Improving water-consumptive processes under conditions of operating viscose fibre manufacture

Conclusions The most water-consumptive technological processes in the basic and auxiliary works in the manufacture of viscose fibre have been identified.Results of realizing the developments of the Khimvolokno NPO and of the Ryazanskii Khimvolokno PO, aimed at reducing water usage and discharge of contaminants into wastewater have been presented.Translated from Khimicheskie Volokna, No. 6, pp. 22–23, November–December, 1984.     

Adaptive system for stabilizing viscose ripeness

Conclusions A control algorithm has been described for the process of viscose ripening, which is based on compensating for current perturbations and predicting their effect using an adaptive mathematical model of the process.The algorithm developed has been realized in the make-up of the ACS TP for viscose tire cord manufacture in the Svetlogorodsk Khimvolokno PO and in cellophane manufacture in the Kiev Khimvolokno PO.Translated from Khimicheskie Volokna, No. 5, pp. 26–29, September–October, 1986.     

Adaptive control system for the viscosity of viscose

Conclusions A structure and algorithm have been developed for an adaptive system for control of viscose viscosity in the manufacture of artificial fibres.The control system has been introduced into the ACS TP for viscose tire cord manufacture of the Svetlogorodsk Khimvolokno PO.Translated from Khimicheskie Volokna, No. 5, pp. 22–25, September–October, 1986.     

Change in degree of polyamidation of polycaproamide during orientation stretch

Conclusions The effect of stretch ratio, the ratio of stretch ratios in the cold and hot zones, and of the relative viscosity of polycaproamide on the degree of its breakdown during stretching have been examined.The degree of breakdown decreases if the viscosity stays within the range 3.25–3.35, and the stretch ratio in the cold zone is the maximum possible.Translated from Khimicheskie Volokna, No. 5, pp. 26–27, September–October, 1983.     

“Banavis”R viscose fibrous filler

Conclusions A technological process has been worked out for preparing a new fibrous filler, Banavis, for technical rubber articles from viscose technical yarns having a linear density of 187 tex by treating them with a mixture of L-7 chloroprene latex and SF-282 resorcinol-formaldehyde resin.Introduction of Banavis filler into rubber mixtures raises the service characteristics of articles made from them, particularly it increases the transverse toughness of variable drive V-belts by 25–30%, and the mean running time of these items more than 2-fold.Translated from Khimicheskie Volokna, No. 1, pp. 40–41, January–February, 1989.     

Catalytic decomposition of nitrous oxide over perovskite type solid oxide solutions and supported noble metal catalysts

The catalytic decomposition of nitrous oxide to nitrogen and oxygen has been investigated over various solid oxide solutions (SOS), La_0.8Sr_0.2MO_3– (M=Cr, Fe, Mn, Co or Y), La_1.8Sr_0.2CuO_4– and supported Pd, Pt catalysts. The reaction was carried out in a gradientless recycle reactor at 1 atm pressure with a feed gas containing about 0.5% N₂O (in helium). Among the various solid solutions, La_0.8Sr_0.2CoO_3– showed a maximum N₂O conversion of 90% at 600C. The order of activity observed for N₂O decomposition was La_0.8Sr_0.2CoO_3–>La_0.8Sr_0.2FeO_3–>La_1.8Sr_0.2CuO_4–> La_0.8Sr_0.2MnO_3–La_0.8Sr_0.2CrO_3–La_0.8Sr_0.2YO_3–. The activity of La_0.8Sr_0.2CoO_3– was compared with supported Pd, Pt and also with unsubstituted LaCoO₃ catalysts under similar reaction conditions. Among all the catalysts tested in this study, Pd/Al₂O₃ showed the lowest light-off temperature for N₂O decomposition. The activity of La_0.8Sr_0.2CoO_3– was found to be comparable to Pd/Al₂O₃ catalyst at temperatures above 500 C. The influence of added oxygen (about 4%) in the feed was examined over La_0.8Sr_0.2CoO_3– and Pd/Al₂O₃ catalysts and only in the case of cobalt catalyst was the conversion of N₂O decreased by 13%. By choosing varied sintering conditions, La_0.8Sr_0.2CoO_3– of different BET surface areas were prepared and the light-off temperature was found to decrease with increase in surface area. The results obtained over solid solutions are discussed on the basis of the cation mixed valency and oxygen properties of the catalyst.     

Supermolecular structure of films based on poly-β-hydroxybutyrate

Conclusions -- Using methods of x-ray diffraction at low or wide angles, it has been shown that films based on polyhydroxybutyrate have a structure corresponding to the structure of a polymer based on 3HB in pure form or with only a slight content of 4HB units.-- Films formed by the dry method from a solution of polyhydroxybutyrate in methylene chloride have a heterogeneous supermolecular structure and less perfected crystallites than films prepared from a solution in chloroform.Khimvolokno LenNII. VNIIPV, Mytishchi. Translated from Khimicheskie Volokna, No. 5, pp. 18–19, September–October, 1992.     

