ABSTRACT:The growth and importance of medical and related health care and hygiene textile sectors are attributed to the improvement and innovations in both textile technology and medical procedures. The aim of this study was to examine some of the structural properties of pure poly(vinyl alcohol) (PVA) and hydroxypropyl cellulose (HPC) doped PVA of different weight percentages. This will lead to the choice of the optimum conditions suited for specific medical and surgical applications for which textile materials are currently used. Thermogravimetry was used to develop an instrumental system for the study of thermal stability and for identification of the individual components of several polymer blends. Derivative thermogravimetry provided clear information and distinguished between different generic types. Also, differential scanning calorimetry and its derivatives gave accurate values of glass-transition temperature and melting temperature and gave detailed features of the steps of weight loss and changes in the heat of fusion. The X-ray diffraction technique was used to determine the crystallinity/amorphosity ratio and the change in crystallite size at different dopant concentrations. The effect of doping with HPC on PVA structure was studied with spectrophotometric analyses. Variations in the group coordination in the IR region were followed. The data obtained indicated that measurable and remarkable changes in the thermal stability of PVA occurred at different doping concentrations. This may have been because the diffusion of dopant caused structural changes in the polymer matrix.

In the present work, composites of poly(methyl methacrylate)/titanium oxide nanoparticles (100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10 and 0/100 wt/wt%) were prepared to be used as bioequivalent materials according to their importance broad practical and medical applications. Thermal properties as well as X-ray diffraction analyses were employed to characterize the structure properties of such composite. The obtained results showed variations in the glass transition temperature (T g), the melting temperature (T m), shape and area of thermal peaks which were attributed to the different degrees of crystallinity and the existence of interactions between PMMA and TiO 2 nanoparticle molecules. The XRD patterns showed sharpening of peaks at different concentrations of nano-TiO 2 powder with PMMA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homopolymers PMMA and nano-TiO 2 powder is possible. The results showed that nano-TiO 2 powder mix with PMMA can improve the thermal stability of the homo-polymer under investigation, leading to interesting technological applications.

ABSTRACT:In this study, we evaluated the effect of ultraviolet/ozone treatments for different times on the characteristics of wool fabrics with respect to wettability, permeability, yellowness index, and weight loss. The beneficial effects of this treatment on dyeability, color parameters, light fastness characteristics, and the change in color difference after exposure of the treated dyed samples to artificial daylight for about 150 h was investigated. The results indicated that the improvement in wetting processes may have been due to to surface modifications; this meant that an increase in the amorphousity of the treated samples, the oxidation of the cystine linkage on the surface of the fabrics, and the formation of free-radical species encouraged dye penetration and aggregation inside the fiber pores as well as bond formation.

Wool fabrics were exposed to ultraviolet (UV)-ozone treatment for different periods. After exposure, the fabrics were analyzed by Fourior transform infrared spectroscopy (FTIR). Also, the crystallinity and amorphousity regions were followed by an X-ray diffraction technique. The results were correlated by mechanical properties measurements. After a certain period of exposure, the dyeability and printability were improved because these abilities are strongly related to the percentage ratio of crystallinity regions to amorphousity regions in wool fabrics.

No abstract