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The purpose of this study is to investigate the authors' previously prepared and fully characterized poly (methacrylamide)-chitosan nanoparticles (CNPs) graft copolymer having 50.2% graft yield with respect to flocculation efficiency for ferric laurate aqueous dispersions. This was done to compare the ability of the latter cheap, biodegradable and ecofriendly hybrid natural-synthetic polymeric substrate as a flocculant in comparison with higher cost, nonbiodegradable and harmful polyacrylamide as a well-known synthetic flocculant counterpart.

The graft copolymerization process was carried out at 450°Cfor 120 min using (1.0 g) CNPs, methacrylamide (1.5 g), 100 mmol/l potassium chromate and 80 mmol/l mandelic acid. Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis and specific viscosity were used to characterize and analyze the resultant copolymer. The flocculation efficiency was conferred in terms of transmittance % and weight removal %. The main factors influencing the flocculation process, such as flocculent dose, flocculation medium pH, stirring speed, flocculation temperature and grafting extent, were comprehensively discussed.

The flocculation efficiency of the prepared copolymers revealed the following findings: increased by increasing the flocculant dose, pH, temperature and stirring speed to a maximum values denoted at 30 ppm, 6.0, 30°C and 50 r/min, respectively, then decreased thereafter; increased by increasing the extent of grafting within the range studied; showed a comparable flocculation efficiency in comparison with polyacrylamide as a synthetic polymeric flocculent; and, finally, a preliminary bridging mechanism representing the attraction between the anionic suspended particles ferric laurate and cationic poly (MAam)-CNPs graft copolymer has been projected.

The advancement addressed here is undertaken with using the authors’ poly (MAam)-CNPs graft copolymers having different extent of grafting (a point which is not cited in the literature especially for the authors’ prepared copolymer) as a hybrid natural-synthetic polymeric substrate as a flocculant for ferric laurate aqueous dispersions in comparison with the high cost and nondegradable polyacrylamide synthetic flocculant.

This study aims to use multi-functional viscose fabric that was facilely developed with with respect to ease and care characteristics, reinforcement effect and antibacterial activity by using novel echo friendly antibacterial finish based on citric acid/sodium hypophosphite and the authors’ previously tailor-made poly meth acrylic acid (MAA)-chitosan graft copolymer via alternative microwave curing approach instead of traditional high-temperature cure one.

Viscose fabric was paddled twice in the cross-linking formulations containing different concentrations of citric acid, poly (MAA)-chitosan graft copolymer and sodium hypophosphite to 90 % wet pick up and dried at 100°C for 3 min in an electric oven. Then, the treated fabrics were placed on the disk spinner of the microwave oven and cured at different power (100–800 Watt) for various durations (60–180 s). The fabric was then water-rinsed and dried at ambient condition before use.

Results revealed that the above echo friendly method for finished viscose fabrics was found to achieve relatively high dry wrinkle recovery angle and maintain the loss in tensile strength within the acceptable range, as well as antibacterial activity against Escherichia coli and Staphylococcus aureus as a gram-negative and gram-positive bacteria, respectively; in addition to durability up to ten washing cycles. Furthermore, scanning electron microscope images, nitrogen content and add on % of the finished fabric confirmed the penetration of grafted chitosan inside the fabric structure. The tentative mechanism for these reactions is advocated.

The novelty addressed here is undertaken with the advantages of using citric acid as a nonformaldehyde, safe and cheap poly carboxylic acid as a crosslinking agent and sodium hypophosphite as a potential catalyst, in addition to the authors’ noncitable multifunctional echo friendly tailor-made poly (MAA)-chitosan graft copolymer for imparting reinforcement and antibacterial characteristics to viscose fabric that uses the pad-dry/cure microwave fixation for progressively persuaded heat within the fabric during curing.

This was done to see the impact of microwave as green and efficient tool with respect to reduction in organic solvents, chemicals and exposer time as well as fixation temperature on the finishing reaction in comparison with traditional pad-dry-cure method.

