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Chitosan (Cs) bis-aldehyde Schiff base derivatives were synthesized by condensation of Cs with three bis-aldehydes namely; butane-1,4-diyl bis(4-formylbenzoate), N,N'-(butane-1,4-diyl)bis(2-(4-formylphenoxy)acetamide) and 4,4'-(butane-1,4-diylbis(oxy))dibenzaldehyde. The prepared Cs derivatives were blended with carboxymethyl chitosan(CMC) and graphene quantum dots (GQDs) to produce semi-IPNs polyelectrolyte complexes (PECs). and characterized with respect to their molecular structure and physio-chemical properties. The antibacterial activity against H. pylori (and in vitro Inosine 5'-monophosphate dehydrogenase IMPDH inhibitory assay) was evaluated. Additionally, a preliminary in vitro assessment for wound healing was performed against PECs in which wound closure percentages, and rates were investigated indicating an accelerated wound healing compared with untreated cells. The PEC based on Schiff base PEC containing amide linkage showed the highest wound healing ability. A minimal inhibitory concentration (MIC) was obtained for the PEC sample containing Cs Schiff base derived from 4,4'-(butane-1, 4-diylbis(oxy))dibenzaldehyde at a dose of 0.98 μg/ml inhibiting H. pylori growth by 100%. Additionally, the selected above-mentioned compound was selected to test its inhibitory activity against the HpIMPDH enzyme in addition to its selectivity towards the hIMPDH2 enzyme and was found to have promising activity against the HpIMPDH enzyme with IC

As huge amounts of hazardous dyes from different industries are causing water pollution, the removal of these compounds from a process or waste effluents becomes a crucial environmental importance. The adsorption method has been found to handle large quantities without the formation of hazardous substances. In spite of the efficiency of the adsorption technique, the high cost of the adsorbent materials is a stumbling block for large scale applications. An eco-friendly, low-cost and efficient adsorbent has been prepared for wastewater management. Hydrolyzed and sulphonated styrene maleic anhydride copolymers, were mixed with chitosan to form nano-polyelectrolyte complexes. Structure, particle size and thermal behavior of the complexes were investigated by spectral and thermogravimetric analyses. The hydrolyzed and sulphonated styrene maleic anhydride chitosan complexes (H-SMA-CS and S-SMA-CS) were examined for the adsorption of Congo red and Maxilon blue as anionic and cationic dyes, respectively. The experimental data of adsorption were found to fit the pseudo-second-order kinetic. The maximum adsorption capacities of Congo red were 234 and 116 mg/g where those of Maxilon blue were 702 and 1830 mg/g on S-SMA-CS and H-SMA-CS, respectively. The isotherm results were well fitted by the Freundlich isotherm.

Ordered meso-porous silica nanomaterials (MCM-41) were prepared by the sol-gel method. Brunauer–Emmett–Teller (BET) analysis shows a surface area of about 1600 m2/g and a wide meso-pores distributi...

Submitted by Vivian Rosa Storti (vivian.storti@unesp.br) on 2020-07-17T19:51:27Z No. of bitstreams: 1 fraceto_lf_preprint_soro_chitosan based.pdf: 1980257 bytes, checksum: b08f727769720bd1c874a20652ecd8ad (MD5) Approved for entry into archive by Vivian Rosa Storti (vivian.storti@unesp.br) on 2020-07-17T19:54:40Z (GMT) No. of bitstreams: 1 fraceto_lf_preprint_soro_chitosan based.pdf: 1980257 bytes, checksum: b08f727769720bd1c874a20652ecd8ad (MD5) Made available in DSpace on 2020-07-17T19:54:40Z (GMT). No. of bitstreams: 1 fraceto_lf_preprint_soro_chitosan based.pdf: 1980257 bytes, checksum: b08f727769720bd1c874a20652ecd8ad (MD5) Previous issue date: 2020-03-17 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Chitosan has been termed as the most well-known of these biopolymers, receiving widespread attention from researchers in various fields mainly, food, health, and agriculture. It is a deacetylated derivative of chitin, mainly isolated from waste shells of the phylum Arthropoda after their consumption as food. Chitosan molecules can be easily modified for the adsorption and slow release of plant growth regulators, herbicides, pesticides, and fertilizers, etc. Chitosan as a carrier and control release matrix offers many benefits including; protection of biomolecules from harsh environmental conditions such as pH, light, and temperatures and slow, prolonged release of active ingredients from its matrix consequently protecting the plant's cells from the hazardous effects of burst release. In the current review, we will discuss the recent advances in the area of chitosan application as a control release system. In addition, future recommendations will be made in light of current advancements and major gaps. Preprint Institute of Biotechnology, Ankara University, Turkey Ankara University, Faculty of Agriculture, Department of Field Crops, Turkey São Paulo State University (UNESP), Institute of Science and Technology of Sorocaba, Department of Environmental Engineering, Sorocaba, Brazil Egyptian Petroleum Research Institute, Nasr City, Cairo, Egypt EPRI-Nanotechnology Center, Egyptian Petroleum Research Institute, Cairo, Egypt Department of Biotechnology and Molecular Biology, Faculty of Science and Letters, Aksaray University, Aksaray, Turkey epartment of Chemistry, Faculty of Science, Cairo University, Cairo, Egypt Biorefinery Processes Research Group, Department of Chemical and Environmental Engineering, University of the Basque Country (UPV/EHU), Donostia-San Sebastian, Spain Department of Agriculture, The University of Swabi, Anbar, Swabi, Khyber Pakhtunkhwa, Pakistan College of Life Science, Linyi University, Linyi Shandong, China FAPESP: 2017/21004-5

