Ultimate Extensibility Research Articles

About Dynamics of Improving the Foam Concrete Technological and Operational Properties upon Disperse Reinforcement with Polypropylene Fibers

Introduction. The efficiency of the foam concrete products manufacture and application in construction is briefly overviewed. The reasons constraining the nomenclature of the manufactured products are listed. The information about evolvement of the foam concrete disperse fiber-reinforcement technology is provided. The need for scientific research aimed at studying the dynamics of the foam concrete technological and operational properties upon disperse reinforcement with polypropylene fibers is formulated.Materials and Methods. The composition and properties of the materials used for manufacturing the foam concrete mixtures are listed. The methods used for assessing the technological and mechanical properties of the materials under study are indicated.Results. The results of the experimental assessment of the polypropylene fiber length and amount influence on the dynamics of the plastic strengthening growth of the equally dense foam and fiber-reinforced concrete mixtures are presented. The scope of the polypropylene fiber influence on the dynamics of the studied mixtures plastic strengthening is analysed. The scientific substantiation of the reasons accelerating the mass transfer processes during the disperse reinforcement of mixtures with fibers is given. The results of the bending tensile strength tests of the large-size D600 concrete specimens are presented.Discussion and Conclusion. The efficient positive influence of the polypropylene fiber, in correlation with its length, on the following foam concrete properties has been distinguished:speed of phase transfer;ultimate extensibility;elasticity and strength modulus of D600 concrete.

Experimental and Theoretical Justification of the Foam Fiber-Reinforced Concrete Application Expediency in Earthquake-Resistant Construction

Introduction. Based on the evolutionary approach to the analysis of the lightweight concrete application expediency in earthquake-resistant construction it has been revealed that development of the above mentioned technologies fosters the reduced material consumption in construction and the increased durability of buildings under the seismic loads. The efficient solutions for constructing the earthquake-resistant buildings are constantly searched for, and the reasons for reducing the range of energy-efficient products made of the autoclaved aerated concrete are noticed. The research is aimed at compiling an inventory of modern technological methods of increasing the buildings seismic resistance.Materials and Methods. The list and properties of raw materials used for single-stage technology manufacture of the foam concrete mixtures have been provided. The list of equipment used for assessing the studied materials’ mechanical properties has been defined.Results. The new experimental data confirming the significant influence of the individual properties of fiber on the value of the dispersedly reinforced foam concrete ultimate deformability and bending tensile strength has been obtained. The positive effect of the length of fiber on the foam concrete mechanical properties has been confirmed. The considerably positive effect of the dispersed reinforcement on the homogeneity of mechanical properties observed in the foam concrete mass has been distinguished.Discussion and Conclusions. The work performed has elucidated the importance of the individual properties of fiber as a tool for managing the operational properties of foam concrete. The ultimate properties of the aerated rock material are influenced by the length of fibers and their ultimate deformability. The length of fiber is important for the bending tensile strength, whereas the values of this parameter in the composite material are regulated by the ultimate extensibility.

Durability of High-Density Polyethylene (HDPE)- and Polypropylene (PP)-Based Wood-Plastic Composites—Part 1: Mechanical Properties of the Composite Materials

Wood-plastic composites (WPCs) have shown exceptional promise as a building material, especially for outdoor uses. Using renewable wood fiber as the reinforcing filler in WPCs increases the material’s environmental sustainability. While virgin commodity thermoplastics are primarily used in these composites, using post-consumer plastic further contributes to their sustainability. While they are beginning to be used in the Gulf countries, information on their performance, especially durability under harsh desert climates, is sparse. The present investigation on WPCs is based on the two most popularly used thermoplastics in WPCs, virgin high-density polyethylene (HDPE) and polypropylene (PP), with the wood content varying between 0 and 36 wt. %. These were prepared with melt processing from a masterbatch and characterized primarily using thermal methods and tensile properties of their injection molded test pieces. Variations in tensile properties, especially the tensile modulus (MPa), the tensile strength (MPa), and the ultimate extensibility (%) of the composite samples were investigated to determine an optimal wood-fiber loading. For either polymer type, exceeding 27 weight percent of wood fiber resulted in unacceptably low ultimate extensibility of the material.

