Viscosity properties of concentrated viscoses

Conclusions The physico-chemical properties of viscose containing up to 15% -cellulose by wt. have been investigated.It has been noted that increasing the -content of viscose affects principally the viscosity of solutions, but shows up only a little in the other characteristics of the viscose.At -cellulose contents up to 13.5% by wt. viscoses retain homogeneity and can present immediate interest for technological processing on appropriate selection of such parameters as temperature and NaOH/-cellulose ratio.Translated from Khimicheskie Volokna, No. 5, pp. 45–47, September–October, 1987.     

Some special features in preparing hydrocellulose fibres and yarns from concentrated viscoses

Conclusions The possibility has been demonstrated of preparing hydrocellulose fibres and yarns with good strength and elastic properties from concentrated viscoses at an -cellulose content of 12% with a DP of 250 and an NaOH/-cellulose ratio of 0.68.Translated from Khimicheskie Volokna, No. 2, pp. 25–26, March–April, 1990.     

Effect of carbon disulfide consumption on the basic properties of viscose prepared from radiation-modified cellulose

Conclusions -- The process of preparing viscose from radiation-modified cellulose using carbon disulfide in the range of 6–32% of the weight of -cellulose in the xanthation has been investigated.-- Equations have been given which describe the dependence of the degree of esterification of the cellulose xanthate, the ripeness index, the byproduct content, the viscosity, and the filterability of the viscoses on CS₂ consumption in xanthation within the range 6–32% by wt.-- It has been found that a decrease in consumption of CS₂ primarily affects the viscosity of the viscoses obtained, and then it affects figures which characterize the content of byproducts, degree of esterification of the cellulose xanthate, ripeness, and the filterability of the spinning solutions.Translated from Khimicheskie Volokna, No. 5, pp. 51–53, September–October, 1991.     

Some special features of spinning textile yarn from highly concentrated viscoses

Conclusions The fundamental possibility of preparing textile yarns with satisfactory physicomechanical properties from viscoses having an -cellulose content of 12.2% has been demonstrated.Structural features of finished yarns prepared from highly concentrated viscoses under standard conditions have been investigated.Basic directions for studies of the spinning process have been selected, with the objective of further improvement in the textile properties of the finished yarns.Translated from Khimicheskie Volokna, No. 6, pp. 30–32, November–December, 1987.     

Spinning viscose technical yarn into a bicomponent precipitation bath

Conclusions -- The possibility has been demonstrated of preparing viscose yarn by the centrifugal method from a viscose containing additions of urea by spinning into a bicomponent precipitation bath containing sulfuric acid and sodium sulfate.-- Optimum conditions for spinning viscose yarn have been established: a sulfuric acid content of 115 g/l in the precipitation bath, a urea content of 2.5% based on weight of -cellulose in the viscose, and an orientation stretch of 22%.-- Specimens of viscose yarn having a linear density of 13.3 tex have been prepared with a relative breaking load of up to 19 cN/tex, an elongation at break of 17–19%, and a mean squared deviation in dyeing nonuniformity of 0.8–1.0.Translated from Khimicheskie Volokna, No. 4, pp. 33–34, July–August, 1990.     

Effect of 1,2-dimethyl-5-vinylpyridinium methylsulfate on properties of viscose

Conclusions Addition of 1,2-dimethyl-5-vinylpyridinium methylsulfate to viscose in an amount of 5–50% based on the weight of -cellulose does not lead to a specific interaction of it with sulfur-containing components of the viscose and does not exert any important effect on the technological properties of the viscose or its ability to form fibres.In the spinning stage, the additive introduced behaves as a modifier which retards neutralization of the fibre being spun.Trasnlated from Khimicheskie Volokna, No. 2, pp. 15–16, March–April, 1989.     