A new antimicrobial polyelectrolyte polymer was prepared based on chitosan and alternating styrene maleic anhydride (SMA) copolymer. The SMA was subjected to alkaline hydrolysis, followed by blending with chitosan and chitosan in the nano form which has been prepared by self-assembly technique with particle size 46±0.08 nm. The composition was investigated and characterized by spectral and, thermogravimetric analysis, dynamic light scattering, and transmission electron microscopy. The nano polyelectrolyte complexes and composite were screened for their antimicrobial behavior and showed excellent antifungal as well as antibacterial efficacy against four bacterial and fungal strains. The hydrolyzed styrene maleic anhydride-nano-chitosan exhibited higher antimicrobial activity than the hydrolyzed styrene maleic anhydride-chitosan.

The review summarizes the various methods of preparing wholly aromatic polyamide–hydrazides (PAHs). Polyhydrazides are a class of polymers that possess in their repeating units one amide (–NHOC–) and one hydrazide (–CONHNHOC–) linking bond between appropriate aromatic nuclei. The review provides several figures of different molecular structures of PAH and expounds the methods of polymerization, low, high temperature, and phosphorylation polycondensation methods. Polyhydrazides exhibit some unique and potentially useful properties such as outstanding thermal and thermo-oxidative resistance, very high mechanical strength, and ultrahigh moduli. PAHs undergo structural transformation into poly(amide-1,3,4-oxadiazole)s upon heating, which are also considered highly thermally stable polymers. The review presents a description of the structure–property relation of PAHs. The application of PAHs in reverse osmosis applications has been discussed, as well as the preparation of fibers and metallized PAHs films. Modification of the PAH with carbon nanotubes and graphene and the future prospects for PAHs were introduced with comprehensive references pertaining to this area of research.

Three heteroaryl pyrazole derivatives; namely 1-phenyl-3-(thiophene-2-yl)-1H-pyrazole-4-carbaldehyde, 1-phenyl-3-(furan-2-yl)-1H-pyrazole-4-carbaldehyde and 1-phenyl-3-(pyridine-3-yl)-1H-pyrazole-4-carbaldehyde were synthesized and reacted with chitosan to form Schiff bases of chitosan. All newly synthesized compounds have been characterized by solubility tests, elemental analysis, spectral (FTIR, 1H NMR) analyses, thermogravimetric analysis and X-ray diffraction (XRD). The Schiff bases were screened for their biological activity against gram-negative bacteria (Escherichia coli and Klebsiella pneumonia), gram-positive bacteria (Staphylococcus aureus and Streptococcus mutans) and fungi (Asperagillus fumigatus and Candida albican). The results indicated that the antimicrobial activity was dependent on the type of the Schiff base moiety. Cytotoxicity of the prepared chitosan derivatives was evaluated by MTT assay and the results indicated the absence of cytotoxic activity.

In this research Poly (styrene-maleic anhydride) (SMA) copolymer was chemically modified with two amino thiophene derivatives; ethyl 2-amino 4, 5, 6, 7-tetrahydrobenzo thiophene-3 carboxylate (EATTC) and of 2-amino 4, 5, 6, 7-tetrahydrobenzo thiophene- 3 cabonitrile (ATTCN). The obtained products SMA-N- thioph- COOEth (E1) and SMA-N- thioph- CN (E2) were investigated by means of IR, NMR, X-ray diffraction (XRD), thermogravimetric and elemental analysis. The adsorption properties of the products toward Cu (II) and Cd (II) ions were evaluated. Various factors affecting the uptake behavior such as pH, concentration and adsorption time on the extent of Cu (II) and Cd (II) absorption were studied. It was found that Cu absorption is higher than that of Cd which may be attributed to the larger size of Cd ions. The equilibrium removal performance of the SMA modified copolymer is analyzed according to the Langmuir and Freundlich adsorption isotherm models that show result fitted to both models. The experimental results showed that copper absorption by the SMA modified copolymer was achieved in 60 min and that the loading capacity reached 453 and 110 mg g−1for Cu (II) and Cd (II) respectively, at pH 5-6 which was found to be an optimum condition.

Siliconized epoxy matrix systems have been developed using diglycidyl ether bisphenol A LY556 epoxy resin as a base, hydroxyl-terminated polydimethylsiloxane as modifier, and γ-aminopropyltriethoxysilane as cross-linking agent together with dibutyltin dilaurate as a catalyst. Triethylene tetramine was used as a curing agent. Electrical-resistant glass (E-glass) and ultra-high-molecular-weight polyethylene (spectra)-reinforced composites are fabricated by hand-layup technique using the siliconized epoxy matrix systems. The effect of siloxane and the two fibers on the thermal and morphological characteristics of the siliconized epoxy polymer composites were studied using thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. The study reveals that the thermal stability of the epoxy systems is enhanced when siloxane is incorporated in them. Morphological studies show that the E-glass fiber reinforcement has better intermolecular adhesion to the epoxy resin than spectra reinforcement due to the presence of ionic sites.

Chitosan is obtained from chitin, which could be considered to be the most abundant polymer after cellulose. Owing to these properties, chitosan alone or chitosan-based composite film production is attaining huge attention in terms of applications from researchers and industrialists coming from divergent fields. To enhance the biological (mainly antimicrobial and antioxidant) and physiological (mainly mechanical, thermal and barrier) attributes of the chitosan-based films, a vast medley of plant extracts and supporting polymers has been blended into chitosan films. Considering the up to date literature reports based on chitosan film production and applications, it can be stated that still, the research ratio is low in this field. Chitosan blend/composite films with specific properties (superhydrophobicity, excellent mechanical strength, acceptable barrier properties) can be produced only for specific applications in food technology. In the current review, we tried to summarize the advancements made in the last 5–7 years in the field of chitosan film technology for its application in the food industry.

