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The present investigation has highlighted the utility of floating aquatic Egyptian hyacinth, which is considered as a significant reason for environmental problems in Nile River, to offer an opportunity to effective disposal of waste and the feasibility of cellulose extraction (16%) utilizing hazard free method. Cellulose was extracted from water hyacinth fiber using mercerization, mercerization-bleaching and Soxhlet extraction method. Dearth of lignin and hemicellulose in all extracted cellulose were affirmed from FTIR spectra. The impact of extraction conditions on crystallinity, aspect ratio and thermal properties of the extracted cellulose is displayed. Mercerization method (5% NaOH) is adequate to obtain cellulose (C-5% NaOH) with high crystallinity (46.9%), high decomposition temperature and high aspect ratio. C-5% NaOH was used for expulsion of crystal violet, Congo red from aqueous solutions by adsorption method. Kinetics models were applied to estimate the rate constant and to depict the equilibrium isotherm for the crystal violet and Congo red adsorption process.

Objectives The purpose of this study was to evaluate the magnitude of vital signs changes during 3 different dental treatments. Study Design A prospective longitudinal multiarm cross-over clinical trial was conducted. Three dental procedures were performed on each participant: supragingival scaling, dental restoration under local anesthesia (LA), and exodontia under LA. The following parameters were recorded for in each dental procedure: body temperature (BT), respiratory rate (RR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), and peripheral oxygen saturation (SpO2). Three repeated measurements of each parameter were recorded at 3 phases of each procedure. Results A total of 150 dental interventions were performed on 50 patients. Scaling caused a statistically significant rise in BT, RR, and SpO2, and a reduction in HR. Restorative treatment caused a statistically significant rise in SpO2 during LA. Exodontia caused a statistically significant rise in BT, RR, SBP (during the procedure), and SpO2 (during LA). Conclusions Scaling and restorative treatment did not significantly impact heart rate. The respiratory rate may temporarily rise during LA injection and some dental procedures, especially exodontia. Increase in systolic blood pressure and heart rate during exodontia was tolerated by healthy patients.

Antibacterial and cytotoxicity of methylene blue (MB), a widely used dye in medicine, loaded onto extracted cellulose was studied against MCF-7 breast cancer cell line. Cellulose (C) was extracted from water hyacinth by three methods (Soxhlet extraction, mercerization with 5%NaOH and acid hydrolysis). MB was loaded on extracted cellulose and examined by physical and morphological characterization. TEM images of cellulose extracted by acid hydrolysis presented a network-like with diameter of 30–50 nm and a length of 270–1290 nm. Release behavior was studied by the kinetic models (Zero-order, First-order, Higuchi, Hixson-Crowell and Korsmeyer-Peppas models). At pH 7.4, MB release percentage reached 52%, up to 1400 h, while at pH 5.4 and 6.7, the release percentage reached 45 and 42%, respectively. Cytotoxicity assay of MB-loaded cellulose was studied against MCF-7 breast cancer cell line and WI-38 normal cell line. In MCF-7 after 48 h, cell viability decreased from 52.4 to 6.9 when the concentration of MB increases from 12.5 to 100 Mg/ml. However, it has a weak cytotoxic effect on normal cell line (WI-38). Antibacterial activity of MB-loaded cellulose was determined against gram-positive bacteria and gram-negative bacteria and revealed an antibacterial activity against all bacterial strains.

Exfoliated organoclay-polystyrene (OC-PS) and organoclay-poly(methyl methacrylate) (OC-PMMA) nanocomposites were prepared using novel modified/clay-polymer through both bulk polymerization and solution techniques. The synthesis was achieved by formation of derivative vinylbenzyl ammonium salt intercalated with montmorillonite (MMT) clay. The clay-vinyl/monomer was dispersed in PS or MMA monomers followed by solution polymerization. The clay-PS and clay-PMMA were used as highly compatibilizer organoclay to produce highly exfoliated nanocomposites. Morphological structure of the nanocomposites was investigated by SEM and XRD which confirmed that the clay is homogenously dispersed and exfoliated in the polymer matrixes with interlayer spacing at least of d001-value ≥4 nm for both PS and PMMA. Thermal properties of the nanocomposites show an increase in the decomposition temperature comparing to neat polymer.