Occurrence and Correlations of Monoterpene Hydrocarbon Enantiomers in Pinus sylvestris and Picea abies

The relative amounts and enantiomeric compositions of monoterpene hydrocarbons in branch and trunk xylem, in needles, and in resin from apical buds in 18 Pinus sylvestris trees have been determined and compared with the terpene content in branch xylem and needles of Picea abies. Besides the high amount of (+)-3-carene, an excess of (+)--pinene has been found in P. sylvestris, whereas in P. abies (–)--pinene dominates over (+)--pinene. In P. sylvestris, clear positive correlations were found between (+)--pinene and (+)-camphene in the four tissues analyzed. Good positive correlations were also observed between (–)--pinene and (–)-camphene in the two types of xylem, between (+)--pinene and (+)--pinene in the resin, and between tricyclene and (–)-camphene in resin and needles. In P. abies, positive correlations were found between (+)--pinene and (+)-camphene in the branch xylem and between tricyclene and (–)-camphene as well as between (–)--pinene and (–)-camphene in the needles. Complex relationships between (–)--pinene and (–)--pinene were found both in the P. abies and in the P. sylvestris tissues. The importance of the enantiomeric composition of -pinene for the host selection of Ips typographus, Tomicus piniperda, and Hylobius abietis is discussed.     

Synergistic Effect of Ethanol to α-Pinene in Primary Attraction of the Larger Pine Shoot Beetle, Tomicus piniperda

-Pinene and ethanol were released in the approximate proportions 1:0.1, 1:0.9 and 1:9 (at 21°C). Ethanol, released in the range of 3–279 mg/day, generally synergized the attraction of T. piniperda to -pinene (30 mg/day at 21°C), although attraction to the mixtures varied within and between years. The low release rate of ethanol together with -pinene attracted a significantly higher number of beetles than -pinene alone in 1995, April of 1996, and in 1997. Lures with the medium release rate of ethanol were the most attractive only in March of 1996. The high dose of ethanol significantly synergized attraction to -pinene in 1995 and 1997. The variable attraction of T. pinipeda to ethanol and -pinene at various release rates and proportions may be due to the temperature dependent nature of beetle antennal sensitivity. At ambient temperatures of 10–13°C. T. piniperda was most attracted to the lures with -pinene and high release rates of ethanol, at 14–17°C it was most attracted to those with medium release rates of ethanol, and at 18°C and higher it was most attraacted to those with low release rates of ethanol.     

The effect of carbon black filling and cross-linking in stretched SBR networks: a 2H-NMR study

Summary The line splitting v in ²H-NMR spectra of deuterated benzene in stretched crosslinked SBR depended linearly on the classical stretch term ² – 1/ for samples with and without carbon black filling. The ratio LS = v/(² – 1/) was measured in dependence on the solvent fraction . The extrapolated value L of this ratio at =0 gave a linear dependence on the inverse molecular mass 1/M_c of inter-crosslink chains. This was expected according to a simple model of chain dynamics and offers a further NMR-method for M_c-determination even in filled networks. However, the slope of the L(1/M_c)-line increases with an addition of carbon black which indicates a higher molecular order. Three reasons for this could be discussed. However, one of them is preferable.     

Synthesis of an EPDM graft terpolymer

Summary An EPDM graft terpolymer was prepared using the macromer poly--methylstyryldicyclopentadiene (P-MSt-DCp) as the diene with ethylene and propylene. The new material was characterized by GPC, osmometry, nmr spectrometry, and TGA measurements. Number average molecular weights are in the 24,000–29,000 range, and the polymer carries two branches per chain.     

Xanthation of alkali cellulose with a limited mixing time

Conclusions The possibility of carrying out a process of dry xanthation of alkali cellulose with limited (as respects time) mixing of the reaction mixture without impairing the quality of the viscose obtained has been demonstrated.Performing the process by the method under study increases the solubility of the cellulose xanthate in the sodium hydroxide solution, reduces the consumption of electrical energy, and reduces wear on equipment.This method is recommended for xanthater apparatus which processes alkali cellulose containing more than 30% -cellulose by weight.Translated from Khimicheskie Volokna, No. 1, pp. 26–27, January–February, 1986.     