Polypropylene (PP) film activated by corona discharge treatment was grafted with methyl methacrylate (MMA) and acrylic acid (AA). The grafted PP was characterized by spectral, thermal analysis and swelling behavior which confirmed the occurrence of the grafting. The water vapor and oxygen permeability (OTR and WVTR) as well as the mechanical properties have been enhanced by grafting with both AA and MMA. The grafted PP was further immobilized with chitosan (CS) using ceric ammonium nitrate (CAN) as an initiator under ultraviolet radiation. The chitosan immobilized grafted film was characterized by FTIR, mechanical properties, thermal properties and swelling measurements. Scanning electron microscope (SEM) confirmed that the CS is bonded to the grafted PP film. The CS modified PP film has acquired enhanced antibacterial and antifungal properties.

Poly(amide-hydrazide)s copolymers were prepared using hydrazide derivative of phenylene diamine to react with aromatic diacid chloride. The wholly aromatic poly(amide-hydrazide)s have better solubility in organic polar solvents, such as N,N-dimethylacetamide, dimethylsulfoxide, 1-methyl-2-pyrollidone, and N,N-dimethylformamide, at room temperature, while still maintaining their high thermal stability. Graphene in the nano size was used as a filler to enhance their thermal and mechanical properties. The polymers as well as the composite were characterized by spectral and mechanical tools as well as by X-ray analysis. POLYM. COMPOS., 38:1311–1318, 2017. © 2015 Society of Plastics Engineers

Copolymer of styrene, and vinylpyrrolidone was prepared by various techniques. Different nanometals and nanometal oxides were added into the copolymer as antimicrobial agents against Sulfate Reducing Bacteria (SRB). The nanocomposite chemical structure was confirmed by using FTIR, 1H NMR spectroscopy and thermogravimetric analysis (TGA). The biocidal action of these nanocomposites against the SRB was detected using sulfide determination method in Postgate medium B. The data indicated that the nanocomposites had an inhibitory effect on the growth of SRB and reduced the bacterial corrosion rate of mild steel coupons. The prepared nanocomposites have high inhibition efficiency when applied as coatings and show less efficiency when applied as solids or solution into SRB medium. The copolymer and its nanocomposites effectively reduced the total corrosion rate as determined by total weight loss method.

Chitosan is a biodegradable biocompatible polymer derived from natural renewable resources with numerous applications in various fields, and one of which is the area of edible films and coatings. Chitosan has antibacterial and antifungal properties which qualify it for food protection, however, its weak mechanical properties, gas and water vapor permeability limit its uses. This review discusses the application of chitosan and its blends with other natural polymers such as starch and other ingredients for example essential oils, and clay in the field of edible films for food protection. The mechanical behavior and the gas and water vapor permeability of the films are also discussed. References dealing with the antimicrobial behavior of these films and their impact on food protection are explored.

In this article, a new aspect of comparing oil dispersion efficiency and stability using eco-friendly surfactants and nanoparticles of the same natural origin was carried out. Nanoparticles effectively disperse oil in water as well as do surfactant but with different actions; surfactants act by reducing the interfacial tension between oil and water leading to the distribution of oil in water while nanoparticles give stable and uniform distribution of oil in water depending on oil trapping inside the polymer matrix. As a result, the dispersion stability of nanoparticles was found to be superior to that of surfactant.

Chitosan was grafted with a novel monomer 1-Cyanoethanoyl-4-acryloylthiosemicabazide (CEATS). The graft copolymerization was conducted using potassium persulfate (K2S2O8) and sodium bisulfite (NaHSO3) as redox initiators. The grafted samples were characterized by FTIR spectroscopy, scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis. The data may indicate that grafting has occurred at the surface of chitosan. The grafted samples showed high water swelling. The antifungal behavior of chitosan and its graft copolymers was investigated in vitro and it has been found that grafting with CEATS noticeably enhances the antifungal activity.

Aromatic diamine and phthaloyl chloride have been copolymerized using interfacial polymerization technique. Ethylene diamine (EDA) in 20, 30, and 40% and diamino butane (DAB) with the same molar ratio were used in addition to p-phenylene diamine to prepare polyamide with aliphatic components in the chain. The copolymers were characterized by FTIR Viscosity measurements were obtained in concentrated sulphuric acid.Thermogravimetric analysis and DrTGA showed that the thermal stability of the prepared polymers decreases by in- creasing of the ratio of the aliphatic diamines. The aliphatic content affects the crystallinity of the prepared polymers as was shown by X-ray diffraction measurements. Scanning electron microscopy revealed that the aliphatic components cause the copolymers to have a more homogeneous appearance with a different morphology. The mechanical parameters (Longitudinal modulus, L, shear modulus, G, Young's modulus, E, bulk modulus, K, and Poisson's ratio, p) were calculated from ultrasonic velocities and the densities of the isotropic materials. All mechanical characteristics were found to decrease with increasing aliphatic percent.

Graft polymerization of N-vinylpyrrolidone onto poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV was carried out in solution. The evidence of grafting was provided by FTIR, and 1H-NMR. The DSC results showed that the cold crystallization temperature from the glass state increased with increase of grafting %. TGA analysis revealed that the thermal stability of the host PHBV was improved remarkably with increasing extent of grafting. The swelling of the graft copolymer in water increases with increasing G%. The antibacterial activity of PHBV-g-PVP copolymers was improved dramatically with the extent of grafting. The biodegradability of PHBV and its graft copolymers was investigated in active soil.