Time-temperature to strength relationship of viscose cord fibres

Conclusions 1. The time-temperature to strength relationship of a representative series of viscose cord fibre specimens has been investigated.2. Change in the structural factor and also departure from linearity of the endurance curve have been established.3. The possibility of alteration in the nature of the rupture process of cord fibre, depending upon a state past second order transition or a viscoelastic state, has been demonstrated.All-Union Research Institute for Synthetic Fibres (VNIIV). Translated from Khimicheskie Volokna, No. 5, pp. 54–55, September–October, 1969.     

Additional male mediterranean fruitfly (Ceratitis capitata wied.) Attractants from Angelica seed oil (Angelica archangelica L.)

Two sesquiterpene hydrocarbons, -copaene and -ylangene, were isolated from bioactive fractions of angelica seed oil and were shown by field bioassays to be attractive to the male Mediterranean fruit fly. Their relative attractiveness, compared with the(+)-and (–)--copaene enantiomers, are: (+)--copaene>angelica -copaene>angelica -ylangene>(–)--copaene. The enantiomer ratios for the two compounds are: -copaene, 61.4% (+), 38.6% (–); -ylangene, 91.9% (+), 8.1% (–).trans--Bergamotene was also isolated from the same fractions, but in sufficient quantity for bioassay [enantiomer ratio: 95.7% (+), 4.3% (–)].     

Critical solution point and chain dimension of branched-polystyrene solutions

Summary Critical solution point and chain dimension were measured for branched polystyrene(BPS) in solution as a function of molecular weight(M) and compared with those for linear polystyrene(LPS). The critical concentration _c of BPS was quite different from that of LPS at a fixed M, but the same at a fixed overlap-concentration ^*, i.e., plots of _c vs. ^* fall on a single straight line for both BPS and LPS (gf_c ^*). Reduced critical temperature _c defined by gt_c=(–T_c)/ [T_c: critical temperature, : the -temperature] was related to _c as _{c c} ² for BPS, whereas _{c c} for LPS.     

Amination of dimethyl ether on zeolite catalysts. 2. Acidic properties of the used T-zeolites and their influence on the catalytic reaction

Freshly prepared and used H/Na, K-T-zeolite catalysts for the conversion of dimethyl ether and ammonia to the three methylamines have been characterized by temperature-programmed desorption of ammonia and IR spectroscopy. Activity and selectivity depend on the nature and number of the acid sites. With time on-stream, deep alterations in the catalyst behaviour have been observed. The activity of the catalyst is decreased by blocking of active sites 5–10 h: furthermore, during an initial period hydrocarbons were formed almost exclusively on strong-acid sites. A second period is characterized by an increased shape selectivity observed in the distribution of the methylamines. The amination will proceed probably on left weak-acid sites and on the outer surface in a third period, however, without shape selectivity due to the progressive blocking of the inner catalyst surface.     

Chemistry of Combustion Waves in Substances with a Complicated Structure of Reagent Molecules. 1. Structure of the Front of Rich Isopentane Flame

Results on the structure of the lowtemperature relaxation zone of the front of a laminar Bunsen flame of isoC₅H₁₂ (2methylbutane) under atmospheric pressure are presented. The flame of a premixed mixture isoC₅H₁₂ + O₂ + Ar with a fueltoair equivalence ratio of 1.7 is examined. The mass fluxes, total rates of reactions of matter consumption and expenditure, balance of substances, and profiles of bulk heatrelease rates are calculated on the basis of the experimental concentration and temperature profiles. The results obtained indicate that there is a vast region of lowtemperature conversion of isopentane in the flame front. It is found that only part of the products sampled by the microprobe from different points of the flame front results from transformations in the lowtemperature region, namely, oxygen, isopentane, water, carbon monoxide, propane, methane, and methanol. Ethylene, propylene, hydrogen dioxide, and formaldehyde are present in the lowtemperature zone in insignificant amounts; they are secondary products of conversion of methyl and propyl radicals. It is assumed that the observed feature is a result of the competing interaction of two mechanisms of fuelmixture conversion: selfcatalysis and thermal selfacceleration. Based on the previously suggested mechanism of oxidation pyrolysis by the scheme of intramolecular quadratic destruction, experimentally observed fragmentation of the isopentane molecule is demonstrated. In contrast to npentane, formation of methyl alcohol has been found in isopentane convection products.     