Kinetics and Mechanism of Copolymerization of α-terpineol with Methylmethacrylate in Presence of Azobisisobutyronitrile as an Initiator

The radical copolymerization of -terpineol with methyl-methacrylate in xylene at 80±0.1C for 50 minutes in the presence of azobisisobutyronitrile (AIBN) follows ideal kinetics and results in the formation of a functional and random copolymer. The activation energy is 33 KJ/mole. The IR spectrum and NMR spectra of the copolymer(s) shows the bands at 1750 and 3400 cm^–1 for ester group of methylmethacrylate and alcoholic group of -terpineol and peaks at 3 to 4 for methoxy group and at 6.5 to 7.5 due to alcoholic group of methylmethacrylate and -terpineol repectively. The values of reactivity ratios, calculated by Kelen–Tüdos method, are r ₁ (MMA) = 0.18 and r ₂ (-terpineol) = 0.046. The Alfrey-Price; Q–e parameters for -terpineol has been calculated as 0.149 and 2.486. The mechanism of copolymerization has been elucidated and it is concluded that the double bond present in the monocyclic ring of -terpineol is an active site for copolymerization and the alcoholic group of -terpineol remain to give functional copolymer.     

Dose and enantiospecific responses of white pine cone beetles,Conophthorus coniperda,to alpha-Pinene in an eastern white pine seed orchard

The white pine cone beetle, Conophthorus coniperda, exhibited dose and enantiospecific responses to -pinene in stands of mature eastern white pine, Pinus strobus, in a seed orchard near Murphy, North Carolina, USA. (–)--Pinene significantly increased catches of cone beetles to traps baited with (± )-trans-pityol. (+)--Pinene did not increase catches of beetles to pityol-baited traps and interrupted the response of beetles to traps baited with (±)-trans-pityol and (–)--pinene. Maximal attraction of cone beetles to pityol-baited traps was obtained with lures releasing (–)--pinene at a rate of 103 mg/day at 23^°C. Lures releasing (–)--pinene at rates lower or higher than 103 mg/day resulted in reduced catches to traps baited with (±)-trans-pityol. The sex ratio in all catches was heavily male biased. Attraction of the clerid predator, Thanasimus dubius, to traps baited with (±)-trans-pityol increased significantly with the presence of -pinene, irrespective of enantiomeric composition. Maximal attraction of T. dubius to pityol-baited traps occurred with devices releasing (–)--pinene at the highest rate tested, 579 mg/d at 23^°C, a sub optimal rate for cone beetles.     

Response of the European elm bark beetle,Scolytus multistriatus (Coleoptera: Scolytidae), to isomers and components of its pheromone

Laboratory bioassays (two methods) and field tests demonstrated synergistic action of the three components [(–)-4-methyl-3-heptanol (I); (–)-2,4-dimethyl-5-ethyl-6,8-dioxabicylo[3.2.1]octane (-multistriatin) (II); and (–)--cubebene (III)] of the pheromone bouquet ofScolytus multistriatus. Individually and in pairs the components were slightly attractive; I+II was clearly the most active doublet. Indirect evidence indicates that only one of the four enantiomers of I is active. Of the , , and isomers of II, only the is active. With the addition of compound I, slightly attractive extract from mated females became nearly as active as extract from virgin females.     

Response ofScolytus multistriatus (Coleoptera: Scolytidae) to α- and δ-multistriatin in Switzerland

Laboratory bioassays and field tests demonstrated that a Swiss population ofS. multistriatus responded much more strongly to - than to -miltistriatin in combination with 4-methyl-3-heptanol and -cubebene. High concentrations of brevicomin appeared to replace -multistriatin in evoking a response byScolytus species, but this effect can be explained by the fact that the brevicomin was contiminated with small amounts of -multistriatin. Frontalin, another bicyclic ketal, showed no biological activity. Field tests indicated thatS. pygmaeus aggregates to the same attractant mixture asS. multistriatus. S. scolytus also responded preferentially to this mixture, but the relative amounts of -multistriatin to 4-methyl-3-heptanol do not appear to be as important as forS. multistriatus.     