The effect of silver-containing sorbent on red blood cells during hemosorption: an <i>in vitro</i> study

The aim of the study was to investigate the influence of the original porous silver–containing sorbent on the morphofunctional parameters of red blood cells during in vitro hemoperfusion. Material and methods. Donor blood was perfused through glass columns filled with a sorbent based on porous aluminum oxide, polydimethylsiloxane and silver nanoclusters and a sorbent without silver. The effect of a silver-containing sorbent on the change in morphofunctional parameters of red blood cells after perfusion through sorbents was determined by scanning flow cytometry. Results and their discussion. Due to the uniformity of the distribution of silver (0.1 %) over the sorbent granules, the parameters of the porous structure – the specific surface area and pore volume – practically do not change compared to the sorbent without silver. Morphological parameters of original donor blood and after hemoperfusion are within the norm. The functional parameters are also normal, although the introduction of silver in to the sorbent slightly increases the number of active band 3 (B3) proteins on erythrocyte membranes, both in comparison with the donor red cell mass as a control and in comparison with the sorbent without silver. There is also an increase in the ultimate extensibility of the erythrocyte membrane compared to the original blood (2.2 times) and the sorbent without silver (1.4 times). Conclusions. A sorbent modified with silver and a sorbent without silver does not have a damaging toxic effect on the morphofunctional parameters of blood under perfusion conditions. The mechanisms affecting the indicators of the ultimate extensibility of the erythrocyte membrane after blood perfusion through a silver-containing sorbent require further research.

Control system of 4-DOF palletizing robot based on improved R control multi-objective trajectory planning

To realize efficient palletizing robot trajectory planning and ensure ultimate robot control system universality and extensibility, the B-spline trajectory planning algorithm is used to establish a palletizing robot control system and the system is tested and analyzed. Simultaneously, to improve trajectory planning speeds, R control trajectory planning is used. Through improved algorithm design, a trajectory interpolation algorithm is established. The robot control system is based on R-dominated multi-objective trajectory planning. System stack function testing and system accuracy testing are conducted in a production environment. During palletizing function testing, the system’s single-step code packet time is stable at approximately 5.8 s and the average evolutionary algebra for each layer ranges between 32.49 and 45.66, which can save trajectory planning time. During system accuracy testing, the palletizing robot system’s repeated positioning accuracy is tested. The repeated positioning accuracy error is currently 10−1 mm and is mainly caused by friction and the machining process. By studying the control system of a four-degrees-of-freedom (4-DOF) palletizing robot based on the trajectory planning algorithm, the design predictions and effects are realized, thus providing a reference for more efficient future palletizing robot design. Although the working process still has some shortcomings, the research has major practical significance.

Studying the Relationship between the Strength and Stress-Related Characteristics of Concrete as a Conglomerate and the Properties of its Components

The concrete conglomerate properties change over time and depend on a number of factors. When considering deformation under the effect of mechanical loads or changes in temperature and humidity, the mechanism of this process is based on three main provisions. Firstly, concrete is a composite material, the matrix of which is cement stone. Secondly, the elastic modulus and strength of the cement stone may be less or more than that of aggregate. Thirdly, the concrete destruction under axial compression occurs at the cement stone stresses exceeding its ultimate extensibility in the direction normal to the external load action. Considering the specifics of deformation under load in different periods and the role of stress-related characteristics in this process, it is advisable to outline ways to regulate them and thereby the main concrete properties in the desired direction. The importance and feasibility of this approach are determined by the need to develop techniques allowing control of properties such as elasticity, shrinkage, and creep. A series of experimental tests and a comparative analysis of the results have been performed. The effect of some aggregate rocks on certain strength and stress-related properties of the concrete conglomerate has been investigated. Limestone and sandstone have been taken as the rocks studied. The properties studied include impact, axial compression, and axial tensile strengths. According to the analysis, concrete prepared on crushed limestone has shown the best results concerning all the properties studied.

Strength and deformability of cement stone, mortar and concrete during loading

The article analyzes the structural strength and the main provisions of the mechanical behavior of cement systems under short-term loading. It presents the results of the research into concrete’s strength and deformability at the structural levels of the cement stone, mortar and concrete in general during loading. To fabricate concretes, manufacturable binders, quarry sands and rock – silica clay of the Penza region were used. The following materials were considered: cement stone with different W/C, cement mortar with different sands and with its addition in different proportions, and concrete with the use of a light aggregate – thermolith. It was found that when the W/C increases from 0.25 to 0.31, the ultimate compressibility and ultimate extensibility of cement stone increases to 9% and 29.5%, respectively. The introduction of various types of sand into the composition caused the reduced compressibility and extensibility of materials, despite the fact that the mortars became more plastic. The authors describe the fabrication technology and properties of a light aggregate based on a silica clay - thermolith. Tests of thermolith concrete showed the character of immediate elastic and rapidly increasing creep deformations development in the context of longitudinal compression and transverse expansion.