Polymer nanocomposites are one of the highly discussed research topics in recent time. It has been reported in the present paper the preparation and the properties of different nanoclays based on sodium montmorillonite (bentonite) and some organic amines of varying chain lengths (dodecylamine, hexadecylamine and octadecylamine) beside amine-terminated butadiene–acrylonitrile copolymer (ATBN). The hybrid clays have been characterized with the help of Fourier Transform Infrared spectroscopy (FTIR). Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Wide angle X-ray diffractions (WXRD), and Thermogravimetric analysis (TGA). X-ray results showed that the intergallery distance of the clay is increased as a result of the intercalation of the amines and ATBN. The nanocomposite clays were incorporated in natural and synthetic rubbers (NR, SBR and NBR). The physico-mechanical properties are greatly improved with loading low concentrations of the nanocomposite clays compared with carbon black.

The rich chemistry of polybenzoxazines allows a wide range of molecular structure design by using appropriate starting materials. A new class of polybenzoxazines has been developed from benzoxazine monomers containing pendent long aliphatic chains. The monomers have been synthesized by the reaction of phenol or bisphenol A with two different long-chain aliphatic amines. The chemical structure of the monomers was confirmed by 1H nuclear magnetic resonance and Fourier transform infrared spectroscopy. The polymerization behavior of the monomers studied by differential scanning calorimetry shows exothermic peaks due to the ring-opening polymerization of benzoxazine monomers centered at 247–255 °C. Dynamic mechanical analysis indicated that the glass transition temperatures Tg were in the range 81–92 °C. The thermal stability of the polymers was also examined by thermogravimetric analysis, demonstrating that the weight loss temperatures decreased in comparison with that of traditional polybenzoxazine. Copyright © 2011 Society of Chemical Industry

The influence of styrene as a reactive diluent on the morphology of vinylester resin-clay hybrids has been studied. Two mixtures of diglycidylether of bisphenol-A diacrylate as vinyl ester resin and styrene (20 and 40%) were prepared. Various weight ratios of styryl-functional organoclay were added to vinylester resin/styrene mixture, followed by polymerization of the mixture up to 160°C. The morphology of the hybrids studied by X-ray diffraction and Scanning Electron Microscope revealed that the dispersion of organoclay increased with the increase of styrene content. The inclusion of styrene to the system gave ordered intercalated nanocomposites. The surface hardness of the hybrid films decreased with adding a higher content of styrene. Thermogravimetric analysis indicates that clay is effective in promoting char-forming reaction of vinylester resin/styrene clay nanocomposites. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers

Vinylester resin-clay hybrids were prepared by the mixing different types of organically-modified montmorillonite (OMMT) with vinylester resin (VER) prepolymer, followed by thermal polymerization. VER prepolymer was synthesized from the reaction of diglycidylether of bisphenol-A (DGEBA) with acrylic acid. Various types of organic ammonium salts have been used as intercalating agents for montmorillonite, including N,N-dimethyl-N-(4-vinylbenzyl)stearyl ammonium chloride (VSA), N-allyl-N,N-dimethyl-stearyl ammonium chloride (ASA) and N,N-dimethyl-stearyl ammonium chloride (SA). The dispersion of OMMT into VER matrix was studied by XRD, which indicates the dependence of the morphology mainly on the OMMT content. UV–vis spectra of the hybrids were used to give a quantitative value of the effect of OMMT content on the transparency of VER/OMMT hybrid films. Also, the Vickers test has been performed to study the effect of OMMT content on the surface hardness of the hybrid films. In addition, the thermal properties of the hybrids have been characterized by measuring the softening points and thermogravimetric analyses of the hybrids in comparison with the pure resin. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Polymer–clay composites carrying atrazine and polymeric atrazine salts as new controlled release systems have been prepared. Polymeric atrazine was prepared by polycondensation of atrazine with diethyl 2,3-O-dichloroacetyl-tartrate and diethyl-tartrate. The intercalation of the atrazine and polymeric atrazine salts onto MMT was carried out through cation exchange process. The characterizations of the prepared materials were determined by a various analytical techniques. The release rate of the active herbicide from the products was determined in both aqueous medium at different pH and salt concentration and in soil column. The release from the intercalated compound in the soil takes place within one month, while the free atrazine was lost completely through leaching after four days. The pots and field applications of the intercalated compounds on some herbs and maize were investigated. The results of this study showed high activity of the prepared compounds on the herbs inhibition and in the same time increasing the growth rate of maize compared with the conventional herbicide.

