Guar gum has seen extensive use in blends, however, its application as a filler in thermoset composites has as yet not been investigated. The effect of the addition of guar gum and its acetyl derivatives on the kinetics of water diffusion in unsaturated polyester composites was studied. The effect of water on the mechanical properties of the composites was studied with respect to the nature of filler, filler concentration and time of immersion. All the mechanical properties were observed to decrease on exposure to water. Further, it was observed that acetylated guar gum, with a degree of substitution of 0.21, showed the best mechanical properties, surpassing the other filled composites and that of the pure unsaturated polyester. Thus, acetylated guar gum showed promise as eco-friendly filler in composite formulation.
Analysis of global electrophilicity and nucleophilicity power of the addends indicate polar character of [2+3] cycloaddition reactions between arylnitrones and trans-substituted nitroethenes. The regioselectivity of these reactions is determined by nucleophilic attack of oxygen atom from nitrone on activated ?-position of nitroalkene. Interaction of this type leads to 4-nitroisoxazolidines, which are the only reaction products.
The coordination complexes of Co(II), Ni(II) and Cu(II) derived from 5-bromosalicylidene-3,4-dimethylaniline (BSMA) and 5-bromosalicylidene-3,4-dichloroaniline (BSCA) have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT-IR, molar conductance, electronic spectra, 1H-NMR, FAB-mass, ESR, magnetic susceptibility, electrical conductivity and thermal analysis. The complexes are coloured and stable in air. Analytical data revealed that all the complexes exhibited 1:2 (metal: ligand) ratio with coordination number 4 or 6. IR data shows that the ligand coordinates with the metal ions in a bidentate manner through the phenolic oxygen and azomethine nitrogen. FAB-mass and thermal data show degradation pattern of the complexes. Solid state electrical conductivity studies reflect semiconducting nature of the complexes. The Schiff base and metal complexes show a good activity against the Gram-positive bacteria; Staphylococcus aureus and Gram-negative bacteria; Escherichia coli and fungi Aspergillus niger and Candida albicans.
Degradation of integral skin polyurethane foams (ISPUFs) was performed using diethylene glycol (DEG)/-sorbitol/water ternary green solvent system as an effective polyurethane bond destroying agent in combination with basic catalysts, namely sodium and potassium hydroxides, sodium acetate and sodium carbonate. The effects of studied catalysts were investigated and data showed the high performances of sodium hydroxide in recycling process. After completion of the reactions, appeared split phases contained recycled polyols in the upper phase. Reactions were studied using various DEG/-sorbitol/water ratios and the recovered polyols were characterized and data compared with an authentic sample.
The synthesis of Triphenylphosphonium trichloroiodoaluminate (III) ionic liquids (ILs) is reported here. The product was characterized by spectroscopic and analytical methods such as 31P-NMR, FT-IR, cyclic voltammetry, CHN, TGA and differential thermal analysis (DTA). Thermal analyses were used to investigate the thermal behavior of this compound. The results show that this ILs has excellent thermal stability below 110?C. Along with the experimental study; this compound has been studied computationally at the B3LYP/LANL2DZ level of theory using the Gaussian 98 program package. From these calculations, optimized geometries, molecular parameters, and vibrational spectra of ILs have been calculated. In addition, calculated frequencies are compared with the experimental frequencies after correction by the appropriate scaling factor. This comparison shows that our theoretical data are in good agreement with the experimental results.