ПОЛИМЕРНЫЙ КОМПОЗИТ ДЛЯ ПЛИТ КОЛЕЙНОГО ПОКРЫТИЯ АВТОМОБИЛЬНЫХ ЛЕСОВОЗНЫХ ДОРОГ

the network of modern temporary highways is operated only during logging, and at the end of the work and during the mud season are practically not used. Consequently, there is a need to create collapsible elements for temporary logging roads, which, if necessary, can be assembled in a fairly short time before starting work, is also easy to disassemble after the completion of logging operations and transported and laid in a new place. The coating is a slab containing a wooden multilayer frame made up of elements representing sawmill waste of low-value species, put on a rib or laid flat with gaps, providing a spillage of concrete or polymer mass based on furfural acetone monomer. Untreated wood provides oriented reinforcement along and across the building element, as a result of which its tensile, bending and chipping strength are increased, and bulk density is reduced. The article also considers the constrained swelling of wood filler when using it as a reinforcing element of concrete based on cement is more dangerous, since it is not possible to significantly increase its ultimate extensibility even when introducing latex into its composition. The use of reinforcing mesh is not possible, since the alkali contained in the wet environment of the cement stone destroys the fiberglass mesh.

Self-Healable Dielectric Polydimethylsiloxane Composite Based on Zinc-Imidazole Coordination Bond

Self-healing material has been intensively studied in the last decade due to its capability of improving materials’ lifetime and safety. Among the numerous proposed self-healing mechanisms, reversible metal-ligand coordination bond is considered as a strong candidate for a healing moiety because of its high tunability of mechanical properties based on the thermodynamic characteristics and kinetic parameters of metal ions or ligands. Furthermore, the dipolar nature of coordination bond can enhance the dielectric property of the material. Herein, zinc-imidazole coordination bond, having a fast ligand exchange rate in ambient condition, was employed as a healing moiety to synthesize room temperature self-healable polydimethylsiloxane (PDMS). Imidazole modified PDMS cross-linked by ligand and zinc ratio 4.5 (IMZ-PDMS-1100 L/Z 4.5) exhibited ultimate tensile strength (UT) of 60.73 kPa with ultimate extensibility (UE) of 211%. These mechanical properties could be adjusted by varying L/Z ratio and IMZ content. In comparison with previously reported metal-ligand based self-healing PDMS, IMZ-PDMS-1100 L/Z 4.5 showed faster healing rate that recovered 98% of UT and UE after 31 h healing and even faster healing rate was achieved with higher IMZ content. Moreover, cross-linked IMZ-PDMS displayed high dielectric constant of 8.30±0.74 at 1 MHz, which was 2.7 times higher than conventional PDMS.

Melt spinning of conducting polymeric composites containing carbonaceous fillers

AbstractFibers produced by melt spinning of conductive polymer composites are attractive for several applications; the main drawback is however reduced processability at high filler concentrations. Carbon nanotubes (CNTs) are considered suitable fillers for conductive polymer composites, replacing conductive grades of carbon black (CB). In this study, the fiber‐forming properties of conductive polymer composites based on a conductive grade of CB and two masterbatches with CNT in a polyethylene matrix were investigated. The CB was also used in a polypropylene matrix for comparison. The rheological properties of the filler‐containing melts in shear and their extensional behavior were evaluated. A piston‐driven device was used to extrude the molten materials through a capillary; different capillary geometries were tested. Fibers were produced at various draw ratios, and their conductivity was determined. To assess the ultimate extensibility, a modified Rheotens method was used. The results showed that a conductive CB grade can have a lower percolation threshold and higher conductivity than a material with CNT. Conductivity decreased with increasing melt draw ratio for both types of fillers. The spinnability of the materials decreased with increasing concentration of filler material and correlations were found between spinnability and melt elasticity. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Preferential Association of Segment Blocks in Polyurethane Nanocomposites

