Sulfonation of polymers is of great importance for the packaging industry mainly due to its effect on the alteration of surface functionality of polymer films. In this study we customized liquid phase sulfonation of low‐density polyethylene (LDPE) swelling the polymer by using a combination of polar and nonpolar solvents. Swollen polymer was treated with sulfuric acid of varying concentrations with continuous mixing for in‐depth sulfonation of the polymer. Presence of cyclohexane and ethanol, as polar and nonpolar reagents, not only kept the batch under isothermal conditions but also homogenously influenced in‐depth functionalization of LDPE. The durability of the sulfonated polymer was determined by grinding the test samples 30 days after the reaction. Fourier transform‐infrared spectroscopy indicated presence of functional group moieties, which is also supported by increase of 5% and 1.35% in density and sulfur contents of the polymer, respectively. Contact angle measurements indicate 30° decrease in values of the sulfonated polymer which corresponds with decrease in carbon to hydrogen ratio (from 5.9 to 5.3) and increase in sulfur to carbon ratio (up to 0.0184) resulting from the sulfonation of the polymer. Differential scanning calorimetery results indicate almost linear reduction in the crystallinity of LDPE with an increase in acid concentration used for the sulfonation reaction. POLYM. ENG. SCI., 54:2522–2530, 2014. © 2013 Society of Plastics Engineers

DSC-TGA was used for screening of commercially available and synthesized catalyst for the degradation of polypropylene (PP). In this study, all the runs were performed with 50% load of the catalyst and the results were compared with those of PP + 50% pure silica having no catalytic activity. The degradation behavior of PP using catalyst Zeolyst-713 exhibited much higher degradation activity among the other catalysts used in this study. Moreover, it contributed to lowering of initial stage temperature showing a shape-selective effect. DSC-TGA tools such as Ton, Tmax, T99%, activation energy, enthalpy change in the process and coke content were used for screening. It was concluded that the pore construction and unique acid properties of the Zeolyst-713 as well as proper reaction temperatures were significant influential factors to fully exert this effect. In this work, kinetics of catalytic thermogravimetric degradation of PP used for domestic purposes was investigated using Alumino-silicate catalyst. Zeolyst-713 was observed to lower activation energy and enhances degradation activity in comparison with thermal degradation without a catalyst.

The drug administered for any disease may play an unwanted function in biological system. They may have multiple counter effects, one of which is their interaction to bioactive metals. Iron is most common bio essential metal and is reported to interact with antihypertensive drug methyldopa. In the present study, above said complex is analyzed by UV-Visible spectrophotometry. Formation constant of the complex is calculated by using mole ratio method and single point statistical method which is in the range of 10 10 , values are also calculated which are independent of pH like formation constant. Absorbance maxima were found to be dependent on pH. At lower pH complex shows two broad bands centered at 430 nm and 730 nm. With the rise in pH later peak shifts toward lower wavelength, so 615 nm is selected for further studies. Molar extinction coefficient of the complex is explored by serial dilution method. At all wavelengths it increases with increase in pH. Mole ratio and slope ratio methods are used for exploring stoichiometry. Metal to ligand combining ratio in the complex is 1:2 at pH 4.0 and pH 4.5 while 1:3 at pH 5.0 and pH 5.5.

During this study, different blends of taro starch-hydrocolloid were incorporated in yeast leavened bread and their effects were investigated. The specific volume, moisture content and slice shape of the bread were found to be improved by the addition of taro starch-guar gum blend. Taro starch-xanthan gum mixture was also found to be a good additive to improve specific volume, slice shape, crumb softness as well as sensory characteristics of bread. The study reveals taro starch-hydrocolloid blend can be utilized as a novel ingredient to improve the physical and sensory characteristics of leavened bread.