyrodextrins). The results obtained were compared with those of several commercial polymers, such as Accostrength®86, cationic starch and polyacrylamide. Findings - The results obtained from this study showed that addition of 0.3 percent of British Gum (BG) (Degree of Substitution at 0.058) grade pyrodextrin to the pulp slurry, especially in case of kaolin as paper filler gave the most significant improvement in paper properties as well as filler retention. The results obtained also showed that the filler retention and paper properties were better/higher for all pyrodextrins studied than those obtained from both Accostrength®86 and polyacrylamide. Research limitations/implications - Using quaternised pyrodextrins as wet-end additives and filler retention aids improved all mechanical properties of treated paper, except the brightness which decreased very slightly. Practical implications - The grade of pyrodextrins used in this work could be used to improve the physical and strength properties of paper sheets. Originality/value - Different types of pyrodextrin namely, Dexy-84 (D-84), Dexy-86 (D-86) and British Gum (BG) could be used as paper wet-end additives and filler retention aids in paper making processing.

Notizen: Purpose - To study the effect of inhibition of new bipyrazole derivatives on the corrosion of steel in HCl media at various temperatures. Design/methodology/approach - In this study, novel corrosion inhibitors, namely bipyrazoles were synthesised and tested as corrosion inhibitors for steel in 1?M HCl. The degree of corrosion was measured using various techniques including weight loss measurements, potentiodynamic polarisation, linear polarisation resistance (Rp) and impedance spectroscopy (EIS). Findings - It was found that 1,5,5'-trimethyl-1H,2'H-3,3'-bipyrazole (P1) gave the best inhibition effect. The inhibition efficiency increased with the concentration of P1 to attain 79 per cent at 10-3?M. Good agreement between the various methods explored was observed. Polarisation measurements also showed that P1 acted essentially as a cathodic inhibitor. The cathodic curves indicated that the reduction of proton at the steel surface was an activating mechanism. P1 adsorbed on the steel surface according to Frumkin adsorption model. Research limitations/implications - The synthesis route offers the possibility of other pyrazolic compounds to be tested in the future. Practical implications - The inhibitory efficiency of P1 increased with the increase of both the concentration and the temperature (in the 298-353?K range). As such, P1 can be used in chemical cleaning and pickling processes. Originality/value - The originality of this work is the synthesis of new inhibitors based on pyrazolic organic compounds.

Notizen: Purpose - To evaluate the efficiency of modifying flax fibre using copper ammonia solution for improved dyeability and to optimise the conditions of such a modification. Design/methodology/approach - Treatments of flax fibre using copper ammonia solution were carried out under various conditions, i.e. the compositions of the solution and the length of time for treatment. The dyeability, the dyeing colour depth, the tensile strength and the structure of the untreated and treated flax fibres were characterised. Findings - The modification of flax fabric using copper ammonia solution could improve the dyeability and the dyeing colour depth of the flax fabric. The treatment appeared to reduce the crystallinity and the orientation index of the flax fibre, which was the main cause to the improved dyeability and dyeing colour depth of the flax fabric. The optimum conditions for the treatment were as follows: concentration of Cu2+ at 20?g/L, Cu2+/NH3 ratio at 12?:?1 and time of treatment at 6?min. Research limitations/implications - Whilst effective in improving the dyeability of the flax fibre, the treatment led to a reduction in the tensile strength of the treated flax fabric. Practical implications - The method developed provided a simple and practical solution to improve the dyeability of flax fibre. Originality/value - The method for treatment of flax fibre was novel and could be used for industrial production process.

Notizen: Purpose - To prepare modified epoxy resins from resorcinol, cresol and phenol for improved adhesion and chemical resistance. To evaluate the properties of such modified epoxy resins. Design/methodology/approach - Epoxy novolac resins (ENRs) were synthesised by condensing epichlorohydrin with novolacs based on different types of substituted phenols for improving adhesion and chemical resistance. Various compositions were made by incorporating different proportions of polyamide resin. The chemical and adhesive strengths of the conventional epoxy and the modified epoxy resins were characterised. Findings - The modified ENR using substituted phenols showed significant enhancement of chemical and adhesive strengths over the conventional DGEBA resin. The modified ENR had an increased number of glycidyl groups (thus increased functionality) of resin, which was responsible for improved chemical and adhesive strengths over the conventional DGEBA resin. Research limitations/implications - The EPN resins used in the present context was synthesised from phenol, resorcinol and cresol and cured by polyamide resin of different amine values. Besides, it could be synthesised from phenolphthalein p-aminophenol and p-ter-butylcatachol, etc. Practical implications - The method developed provided a simple and practical solution to improving the adhesive and chemical resistance of cured epoxy phenol novolac resins. Originality/value - The method for enhanced adhesive and chemical resistance of cured epoxy was novel and could find numerous applications in surface coating and adhesive.