Controlling the level of dispersion of silicate layers in polymer matrices through intermolecular interactions and exploiting these interactions to enhance thermomechanical behavior are key challenges in the field of polymer nanocomposites. In this investigation, unmodified Laponite platelets are dispersed in a segmented polyurethane containing a polar, hydrophilic soft segment and a hydrophobic hard segment using a novel solvent exchange method and compared to polyurethane nanocomposites containing more hydrophobic hard and soft domains. It was determined that the silicate layers were preferentially, but not exclusively, attracted to the hydrophilic, polar soft domains. An apparent microphase-segregated morphology was observed in transmission electron microscopy for this system, revealing regions of exfoliation and intercalation. According to polarizing optical microscopy, strain-induced alignment is inhibited for this polyurethane nanocomposite, which is reflected in dramatic reductions in tensile strength and ultimate extensibility. In comparison, the Laponite disks appear to be preferentially, but not exclusively, embedded within the hard domains in the segmented polyurethanes containing more hydrophobic hard and soft domains. Exfoliation of the clay platelets leads to enhanced modulus and toughness without a reduction in extensibility. This study provides clues for exploiting silicate-polymer interactions to tune material properties without chemical modification.

Biomechanical changes in the anterior lens capsule after trypan blue staining

Purpose: To examine the effect of trypan blue staining on the biomechanical behavior of the porcine anterior lens capsule. Setting: Department of Ophthalmology, Technical University of Dresden, Dresden, Germany. Methods: Fifty-five anterior lens capsules from porcine cadaver eyes were used. Two parallel 8.0 mm × 4.0 mm large capsule strips were prepared from each capsule. After trypan blue staining for various time intervals combined with exposure to white light (6000 lux) or with no light exposure, biomechanical stress-strain measurements were performed using an automated material tester. Untreated specimens and specimens treated with glutaraldehyde 0.1% were used as controls. The absorption spectrum of trypan blue 0.1% solution and the emission spectrum of the light source were measured. Results: After treatment with light and trypan blue, at 25% strain, there was a statistically significant increase in stress of up to 70.1% and in elastic stiffness of 47% and a decrease in the ultimate mechanical strain of up to 13%. There were no biomechanical changes in capsules with trypan blue staining in the absence of light or after a short illumination time of 30 seconds, indicating a light-dependent process. After 30 minutes of glutaraldehyde 0.1% treatment, there was an increase in stress of 321.6% at 25% strain and a decrease in the ultimate strain of 47.6%. The emission spectrum of the light source included the absorption peak for trypan blue at 580 nm. Conclusions: Trypan blue staining of the lens capsule combined with light irradiation for at least 1 minute led to an increase in elastic stiffness at 25% strain and a reduction in the ultimate extensibility. This effect is probably due to the photosensitizing action of trypan blue, leading to light-induced collagen crosslinking of the capsule collagen similar to age-related crosslinking. Nucleus expression might be impeded by the increased capsule stiffness. Continuous curvilinear capsulorhexis is facilitated.

Influence of indocyanine green staining on the biomechanical properties of porcine anterior lens capsule

Purpose. Indocyanine green (ICG) has recently been introduced in cataract surgery to stain the anterior lens capsule for better visualization of the capsulorhexis. The aim of the current in vitro study was to examine the effect of ICG staining on the biomechanical strength of the anterior porcine lens capsule.Methods. Two parallel, 8 × 4 mm anterior lens capsule strips were prepared from each of 65 porcine postmortem eyes. ICG staining combined with white light exposure of 0.5, 1, 3, and 30 min duration was conducted. Unstained, nonilluminated and 0.1% glutaraldehyde-treated specimens were used as controls. Biomechanical stress-strain measurements were performed using an automated material tester. The absorption spectrum of the 0.5% ICG solution and the emission spectrum of the light source were controlled.Results. After ICG staining combined with at least 3 min light exposure, a significant increase of stress (31%) at 25% strain and a significant decrease (7%) in ultimate strain was found. Without light exposure, there was no such effect, suggesting a light-dependent process. After 30 min of 0.1% glutaraldehyde treatment, there was a similar increase in stress (322%) at 25% strain and a decrease (47.6%) in ultimate strain.Conclusions. ICG staining of the lens capsule causes a significant increase in elastic stiffness and a reduction in ultimate extensibility, thereby facilitating a smooth continuous capsulorhexis. The effect is due to a photosensitizing effect of ICG, leading to collagen cross-linking.

