Methods of evaluating the degree of orientation of noncrystalline (amorphous) regions of fibre structure

Conclusions Attention has been directed to the internal inconsistency of the equations which are used to calculate the degree of orientation of amorphous regions, and the correctness of characterizing the entire noncrystalline region of fibres by specific quantities which pertain to a hypothetical amorphous region has been put in doubt.A method has been suggested for determining the mean-molecular orientation of the noncrystalline regions of polyethylene terephthalate fibres which is based on Eq. (10) derived by the author.Published for purposes of discussion.Translated from Khimicheskie Volokna, No. 4, pp. 4–8, July–August, 1988.     

Problems in preparing organoplastics based on highly oriented polyethylene fibres

Conclusions -- Some special features of epoxy organoplastics based on highly oriented polyethylene fibres have been determined, which consist in a low strength in shear, compression, or transverse extension, which are 4–6 times less than those of composites based on aramide fibres and which are caused by low adhesive interaction.-- Some basic ways of preparing monolithic polyethylene plastics have been shown, the most important of which are based on increasing the adhesive strength of fibres to the binder or by autohesive binding of the fibres.-- The possibility of preparing organoplastics of various types based on polyethylene fibres with a strength level in extension not less than 1.5 GPa, and elastic modulus up to 90–120 GPa, at a density not over 1100 kg/m³ has been confirmed.Translated from Khimicheskie Volokna, No. 4, pp. 36–39, July–August, 1990.     

Water-soluble copolyesters as antistats for Lavsan fibre

Conclusions Water-soluble copolyesters based on ethylene terephthalate, containing more than 25 mole percent of sodium 5-sulfoisophthalate and polyethylene oxide blocks, have an antistatic action with respect to Lavsan fibre.The water-soluble copolyesters synthesized may present interest as brightening or sizing preparations for polyester fibres in textile processing.Translated from Khimicheskie Volokna, No. 3, pp. 19–21, May–June, 1987.     

Effect of orientation stretch on structure of a composite fibre based on high-density polyethylene and polybutylene terephthalate

Conclusions Due to the effect of the HDPE matrix in composite fibres based on HDPE-PBTP it is possible to draw the polybutylene terephthalate component to degrees of orientation which exceed the degree of orientation attained for pure PBTP.The introduction of chemical cross-links between the HDPE and the PBTP under radiative treatment permits one to expand the temperature service range of polyethylene fibres containing a small amount of the polyester.The possibility of transition from orthorhombic chain packing to a mesomorpohic state in a HDPE composite fibre on heating above the equilibrium melting point under isometric conditions has been demonstrated.Translated from Khimicheskie Volokna, No. 5, pp. 33–35, September–October, 1989.     

Special features in the deformation behavior of polyethylene gel-fibres

Conclusions The effect of stretching rate on the deformation behavior of polyethylene fibres prepared by the gel-technology method and which have different stretch ratios has been investigated.An invariance in failure mechanism of fibres over a wide range in stretch ratio has been found.Features of the deformation behavior of polyethylene fibres which are important from the point of view of practical application of materials have been studied in detail.VNIISV (Tver'). Translated from Khimicheskie Volokna, No. 3, pp. 36–38, May–June, 1993.     

Effect of alkali treatment on structure of surface layers of elementary polyethylene terephthalate filaments

Conclusion The change in supermolecular structure of polyethylene terephthalate as a result of hydrolytic degradation of macromolecules in hydrolysis of yarns from Lavsan yarns has been studied by the method of internal reflection IR spectrophotometry. The nonlinear decrease in degree of orientation of macromolecules thereupon has been connected up with a nonlinear decrease in fabric stiffness caused by etching of the surface layer of elementary filaments.The development of the surface microrelief of elementary Lavsan fibres on alkali treatment has been studied by scanning electron microscopy, and it has been shown that the supermolecular structure of these fibres is nonuniform in the cross-section.Deceased.Translated from Khimicheskie Volokna, No. 5, pp. 52–54, September–October, 1988.     

Synthesis of organic boron compounds and their use to stabilize polyethylene terephthalate

Conclusions The possibility of using aromatic esters of boric acid as thermostabilizers for polyethylene terephthalate has been investigated.It has been found that the use of borates containing a naphthyl or p-hydroxyphenyl group as thermostabilizers makes it possible to obtain a polyethylene terephthalate with improved mechanical properties and an increased thermal stability.Translated from Khimicheskie Volokna, No. 6, pp. 24–26, November–December, 1986.     