Notizen: Purpose - To investigate the effects of acetylation process as a chemical treatment method to improve the dimensional stability of wood, or as a pre-treatment step to enhance the dimensional stability of wood by impregnates. Design/methodology/approach - Esterification of two species of wood were carried out by vapour and liquid phase acetylation processes. With the vapour phase acetylation process, wood with different acetyl contents were obtained by changing the length of time of treatment. With the liquid phase acetylation, different acetyl content were obtained by changing the acetylating mixture or by activating wood with acetic acid for different periods of time and at different temperatures prior to the acetylation processes. The acetyl content and the conditions of impregnation improving the dimensional stability were modelled and optimised. The success of acetylation process for improving the affinity of wood towards the impregnation was also demonstrated. Findings - Vapour phase acetylation process was preferable over liquid phase acetylation for improving both water resistance and dimensional stability of wood species examined. Liquid acetylating of wood, as a pre-treatment step enhanced the effect of impregnates, especially the linseed oil to improve relevant wood properties. The greater improvement was obtained at 3?h impregnation time and 190°C curing temperature for 1?h. Research limitations/implications - Despite the success in improving the affinity of wood species to novolac by pre-acetylation, increasing the curing time and curing temperature led to deterioration of the water resistance and dimensional stability. Practical implications - Pre-acetylation of the wood provided a practical solution to rendering the natural wood greater water resistance property using commercial impregnates. Originality/value - The method for acetylation of wood prior to impregnation was novel and could be used for inhibiting wood against moisture absorption during storage.

Notizen: Purpose - The preparation and characterisation of new bioactive polymeric materials. Design/methodology/approach - New bioactive polysaccharide were prepared by grafting of acrylonitrile onto water soluble starch and then reacting with bioactive heterocyclic rings. The biological activity, against bacteria, of the materials prepared was studied. Findings - Some of the prepared bioactive materials show high disinfecting power against bacteria. Research limitations/implications - The bioactive materials were prepared by grafting acrylonitrile onto starch and then reacting the resulting material with cyanuric acid and 2-aminothiazole. Many other heterocyclic rings that contain tertiary nitrogen atom or amide nitrogen can also be used. Practical implications - The new bioactive materials prepared can be used for disinfecting purposes. Originality/value - Some of the materials prepared were used successfully in killing bacteria, as such, can be used as disinfecting materials.

Notizen: Purpose - To evaluate the photochromic performance of photochromic compounds in polymer matrices. Design/methodology/approach - The epoxy resin doped with photochromic fulgide were prepared and the effect of UV irradiation were studied using spectrophotometer. The reversible reaction was effected using white light. The effect of heat was also determined. Findings - A film of fulgide 1-E doped in epoxy polymer was irradiated with UV light (366?nm), the film turned pink. The later colour was switched back to the original colour when the film was irradiated with a white light. The photocoloration and photobleaching obeyed first order rate equations with rate constants being 4.19×10-3?s-1 and 2.86×10-2?s-1, respectively. It was found that the film showed a good fatigue resistance. Another film was preheated at 80°C for 1-4?h. No change in the UV absorption spectra of the film was observed. Similarly, the photocoloration and photobleaching of the annealed film showed first order rate equations with rate constants being 8.77×10-3?s-1 and 4.02×10-2s-1, respectively. Interestingly, the photocoloration and photobleaching reactions of the annealed film were faster than those of the non-annealed film. Research limitations/implications - The epoxy resin doped photochromic fulgides described in the present paper was prepared and studied. The principle of study established can be applied to any type of resin or to any type of photochromic compounds. Practical implications - The photochromic materials developed can be used for different applications, such as coatings and holography. Originality/value - The method developed may be used to enhance the performance of photochromic materials.