A different series of polymer–clay hybrid materials have been prepared by modification of the clay with different vinyl monomers, followed by polymerization of different ratios of vinyl monomers–clay with the monomers, such as methyl methacrylate, hydroxyethyl methacrylate, and styrene-maleic anhydride. The materials were investigated by IR, which confirmed the intercalation of vinyl-cation within the clay interlayers, and by TGA, which illustrated that phosphonium cation has high thermal stability than ammonium cation. Swelling studies of these materials in different organic solvents showed that the swelling degree increases as clay ratio decrease, and also showed higher swelling relative to vinyl–clay. X-ray diffraction illustrated that the nanocomposites were exfoliated up to a 25 wt % content of organoclay relative to the amount of polymer. SEM and TEM examined the micrograph, which showed a good dispersion of the polymers into clay galleries, and formation of nanosize particles ranged 150–300 A. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

A number of pesticide monomers containing pentachlorophenol as active group attached to vinyl groups, through oxyethylene as spacer group, have been prepared. The resulting monomers were homopolymerized under free-radical conditions and also copolymerized with styrene and 2-(2-hydroxyethoxy)ethyl methacrylate to introduce hydrophobic and hydrophilic nature to the resulting polymers. In addition, crosslinked copolymers were prepared by using different ratios of divinylbenzene. Data on the pentachlorophenol released through hydrolysis show that the degree of crosslinking, the hydrophilicity and the spacer group, as determined by the chemical structure and the polymer composition, as well as the pH, time and temperature appear to be major factors governing the rate at which a given polymer undergoes hydrolysis.

Nanocomposite polyurethane (PU)–organoclay materials have been synthesized via in-situ polymerization. The organoclay is first prepared by intercalation of tyramine into montmorillonite (MMT)-clay through ion exchange process. The syntheses of polyurethane–organoclay hybrid films containing different ratios of clay were carried out by swelling the organoclay into diol and diamine followed by addition of diisocyanate and then cured. The nanocomposites with dispersed and exfoliated structure of MMT were obtained as evidenced by X-ray diffraction and scanning electron microscope. X-ray diffraction showed that there is no peak corresponding to d001 spacing in organoclay with the ratios up to 20 wt%. SEM images confirmed the dispersion of nanometer silicate layers in the polyurethane matrix. Also, it was found that the presence of organoclay leads to improvement in the mechanical properties. The tensile strength was increased with increasing the organoclay contents to 20 wt% by 221% in comparision to the PU with 0% organoclay. POLYM. COMPOS. 28:108–115, 2007. © 2007 Society of Plastics Engineers

New nanocomposite materials based on polyurethane intercalated into organoclay layers have been synthesized via in situ polymerization. The syntheses of polyurethane–organoclay hybrid films were carried out by swelling the organoclay [12-aminododecanoic acid montmorillonite] into different kinds of diols followed by addition of diisocyanate then casting in a film. The homogeneous dispersion of MMT in the polymer matrix is evidenced by scanning electron microscope and x-ray diffraction, which showed the disappearance of the peak characteristic to d001 spacing. It was found that the presence of organoclay has improved the thermal, solvent resistance and mechanical properties. Also, the tensile strength is increased with increasing the organoclay contents to 20% by the ratio 182% related to the PU with 0% organoclay. On the contrary, the elongation has decreased with increasing the organoclay contents. Copyright © 2007 John Wiley & Sons, Ltd.

