Application of Pomegranate Rind Extract for Improvement of Functional Properties of Various Materials—A Critical Review

Pomegranate rind is abundantly available as a waste material. Pomegranate Rind Extract (PRE) can be applied to cotton fabrics for its natural colours, as a mordanting agent and also for imparting certain functional properties such as fire retardancy and antimicrobial properties. This paper reviews the feasibility of Pomegranate Rind Extract to improve the functional properties of cellulosic fabrics. Studies show that varying concentrations and higher temperatures that were used to apply the extract on the fabric, resulted in enhanced functional properties. At a particular concentration, the treated fabric showed a 15 times lower burning rate in comparison with the control fabric. Also, antimicrobial efficacy has been observed against Gram-positive and Gram-negative bacteria. Due to the natural colouring material, it can be used as a natural dye on cotton material. The fire retardancy of pomegranate rind extract was tested on jute material under varying alkalinity. Research has indicated that pomegranate rind extract could be used to dye polyamide as well. The rubbing and wash fastness of the finished fabrics is good. The light fastness was fair, and its antibacterial efficiency against tested bacteria was good.

KINETICS OF NON-ISOTHERMAL CRYSTALLIZATION

A kinetic equation of non-isothermal crystamzation was derived by extending Avrami's equation to the non-isothermal situation. More crystallization information can be obtained from this kinetic equation. The curves of non-isothermal and isothermal crystallizations were analysed and compared for poly (ethylene terephthalate) (PET), and the results were discussed.

STUDY ON FUNCTIONAL GROUPS OF CARBON FIBER SURFACE

Rayon-based carbon fibers were anodically oxidized in the presence of a variety of electrolytes. The functional groups produced on carbon fiber surface were characterized by Fourier Transform Infrared Spectroscopy (FTIR). Both K Br pellet spectra and ATR difference spectra indicate that carboxyl and phenolic and carbonyl groups were produced. The acidic groups, carboxyl and phenol, were measured by potentiometrie titration with standard solutions of acid and alkali. The results show that the amount of acidic groups is related to the electrolyte used.

Effect of Electron Irradiation on Polypropylene Films

Effects of both electron beam irradiation on the properties of polypropylene （PP） films and the irradiation on the different layers of a multilayer PP film are studied. A Fourier transform infrared spectroscope was used to investigate the chemical structure of the films. The results showed that the chemical properties of the first layer were improved, that is, more functional groups responsible for dye ability and hydrophilicity of the film were produced on its surface, while noticeable improvement was not detected on the surface of other layers. This was also confirmed by testing the dye ability of the layers. However, the results obtained by atomic force microscopy showed that the electron irradiation caused some topographical changes, not only on the surface of the first layer but also on the others.

Surface Modification of Poly Vinyl Chloride (PVC) Using Low Pressure Argon and Oxygen Plasma

In this study, commercial poly vinyl chloride （PVC） films were treated by oxygen and argon plasmas in a cylindrical glass tube which was surrounded by a DC variable magnetic field, with different sample positions in the plasma reactor and also different exposure durations. Effects of the plasma treatment on the hydrophilic properties of the films were studied by mea- suring the water drop contact angle on the surface of the samples. The surface topography of the untreated and plasma treated films was analyzed and compared by atomic force microscopy （AFM）. The optical characteristic changes in treated samples were investigated using reflective spectrophotometry. Also, the chemical changes which appeared on the surface of the samples were investigated using Fourier transform infrared spectroscopy （FTIR）. The results show that the plasma treated PVC becomes more hydrophilic with an enhanced wettability. A sharp de- crease in the water contact angle may also be a consequence of the surface texturization. The aging effect on wettability of the samples was also investigated. The results show that the effect of oxygen plasma on the surface properties of the samples is more pronounced compared with that of argon plasma.