Notizen: Purpose - To evaluate the corrosion inhibition potential of Datura metel in acid medium on mild steel (MS) with a view to develop green corrosion inhibitors. Design/methodology/approach - Acid extract of the D. metel was studied for its corrosion inhibitive effect by electrochemical and weight loss methods. Using weight loss measurement data, an attempt has been made to probe the mechanism of inhibitive action by fitting adsorption isotherms. Findings - D. metel has been found to show significant corrosion inhibitive effect in acid medium on MS. Inhibition is through adsorption of the phytoconstituents on MS following Tempkin and Langmuir adsorption isotherms. The results of A.C. impedance and polarisation studies correlate well with the weight loss studies. Originality/value - The plant has been investigated for the first time for its corrosion inhibitive effect. The effect has been studied by proven methods. This green inhibitor can find use in the inhibition of corrosion in industries where MS is used as a material of choice for the fabrication of machinery.

Notizen: Purpose - Trials to develop environmentally friendly marine paints based on natural materials as replacement for copper and tin compounds for fouling and marine corrosion control. Design/methodology/approach - Green algae, tubeworms in dead powder form and garlic were used as natural anti-fouling components in the paints developed. Electrochemical technique was employed for testing the potential of both tubeworms and garlic in terms of inhibition of steel corrosion in seawater. Marine paint formulations containing each of the three selected natural materials were applied onto PVC and un-primed steel surface, which were immersed in natural seawater for the assessment of their anti-fouling and anti-corrosion properties. The results of visual assessment and seawater analysis were also used for such an evaluation. Findings - Tubeworms act as mixed type inhibitor while garlic affects the potential cathodic process of steel in seawater. Tubeworms-based paint, with 25 per cent in the dry paint film, could protect steel surface from marine corrosion up to 7 months. The paints containing algae and garlic, and the corresponding algae/garlic free paints, resisted slime film formation. Steel and PVC coated surfaces with paint containing algae showed the best anti-fouling potential within the prepared series. Research limitations\implications - The investigation only involved the application of the dead form of green algae and tubeworms as effective pigments in the developed paints. It is recommended that further research should focus on extracting and identifying the active components in each organism against fouling and marine corrosion. Practical implications - The paint formulations developed (containing 25 per cent by weight tubeworms in the paint film) could be used to protect un-primed steel surface against fouling and marine corrosion for a reasonably long duration. Originality/value - The application of one paint formulation on un-primed steel surface for its protection from both fouling and marine corrosion is novel. The electrochemical studies of steel in natural seawater in presence of tubeworms and garlic are original.

Notizen: Purpose - To investigate a new approach for the prevention of lignocellulosic composites based on agro-fibres (e.g. sugar-cane bagasse) from the emission of toxic formaldehyde. Design/methodology/approach - Five organic polymer containing nitrogen-urea formaldehyde (UF) adhesive systems were used as bonding agents for bagasse fibres. The environmental performance of the lignocellulosic composites prepared were evaluated in terms of the effect of the organic polymers on the percentage of free formaldehyde in the adhesive system and the adhesion properties (static bending and water resistance properties) of the composite produced, in comparison with that prepared from un-modified UF. The nitrogen content of the polymer and the amount of organic polymers incorporated in the adhesive system were optimised using the 3D response surface methodology and the multi-linear regression technique. Findings - All investigated organic polymers (crude PAM-g-starch, PAM-g-starch, PAM, CE-starch and Cm-starch) were found to enhance the performance of the UF-adhesive for producing environmentally friendly bagasse-composite, whereas the reduction of free-HCHO in UF-adhesive systems ranges from 26 to 100 percent. The performance of the composite produced exceeded the ANSI requirements for Grade H-3 particle-board. Research limitations/implications - Despite the success in improving the performance (mechanical properties and reduction of free-formaldehyde) of the UF-adhesive and agro-composites, the polymers needed to be incorporated at a high percentage (12-20 percent) resulting in reduced water resistance of the product. Further investigation is needed to resolve this problem. Practical implications - The approach developed provided a simple and practical solution to enhancing the performance of waste agro-fibres and commercial amino adhesive in the production of high performance lignocellulosic composite. Originality/value - The organic polymers UF adhesive systems are novel bonding agents for agro-fibres and could be used in timber mills for production of particle-board and medium density fibre-board.