Ethyl 2-acrylamido-4,5,6,7-tetrahydrobenzo [b] thiophene-3-carboxylate (ETTCA) has been synthesized and its structure has been elucidated by elemental analysis and spectral tools. Free radical polymerization of (ETTCA) has been conducted in several solvents using azobisisobutyronitrile (AIBN) as an initiator. The kinetic parameters of polymerization of the ETTCA were investigated, and it was found that the polymerization reaction follows the conventional free radical scheme. The overall activation energy of polymerization Δ E was determined (Δ E = 45.11 kJ mol −1 ). The copolymerization of ETTCA with three conventional monomers was carried out in dioxane at 65 °C. The monomer reactivity ratios for the copolymerization of ETTCA with methyl methacrylate (MMA), vinyl acetate (VA) and vinyl ether (VE) were calculated. Thermal stability of the ETTCA polymer and its copolymers were investigated by thermogravimetric analysis. It has been found that the prepared polymer (PETTCA) and its copolymers with VA have moderate biological activity and highly dependent on the copolymer composition.

Chitosan is a polysaccharide that has gained interest in recent to encapsulate active compounds due to its non-toxicity, biodegradability, biocompatibility and immunity system induction. The chitosan nanoparticle was prepared by adding vitamin C to tripolyphosphate (TPP) solution and then blending it stepwise to the chitosan solution under stirring. Nanoparticle characterizations were analyzed by scanning electron microscopy (SEM) and Zetasizer. The release profile of vitamin C into the gastrointestinal and serum of rainbow trout (Oncorhynchus mykiss) was portrayed and its effect on the immunity system of the fish was determined as well. The results showed that the chitosan nanoparticle had spherical shape; positive charge with particle size of 185 nm and in vivo controlled release until 48 h. Lysozyme and complement contents in the fish serum increased as long as they were provoked by the nanoparticle. This nanoparticle is a promising technique to boost immunity system of fish.

Lactosaminated N-succinyl-chitosan (LNSC), a water-soluble biodegradable derivative of chitosan, was prepared, characterized, and investigated for nuclear imaging and body distribution. The labeling efficiency of LNSC was examined with 99mTc, and the obtained complex was used as liver-targeted delivery system in vivo for nuclear imaging, and its biodistribution within the body was studied. The labeling efficiency with 99mTc was investigated for time of reaction, effect of substrate amount, effect of stannous chloride (SnCl2) concentration, and effect of the pH of the reaction mixture, in order to approach the optimum condition for labeling technique. It was found that the maximum yield for labeling of 2.5-mg 99mTc-LNSC was 96.9% when 50 µg of SnCl2 was used at pH 3.5–5, at room temperature and 5-min reaction time. An in vivo biodistribution study of radiolabeled LNSC was carried out in female Wistar rats, and the body distribution profile was recorded by gamma scintigraphy. The biodistribution of 99mTc-labeled LNSC (99mTc-LNSC) in each organ was calculated as a percentage of the injected dose per gram of tissue (%ID/g). 99mTc-LNSC was shown to be a highly potential approach for liver imaging. Moreover, the rapid excretion of LNSC through the kidneys suggests that water-soluble chitosan derivatives are good carriers of radioactive elements that do not accumulate in the body. The results indicate that the easy and inexpensive extraction, and thus the ready availability, of chitosan and its derivatives makes them potentially useful for applications in scintigraphic imaging.

Carboxymethyl chitosan, (CMC), and N-lauryl-carboxymethyl chitosan (LCMC), have been prepared as water soluble derivatives of chitosan. These biodegradable chitosan derivatives were characterized and investigated for nuclear imaging and body distribution. They were labeled with 99mTc to use them as targeted delivery to some organs in vivo for nuclear imaging and to follow their biodistribution within the body. The factors controlling the labeling efficiency have been investigated. The percent labeling yield was determined by using ascending paper chromatographic technique. In vivo biodistribution studies of radiolabeled chitosan derivatives were carried out in groups of female Wistar rats, the body distribution profile in rat was recorded by gamma scintigraphy and the biodistribution of 99mTc-labeled compounds in each organ was calculated as a percentage of the injected dose per gram of tissue (%ID/g). It has been found that the biodistribution of the two compounds and the pattern of their liver uptake were markedly different. The present study demonstrates a high potential approach for liver imaging using 99mTc-LCMC. An intriguing finding of this study was that the three samples were excreted rapidly via the kidneys because of the water-soluble nature of chitosan derivatives. This suggests that water-soluble chitosan derivatives are good polymeric carriers for radioactive element that overcomes accumulation in the body. Moreover, the easy and inexpensive availability of chitosan could be beneficial for applications in scintigraphic imaging.

This work deals with the grafting of N-isopropyl acrylamide (IPA) onto poly (3-hydroxybutyrate-3-hydroxyvalerate), (PHBV) (5.4 mole % 3-hydroxyvalerate), using benzoyl peroxide as free radical initiators. The effect of N-isopropyl acrylamide and initiator concentrations and reaction time on the degree of grafting has been investigated. The maximum degree of grafting was 82%. The grafted products were characterized by FTIR, 1 HNMR, DSC, wide-angle X-ray diffraction and TGA analysis. The DSC results showed that the cold crystallization temperature from the glassy state increased with increasing the extent of grafting, while the Tg and Tm are not affected significantly. TGA analysis revealed that grafting of the host PHBV polymer did not affect much its onset decomposition temperature. The Grafted products swell in aqueous solution and the swelling is controlled by the extent of grafting, temperature, and pH. The biodegradability of PHBV and its graft copolymers solution-cast films was investigated in active...

