Open Access Original Research Article

Synthesis and Characterization of Epoxy Resins-Modified Waterborne Polyurethane Emulsion

Chenhan Zhuang, Weilan Xue, Zuoxiang Zeng

Asian Journal of Applied Chemistry Research, Page 1-9
DOI: 10.9734/ajacr/2021/v9i330213

Aqueous polyurethane emulsion was prepared with diphenylmethane diisocyanate (MDI), polybutylene adipate diol (PBA-1000) as main raw materials and 2, 2-dihydroxymethyl propionic acid (DMPA) as hydrophilic chain extender. On this basis, epoxy resin E-44 was introduced to modify the polyurethane prepolymer, and epoxy resin modified waterborne polyurethane emulsion was obtained. In order to obtain better performance waterborne polyurethane, the effect of DMPA content、the amount of epoxy resin added and modification method on the properties of polyurethane was discussed. The results show that when the DMPA content is 4wt%, the overall performance of the emulsion and the film is the best. And the addition of epoxy resin significantly improves the water resistance, solvent resistance and tensile strength of the waterborne polyurethane film, and its hardness and thermal stability are also improved to a certain extent. When the amount of epoxy resin added is 8wt%, the storage stability decreases significantly, the suitable amount of epoxy resin added is 6wt%. The overall performance of the film obtained by chemical modification is better than that of physical modification.

Open Access Original Research Article

Ab initio Study of Diels-Alder Reaction between Cyclic Dienes and Olefin

Haydar A. Mohammad-Salim

Asian Journal of Applied Chemistry Research, Page 10-17
DOI: 10.9734/ajacr/2021/v9i330214

Theoretical modeling of organic synthesis is a powerful tool and leads to further insight into chemical systems. Computational chemistry allows obtaining the potential energy surface that experimentally cannot be observed, in addition to transition state calculations, which lead to better understanding the reactivity of an organic synthesis work. The Diels-Alder (DA) reaction of cyclopentadiene 1 and N-phenylmaleimide 2 has been studied at the MP2/6-311++G(d,p) level of theory. This DA reaction occurs through a one-step mechanism. It was expected that this reaction undergoes two regio-isomeric reaction paths passing through two different transition states to form two different products 3  and 4. The reaction paths are irreversible due to the exothermic character of -41.24 and -41.73 kcal.mol-1. This DA reaction are exergonic with reactions Gibbs free energies between -27.26 and -27.74 kcal⋅mol−1. Analysis of the CDFT indices predict the global electronic flux from the strong nucleophilic cyclopentadiene 1 to the electrophilic N-phenylmaleimide 2.

Open Access Original Research Article

Batch Adsorption Assessment of Neem Nut Carbon for Abating Chromium(VI) in Wastewater

S. Sophie Beulah, K. Muthukumaran

Asian Journal of Applied Chemistry Research, Page 18-24
DOI: 10.9734/ajacr/2021/v9i330215

Discharge of Cr(VI) laden effluents is highly toxic and decontaminating the wastewater from Cr(VI) is necessary for Environmental Protection. An investigation on the adsorption characteristics of activated carbon prepared from neem nut (NNC) for the removal of Cr(VI) from wastewater by varying the parameters such as carbon dose, pH, equilibration time by batch studies was found to be effective for the removal of Cr(VI) from wastewater. Carbon characteristics of activated neem nut carbon were ascertained. Evaluation were done by varying the pH from 1 to 6, carbon dose from 0.1 g to 0.5 g and equilibration time from 1 to 6 hours. Maximum Cr(VI) removal of 95% took place when batch studies were done at an optimal pH of 2, carbon dose of 0.2 g//100mL, and equilibration time of 4 hours. Freundlich and Langmuir adsorption isotherm models were considered for analysis.

Open Access Original Research Article

Phytoremediation Potentials of Cynodon dactylon on Heavy Metal Contaminated Soils from Challawa Industrial Estate, Kano-Nigeria

L. Shuaibu, U. Abdullahi, A. I. Yaradua, J. I. Bungudu

Asian Journal of Applied Chemistry Research, Page 25-36
DOI: 10.9734/ajacr/2021/v9i330216

This study investigated the phytoremediation potentials of Cynodon dactylon in heavy metal contaminated soils of Challawa Industrial Estate, Kano, Kano State, Nigeria. A total of 100 samples comprising of 50 soils and 50 plant parts of C. dactylon were evaluated for the presence of heavy metals by the use of atomic absorption spectrophotometry (AAS) method. Extent of heavy metal soil contamination and phytoremediation potentials of the study plant were assessed by the use of metal contamination factor (Cf) for soil; Bioaccumulation and translocation factors for the plant sample respectively. From the results, levels (mg/kg) of the metals in the C. dactylon from contaminated and control sites were found to be in the sequence of Fe (442.60) > Cu (138.35) > Zn (133.53) > Cd (61.50) > Pb (42.47) > Mn (28.40) > Ni (18.40) > Cr (17.73) and Fe (88.60) > Zn (38.18) > Cu (33.60) > Ni (13.70) > Mn (12.67) > Pb (6.07) > Cd (5.60) > Cr (5.03) respectively. The contamination factor values Cf, (mg/kg) of all the metals in the soils were found to be in the sequence of Cd (10.73) > Cu (5.64) > Cr (3.07) > Pb (2.98) > Ni (2.17) > Zn (2.09) > Mn (2.00) > Fe (1.72). The results showed that the soils are highly contaminated with Cd, considerably contaminated with Cu and Cr, and moderately contaminated with Fe, Mn, Zn, Ni and Pb. The bioaccumulation and translocation factor values (BAF>1 and TF<1) for Cd, Cr, Cu, Mn, Ni, Pb and Zn suggest accumulation in roots and qualify the plant as good candidate for phytostabilization. Moreover, the bioaccumulation and translocation factor values (BAF and TF>1) for the plant species were greater than 1 for Fe suggesting efficient accumulation in the shoot. However, C. dactylon could be recommended as good candidate for phytoextraction of Fe and phytostabilization of the study investigated metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) in multi-metal contaminated soils.

Open Access Original Research Article

Investigation of Heavy and Trace Metals in Some Kurdistan Region Crude Oils by Spectroscan MAX-G

Sherwan Mohammad Simo, Salah Aldin Naman, Kanaan Ramadan Ahmed, Anastasiya Vladimirovna Razina, Akhmetov Arslan Faritovich

Asian Journal of Applied Chemistry Research, Page 37-44
DOI: 10.9734/ajacr/2021/v9i330217

Four types of Kurdistan crude oils have been studied to determine the heavy and trace metals. The significance of determining trace elements that exist in crude oils is helpful for further information about exploration, production and the refining process. In this work crude oil can be separated into products such as (gasoline, kerosene, diesel, and atmospheric distillation residue +350°C) by using atmospheric distillation unit and vacuum distillation unit. The trace metals can be determined with acceptable accuracy and precision by spectroscan MAX-G. However, the values of Ni concentration were the best in accuracy among the group of metals of interest. The average values of the results will be employed as reference values of the trace metal content in the coming discussion and using Ni and V as test elements. The crude oil samples are characterized by with a dominance of V over Ni with a V/Ni ratio of 3.7 to 2.5. Trace element analysis of the five metals in crude oils and atmospheric distillation residues +350°C, for each crude oils and atmospheric distillation residues +350°C is investigated, samples of these areas has not been previously examined for trace element contents. In this study to find the relation between metals in crude oils and atmospheric distillation residue of samples. To detect the concentration of trace elements by using this instrument.