Notizen: Purpose - To evaluate the efficiency of modifying epoxy resin using amine terminated poly(ethylene glycol) benzoate (ATPEGB) for improved toughness and to optimise the results of such a modification. Design/methodology/approach - For effective toughening, various compositions were made by incorporating different concentrations of ATPEGB. The impact and adhesive strengths of the unmodified and modified epoxy networks were characterised. Findings - The modification of epoxy resin using ATPEGB showed significant enhancement of impact and adhesive strengths over the unmodified one. The modification caused a chemical linkage between ATPEGB and resin which led not only to a phase separation but also to ensuring the intrinsically strong chemical bonds across the ATPEGB phase/resin matrix interface, which was the main cause to the improved impact and adhesive strengths. The optimum results were obtained at 12.5?phr (parts per hundred parts of epoxy resin) of modifier. Research limitations/implications - The modifier, ATPEGB, used in the present context was synthesised from poly(ethylene glycol) (PEG) of molecular weight 600. Besides, it could be synthesised from PEG of molecular weight 200, 400, 4,000, 20,000 etc. In addition, the efficiency of modification of epoxy resin using these could also be studied. Practical implications - The method developed provided a simple and practical solution to improving the toughness of cured epoxy. Originality/value - The method for enhanced toughness of cured epoxy was novel and could find numerous applications in surface coating and adhesive.

Notizen: Purpose - Synthesis and evaluation of new naphthopyran and related compounds as ultraviolet absorbers. Design/methodology/approach - The new naphthopyran and related compounds were prepared using new synthesis methodology which gave new derivatives via positions not accessible by traditional methods. Findings - A new method for the preparations of naphthopyran was developed. The naphthopyran compounds prepared had promising UV absorption/protection capabilities. Practical implications - The new compounds synthesised had unique character enabling them to be used in applications such as UV absorber and sunscreen. Originality/value - New method of synthesis and the possibility of using the naphthopyran derivatives as UV absorber in many applications.

Notizen: Purpose - To determine the optimal general condition for the synthesis and polymerisation of 2-(N-phthalimido)ethyl acrylate (NPEA), as well as the exchange reactions of poly-NPEA with aminated and hydroxylated compounds as a model compound. Design/methodology/approach - Preparation of 2-(N-phthalimido)ethyl acrylate by the reaction of N-(2-hydroxyethyl) phthalimide with acrylic acid and polymerisation of the resulting monomer. The exchange reactions of the resulting polymer with amines and hydroxy compounds were carried out. The structure of the resulting compounds were characterised. Findings - NPEA was prepared by the reaction of N-(hydroxyethyl)phthalimide with acrylic acid. The monomer prepared was easily polymerised. The reactions of the resulting polymer with amines and hydroxy compounds were studied. In all cases, the exchange reactions were almost practically quantitative, which was confirmed by elemental analysis, IR and 1HNMR spectroscopy. Also, it was clear that poly-NPEA showed a good behaviour as a model compound for a long active polymeric-drug. Research limitations/implications - The new monomer described in the present investigation may be useful for the preparation of polymeric-drug adducts. Also, similar monomeric phthalimides may be synthesised starting from a number of other hydroxy or amino acids, thus providing wider possibilities for the synthesis of pharmacologically active polymers. Practical implications - The method for preparation of monomer is simple and the exchange reactions provide a simple and practical solution to prepare some classes of macromolecular drugs. Originality/value - The method of preparation of polymers was novel and may be useful for preparation of polymeric-drug adducts.

Notizen: Purpose - The print fault "dot bridging" reduces the printing press efficiency. This study was designed to find the best combination of materials used in normal production which would reduce or eliminate the problems thus increasing efficiency. Design/methodology/approach - Various statistical methods were used to design the experiments and to analyse the experimental results. The experiment included all of the factors which were considered to have an effect on the "dot bridging" print fault. Findings - The most important conclusion that can be drawn from the results is that the complex interactions between factors included in the process can be characterised. The experiment proved that the problem was not random. The data gathered during the experiment had a direct correlation with the psychometric results. Various factors included in the experiment were found to have a significant influence on print density and print contrast. Contrast and density were selected for analysis as ink film thickness was thought to have an influence on the best looking print samples and the "dot bridging" print fault. Research limitations/implications - The results of the experiment were used to optimise the production process particularly the platemaking technique. Data from further experiments would help to optimise more process parameters. Practical implications - Minitab computer software was used to analyse the results of the experiment thus making it easier to communicate the results to non-scientific production staff. Originality/value - This was the first time that the printer concerned had used a scientific approach to problem solving. The end result for the printer was an increase in production efficiency which saved the printer a considerable amount on money.

