Steam treatment of viscose textile yarn in centrifugal machine twisting

Conclusions On steam treatment of centrifugal yarn during the cake-spinning process, the uniformity of yarn properties through the cake layers is improved.The coefficients of variation in primary and secondary swelling, and also in strength and elongation are reduced by a factor of 2.5–3. The -cellulose content of the yarn is increased by 5–10% (by wt.), and the contents of sulfuric acid, zinc sulfate, and sodium sulfate are reduced by factors of 4, 3.5, and 4, respectively. Carbon disulfide is practically completely removed from the cake.Translated from Khimicheskie Volokna, No. 4, pp. 34–35, July–August, 1983.     

Kinetics of dye sorption by viscose textile yarn

Conclusions Viscose textile yarns which have been spun from viscoses of different ripeness indexes and have been dried at different temperatures have the smallest differences in dyeing after 8–12 min or 50–60 min after the start of the dyeing process.Translated from Khimicheskie Volokna, No. 6, pp. 17–18, November–December, 1989.     

High-speed stretching of polyamide textile yarns

Conclusions Studies of the process of drawing 5-tex polyamide textile yarn at take-up speeds up to 1650 m/min have been performed on a laboratory stand.It has been found that, with increase in stretching speed, within the investigated limits the drawing force and physicochemical properties of the yarn essentially do not change. This permits us to recommend an increase in stretching speed for industrial adoption.Translated from Khimicheskie Volokna, No. 1, pp. 22–24, January–February, 1986.     

Improved performance of polyamide nanofiltration membranes by incorporating reduced glutathione during interfacial polymerization

Inspired by the specific amino acid sequence Asn-Pro-Ala (NPA) of water channel aquaporins (AQPs), we fabricated polyamide (PA) nanofiltration (NF) membranes by introducing reduced glutathione (GSH) in interfacial polymerization (IP) method. Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectrometry (XPS), scanning electron microscope (SEM), atomic force microscopy (AFM), zeta potential and static water contact angle measurement were employed to characterize the chemical composition, morphology, electronegativity and hydrophilicity of the NF membranes. The water flux of GSH/PIP-TMC NF membrane reached 32.00 L m^-2 h^-1 at 0.2MPa, which was approximately twice than that of pristine PIP-TMC NF membrane when the ratio of GHS to piperazidine (PIP) was 40% during IP process. More water channels were built as GSH was embedded into PA layer. The fabricated NF membranes also took on potent rejection for dyes and Na₂SO₄. This study presents a simple and facile method to simulate water channels-based biological materials which may find potential application in water treatment.     

Shrinkage and retractive force of drawn isotactic polypropylene during heating

The semi-crystalline isotactic polypropylene was drawn to λ = 6,7,8,9,11 and the drawn samples heated to temperatures between 40 and 160°C. The shrinkage of the sample with λ = 7 and 11 was measured as function of time and temperature. The effect of shrinkage is higher with the smaller draw ratio as if the drawing increased the thermal stability of the sample. With fixed ends the drawn samples were heated at a constant rate and the retractive stress observed. It increases with λ and the heating rate. At the same drawing ratio λ, the curves of the retractive stress show a maximum and subsequently drop to a substantially smaller value that increases with the draw ratio and the distance of the highest temperature of the heating from the melting point of the sample. The cooling curve of the first run almost coincides with the heating and cooling curve of the next runs if one does not surpass the maximum temperature of heating of the first run. The time dependence of the retractive stress after an inital maximum decays more rapidly to the limiting value σ_∞ (T) the higher the temperature of the experiment. The limiting value σ_∞ (T) rapidly decreases with T and increases with λ.     

Effect of temperature on the adsorption of nonionic surface-active substances by polyamide yarn

Conclusions The adsorption of seven nonionic surface-active substances (NSAS) by polyamide yarn has been studied in the temperature range 25–55°C.It has been shown that the NSAS OP-10 has the least adsorption ability; NSAS of the DS type have the greatest.It is recommended to use NSAS of the DS type in developing new thermally resistant lubricants.Translated from Khimicheskie Volokna, No. 3, pp. 21–22, May–June, 1987.