Biomechanical Properties of the Internal Spermatic Vein in the Normal Population and Patients with Left-Sided Varicocele Testis

Objective: The aim of the study was to investigate a possible decreased strength of the wall of the left internal spermatic vein between patients with varicocele testis and controls. Materials: From 14 patients with varicocele testis, 2 cm of the vein was obtained during operation per varicocele and compared to samples of the left internal spermatic vein taken from the same anatomical localization of 19 patients with no varicocele testis or other conditions with relation to the scrotum; additionally, samples from the right internal spermatic vein similar to those described above were taken from 12 patients. The biomechanical properties of ring-shaped venous specimens were investigated by loading the specimens at a constant deformation rate until rupture. Main Results: The regression coefficient, standard error and p value revealed no significant differences in ID (diameter), UC (unit collagen/ID), E-max (ultimate extensibility), Max (maximum strength), Tan-a (maximum stiffness), E-fail (relative failure energy). The trend to significance was shown in ID between the varicocele and left-sided veins (p = 0.05) and between left- and right-sided veins (p = 0.05). Conclusions: These biomechanical tests of the spermatic veins from healthy subjects and patients operated for varicocele showed that biomechanical differences were associated with age and could play a part in the development of varicocele testis in an age-matched group.

Biomechanical Properties of Normal and Varicose Internal Spermatic Veins

To investigate possible differences in biomechanical properties between varicose spermatic veins and controls. During surgery on 12 patients for grade 3 left-sided varicocele testis, 2 cm of the vein was obtained for comparison with: (i) samples of the left internal spermatic vein taken from the same anatomical localization from 8 patients without scrotal disease, and (ii) samples from the right internal spermatic vein from 7 other patients also without scrotal disease. The biomechanical properties of ring-shaped venous specimens were investigated by loading the specimen at a constant deformation rate until rupture. The relative amounts of collagen in the specimens were determined as the contents of hydroxyproline. There was a significant difference between varicocele testis/right spermatic vein in UC (unit collagen), F-max (maximum strength), Strain (ultimate extensibility) and E-fail (relative failure energy), but not in LD (diameter) and Tan-a (stiffness of the specimen). There were no significant differences between left and right spermatic vein in LD, UC, F-max, Strain, Tan-a and E-fail. There was a significant difference in LD between varicocele testis/left spermatic vein, but no relationship in UC, F-max, Strain, Tan-a and E-fail. Biomechanical analyses of the spermatic veins from patients operated for varicocele seem to support the hypothesis that a difference in biomechanical properties plays a part in the development of varicocele because a significant increase in extensibility of varicocele samples was found compared with normal right spermatic vein samples.

The role of molecular networks in the deformation behaviour of solid polymers

In early research on polyethylene terephthalate, studies of shrinkage force, shrinkage and birefringence on melt spun fibres confirmed the existence of a molecular network which was of key importance in determining the strain hardening behaviour and hence the natural draw ratio. These ideas were translated to the ultra drawing of polyethylene, where it was found that molecular weight and initial morphology determined the ultimate extensibility of the polymer. The existence of the network in the drawn polymer was confirmed by measurements of thermal expansion and shrinkage force.Recently this research has been extended to define the network which forms in the spinning threadline for very high wind up speeds and how this subsequently affects the drawing behaviour and the final properties of the drawn yarns. Specific issues addressed have included the effect of molecular weight on the behaviour of polyethylene terephthalate fibres and the extension of the studies to polybutylene terephthalate where changes in the crystalline structure can occur.In films, a comparison has been made between uniaxial and uniaxial planar (constant width) films. Refractive index and infrared spectroscopic measurements have been undertaken to determine the chain axis orientation and conformational changes. It has been shown that a quantitative description can be obtained in terms of the deformation of a rubber-like network. More recently, studies have been undertaken of two-stage stretching, with the additional objective of determining the factors influencing the development of crystalline orientation in the second draw direction.