A different series of new polystyrene–clay nanocomposites have been prepared by grafting polymerization of styrene with vinyl-montmorillonite (MMT) clay. The synthesis was achieved through two steps. The first step is the modification of clay with the vinyl monomers, such as N,N-dimethyl-n-octadecyl-4-vinylbenzyl-ammonium chloride, n-octadecyl-4-vinylbenzyl-ammonium chloride, triphenyl-4-vinylbenzyl-phosphonium chloride, and tri-n-butyl-4-vinylbenzyl-phosphonium chloride. The second step is the polymerization of styrene with different ratios of vinyl-MMT clay. The materials produced were characterized by different physical and chemical methods: (1) IR spectra, confirming the intercalation of the vinyl-cation within the clay interlayers; (2) thermogravimetric analysis (TGA), showing higher thermal stability for PS–nanocomposites than polystyrene (PS) and higher thermal stability of nanocomposites with of phosphonium moieties than nanocomposites with ammonium moieties; (3) swelling measurements in different organic solvents, showing that the swelling degree in hydrophobic solvents increases as the clay ratio decreases; (4) X-ray diffraction (XRD), illustrating that the nanocomposites were exfoliated at up to a 25 wt % of organoclay content; and (5) scanning electron microscopy (SEM), showing a complete dispersion of PS into clay galleries. Also, transmission electron microscopy (TEM) showed nanosize spherical particles of ∼ 150–400 nm appearing in the images. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3739–3750, 2007

Polymer–clay composite material has been prepared by intercalation of polymeric ammonium salt onto the montmorillonite (Na–MMT) followed by grafted polymerization of hydroxyethyl methacrylate onto amine-terminated poly(butadiene-co-acrylonitrile)–montmorillonite (ATBN–MMT) intercalate. The hydroxyl groups were modified to chloromethyl groups followed by conversion to onium salts, which are suitable as phase transfer catalysis. The catalytic activities of the supported catalysts were investigated in nucleophilic reactions of thiocyanate and cyanate ions with alkyl and aryl halides. The rates of the reactions have been investigated under different factors such as the nature and structure of the support, the amount of catalyst, the solvent, and the temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1121–1129, 2006

A series of polymer–clay composites carrying metribuzin as herbicide moieties were prepared. Linear copolymers containing metribuzin via an imide linkage were prepared by the free-radical polymerization of metribuzin monomer (N,N-diacryloyl metribuzin) with different comonomers. The intercalation of the copolymers onto montmorillonite through a cationic exchange process was carried out and yielded metribuzin composite products. The prepared materials were characterized with a wide variety of analytical techniques, including gel permeation chromatography, NMR, IR, elemental microanalysis, gravimetric analysis (calcination), and swelling measurements. The release rates for the prepared materials were investigated in media of different pHs with an ultraviolet spectrophotometer. Also, these compounds were studied for the control of herb growth. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2513–2525, 2002

Poly(styrene-maleic anhydride)-montmorillonite nanocomposites were prepared by intercalation of layered montmorillonite with the polymer ions. Synthetic approaches including polymerization and phosphonium salt formation have been used for polymer intercalation and dispersion of the host layers in the polymer matrix. The ratio of the mineral in the composites ranged 30–50%. Wide-angle X-ray diffraction (WAXD) disclosed that the d(001) spacing between the internal lamellar surface were only expanding to about 13 and 15 A according to the type of phosphonium salt suggesting packing of polymer molecules between the layers. Examination of these materials by scanning and transmission electron microscopy showed spherical nano size particles of average diameter, 350 nm. Copyright © 2002 John Wiley & Sons, Ltd.

A composite material was prepared by ion exchange between the ammonium salt of the α,ω-diamine-terminated oligo(butadiene-co-acrylonitrile) (ATBN) and the interlamellar cation of the montmorillonite (Na-MMT). Grafted free radical polymerization of both oligo(oxyethylene)methacrylate and chloromethylstyrene supported onto the above composite was prepared. The chloromethyl groups were modified to produce onium salts which are suitable as phase transfer catalysts. The catalytic activities were investigated in nucleophilic reactions of thiocyanate, cyanate and nitrite with alkyl or aryl halides. The effects of the nature and structure of the support, amount of catalyst, solvent, and the temperature on the rate of reactions were studied.