Chitin is the second most abundant carbohydrate polymer in nature next to cellulose. The main source of chitin is crustacean shells. Chitosan, derived from chitin by alkaline deacetylation, characteristically plays an important role in applications. Several parameters determine the chitosan specifications, namely, chitosan sources, incubation time, pretreatment conditions, temperature and acid and alkaline treatment. Chitosan extraction has been achieved by microwave heating and compared with that of conducting the deacetylation in an autoclave. High molecular weight chitosan (as determined by viscosity measurements of chitosan in dilute acetic acid solution), white color, high water binding capacity (WBC) and fat binding capacity (FBC) has been obtained by microwave treatment. In addition, microwave treatment saves a large amount of energy (due to the shorter time of heating) which is a very important factor for commercial productions. The data extracted from X-ray diffraction, nuclear magnetic resonance and Fourier transforms infrared spectroscopy have shown more crystalline and higher DDA of chitosan produced in microwave than the one in autoclave. Moreover, the antibacterial activity of chitosan prepared by microwaves was higher than that produced using the autoclave.

Chitosan with different molecular masses was reacted with sodium tripolyphosphate (STPP) to prepare different size nanoparticles, in which vitamin C was encapsulated. The effect of molecular weight (Mw) on nanoparticles efficiency, nanoparticles yield, size, and zeta potential was investigated in detail. Low Mw chitosan generated nanoparticles with better size, morphology, and delivery rate. In addition, the shelf life of encapsulated vitamin C increased as compared with its non-encapsulated counterpart. The release of vitamin C from the nanoparticles was pH-dependent. Quick release took place in 0.1 M phosphate buffer solution (PBS, pH 7.4), while the release was slow in 0.1 M HCl. In addition, in vivo release rate in digestive tract of rainbow trout nearly showed the same trend as the in vitro one.

Two modified chitosan polymers were obtained by reaction of chitosan with cinnamoyl chloride and cinnamoyl isothiocyanate to produce two new derivatives. The new modified polymers were characterized by elemental and spectral analysis to confirm their structures. Their metal up take capacity was investigated both under competitive and noncompetitive conditions. At pH 5.6, the (ChitoCin and ChitoThioCin) polymers exhibit higher capacity for Cu(II) (0.461–0.572 mmol/g) than the other metal ions used. Where the capacities of the other metal ions are: Fe(III) (0.235–0.341 mmol/g), Cr(III) (0.078–0.099 mmol/g), Co(II) (0.046–0.057 mmol/g) and Ni(II) (0.041–0.053 mmol/g). These results show that the capacity of ChitoThioCin polymer is higher than that of ChitoCin for each metal ion. However, at lower pH the capacities (for Cr(III) pH

Fifteen organic compounds were prepared from triethanolamine and its derivative. The triethanolamine was polymerized by condensation to get P4, P6, and P8 at different molecular weight. The P8 was ethoxylated at different ethylene oxide units (en) (40, 100, and 120) to obtain three compounds (E(en)P8). Every degree of ethoxylate was esterified with 1, 4, and 8 moles of oleic acid to get on 9 ethoxylated polytriethanolamine esters (E(en)P8Om). The effect of adding these organic compounds on the electrochemical behavior of carbon steel in 1 M HCl was investigated by using the weight loss technique. The reported results in this study show that the addition of these surfactants inhibits the corrosion of carbon steel. The inhibition efficiency (I%) for each inhibitor increases with increasing the concentration. The maximum inhibition efficiency (95%) was obtained by (E(40)P8O1) at 600 ppm. The inhibitive efficiency was discussed on the light of chemical structure of the used inhibitors.

New modified surfactants were developed by esterification of ethoxylated polytriethanolamine with oleic acid. Triethanolamine was polymerized at three different times 1.30, 2.30, and 3.30 hours to give (P4, P6, and P8) where 4, 6, and 8 refer to the degree of polymerization. The prepared polymer (P8) was ethoxylated at three different molar ratios of ethylene oxide (40, 100, and 120) and named E(en)P8. Then the ethoxylated polymers were esterified with oleic acid and abbreviated as E(en)P8Om. The surface properties for these surfactants were determined by measuring the surface tension. The structure was confirmed using the elemental analysis, (FTIR, 1H, 13C NMR) spectroscopic.

Ethyl 2-amino 4,5,6,7-tetrahydrobenzo thiophene-3-carboxylate maleimide (ETTCM) has been synthesized and investigated as a new thio-maleimide derivative. The structure of the prepared compounds has been elucidated by elemental and spectral analyses. The free radical polymerization of (ETTCM) has been conducted in several solvents using azobisisobutyronitrile (AIBN) as an initiator. The kinetic parameters of polymerization of ETTCM were investigated, and it was found that the polymerization reaction follows the conventional free radical scheme. The initial rate of polymerization, the overall activation energy Ea was determined (Ea = 57.013 kJmol−1) and intrinsic viscosity was measured ([η] = 0.04 dl/g). The prepared polymer is a good chelating agent with some metal ions and a moderate antifungal and antibacterial effect. The monomer reactivity ratios for the copolymerization of ETTCM with methyl methacrylate MMA, vinyl acetate VA, and vinyl ether VE were calculated by two methods, the Kelen-Tudos and a non...