Notizen: Purpose - To investigate the effects of the temperature of synthesis and of the thermal treatment of zinc chromate on the properties of the zinc chromate pigments. Design/methodology/approach - Zinc chromate pigments was prepared using zinc salt solution, sodium hydroxide and potassium dichromate solutions. The reaction temperature was varied in order to evaluate the effect of the reaction temperature on the properties of the pigment synthesised. The pigment obtained was heated to 10°C above the critical temperature in order to investigate the effect of thermal treatment on the pigment properties. SEM, XRD, XFR and STA were employed for the characterisation of the pigments synthesised. Findings - Reaction temperature had a significant effect on the properties of the resulting pigment. Thermal treatment of the pigment caused the decomposition of the zinc chromate phase to ZnO, ZnCr2O4 and K2CrO4 phases. The glaze containing zinc chromate had satisfactory colour characteristics. Research limitations/implications - The study focused on the preparation and evaluation of zinc chromate as a substitute for praseodymium zircon in glaze. The study could be extended to investigation of similar inorganic pigment for similar purposes. Practical implications - The information on the effects of the reaction temperature of pigment synthesis and of thermal treatment of the pigment is useful for industrial production of the pigment of satisfactory properties. Originality/value - Novel use of zinc chromate as a lower-cost substitute for praseodymium zircon in glaze and understanding of the effects of the production conditions on the properties of the resulting pigment and the glaze.

Notizen: Purpose - To study the effect of feldspars as inorganic filler on the mechanical and dielectric properties of epoxy coatings. Design/methodology/approach - Coating systems used were of either filler-free epoxy resin (as reference), or epoxy resin filled with feldspars powder at four different levels by weight. Mechanical properties of the coatings were evaluated via damping hardness and abrasion and impact resistance measurements. Electrochemical impedance spectroscopy measurements were used for the evaluation of the dielectric properties while visual observations of the test panels after salt-spray test were also made. Findings - The addition of 15 per cent w/w feldspars resulted in a formulation giving the most positive results, e.g. improvement of the coating's mechanical characteristics and dielectric behaviour similar to that of filler-free epoxy coatings. Practically comparable to this behaviour was that possessed by coatings with 30 per cent w/w feldspars, while further increase of the feldspars content resulted either in a reduction in the extent of the enhancement of the mechanical behaviour or even in a worsening of both mechanical and dielectric characteristics. Originality/value - Feldspars are the most abundant group of minerals in the earth's crust; it is an inorganic, environmentally friendly material, which exhibits high Mohs hardness. The effects of feldspars in improving the mechanical characteristics of organic coatings, while not causing any reduction in the anticorrosive performance of the polymeric matrix was found through the study.

Notizen: Purpose - To evaluate the efficiency of modifying epoxy resin using phenol-nonyl phenol based polymer (PNPF) for toughness improvement and optimise the results of such a modification. Design/methodology/approach - For effective toughening, various compositions were made by incorporating PNPF at different concentrations. The impact and adhesive strengths of the unmodified and modified epoxy networks were characterised. Findings - The modification of epoxy resin using PNPF showed significant enhancement of impact and adhesive strengths over the unmodified one. The modification caused the formation of a chemical linkage between PNPF and resin which led not only to a phase separation, but also to formation of intrinsically strong chemical bonds across the PNPF phase/resin matrix interphase, which was the main cause of the improved impact and adhesive strengths. The optimum results were obtained at 10?phr (parts per 100 parts of epoxy resin) of modifier. Research limitations/implications - The modifier, PNPF, used in the present context was synthesised from phenol, nonyl phenol and formalin using oxalic acid as catalyst. Practical implications - The developed method provided a simple and practical solution to improving the toughness of a cured epoxy. Originality/value - The method for enhancing toughness of a cured epoxy was novel and could find numerous applications in the surface coating and adhesive.