Chapter 3 describes the uses of polymeric materials in agriculture for controlled release formulations of agrochemicals, which are released into the environment of interest at relatively constant rates over prolonged periods to avoid the risk of the active agents being washed away by rain or irrigation. There are a number of agrochemical areas where polymers have been employed either as encapsulation membranes or as convenient supports to chemically attach the active agrochemical groups. In general, all principal classes of polymers have been utilized in agricultural applications for the controlled release of agrochemicals. The polymeric agrochemicals and related biocides described in this chapter include polymeric herbicides, polymeric plant growth regulators, polymeric fertilizers, polymers in stored food protection, polymeric insecticides, polymeric molluscicides, polymeric antifouling paints, polymeric fungicides in wood preservation, and polymeric antimicrobials.

Chapter 4 provides the basic principles for the contribution of reactive polymers in solving problems associated with the procedures used in some areas of food production. Their broad range of applications to food industries include the various types of polymers that have interesting potential for continuous processes, in particular those used in dairy and sugar, fruit juices and beverages industries, beer and wine production. It covers also the potential uses of polymers in tomato sauce production and in potable water. Polymeric materials do not become substantial components of food and are used especially for the purification, recovery, and utilization of by-products. They serve as an aid in food processing and improve food characteristics make food more attractive. The food industry requires suitable polymers to meet the specific requirements for the food industry that simplify food production processes and reduce food production costs, do not deteriorate foods, and do not alter food characteristics. In general, the fundamental principles are based on health protection and preservation of foods quality. The reactive polymers in the form of ion exchange resins, immobilized enzymes, membranes, as well as polymeric smart and nanomaterials, have been utilized in the various areas of the food processing and fabrication industries.

Chapter 1 is divided into two sections that give the background knowledge of the synthesis of polymers and some of their physical properties. The first section is concerned with fundamental and background aspects of the preparation techniques of synthetic polymeric materials either by the condensation or addition polymerization as well as the chemical modification of synthetic and natural polymeric materials (organic and inorganic). In an attempt to examine the fundamental aspects necessary for the utilization of polymeric materials in the various fields of agriculture and food industry, the second section is devoted to the characterization and explanation of some aspects of polymers properties. These properties of the polymeric materials include their physical forms as linear, branched, and cross-linked polymers (micro- and macroporous, micro- and macroreticular, popcorn and macronet polymers), porosity and surface properties, solvation behavior (swelling and solubility), permeation and diffusion, adhesion, and polymer deterioration and stabilization. In addition, it included the conditions employed during the design of the preparation of the advanced polymeric materials such as reactive functionalized polymers, polymer–inorganic nanocomposites, and smart materials.

Chapter 6 focuses on the applications of polymers in food packaging and protection that include polymeric traditional packaging, polymeric coatings in metal-can food packaging, polymeric biodegradable and preservative food packaging, polymeric active packaging, and modified atmospheric and smart food packaging. Traditionally, food packages are used to provide protection for the food products and designed to retard or delay the undesirable effects of the physical, chemical, biological, and environmental factors that extend shelf life and food quality by keeping the food contents clean, fresh, and safe to aid consumers in using the nutritional contents of the food products. Their primary role in food safety is preservation and protection from external contamination, maintenance of food quality, and increase shelf life. They protect foods from the influences of environment effects such as light, heat, oxygen, moisture, enzymes, microorganisms, insects, dust, gaseous emission, and pressure, which lead to the deterioration of food products. Food packages are labeled to show required information on the nutrition of the food content and to communicate the consumer how to use, transport, recycle, or dispose the package, as well as the nature of the deterioration of the product and any subsequent health problems if food is consumed beyond expiry date due to the potential serious nature of consumption of pathogens