Chitosan was grafted with a novel monomer namely Acryloyl cyanoacetohydrazide (ACAH) which contains carbonyl and cyano groups. The graft copolymerization was conducted in heterogeneous phase using potassium persulfate (K2S2O8) and sodium bisulfite (NaHSO3) as redox initiators. The effect of monomer concentration, initiator concentration and ratio, time and temperature on the extent of grafting (G%) and the efficiency of grafting were studied. Homopolymer formation has not been observed under all the investigated conditions. The grafted samples were characterized by FTIR spectroscopy, X-ray diffraction and thermogravimetric analysis. The crystallinity of the used chitosan was reduced by grafting. Dye uptake of the grafted samples towards the different types of dyes (acidic, and basic) was investigated and was found to improve profoundly over the native chitosan with a higher uptake for the acidic dye. The grafted samples showed an increased swelling in water, which increased further upon quaternization of the graft copolymers. The extent of swelling is higher in acidic and basic media more than in neutral pH. The quaternized graft copolymer was found to be soluble in water. The fungicidal activity of the quaternized graft copolymers towards three soil-borne sugar beets pathogens was investigated in vitro. The effect on the micro organisms is proportional to the amount of ACAH in the graft copolymer.

This review discusses the definition of surface active agents and specifically natural polymeric surface active agents. Chitosan by itself was found to have weak surface activity since it has no hydrophobic segments. Chemical modifications of chitosan could improve such surface activity. This is achieved by introducing hydrophobic substituents in its glucosidic group. Several examples of chitosan derivatives with surfactant activity have been surveyed. The surface active polymers form micelles and aggregates which have enormous importance in the entrapment of water-insoluble drugs and consequently applications in the controlled drug delivery and many biomedical fields. Chitosan also interacts with several substrates by electrostatic and hydrophobic interactions with considerable biomedical applications.

Chitin in the α and the β forms has been extracted from different marine crustacean from the Arabian Gulf. The contents of the various exoskeletons have been analyzed and the percent of the inorganic salt (including the various elements present), protein and the chitin was determined. Deacetylation of the different chitin produced was conducted by the conventional thermal heating and by microwave heating methods. Microwave heating has reduced enormously the time of heating from 6–10 h to 10–15 min, to yield the same degree of deacetylation and higher molecular weight chitosan. This technique can save massive amount of energy when implemented on a semi-industrial or industrial scale. The chitin and the obtained chitosan were characterized by elemental analysis, XRD, NMR, FTIR and thermogravimetric measurements. XRD analysis showed that chitosan has lower crystallinity than its corresponding chitin; meanwhile its thermal stability is also lower than chitin.

The free radical terpolymerization of indene (In), methyl methacrylate (MMA) and acrylonitrile (AN) has been investigated. The rate of polymerization of all the binary systems involved has been measured dilatometrically for the homogeneous polymerization. The reactivity ratios of the three binary systems were calculated and were found to be equal to 0.031 and 0.397 for In/AN copolymers and 0.02 and 3.82 for In/MMA copolymers and finally 0.152 and 1.20 for AN/MMA copolymers. The rate of terpolymerization in bulk has been measured as well as the relationship between the monomer mixture composition and the obtained terpolymer in order to construct the compositional triangle. Also the effect of initiator concentration on the rate of terpolymerization was investigated. The activation energy of terpolymerization was determined. The terpolymers were characterized by spectral and thermo-gravimetric analyses. The data indicates that polyindene improves the thermal stability of the prepared terpolymers.

A series of castor oil adducts were synthesized by esterification of castor oil with acid anhydrides: phthalic, maleic and succinic anhydrides. The chemical structure of castor oil and the prepared adducts were characterized by means of IR and 1 H NMR spectroscopy. The number-average and weight-average molecular weights were measured by gel permeation chromatography. The electrical properties were studied through the permittivity, dielectric loss and conductivity measurements, which are considered to be in the range of electrical insulation. The electrical conductivity, which describes the ionic mobility of the systems, was found to be in the range of 10 -9 to 10 -12 S/cm. This indicates that castor oil and its esters could be used for antistatic applications. The viscosity η and the activation energy E n , obtained from the dependency of viscosity on temperature using the Arrhenius equation, were found to increase with increasing molecular weight of the system. The effect of different concentrations of castor oil and its esters on the growth activities of the sugar beet pathogens R. solani and S. rolfsii was studied through the determination of percent germination, average length of hyphal extensions, dry mass yield and the production of sclerotia. The obtained data indicate that the esterification of castor oil with anhydrides improves the antifungal activity.

Polypropylene (PP) films were irradiated with corona discharge then dipped into acidic solutions of chitosan extracted from different sources. The films were examined as for their antifungal and antibacterial properties. Carboxymethyl chitosan and carboxymethyl chitin were found also to adhere to these corona treated PP films. The antifungal and antibacterial properties of these derivatives were also examined and found to be even superior to the chitosan itself. Chitosan forms complex compounds with pectin and this property was used to build up a stable multilayered structure on the PP film surfaces to produce a much better antimicrobial films which can be used to fabricate excellent packaging materials for post-harvest crop protection.