Rheological properties of a fibre-forming composition based on high-density polyethylene and polybutylene terephthalate

Conclusions Composite fibres based on high-density polyethylene and polybutylene terephthalate have been prepared with different types of phase structure, depending on spinning conditions.An effect of the ratio of effective viscosities and of elasticity of the components of the specific fibre-formation process has been shown in spinning a structure of the fibrils in matrix type under the conditions of Poiseuille flow.The concentration dependence of the swelling of mixture extrudates at a constant shear rate is a characteristic which is more sensitive to change in phase morphology of the composition than the concentration dependence at a constant shear stress.Translated from Khimicheskie Volokna, No. 4, pp. 12–14, July–August, 1988.     

Hollow fibre based on polyphenylene isophthalamide as the highly-porous backing

Conclusions -- The possibility of preparing a highly-permeable backing from polyethylene isophthalamide in spinning composite hollow fibres for gas separation has been demonstrated.-- A connection has been established between spinning parameters and their effect on the gas permeability of the backing.-- A regime for the preparation of hollow fibres which have an optimum morphological structure for the wall pore structure has been determined.Translated from Khimicheskie Volokna, No. 4, pp. 47–48, July–August, 1991.     

Synthesis of polyethylene terephthalate in the presence of 4-carboxybenzaldehyde

Conclusions Contamination of terephthalic acid with 4CBA causes a decrease in the whiteness of the finished polyethylene terephthalate and the appearance of branched structures due to reactions of the aldehyde group.To obtain high-quality polyethylene terephthalate with good color characteristics, it is very advisable to use stabilizers which reduce the aldehyde group in 4CBA, phosphites for example.Translated from Khimicheskie Volokna, No. 4, pp. 9–11, July–August, 1983.     

Effect of pneumotexturizing on surface topography of polyethylene terephthalate and viscose yarns

Conclusions A classification of the basic types of defects in the surface of viscose yarns and yarns from polyethylene terephthalate which arise as a result of actions which take place during the pneumotexturizing process has been made.A qualitative estimate of the density of defects agrees with data on the strength characteristics of yarns which have been subjected to texturizing at various fibre movement speeds and air pressures in the nozzle of the aerodynamic device.Translated from Khimicheskie Volokna, No. 4, pp. 28–29, July–August, 1988.     

An adaptive system of automatic control of the quality indices in the process of polyethylene terephthalate

Conclusions -- Principles for constructing an adaptive control system for qualitative indices of the polyethylene terephthalate synthesis process have been examined.-- A mathematical assurance of a control system for the basic technological stages has been developed.-- A control algorithm has been realized in the esterification stage of the synthesis process of an industrial unit, which ensures a degree of completion of the process within assigned limits.Translated from Khimicheskie Volokna, No. 5, pp. 48–49, September–October, 1990.     

Photoinitiated graft polymerization of acrylamide to polyethylene terephthalate and properties of the modified fibres

Conclusions A study of the process of photoinitiated grafting of acrylamide to fibres of polyethylene terephthalate in the presence of benzophenone introduced into the fibre by preliminary treatment in a mixture of organic solvents indicates the possibility of carrying out a graft polymerization reaction without significant homopolymer formation.The modified fibre is characterized by an increased hydrophilicity and dyeability with cationic dyes, and by a good antistatic response. No impairment in breaking characteristics of the fibre or in its thermal properties takes place as a result of the grafting.Yugoslavia. Translated from Khimicheskie Volokna, No. 4, pp. 49–51, July–August, 1985.     

Adsorption of moisture from the air in polyethylene terephthalate dryers

Conclusions Results of a study of the operation of air drying adsorbers for polyethylene terephthalate dryers have been given.It has been shown that overloading the adsorbers with air to be dried which has a reduced moisture content as a result of mixing fresh air and circulating air adversely affects the adsorbent activity.It has been proposed to replace the existing scheme of connecting up adsorbers with two seasonal variants which eliminate drying of the circulating air.Translated from Khimicheskie Volokna, No. 5, pp. 43–45, September–October, 1985.     

Materials for protection from ballistic injury

It was noted that stiff-chain (para-aramid) and flexible chain (polyethylene) high-strength, high-modulus polymer fibres have been successfully used for ballistic protection of humans. It was hypothesized that new high-strength, high-modulus fibres based on aromatic polyesters could be successfully used for this purpose in the very near future.All-Russian Scientific-Research Institute of Polymer Fibres, Mytishchi. Translated from Khimicheskie Volokna, No. 3, pp. 15–17, May–June, 1995.     

