Ahmed M. El-Masry

Halamine polymers: 2. Preparation of new triazine‐diones biocidal polymers by grafting polymerisation

New N‐halamine polymeric compounds were prepared by reacting cyanuric acid and polyacrylonitrile. Grafting of acrylonitrile monomer onto cotton linters was carried out and the product was reacted with cyanuric acid and finally was chlorinated. Cyanoethylation of polyvinyl alcohol was performed using acrylonitrile monomer to give polyvinylcyanoethyl ether, which, in turn, was reacted with cyanuric acid. The biological activity of the various chlorinated compounds obtained was examined against Gram (+) and Gram (−) bacteria using columns and dishes methods. A high disinfecting power of the chlorinated compounds obtained was observed. Thus, the bacteria was deactivated after the first cycle without contact with the product. All of the compounds prepared were insoluble in water and most of inorganic solvents. These compounds were also found to be very stable and did not decompose to give any toxic compounds. Thus, the chlorinated compounds prepared had no harmful effects on humans.

Halamine polymers: 1. Preparation and characterisation of new pyrimidinone biocidal polymers based on poly‐4‐vinylacetophenone

A series of novel halamine polymers known as pyrimidinone biocidal polymers were prepared by reacting poly‐4‐vinylacetophenone with urea and benzaldehyde to form 1H,3H,6H,‐4(4′‐polystyreno)‐6‐phenyl‐pyrimidin‐2‐one, which on chlorination yielded 1Cl,3H,6H,‐4(4′‐polystyreno)‐6‐phenyl‐pyrimidin‐2‐one. The same reaction was also carried out using the derivatives of benzaldehyde such as p‐nitrobenzaldehyde and p‐methoxybenzaldehyde under the same reaction conditions. .

Preparation and characterisation of new bioactive polysaccharides based on grafted starch

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.

Bagasse hydrogels: water absorption and ions uptake

Purpose – The purpose of this paper is to prepare and optimize the preparation conditions of some new hydrogels and in addition, evaluate their water absorbance at different mediums and their ability to remove ions from aqueous solutions.Design/methodology/approach – Cellulose was extracted from depithed bagasse at two different pulping conditions; 3 and 6 hours cooking times, pulp (I) and (II), respectively. These pulps, in addition to cotton linter for comparison, were grafted with acrylamide followed by cross‐linking with glutaraldehyde. The networks were partially hydrolyzed and the structures of products (before and after hydrolysis) were studied using FTIR, SEM, TGA and X‐ray. The optimum preparation conditions were identified, before and after hydrolysis, to achieve maximum absorbance and the ability of prepared hydrogels to remove ions from solutions was investigated.Findings – Maximum level of absorption was recorded using hydrogels prepared with monomer concentration =0.8 mol/l, cross‐linker con...

Grafting copolymerisation of vinyl monomers onto cellulose Egyptian cotton linters

Purpose – The purpose is to focus on improving the water or metal ion uptake of modified cellulose.Design/methodology/approach – Grafting copolymerisation of hydrophilic monomers such as acrylamide or hydrophobic monomers as acrylonitrile onto cotton linters was performed.Findings – The grafting process has two advantages. The first is to replace the hydroxyl group of C6 of the glucose units in the substrate by carboxyl group that attract the metal ions from the solution. The second is to decrease the number of the hydroxyl groups in the cotton linters so that the hydrogen bonding between the cotton linters strands decreases and so the crystallinity index of substrate decreases by introduction of this hydrophilic group so it becomes more chemically active.Research limitations/implications – Partial substitution of hydroxyl groups of cellulose by more hydrophilic ones via grafting reaction followed by alkaline hydrolysis was performed. The effects of different conditions such as temperature, time, initiato...

Novel Core–Shell of Polymethyl Methacrylate/butyl Acrylate/vinyl Silica Nanocomposite Particles through Seed Emulsion Polymerization

ABSTRACT A new core–shell structure of polymethyl methacrylate/butyl acrylate copolymer/vinyl silica nanocomposite was successfully prepared in aqueous solution through seed emulsion polymerization. Vinyl-functionalized silica nanoparticles were synthesized using sol–gel technique of triethoxyvinylsilane in aqueous solution. New established covalent bond between the vinyl groups located on the surface of vinyl-functionalized silica nanoparticles and vinyl group of monomers and the encapsulation into methyl methacrylate/butyl acrylate copolymer through seed emulsion polymerization process. The prepared core–shell latex polymers were characterized by Fourier transform infrared, UV–vis, thermal analyses, tensile strength, elongation at break, field emission scanning electron microscope, transmission electron microscope, and zeta potential. The tensile strength improved by introducing vinyl silica into the matrix up to 5%, which proved the reinforcing role of vinyl silica in the matrix of polymer. GRAPHICAL ABSTRACT

Water absorption and ion exchange properties of some derivatives of peroxyacid viscose grade pulp

Purpose – The purpose of this paper is to study some chemical reactions of viscose grade pulp (alpha cellulose around 96 per cent) prepared by preoxyacetic acid pulping of bagasse for the preparation of some cellulose derivatives.Design/methodology/approach – Viscose grade pulp was prepared by using ecological chemicals. The viscose grade pulp was subjected to some chemical reactions (e.g. carboxymethylation, cyanoethylation and phosphorylation reactions). The pulping and bleaching which are two important stages involved in the complex process of converting fibrous raw material (bagasse) into viscose grade pulp are also investigated in this paper.Findings – The viscose pulp prepared by peroxyacid pulping of bagasse was subjected to a number of chemical reactions such as: hydrogel and fibrous carboxymethyl cellulose; cyanoethyl cellulose, in which this cyanoethylcellulose (of gel properties) was prepared, the hydrophobic character of the cyanoethylcellulose was changed into hydrophilic character via hydrol...