Four demulsifiers were prepared in three steps. In the first step, styrene and maleic anhydride were copolymerized. In the second step, a long-chain alcohol (dodecanol) was reacted with the prepared copolymer to form the monoesterified copolymer. In the final step, the resulting product was further esterified with poly(propylene oxide) (PPO)–poly(ethylene oxide) (PEO) block copolymers of different molecular weights (1.1, 2.5, 3.0, 5.0, and 8.0 × 103) and different PPO/PEO ratios. The demulsification efficiency of these demulsifiers was investigated with the bottle test (Sany glass). The effects of the molecular weight and ratio of the PPO–PEO block copolymers on the demulsification efficiency were studied. The demulsification efficiency could be enhanced from 66% by an individual demulsifier to 100% by demulsifier blends. The surface-active and thermodynamic properties of the prepared demulsifiers were measured at 25, 35, and 45°C. The kinematics of the demulsification process were photographed with a binocular microscope. The demulsification mechanism was found to occur in three stages, that is, adsorption and flocculation, coalescence, and channel formation followed by separation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Nonwoven polypropylene and cotton fabrics were subjected to plasma pretreatment followed by flash evaporation and radiation crosslinking acrylate polymer coating, which is based on a vacuum deposition, solvent free, process that produces high quality, uniform fabrics with various thicknesses (0.05–5.0 μm). These treated fabrics were then dipped into chitosan, carboxymethyl chitosan, and carboxymethyl chitin solution. These polysaccharides form strong complexes with the modified surface. The antimicrobial activity of these treated samples was then evaluated for their antifungal and antibacterial properties. The antifungal activity for Fusarium oxysporum f. sp. lycopersici, Verticillium albo-atrum, and Alternaria solani (A. alternata) were examined by the disc plate method. The antibacterial activities of the modified fabrics against Clavibacter michiganensisand Pseudomonas solanacearum were also examined by the viable cell counting method. The inhibition zone of the chitosan covered samples has increased by a factor of 2–3.1 over the original pretreated samples. The chitosan-modified fabrics showed a good antibacterial activity in killing almost 105 cells/mL within 18–23 h. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

A series of alkyl-grafted copolymers based on styrene-maleic anhydride (SMA) copolymers were synthesized by esterification of SMA with several long chain normal aliphatic alcohols. The prepared copolymers were characterized by FT-IR and 1H NMR and DSC. The dielectric behavior of these copolymers was investigated in the frequency 20–105 Hz and temperature −40 to 180 °C ranges. Two relaxation processes were observed, α, and β-relaxation. The former is associated with the glass-rubber transition and is characterized by the Vogel–Fulcher–Tammann temperature dependence and the latter relaxation is related to the local motion of the ester side groups attached to the polymer backbone. The apparent activation energy for the β-relaxation was found to depend significantly on the alkyl chain length. The dielectric analysis of the β-relaxation process detected is discussed.

Chitosan (CS) was modified by reaction with benzoyl thiocyanate to give a thiourea derivative (TUCS). The antifungal behavior of chitosan and its thiourea derivative was investigated in vitro on the mycelial growth, sporulation and germination of conidia or sclerotia of the following sugar-beet: Beta vulgaris pathogens isolated in Egypt, Rhizoctonia solani Kühn (AG(2-2)) Sclerotium rolfsii Sacc. and Fusarium solani (Mart.) Sacc. All the prepared thiourea derivatives had a significant inhibiting effect on the different stages of development on the germination of conidia or sclerotia of all the investigated fungi in the polymer concentration range of 5-1000 microg ml(-1). In the absence of chitosan and its derivative, R. solani exhibited the fastest growth of the fungi studied. However, growth tolerance of the modified chitosan was highest for F. solani and lowest for R. solani. The most sensitive to the modified chitosan stress with regard to their germination and number produced were the sclerotia of S. rolfsii. It has been found that the TUCS is a much better fungicidal agent (about 60 times more) than the pure CS against most of the fungal strains tested. The molecular weight and the degree of deacetylation were found to have an important effect on the growth activities of the pathogens.

Modification of chitosan by grafting with 4-vinylpyridine (VP) was carried out both in homogeneous and heterogeneous phases, using potassium persulfate (K2S2O8) and sodium bisulfite (NaHSO3) as redox initiators. The effect of monomer concentration, initiator concentration and redox ratio, time and temperature on the extent of grafting (G%), homopolymer formation, and the efficiency of grafting were studied. Values of grafting percentages up to 96% were reached in heterogeneous conditions and up to 130% in homogeneous conditions (in 5% acetic acid). The grafting was confirmed by FTIR and 1H NMR spectroscopy. The grafted samples were characterized by scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis. The crystallinity of the used chitosan was not affected by grafting, it even increased slightly. Dye uptake of the grafted samples towards the different types of dyes (acidic and basic) was investigated and was found to improve profoundly over the native chitosan with a higher uptake for the acidic dye. The grafted samples showed an increased swelling in water, which increased further upon quaternization of the graft copolymers. The extent of swelling is higher in acidic and basic media more than in neutral pH. The grafted copolymers are soluble with difficulty in warm acetic acid solution. The quaternized graft copolymer was found to be soluble in water. The biological activity of the quaternized graft copolymers (G = 130 and 80%) was investigated and was found to have an inhibition effect on both the Azotobacter fungus and the bacterium Fusarium oxysporium. The effect on the micro organisms is proportional to the amount of VP in the graft copolymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3308–3317, 2006