Notizen: Purpose - To develop a method based on urea/microwave treatment for improving the dyeability of the flax fibre. Design/methodology/approach - The treatment was carried out under a variety of conditions in terms of the power of the microwave, the time of microwave treatment and the use of urea in the treatment solution. The physical chemical properties of the treated flax fibres were characterised using a variety of techniques including scanning electron microscopy (SEM), X-ray diffractometry, spectrophotometric measurement and tensile measurement. Findings - It was found that the treated flax fibres had significantly improved dyeability. The causes to the improvement of the dyeability of the flax fibre were found to be the increased absorption of dye on the fibre and the increased reaction probability between the dye and the fibre. The procedure for optimum modification appeared to be soaking the flax fabrics in 10 per cent urea solution; treating the fabrics with microwave at 350?W for 2.5?minutes; and treating the fabrics with microwave at 700?W for one minute. Practical implications - The treatment method developed addressed a problem of great concern in textile coloration, i.e. poor dyeability of flax fibre. The method developed provided a practical and effective solution to such a problem. Originality/value - The method of treatment of flax fibre, involving soaking in urea and baking in microwave, for the improvement of dyeability was novel. The method could be adapted for use in industrial scale flax dyeing with satisfactory levels of exhaustion and fixation.

Notizen: Purpose - To evaluate the performance of the compatibiliser of epoxidised soyabean oil-free fatty acid prepared on the NBR/EPDM blends compared with maleic anhydride and also to explore the effect of loading the compatibiliser NBR/EPDM rubber blend with unmodified and modified polypropylene fibres on the mechanical properties of the blend. Design/methodology/approach - To achieve desirable rheological and physico-mechanical properties of NBR/EPDM rubber blend, various compositions were made by incorporating different doses of the compatibiliser of epoxidised soyabean oil-free fatty acid prepared and maleic anhydride to form NBR/EPDM blends. The effect of loading the compatibiliser rubber blend with unmodified and modified polypropylene fibres on the mechanical properties of the blend was investigated. Findings - The incorporation of epoxidised soyabean oil-free fatty acid or maleic anhydride into NBR/EPDM blend greatly enhanced their compatibility improved the rheological, as well as physical properties of rubber blends. The addition of NBR to EPDM improved the motor oil swelling resistance of EPDM. Blending of the two individual rubbers without a compatibiliser generally exhibited a non-synergistic effect with respect to the physical properties. The strain energy, tensile strength, Young's modulus and strain at yield varied linearly with composition in the presence of compatibiliser, but deviated from linearity in the absence of compatibiliser. Reinforcement of the NBR/EPDM blend with modified polypropylene fibres enhanced the physical properties more significantly than with the unmodified ones. Research limitations/implications - The compatibiliser of epoxidised soyabean oil was prepared by reacting in situ soyabean oil-free fatty acid with per-acetic acid. Practical implications - The method developed provided a simple and practical solution to improving the rheological and physico-mechanical properties of the NBR/EPDM rubber blend. Originality/value - The method for enhancing rheological and physico-mechanical properties of NBR/EPDM rubber blend loaded with modified polypropylene fibres was very important and showed a synergistic effect and could find numerous applications in the rubber and plastic industries.

Notizen: Purpose - To develop a water repellent (WR), rodent repellent (RR) and UV resistant (UVR) formulation for woven nylon tapes to be used in aircraft arrester system. Design/methodology/approach - UVR, WR and RR formulation for woven nylon tapes were prepared using silicone oil as WR, oleoresin (OR) (red chilly extract) and denatonium benzoate (DB) as RRs, carbon black for UV resistance and butyral resin as binder. Findings - Incorporation of silicon oil improved the water repellency of the processed nylon tapes. DB and OR in the formulation protected the tapes from rats. The former showed excellent protection for nylon tapes in the experimental conditions. More than 150 days of protection has been achieved in comparison to 27 days using OR. The presence of carbon black along with silicon oil and DB in the formulation enabled the nylon tapes UVR-WR-RR in a single processing step. The presence of RRs and WRs within the same formulation did not affect each other's performance. Research limitations/implications - OR and DB were used as RR materials and silicone oil as WR material. In addition, some other RR and WR materials could have been evaluated. Practical implications - The formulation imparts UV resistance, water and rodent repellency to the nylon tapes after processing. Originality/value - This type of formulation is novel for processing of nylon tapes to be used in aircraft arrester systems.

