Degree of cross-linking and fiber, yarn, and fabric properties

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Analysis of Flame-retardant Finishes on Textiles Using Laser-Raman Spectroscopy

135-138<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Laser-Raman investigations have been carried out on polyester-cotton blend fabrics finished with various phosphorus based flame-retarding chemicals. From the spectra obtained, it has been possible to identify not only the bands characteristic of fibres constituting the blends but also certain frequencies associated with the vibrations of P-N and P-CI bonds present in the flame-retardant chemical finish. Though the application of laser-Raman spectroscopy to the study of the chemical nature of textile surface chemical finishes is still in its infancy, it seems to provide more detailed information than is possible through infrared spectroscopy.</span

Studies on Decrystallization of cotton

X-ray methods have been used to measure crystallinity and crystallite dimensions in cotton fibers that have been swollen in aqueous solutions of caustic soda, ethylene diamine, and zinc chloride. Different times, temperatures and concentrations of swelling agent have been used. Optimal decrystallizing conditions are given, together with re sidual crystallinities and crystallite sizes. The inter-relation between crystallinity and crystallite size is discussed

X-ray measurements of crystallinity and crystallite size in swollen and hydrolyzed cottons

Crystallinity and crystallite size determinations have been carried out on a number of samples of swollen, hydrolyzed, and swollen and hydrolyzed cotton fibers, employing X-ray diffraction techniques and a Geiger counter recording spectrometer. A new hi variate analysis technique has been developed in order to determine the crystalline con tent of samples in which two crystalline phases are present, namely cellulose I and II. In the determination of crystallite dimensions the tilted fiber technique has been adopted for measuring crystallite lengths. A new method of resolving superposed line profiles for the measurement of crystallite width has also been developed. The results of these studies seem to suggest that there is a very close relationship between crystallinity and crystallite volume for all the types of chemical treatment studied, and that increasing crystallinity is a measure of increasing crystallite volume. On the other hand, no unique relationship between crystallinity and any one crystallite dimension has emerged for all the treatments studied. However, there are relationships which are specific to different kinds of chemical treatment of cotton

Polyester Fibres Compatible for Blending with Cotton in Blended Fabrics: Part I—Stress-Strain Curves

55-59<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">An attempt has been made to alter polyester fibre properties through physical modification using simple drawing and heat setting operations with a view to producing a compatible fibre with properly matched stress-strain curves for blending with cotton. It is observed that the cold-drawn and subsequently tension heat set polyester fibres give stress-strain curves matching those for some superior cottons and therefore these fibres can be better alternatives for commercial medium and high tenacity polyester fibres normally used in India for blending with cotton for getting apparel fabrics. The new anti-pill polyester fibres can also be used for blending with cotton provided they are heat set under tension. When these fibres are stretched beyond their original length and heat set under tension, their stress-strain curves match those for most cotton fibres.</span

The chemical composition of the diatom frustule

This paper describes the X-ray diffraction studies carried out on a large number of present-day, as well as fossil diatom frustules. From the diffraction patterns given by the various specimens, it has been concluded that the silica present in diatom frustules is not in an amorphous or sub-colloidal state as was spposed by previous workers but that it is crystalline α -quartz. Although crystalline α -quartz is present in present-day diatoms, the degree of crystallisation is much less than in the fossilized specimens. In addition to the crystalline quartz content, there is present in all diatoms an organic component which might possibly be a protein. In the present-day diatoms this organic component occurs in considerable proportion so that its X-ray diffraction pattern tends to mask the pattern due to crystalline α-quartz. On fossilization, however, a considerable amount of the protein content is lost, while the silica content becomes more predominant, and more and more crystalline with time. Evidence for the occurrence of pectin in diatoms is also presented

Peripheral Acid Hydrolysis of Crosslinked Viscous Medium

91-99<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Crosslinks formed between cellulose chains to impart durable press properties to the treated cotton fabrics differ considerably in their resistance to acids. Fabrics crosslinked by the pad-dry-cure technique were treated with sulphuric acid of different concentrations in a viscous medium to obtain peripheral hydrolysis of crosslinks, washed and air dried. Greater dye uptake by the acid treated samples than pad-dry-cure controls at comparable nitrogen contents indicates that the resin is peripherally hydrolyzed for these fabrics. These fabrics exhibit higher abrasion resistance, higher wet crease recovery and lower tensile strength then the pad-dry-cure samples at comparable dry crease recovery levels. Electron microscopical observations also lend support to the conclusion that hydrolysis of crosslinks at the surface of pad-dry-cure fabrics has been achieved by treating with sulphuric acid in a highly viscous medium.</span