Poly (MAA)-chitosan graft copolymer as amphoteric biopolymer was expected to impart multifunctional properties to viscose fabrics especially with comparable dry wrinkle recovery angle and minimize the loss in tensile strength in addition to antibacterial properties in comparison with untreated one.

The purpose of this study is to undertake surface graft copolymerization of viscose fabric via altering its fibrous properties by using acrylic acid (AA) as a carboxyl-containing monomer and peroxydisulfate (PDS) in presence of ferrous sulfate as a novel redox pair for initiating grafting. The latter process acted as an energy-saving process with respect to the reduction in polymerization temperature and maximizing the graft yield %, in addition to rendering the grafted viscose fabrics dye-able with cationic dye (crystal violet), which has frequently no direct affinity to fix on fabric.

To make graft copolymerization more efficient and economic, the optimum conditions for graft copolymerization were established. The graft yield % was determined as a function of initiator, catalyst and monomer concentrations and the material to liquor ratio, in addition to polymerization time and temperatures. Metrological characterizations via Fourier transform infrared spectroscopy and scanning electron microscopy of topographic morphological surface change have also been established in comparison with the ungrafted samples.

The maximum graft yield of 70.6% is obtained at the following optimum conditions: monomer (150 % based on the weight of fabric), PDS (50 m mole), ferrous sulfate (80 m mole) and sulfuric acid (30 m mole) at 40° C for 1.5 h using a liquor ratio of 30. Remarkably, grafting with AA enabled a multifold upsurge in color strength, with improvements in the fastness properties of cationically dyed grafted viscose fabric measured on the blue scale in comparison with untreated viscose fabric.

The novelty addressed here is undertaken with studying the effect of altering the extent of grafting of poly (AA)-viscose graft copolymers expressed as graft yield % in addition to carboxyl contents on cationic dyeing of viscose fabric for the first time in the literature. Moreover, rendering the viscose fabrics after grafting is dye-able with cationic dye with high brilliance of shades, which has regularly no direct affinity to fix on this type of fabrics.

This study aims to address a comprehensive and integrated investigations pertaining to the preparation of AgNPs with well-defined nano-sized scale using the aforementioned poly (meth acrylic acid [MAA])–chitosan graft copolymer, which is cheap, nontoxic, biodegradable and biocompatible agent as a substitute for the traditionally used toxic reducing agents.

AgNPs are prepared under a range of conditions, containing silver nitrate and poly (MAA)–chitosan graft copolymer concentrations, time, temperature and pH of the preparation medium. To classify AgNPs obtained under the various conditions, ultraviolet–visible spectroscopy spectra and transmission electron microscopy images are used for characterization of AgNPs instrumentally in addition to the visual color change throughout the work. The work was further extended to study the application of the so prepared AgNPs on cotton fabric to see their suitability as antibacterial agent as well as their durability after certain washing cycles.

According to the current investigation, the optimal conditions for AgNPs formation of nearly 3–15 nm in size are 5 g/l, poly (MAA)–chitosan graft copolymer and 300 ppm AgNO₃ in addition to carrying out the reaction at 60°C for 30 min at pH 12. Besides, the application of the so prepared AgNPs on cotton fabric displayed a substantial reduction in antibacterial efficiency against gram-positive and gram-negative bacteria estimated even after 10 washing cycles in comparison with untreated one.

To the best of the authors’ information, no comprehensive study of the synthesis of AgNPs using poly (MAA)–chitosan graft copolymer with a graft yield of 48% has been identified in the literature.

Introduction The application of organic coatings is the most extensive way of protecting metal products from corrosion. Developments of organic coatings and their applications are subject to the effects of many factors at present. The most important among these factors are ecological requirements aimed at the protection of the living and working environments, and the lack of raw materials and energy.

Introduction Over the last few years there have been several trials to replace inorganic corrosion inhibitors, which in organic coatings are pigments, with materials which are, in principle, organic corrosion inhibitors. This coincides primarily with the toxic properties of the anti‐corrosive pigments employed and also with the scarcity of raw materials for their production.

Over the last few years there have been several trials to replace inorganic corrosion inhibitors, which in organic coatings are pigments, with materials which are, in principle, organic corrosion inhibitors. This coincides primarily with the toxic properties of the anti‐corrosive pigments employed and also with the scarcity of raw materials for their production.