Reduced Strength of Skin in Ehlers Danlos Syndrome, Type III

The biochemical properties, ratio collagen type I/type III and the pattern of reducible collagen crosslinks were studied in skin biopsy samples from 10 patients with Ehlers Danlos syndrome type III (ED III) and 10 age- and sex-matched controls. The ED III patients had marked reductions in skin strength and stiffness (42% and 22%, respectively). The ultimate extensibility of the skin, however, was not different from that of the controls. Consequently, a certain load applied to the skin of these patients results in greater deformation than in that of the controls, due to reduced stiffness. The bursting limit is no different from that of the controls. Thus the skin in the ED III patients is not hyperextensible, it merely has reduced strength and stiffness. The reduction in strength could not be explained by differences in skin thickness or collagen content. Skin thickness, collagen content and ratio collagen type I/type III were the same as in the controls, as also was the pattern of reducible collagen crosslinks. These alterations in the mechanical properties of the skin of patients with ED III may be attributable to the molecular structure of the mature collagen or the arrangement of the collagen fibres.

Effect of the maximum size of coarse aggregate on the main parameters of concrete

1. A decrease of the water requirement and content of cement and an increase of the density of concrete due to a decrease of the sand content and corresponding increase of the stony component are a positive aspect of increasing the size of the aggregate. 2. The consumption of cement with an increase of the size of the aggregate from 40 to 80 mm, other conditions being equal, decreases by 20–30 kg per 1 m3 of concrete (Figs. 1 and 3), which amounts to 10–12% and, accordingly, the density of the concrete mix increases. 3. With an increase of the size of the aggregate from 40 to 80 mm for concretes with a water/cement ratio from 0.40 to 0.68, the compressive strength increases insignificantly (up to 9%) and the splitting strength, conversely, decreases up to 10%. 4. A decrease of the tensile strength, accompanied by an increase of the modulus of elasticity, led to a substantial decrease of the ultimate extensibility of concrete (up to 28%), which occurs as a result of an increase of the inhomogeneity of the concrete and decrease of the cohesive strength of the aggregate with the hardened cement. 5. The limiting value of the maximum size of aggregate should be selected on the basis of the fractional composition of natural deposits planned to be used for obtaining aggregates with consideration of their rational use and the design characteristics of the structures and feasibility study.

Polymer composite of rigid and flexible molecules: Blend systems of poly(p‐phenylene terephthalamide) and ABS resin

AbstractHomogeneous coagulant of poly(p‐phenylene terephthalamide) (PPTA) and ABS resin was obtained by pouring the dimethylsulfoxide solution of N‐sodium PPTA and ABS into acidic water. Transmission electron microscopic observation proved that PPTA was dispersed in the matrix in a form of microfibril with a diameter of 10–30 nm. The Tg of the resin component in ABS shifted to higher temperatures with increasing fraction of PPTA. Stress‐strain behavior of the polymer composite showed increased tensile modulus and strength with addition of PPTA. The transition temperature from brittle to ductile fracture, however, shifted to higher temperature resulting in lower extensibility. Incorporation of the block copolymer of PPTA and polybutadiene into ABS improved the ultimate extensibility, i.e., increased toughness was provided compared with the simple composite systems of ABS and PPTA microfibrils. Scanning electron microscopic observation showed that the polymer composite made with the block copolymer generated many crazes upon deformation, while the composite with PPTA homopolymer fractured without remarkable craze formation. Thus, a new type of thermoplastic with improved mechanical properties was obtained by use of PPTA block copolymer as compatibilizer.

Transition of polymers from the fluid to the forced high-elastic and leathery states at temperatures above the glass transition temperature

The transition from the fluid to the forced high-elastic (rubber-like or quasi-vulkanizate) state and then to the leathery state (that is between rubbery and glassy states ∗∗ ∗∗ FHES and FLS in abbreviated form ) has been systematically studied by increasing stresses and deformation rates, using an uncured high molecular-mass 1, 2-polybutadiene characterized by a rather high glass transition temperature (−18°C). Investigation of polymers in simple shear is possible up to critical stresses corresponding to the transition of fluid polymers to FHES. Uniaxial extension offers wide possibilities for characterizing polymers in FHES and FLS since it covers the range of 4–6 decades of deformation rates over the range of simple shear. The deformability of polymers is limited by their fracture even in FHES, and the fracture process is determined only by recoverable deformation. The failure envelope covering FHES and transition to FLS has been constructed and the long-term durability in the range of 7 decades of time measured. The maximum extensibility corresponding to the transition of the polymer to FLS is determined by the ultimate extensibility of macromolecular coils. Over a wide range of stresses the polymer behaves like a linear viscoelastic body. This makes it possible to correlate the data obtained for uniaxial extension and low-amplitude sinusoidal shear deformation, which is important for the prediction of fracture phenomena by means of the low amplitude non-destructive dynamic method.