Removal of Toxic Metal Ions from Water Using Chelating Terpolymer Resin as a Function of Different Concentration Time and pH

Terpolymer resin 4-ASAUF was synthesized by the condensation of 4-aminosalicylic acid (4-ASA) and urea (U) with formaldehyde (F) in the presence of 2 N hydrochloric acid. The structure of the resin was characterized by various spectral techniques like infrared (FTIR) and nuclear magnetic resonance (1H and 13C-NMR) spectroscopy. The empirical formula and empirical weight of the resin were determined by elemental analysis. The physiochemical properties of terpolymer resin were determined. The morphological feature of the 4-ASAUF terpolymer resin was studied by scanning electron microscopy (SEM). The chelating ion-exchange property of this copolymer was studied for eight metal ions, namely, Fe3+, Cu2+, Ni2+, Co2+, Hg2+, Zn2+, Cd2+, and Pb2+ ions by using batch equilibrium method. The chelating ion-exchange study was carried out over a wide pH range at different time intervals using different electrolyte of various ionic strengths.

Synthesis and Characterization of New Organosoluble and Thermally Stable Poly(thioether-amide)s Bearing Pyridine Subunit in the Main Chain

We report the synthesis of new polyamides containing 2,6-bis(2-thio-2-(4-carboxyphenyl)-1-oxo)pyridine subunit, under microwave irradiation using Yamasaki phosphorylation method. The solubility, thermal behavior, and viscosity of polyamides were evaluated. The structures of polymers have been characterized using IR and 1H NMR spectroscopy. These polyamides showed good solubility, viscosity, high thermal stability, and glass transition temperatures. Their viscosities and glass transition temperatures are in the range of 0.63–0.88 and 223–295°C, respectively. Thermal stabilities for 10% weight loss (T10) are 137–173°C and for 50% weight loss (T50) are in the range of 483–523°C. The study of surface morphology showed particle and amorphous structures.

In Situ Disassembling Behavior of Composite Hydrogels for the Efficient Removal of Crystal Violet Dye from Aqueous Solution

A novel method for the disassembly of synthetic hydrogels in situ and thereby enhanced adsorption of crystal violet dye is reported. Silicon present in the husk ashes of Panicum miliare is used as the trigger for disassembly of poly(2-acrylamido-1-propane sulfonic acid-co-itaconic acid) hydrogels. Disassembling ability of the ash was determined by changing the temperature of the husk ash. Surface area and particle sizes of both the disassembled and assembled forms of the hydrogels were determined by E. Suito’s method. Removal of crystal violet dye from aqueous solution and the respective adsorption capacities of disassembled and assembled forms of hydrogels were compared by varying parameters such as pH, temperature, and agitation speed. Concentration of the dye in aqueous solution was determined by using UV-Visible spectrophotometer. FTIR analysis was carried out for the characterization of the hydrogels, ash blended hydrogels, and the free ashes. SEM imaging was carried out to differentiate the surfaces of the assembled and disassembled hydrogels.

The Manufacture of Hot-Compacted Layered Composite Systems Made of Oriented Semifinished PP-Films

Monoaxial stretched PP-films are used for the manufacture of hot-compacted layered composites. These are layered with stretched co-extruded coupling agent films, and are consolidated to laminates by means of a hot-compaction process, which employs pressure and temperature. This paper aims to examine the influence of the process settings on the properties of the composites during the hot-compaction process. For this purpose, the mechanical values will be determined by means of tensile testing variously compacted and configured layered film composites.

Preparation and Drug-Release Kinetics of Porous Poly(L-lactic acid)/Rifampicin Blend Particles

Porous polymer spheres are promising materials as carriers for controlled drug release. As a new drug-carrier material, blend particles composed of poly(L-lactic acid) (PLLA) and rifampicin were developed using the freeze-drying technique. The blend particles exhibit high porosity with a specific surface area of 10–40 m2 g−1. Both the size and porosity of the particles depend on the concentration of the original solution and on the method of freezing. With respect to the latter, we used the drop method (pouring the original solution dropwise into liquid nitrogen) and the spray method (freezing a mist of the original solution). The release kinetics of rifampicin from the blend particles into water depends significantly on the morphology of the blend particles. The results show that the release rate can be controlled to a great extent by tuning the size and porosity of the blend particles, both of which are varied by parameters such as the solution concentration and the method of freezing.