Orientation stretching of a composite fibre based on high-density polyethylene and polyethylene terephthalate

Conclusions An effect of the components on the possible stretch ratio of a composite fibre based on high-density polyethylene (HDPE) and polyethylene terephthalate (PET) has been detected, depending on the orientation stretch temperature, and on the composition and phase structure of the composite.In spite of the fact that the total degree of stretch of the composite fibre is greater than the possible degree of stretch for pure PET, the actually attained degree of orientation of the PET component does not exceed the degree of orientation of the homopolymer.The presence of two types of HDPE has been detected in the oriented fibres — weakly oriented and strongly oriented.Translated from Khimicheskie Volokna, No. 1, pp. 17–19, January–February, 1988.     

Evaluation of the effect of an organic solvent on the state and diffusion permeability of polyethylene terephthalate

A fast method of evaluating the limit of compatibility of organic solvents with polyethylene terephthalate was proposed. The correlation between the nature of the solvent, its solubility limit with the polymer, and the diffusion rate of disperse anthraquinone dye in plasticized polyethylene terephthalate was investigated.Institute of Chemistry of Nonaqueous Solutions, Russian Academy of Sciences, Ivanovo. Translated from Khimicheskie Volokna, No. 4, pp. 37–40, July–August, 1996.     

Selective properties of hollow fibres for ultrafiltration

Conclusions The selective properties of hollow fibres used in the separation of solutions of poly-ethylene glycols and proteins have been investigated. It has been shown that the increase in retention coefficient and specific permeability as the velocity of the stream increases, in the separation of solutions of kinetically relatively flexible polyethylene glycol molecules, is not connected with the phenomenon of concentration polarization. but can be explained by the deformability of the tangles of polyethylene glycol macromolecules on flow of the solution in thin capillaries (hollow fibres).Optimum ultrafiltration conditions have been determined.Complete retention curves have been constructed for the hollow fibre, which make it possible to determine its region of use.Translated from Khimicheskie Volokna, No. 6, pp. 14–16, November–December, 1984.     

Organoclays assisted vat and disperse dyeing of poly(ethylene terephthalate) nanocomposite fabrics via melt spinning

Polyethylene terephthalate nanocomposites containing six modified montmorillonite nanoclays were prepared by a melt compounding technique. The effect of intercalated compounds of montmorillonite on textile mechanical properties of resultant polyethylene terephthalate nanocomposite fabrics was investigated. Winding was not possible, when the polymers were first compounded with the desired amount of montmorillonite and then spun, as filament breakage occurred. Spinable polymer were only obtained by mixing polyethylene terephthalate master batches with 4 wt% montmorillonite, which contained tallow intercalating compound with pure untreated polyethylene terephthalate to a montmorillonite content of 0.5 wt%, thus decreasing the concentration of thermally degraded polymer chains. After spinning the fibres were drawn and knitted into fabric samples for further testing. The prepared polyethylene terephthalate nanocomposite fabrics using montmorillonite exhibited higher colour strength using vat and disperse dyes compared with those of the reference fabrics made from fibres spun without montmorillonite clay content and regular fabrics. The carbocyclic‐based vat dyes have higher colour strength values on polyethylene terephthalate nanocomposite fabrics if compared with heterocyclic‐based vat dyes. The colour fastness ratings for both vat and disperse dyeings secured very good to excellent washing and perspiration fastness on polyethylene terephthalate nanocomposite fabrics. All dyed fabrics showed excellent light fastness using vat and disperse dyes. The preparation of polyethylene terephthalate nanocomposite fabrics with improved textile mechanical and vat dyeing properties needs further investigations.     

Acidity and corrosivity of the volatile distillates in the synthesis of polyethylene terephthalate from dimethyl terephthalate and ethylene glycol

Conclusions The acidity and aggressive properties of volatile distillates in the synthesis of polyethylene terephthalate from ethylene glycol and dimethyl terephthalate have been studied on industrial technological lines. It has been shown that the acidity of the distillates increases as the synthesis process approaches completion. The composition of some of the acidic impurities in the distillates has been identified. It has been shown that the aggressive properties of distillates are determined by their content of strong acids.The effect of the acidity of the original ethylene glycol on the aggressive properties of distillates has been described. It has been shown that the use of neutral ethylene glycol sharply reduces the aggressive properties of the distillates.Measures have been recommended for reducing the aggressive action of distillates and of their distillation products on apparatus and pipelines of nonalloyed steels or cast iron.Translated from Khimicheskie Volokna, No. 2, pp. 12–14, March–April, 1988.