Notizen: Purpose - To prepare of fine particle size magnesium ferrite pigments by sol-gel method. Design/methodology/approach - Different magnesium ferrite pigments with stoichiometric ratios were prepared by sol-gel and dispersion methods. The characterisation of magnesium ferrite pigments were based on X-ray diffraction, transmission electron microscope, particle size distribution, thermal and magnetometric analyses. Findings - The type of polymer and the starting inorganic materials (oxides or salts) have a significant effect on the properties of the magnesium ferrite pigments prepared. Research limitations/implications - The magnesium ferrite pigments, prepared and used in the work reported here were synthesised from magnesium and iron oxides, oxalates and chlorides. Urea formaldehyde resin and acrylic polymer were used as the dispersing media. Various other materials, e.g. carboxymethyl cellulose, ethoxy methyl cellulose, polyvinylalcohol and 2-hydroxyethyl methacrylate and polyacrylamide can also be used to achieve similar effect. Practical implications - The sol-gel method provided a fine particle size and different particle shapes. Therefore, the method of preparation could be used to produce fibres, films and monoliths. Originality/value - The magnesium ferrite pigments prepared could be use in numerous paints for steel protection.

Notizen: Purpose - To investigate the efficacy of Telfaria occidentalis extract as a corrosion inhibitor for mild steel in 2?M HCl and 1?M H2SO4 solutions, respectively, and to assess the effect of temperature and halide additives on the inhibition efficiency. Design/methodology/approach - Corrosion rate was monitored by careful volumetric measurement of the evolved hydrogen gas at fixed time intervals. Inhibition efficiency was determined by comparing the corrosion rates in the absence and presence of additive. Attempts were made to elucidate the inhibition mechanism from the trend of inhibition efficiency with temperature. The adsorption mode of inhibiting species in the extract was assessed by considering the influence of both acid and halide ions on inhibition efficiency. Findings - Telfaria occidentalis extract inhibited mild steel corrosion in 2?M HCl and 1?M H2SO4 solutions. Inhibition efficiency increased with extract concentration but decreased with rise in temperature. Synergistic effects increased the efficiency of the extract in the presence of halide additives in the order KCl〈KBr〈KI. Protonated species in the extract composition played a vital role in the inhibiting action. Originality/value - This paper provides new information on the inhibiting characteristics of Telfaria occidentalis extract under the specified conditions. This environmentally friendly inhibitor could find possible applications in metal surface anodising and surface coatings.

Notizen: Purpose - Preparation of chelating resin to be used in the removal of heavy metal ions from solutions. Design/methodology/approach - Chelating resin based on poly (glycidyl-methacrylate-co-N, N-methylene-bis-acrylamide) containing ethylenediamine was synthesised and used in removal of heavy metals from solutions. Findings - The optimal pH values for adsorption of different metal ions occur in the range 4.0-10.0 depending on the metal ion used. The adsorption of metal ions increases with increasing treatment duration to reach to the equilibrium state. Also, the adsorption of metal ions depends on the degree of cross linking of the chelating resin, and a higher degree of cross linking results in a lower degree of metal ion adsorption. The chelating resin was highly effective for the collection of metal ions by batch and column methods. The metal ions adsorbed could be eluted with 2M HNO3 except Co2+ and the resin could be reused. Research limitations/implications - The different factors affecting the metal ions (Cu2+, Co2+, Cd2+, Zn2+, Pb2+ and Hg2+) loading in resin such as pH, contact time and cross linking density were studied. Practical implications - The practical applicability of the chelating resin for final stage of waste water treatment is recommended for use as a polishing agent. Originality/value - The resins prepared were used successfully in removing heavy metals from water.

Notizen: Purpose - The study reported here concerned production of green pigments, hydrated nickel(II) silicates and oxides, obtained by precipitation from solutions of sodium metasilicate and sodium hydroxide using nickel(II) sulphate. Design/methodology/approach - The pigments were analysed using a number of techniques including scanning electron microscopy for particle surface morphology and dynamic light scattering for particle structure and the tendency of the particles to agglomerate. Findings - The most desirable physicochemical parameters were shown by highly dispersed nickel(II) silicates precipitated in presence of the modifying agents. Silicate pigments precipitated in the presence of Rokanol K-7 had low bulk densities, a high capacity to absorb water, dibutyl phthalate and paraffin oil within the primary particles, which is particularly noteworthy. Practical implications - Due to their good dispersibility, well developed surface and appropriate coating power, coloured silicates of, e.g. chromium(III) and nickel(II) may be used as pigments and fillers for surface coatings. Originality/value - The method of obtaining nickel(II) pigments developed was novel and provided a solution for problem of post-galvanic nickel solutions.