Damping Evaluation of Linseed Oil-Based Engineering Elastomers by Vibration Response Method

A low cost experimental setup has been fabricated for evaluation of vibration damping properties of a variety of elastomers developed from linseed oil. Free and forced vibration principles were utilized in this experimental setup. Under forced vibration, the shear loss factor varies from 0.37 to 1.03 at 2nd bending vibration mode and 0.43 to 0.99 at 3rd bending vibration mode for different elastomers. The loss factor varies from 0.52 to 0.94 under free vibration. The loss factors determined by both forced and free vibration techniques are in good agreement with the loss factors obtained from dynamic mechanical analysis. The ultimate tensile strength and Young’s modulus of the elastomers vary from 0.37 to 3.71 MPa and 0.27 to 10.27 MPa, respectively, whereas these properties in compression are in the range of 3.1 to 72.9 MPa and 1.5 to 30.1 MPa, respectively. Thus, these elastomers are mechanically stable for vibration damping applications.

Synthesis of Carbon Nanotube Incorporated Molecular Imprinted Polymer with Binding Affinity towards Testosterone

A novel polymer was synthesised using functionalized carbon nanotube and acrylamide as the polymer support for the separation of testosterone. The developed polymers were characterised using FT-IR, XRD, and SEM techniques. Imprinted polymer showed specificity towards the template testosterone. Among the various polymers, the MWCNT incorporated polymer showed high binding towards the used template. Investigation of the selectivity characteristics revealed that the developed polymer showed selectivity toward the template testosterone than similar compounds. The bound template could be totally recovered and regenerated polymer maintains its recognition property after repeated use. On the basis of the results, the imprinted polymer can be applied for the direct extraction of testosterone in clinical analysis.

Natural Rubber Latex: Study of a Novel Carrier for Casearia sylvestris Swartz Delivery

Natural rubber latex (NRL) from Hevea brasiliensis has showed interesting biomedical properties as improving wound healing, cell adherence, tissue formation, and angiogenesis. It is used for biosynthesis of nanoparticles, sensors and prosthesis and for drug delivery systems (for drugs, plant extracts, and nanoparticles). To enhance its wound healing properties was incorporated Casearia sylvestris Swartz extract, whose pharmacological activity includes anti-inflammatory, analgesic, antiseptic, antiulcer, and antitumor due to its casearins and phenols. Results showed the prolonged release of its compounds (35 days) and the mechanism of release is super case II (n>1) by Korsmeyer-Peppas model. Although SEM shows different sizes of clusters at the surface, the release is homogeneous through the biomembrane. FTIR shows no interaction between the matrix and the extract, with computation of the presence of some casearins.

Characterization of Some Spelt Wheat Starches as a Renewable Biopolymeric Material

The aim of this work was to analyze selected physical, chemical, thermal, and rheological properties of starches isolated from different spelt wheat varieties. The analyzed starches contained from 22.5 to 24.6 g/100 g of amylose and from 45.9 to 50.6 mg/100 g of phosphorus. Ranges of characteristic gelatinization temperatures, TO, TP, and TE, were 55.7–58.5°C, 61.1–62.6°C, and 67.4–68.2°C, respectively, while gelatinization enthalpy ranged from 8.87 to 9.96 J/g. The pasting curves showed significant differences in pasting characteristics of the starches. The values of maximum viscosity (ηmax) and viscosity after cooling (η50) determined for the starch pastes were in the range of 82.3–100.7 B.U. and 149.3–172.7 B.U., respectively. The starch pastes demonstrated non-Newtonian, shear thinning flow behaviour and thixotropy phenomenon. After cooling the resulting starch gels were characterized by different viscoelastic properties, with a dominance of elastic features (G′>G′′). The starches exhibited different tendency to retrogradation, with its degree (R=ΔHR/ΔHG) in the range of 21.1–37.4%.

Thermal Expansion Behavior of Nonoriented Polypropylene/Clay Composites

Linear thermal expansion coefficient (LTEC) was measured for compression molding samples of polypropylene (PP)/clay composites with clay loading of 0 to 7 wt%. Composites were prepared by internal batch mixer and specimens were prepared by compression molding. These processing methods are not anticipated to have a preference for orientation; therefore effect of anisotropy was minimal. The LTEC was measured along three different faces of the compression molding sheets, parallel to compression direction S1 and perpendicular to compression directions S2 and S3. The LTEC for neat PP measured by current research, 1×10-4 mm/mm/°C, was not found to be altered by direction of the measurements. Similar behavior was observed with composites having very moderate clay content, that is, 5 wt%. An interesting finding by current study was that incorporating clay particles into the PP matrix led to better shrinkage or contraction behavior of the samples prepared by compression molding.