The effects of antimony and glue on zinc electrowinning from Kidd Creek electrolyte

The individual and combined effects of antimony and glue on zinc deposition current efficiency and polarization and on the morphology and orientation of 6h zinc deposits electrowon at 500 A m^–2 and 38° C from Kidd Creek zinc electrolyte were determined. Glue increased zinc deposition polarization, reduced the deposit grain size, changed the preferred deposit orientation from basal to intermediate, but decreased the current efficiency. At concentrations above 0.02 mgl^–1, antimony had a strong depolarizing effect on zinc deposition resulting in a basal deposit orientation and very low current efficiency. Certain combinations of antimony and glue, however, optimized zinc deposition current efficiency and consistently gave an intermediate 114 112 103 102 101 preferred deposit orientation. A correlation was observed between the current efficiency (CE) and the nucleation overpotential (NOP) for zinc deposition such that the CE was a maximum when the NOP of the initial cell electrolyte was 120–130 mV and when the NOP of the final cell electrolyte was 100–110 mV.     

Formation of a phase structure of the “fibrils in matrix” type in a composite fibre based on high-density polyethylene and polyethylene terephthalate

Conclusions Regions of component ratio and conditions for obtaining a composite fibre of the fibrils in matrix type have been determined for the HDPE-PET system.At an HDPE-PET ratio of 60:40, phase inversion takes place and a structure of the interpenetration networks type is realized.Under identical fibre spinning conditions, the formation of a phase structure of the fibrils in matrix type can be regulated by varying the temperature.Translated from Khimicheskie Volokna, No. 4, pp. 38–40, July–August, 1987.     

Increasing the uniformity of viscose textile yarn properties by changing the drying regime

Conclusions An effect of the drying regime on the uniformity of viscose textile yarn properties has been found.Yarns from the outer and inner layers of a cake which has been dried by the from outside in method have differences in strength, elongation, swelling in water, and shrinkage in alkali which are twice as small as yarn which has been dried by the usual method. Uniformity of dyeing of such yarn, which is characterized by the coefficient of variation in the reflective index, is four times as large.Translsted from Khimicheskie Volokna, No. 3, pp. 40–41, May–June, 1984.     

Effect of high shear rate gradients on the gel particle content of viscose

Conclusions It has been found that a decrease in gel particle content takes place during the process of a short-term rheological treatment of a viscose in a high shear velocity gradient field.The advisability of carrying out the process of dissolving cellulose xanthate in apparatus having a rheological action has been demonstrated.Translated from Khimicheskie Volokna, No. 1, pp. 29–30, January–February, 1984.     

Reductive transamination of methoxyacetone with benzylamine over Pd/SiO2 catalyst modified with anchored chiral compounds

Methoxyacetone was transaminated with benzylamine to methoxyisopropylamine over a Pd/SiO₂ catalyst modified with Lalaninol or Lphenylalaninol covalently anchored to the surface of the support via an organosilicon spacer group. In the first step of transamination a Schiff base was formed from the ketone and benzylamine, and then it was hydrogenated in the second step on the chirally modified Pd/SiO₂ catalysts to an asymmetric secondary amine (Nbenzylmethoxyisopropylamine). In the third step the hydrogenolysis of the asymmetric secondary amine resulting in methoxyisopropylamine and toluene was carried out over a 10 wt% Pd/C catalyst. The highest enantiomeric excess of (S)methoxyisopropylamine was observed in cyclohexane (ee = –20–21%) using anchored Lalaninol as a chiral modifier.     

Microinterferometry of poly-p-phenyleneterephthalamide fibres dried at various temperatures

Conclusions Poly-p-phenyleneterephthalamide fibres which have been subjected to drying at various temperatures have been studied by use of the Biolar polarizing interference microscope.A significant change in the n(r) curves on change in temperature has been detected. Temperature elevation essentially does not show up in the axial orientation of the polymer macromolecules; however, the transverse orientation of the structural elements changes considerably.Translated from Khimicheskie Volokna, No. 3, pp. 40–41, May–June, 1989.     

Evolution of weak shock waves in dense media

Relations describing the evolution of a weak shock wave (SW) in a dense medium with account of its attenuation and spreading are derived. The evolution is presented as a result of superposition of two processes: propagation of a stepped weak shock wave and pursuit of the shock by a rarefaction wave.Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 31, No. 2, pp. 139–143, March–April, 1995.     

Clean-up of industrial wastewater from viscose manufacturing on filters having a foamed polystyrene charge

Conclusions Basic technological parameters of the process of filtering industrial wastewater from viscose manufacturing on filters having a polystyrene charge have been determined.It is recommended to use filters with a foamed polystyrene charge in the clean-up units of the Kalinin, Cherkassk, and Ryazansk Khimvolokno Industrial Association and the Sibvolokno PO to attain the required degree of wastewater clean-up in mechanochemical clean-up units.Translated from Khimicheskie Volokna, No. 5, pp. 13–14, September–October, 1988.