Special features in spinning high-modulus viscose fibre of high linear density

Conclusions On transition to spinning 0.13–0.17 tex HMV fibres to 0.22–0.44 tex fibres, to maintain diffusion conditions in spinning, the H₂SO₄ content of the precipitation bath should be kept at a level of 70–75 g/liter or increased by no more than 1–2 g/liter. Process stability is achieved by reducing the spinning speed. However, the round cross-sectional form of the fibre is not retained, and its physicomechanical properties are diminished.A further rise in fibre quality may be attained by invreasing the -Cellulose content of the viscose to 7.5% by wt., with a simultaneous increase in the viscosity of the viscose to 250–300 sec.Translated from Khimicheskie Volokna, No. 4, pp. 28–29, July–August, 1989.     

13C NMR spin-lattice relaxation in solid poly(methyl methacrylate)

Summary ¹³C spin-lattice relaxation rates R₁ in samples of solid PMMA have been measured with CP MAS NMR. Isotactic, atactic, syndiotactic, and the 12 i-s PMMA complex were measured, along with atactic samples containing bisdioxan or the monomer as a plasticizer. The reorientation of the -methyl protons is the dominant relaxation source for the methylene, -methyl and quarternary carbon nuclei. Increased mobility of the polymer in the presence of a plasticizer is not reflected in significant changes in R₁.Presented at the 22nd Microsymposium, Characterization of Structure and Dynamics of Macromolecular Systems by NMR Methods, Prague, July 20–23, 1981     

Computer-controlling system in systems for controlling the mercerization process

Conclusions Increasing the accuracy of controlling or regulating the slurry ratio and the use of a cascade control of -cellulose content in the alkali cellulose has made it possible to increase stability in its composition.Pulse duration control of the metering of starting cellulose makes it possible to increase the accuracy in regulating the slurry ratio and to simplify the control system.A balanced system for controlling mercerization output and the -cellulose content of alkali cellulose has been developed, plus a sheet delivery machine with control of its output from the consumption of starting cellulose.Translated from Khimicheskie Volokna, No. 2, pp. 30–32, March–April, 1990.     

Synthesis,electroconductivity and third-order nonlinear optical property of poly(2-isopropoxy-5-methoxy-1,4-phenylenevinylene)

Summary Asymmetrically disubstituted poly(2-isopropoxy-5-methoxy-1,4-phenylene-vinylene), PIMPV, was prepared in thin films via organic-soluble precursor polymer method. These polymer films could be easily stretched up to 7 times, and the drawn films of the PIMPV could be doped with FeCl₃ and I₂ to give conductivities of 26.9 and 11.3 Scm^-1, respectively. The third-order nonlinear optical susceptibility of the polymer was determined using third harmonic generation(THG) method at 1907 nm, fundamental wavelength. Measured ⁽³⁰⁾ (-3: , , ) value was 3.7x10^-12 esu.     

Determination of the gel-particle and other contaminant content of viscose

Conclusions An advantage of the FS-112 type of analyzer as compared with other domestic instruments is the possibility of determining gel-particles and mechanical contaminants contained in a viscose, and of determining their disperse composition in five measurement ranges — from 5 to 500 µ.The use of this instrument permits one to investigate viscose quality in more detail, and to select filtration conditions appropriately.The procedure developed has good reproducibility and can be recommended for introduction in laboratory practice and manufacturing conditions instead of the Tsellosko-202 counter.It is inadvisable to carry out the determination of the content of gel-particles and other inclusions by the procedure described on unfiltered viscoses, since these viscoses contain much fibre and film, which may choke the instrument capillary.Translated from Khimicheskie Volokna, No. 5, pp. 38–40, September–October, 1987.