The application of organic coatings is the most extensive way of protecting metal products from corrosion. Developments of organic coatings and their applications are subject to the effects of many factors at present. The most important among these factors are ecological requirements aimed at the protection of the living and working environments, and the lack of raw materials and energy.

This study aims to explore the incorporation of the authors previously prepared chitosan nanoparticles (CNPs) of size around 60-100 nm in the cross-linking formulation of viscose fabrics to see CNPs impact in terms of imparting multi-functional characteristics such as tensile strength, dry wrinkle recovery angles and antibacterial properties.

CNPs of size around 60-100 nm were incorporated in cross-linking formulations for viscose fabrics, including different concentrations of glutaraldehyde as a non-formaldehyde cross-linking agent and magnesium chloride hexahydrate as a catalyst. The formulations were applied at different curing times and temperatures in 100 mL distilled water, giving rise to a wet pickup of ca. 85 per cent. The fabrics were dried for 3 min at 85°C and cured at specified temperatures for fixed time intervals in thermo fixing oven according to the traditional pad-dry-cure method.

The above eco-friendly method for finished viscose fabrics was found to obtain high dry wrinkle recovery angle and maintain the tensile strength of the finished fabric within the acceptable range, as well as antibacterial properties against Escherichia coli and Staphylococcus aureus as a gram-negative and gram-positive bacteria, respectively. Both, scanning electron microscope and nitrogen percent on the finished fabric confirm the penetration of CNPs inside the fabric structure. Finally, viscose fabrics pageant antibacterial activity against gram-positive and gram-negative bacteria assessed even after 20 washing cycle.

CNPs with its flourishing effect with respect to cationic nature, biodegradability, reactivity, higher surface area and antimicrobial activity; in addition to glutaraldehyde as non-formaldehyde finishing agent can be used as multi-functional agents for viscose fabrics instead of DMDHEU, polyacrylate and monomeric composites as hazardous materials.

CNPs as cationic biopolymers were expected to impart multi-functional properties to viscose fabrics especially with obtaining reasonable dry wrinkle recovery angle and tensile strength in addition to antibacterial properties.

The novelty addressed here is undertaken with a view to impart easy care characteristics and antibacterial activities onto viscose fabrics using CNPs as antimicrobial agent and glutaraldehyde as non-formaldehyde durable press finishes to-replace the traditional formaldehyde-based resins. Besides, to the authors’ knowledge, there is no published work so far using the above cross-linking formulation written above.

Several research and developmental work attempts have been made in this manuscript to synthesize what is called tailored polymeric materials with new characteristics based on pregelled starch through a number of processes which, in turn, entail several chemical treatments. This is done by subjecting pregelled starch as a starting substrate to acid hydrolysis to obtain different molecular sizes. Pregelled starch with different molecular sizes are carbamoylethylated by using acrylamide and sodium hydroxide at different durations, then grafted with different monomers by using a potassium permanganate/citric acid redox system to initiate grafting. Furthermore, application of the newly tailored pregelled starch derived products as a sizing agent of cotton textiles is systematically studied. It is shown from the data that (a) the extent of carbamoylethylation expressed as N% increases by increasing the extent of hydrolysis and duration; (b) the graft yield expressed as mmol. monomer/100 g sample of different monomers onto carbamoylethylated and carbamoylethylated hydrolyzed pregelled starches increases by increasing the extent of carbamoylethylation and degree of hydrolysis, and follows the order: methacrylamide (MAam) > methacrylonitrile (MAN) > methacrylic acid (MAA), and (c) cotton fabrics sized with grafted carbamoylethylated hydrolyzed pregelled starch acquire higher mechanical properties, i.e. TS, elongation at break, and abrasion resistance values than hydrolyzed, carbamoylethylated and carbamoylethylated hydrolyzed pregelled starches. Finally, the use of the above tailored modified pregelled starch derived products in the sizing of cotton textiles contribute to reinforcement of the cotton textile after sizing to overcome the forced loss in fabrics/yarns during the spinning process as shown above.