Modification of chitosan by grafting with vinyl acetate (VAc) was carried out using potassium persulfate and sodium bisulfite as redox initiators. The effect of monomer, initiator concentration, time, and temperature was studied. The grafted samples were subjected to alkaline hydrolysis and the polyvinyl acetate (PVAc) branches were consequently partially converted into polyvinyl alcohol (PVAl) graft, which showed enhanced swelling in water. The graft copolymers showed a better dye uptake for both acidic and basic dyes. Chitosan/VAc and chitosan/VAl copolymers were both subjected to reaction with dimethyl sulfate in alkaline medium to yield quaternized copolymers. The antifungal behavior of chitosan and its graft copolymers was investigated in vitro on the mycelial growth, sporulation, and germination of conidia or sclerotia of the following sugarbeet: Beta vulgaris pathogens isolated in Egypt, Rhizoctonia solani Kuhn (AG2-2) Sclerotium rolfsii Sacc. and Fusarium solani (Mart.) Sacc. These polymers were also screened against several fungi and it has been found that grafting with polyvinyl alcohol branches enhances the antifungal activity dramatically. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1651–1663, 2007

The blends of chitosan, polyvinyl alcohol and chitosan polyvinyl pyrrolidone in dilute acetic acid were found to be compatible by viscosity measurements. The dielectric behavior of the investigated blends were studied using frequency response analyzer covering a frequency range from 10 2 to 10 6 Hz and in a wide range of temperature. The permittivity e ′ was found to decrease by increasing the frequency showing an anomalous dispersion. The dielectric loss e ″ data on the frequency domain were found to be broad indicating that more than one relaxation mechanism is present. The data for the whole investigated systems were fitted using Frohlich and/or Havriliak–Negami functions in addition to the conductivity term. The function detected below T g could be ascribed to an orientation movement related to the side chain. A second function in the lower frequency range could be ascribed as a Maxwell Wagner effect which arises from the interfacial polarization caused by the multi-constituents of the investigated systems. The biological activity of such investigated systems was tested against a representative number of pathogenic organisms by determining the minimum inhibitory concentration (MIC). The activity was found to increase by increasing the amount of CS in the blend.

Terpolymer samples were prepared by free radical polymerization of methyl methacrylate (MMA), indene (In) and acrylonitrile (AN) in bulk. The samples were chosen so that the molar ratio of AN to MMA varied from 1.00:4.39 to 1.00:0.83, while the molar ratio of In was kept almost unchanged. The glass transition temperatures (Tg) of the samples were determined using differential scanning calorimetry. Moreover, isochronal dynamic mechanical measurements of the complex bending modulus as well as the complex dielectric permittivity were carried out over wide temperature ranges, namely from 50 to 190 °C, depending on the material investigated. All samples exhibited a single common Tg value, which increased to higher temperature upon increasing the content of AN. In addition, the results were investigated quantitatively in the framework of a molecular model. Copyright © 2006 Society of Chemical Industry

N-p-Cyano-phenyl maleimide PCPMI was prepared and copolymerized with ethyl and butyl methacrylate in order to study the effect of introducing a strong dipole along the polymer backbone. The copolymer composition was determined by elemental analysis and 1H NMR spectroscopy. The molecular mass of the copolymers was determined by GPC. The glass transition temperature was measured and it was found to correlate well with the chemical structure, and increases with the increase of the maleimide content. The dielectric behavior of the homo methacrylate polymers and the copolymers was measured in the frequency range of 0.01 Hz to 10 MHz at different temperatures. The dielectric data were compared with the two Cole–Cole parameters equation. The glass transition temperature obtained from DSC measurements agreed well with the dielectric relaxation data.

1-Cyanoethanoyl-4-acryloyl thiosemicarbazide (CEATS) has been prepared and polymerized by a free radical mechanism. The polymer PCEATS has chelating affinity, and metal-uptake capacities were determined for the chlorides of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) in the pH range 1.04–6.0. The extraction experiments show high capacity for Cu(II), (0.26 mmol/g) at pH 5.34 and lower uptake capacities for the other divalent metal ions around pH 5 in buffered solutions, under noncompetitive conditions. However, competitive experiments, performed with solutions containing a mixture of metal chloride salts and acetate buffer, showed a high selectivity for Cu(II) and Cd(II) over other cations. Distribution coefficients determined for the polymer and the metal ions indicate that the Cu(II) complex is more stable than the Cd(II) are and suggest that the stability of the complex decreases rapidly with decreasing pH. Kinetic experiments have shown that uptake of Cu(II), is slow, with t 0.5 = 10 h. Ligand regenerati...

The terpolymerization of ethyl methacrylate (EMA), N-phenylmaleimide (NPMI), and itaconic acid (IA) was investigated. The terpolymer composition was determined by elemental analysis and 1H NMR spectroscopy. The reactivity ratios of the three binary systems (EMA/NPMI, EMA/IA, and NPMI/IA) were calculated and used for the calculation of the terpolymer composition with the terminal model equations. A comparison between the experimental and theoretical compositions was made. The rate of the terpolymerization process was measured dilatometrically at two total monomer concentrations; this was done to establish the presence of intermolecular interactions between the investigated monomers. The thermal analysis of the obtained terpolymers was performed by thermogravimetric analysis. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3180–3187, 2003

N-p-Bromophenylmaleimide (BrPMI) does not polymerize in solution by conventional free radical mechanism. However, it readily polymerized in bulk when mixed with a free radical initiator and heated in a microwave oven for 7–8 min. Copolymerization of ethyl methacrylate or butyl methacrylate with BrPMI was conducted in dioxane. The copolymers were characterized by IR and 1H NMR spectroscopy and gel permeation chromatography. The monomer reactivity ratios were calculated by a non-linear least-square analysis. Thermal analysis indicated a great improvement in thermal stability of the copolymers compared with the methacrylate homopolymers. BrPMI was also polymerized in bulk in the DSC pan, which allowed the calculation of the activation energy of its polymerization. Copyright © 2003 Society of Chemical Industry