Effect of Plasma on the Zeta Potential of Cotton Fabrics

In this work, the effect of a low-temperature plasma on the zeta potential of cotton fabric was studied. The silver particle absorption on cotton fabric when modified by a low-temperature plasma was also investigated. The modification consisted of plasma pre functionalization followed by a one-step wet treatment with silver nitrate solution. The process was performed in a low-temperature plasma medium, using a magnetron sputtering device. Oxygen and nitrogen were used as working gases in the system, and the results were compared. After preparing the samples, the zeta potentials of the untreated and plasma-treated cotton under a constant pH value solution were estimated and compared. Also, Fourier transform infrared spec troscopy （FTIR） was used to examine the functional groups of the corresponding samples. The amounts of silver absorption on plasma treated and untreated cotton were examined using the energy dispersive X-ray （EDX） method. The results show that the amount of zeta potential for the nitrogen plasma treated sample is less and the absorption of silver particles by cotton can be increased strongly with nitrogen plasma treatment.

Preparation and Characterization of Conductive Cellulosic Fabric by Polymerization of Pyrrole

Preparation of conductive cotton fabrics, by polymerization of pyrrole in presence of FeCl3 as an oxidizing agent and tetraethylammonium p-toluene sulfonat (TEAp-TS) as a doping agent which in turn caused a reduction in the moisture regain of the substrate, resulted in production conductive cotton fabrics in laboratory scale. Factors affecting the properties of the fabrics were studied, such as ratio between FeCl3 and TEAp-TS and pyrrole concentration. Polypyrrole coated cotton fabrics were characterized by scanning electron microscopy (SEM) and Fourier transform-infrared (FT-IR) spectroscopy. Resistivity, weight gain, color strength, tensile strength and elongation of the coated fabric with polypyrrol were monitored according to ASTM procedures. The results had shown that, the conductivity, weight gain, color strength, tensile strength and elongation increase by increasing FeCl3, TEAp-TS and pyrrole concentration. This is due to the increase of amount of the conductive polymer on the fabric surface. FeCl3 (0.25 M/L), TEAp-TS (0.125 M/L), pyrrole (0.3 M/L), temperature (25°C) and time (4 h) represented the most appropriate formulation for effecting polymerizing of pyrrole and anchoring on cotton fabrics.

WHOLLY-AROMATIC COPOLYESTERS CONTAINING IPA, 2.6-NDA, TPA, CLHQA AND PABA MONOMERS

The crystallinities, thermal properties, liquid crystal properties and rheologic properties oftwo series of the aromatic copolyesters are studied. One of them is composed of IPA, 2,6-NDA,CLHQA, PABA and. the other composed of TPA, 2.6-NDA, CLHQA, IPA. The results showthat the crystallinities of the aromatic copolyesters are relatively low and the melting point of thecopolyesters decreases with an increase of the unsymmetrical contents. These two series of aro-matic copolyesters are both suitable for the conventional melt spinning process and have a goodfiber forming property and a good thermal stability. The viscosities of aromatic copolyestermelts are greatly affected by the shear rate, hence the so-called" thinning under shearing" phe-nomenon. The melts have a rather high viscosity flow activation energy and a relatively lowelasticity.

IONIC ENTROPIES ON A BOND PARAMETER SCALE

Some expressions were proposed in the previous report to exp-ress the relation between the entropies S°298 and the bond parameterZ/r in the same type of compounds.Based on this we derived a rela-tion formula for calculating the ionic entropies and established a

RELATION BETWEEN DYNAMIC LOSS MODULUS AND DIFFUSION COEFFICIENT IN A MODIFIED PET FIBER

The mobility of polymer chain segments is shown to play a major role in the diffusion ofdisperse dyes in a copolymerization modified PET system, monoepoxy compoundCH_3 (CH_3),OCH_2CH--CH_2 modified PET. The rate of dye diffusion (diffusion coefficient D) hasbeen related to the time-dependent mechanical property, dynamic loss modulus E', which iscontrolled by the mobility of chain segments. In this modified copolyester system, the variance ofamount of modifier in the copolyester fibers causes the change in disperse dye diffusion coefficientto fiber, and in the dynamic loss modulus of the fibers, but the relationship between the diffusionand the dynamic loss modulus is in agreement with the theoretical relation derived by Bell andDumbleton. The relation obtained in this paper is:Ln D=-2. 28Ln E'+26. 81

THE APPROXIMATE FORMULAS WITH Z/r FOR THE STANDARD ENTROPIES OF IONIC CRYSTAL COMPOUNDS

The ionic crystal compounds which have the same speeices and number of anions and the same charge number of cations are called the same typical compounds. Based on this concept, the standard entropies of the same typical com-