Some physicomechanical properties of polyformaldehyde (acetal resins)

A method of testing polyformaldehyde (acetyl resin) film has been developed. Comparative tests have been carried out on the homopolymer and trioxane-dioxolan copolymer. Certain physicomechanical characteristics of these polymers have been obtained.Mekhanika Polimerov, Vol. 3, No. 5, pp. 812–820, 1967     

Stability of the physicomechanical properties of carbon filaments (fibers)

The relationship between the tensile strength and cross-sectional area of high-modulus carbon fibers is examined. An equation is given for the strength of these promising fillers of composite materials; it is shown that the stability of their tensile strength is determined by the average defectiveness of the surface and degree and stretch, as well as variations in these quantities over any particular group of fibers. The elastic modulus and strength of the carbon fibers are related to the degree of stretch.     

Diagnostics of the physicomechanical properties of glass textolites in articles of three-layer construction

Possibilities are examined for the diagnostics of some indicators of durability and stiffness of glass textolites in articles of three-layer construction (cemented three-layer combined construction, the two outer layers of which are of glass textolite and the inner layer of which is a foam layer) from a complex of structural parameters and physical characteristics measured directly in the article by nondestructive methods.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 2, pp. 362–364, March–April, 1976.     

The effect of introduction of carbon nanotubes on the physicomechanical properties of polyvinylacetate

The physicomechanical properties of polyvinylacetate (PVA) with small, no more than 2 wt.%, additions of carbon nanotubes (CNTs) are investigated. Data on the influence of CNT concentration on the differential scanning calorimetry thermograms, thermal destruction, electrical resistance, water vapor sorption, as well as indices of the mechanical properties of PVA/CNT (yield stress, strength, elastic modulus, ultimate elongation, and short-term creep) are reported. A variant of calculation of the elastic constants of the nanocomposite is considered with account of the effect of nanotube agglomeration.     

Experimental study of the effect of technological parameters on the residual stresses in thin-walled coiled parts

The effect of the parameters of heat treatment and programmed winding under tension on the residual stresses in thin-walled coiled parts made from glass plastic by the "dry" winding of a heated glass strip on an unheated mandrel is studied experimentally. The effect of the thickness of the parts on the maximum radial residual stresses is considered. A method is proposed for regulating the residual stresses in parts with very thick walls.Translated from Mekhanika Polimerov, No. 1, pp. 75–80, January–February, 1972.     

The effect of the concentration and dispersion of quartz on the physicomechanical properties of polyvinylacetate films

Data are given from a study of the effect of the concentration and dispersion of quartz on the structure, the coefficient of thermal expansion, the elastic modulus, the strength, and the extension under tension of polyvinylacetate films. The change in the properties of these films is associated with a change in the structure of the polymer on filling.Institute of Physical Chemistry, Academy of Sciences of the USSR, Moscow. Translated from Mekhanika Polimerov, No. 1, pp. 63–67, January–February, 1972.     

A study of the physicomechanical properties of carbon fibers at high temperatures

Conclusions 1. Carbon fibers, similar to graphite materials, are heat-resistant and do not Iose their short-term tensile strength in the temperature range studied — 20 to 2000°C.2. Young's modulus of carbon fibers hardly changes in the temperature range 20 to 1200°C, but a significant decrease is observed upon a further increase in temperature.Translated from Mekhanika Polimerov, No. 4, pp. 626–630, July–August, 1977.     

Effect of silane coupling agents on the physicomechanical properties of glass-reinforced plastics

The chemical nature of the coupling agent is investigated in relation to its effect on the wet and dry flexural strength of specimens of polyester glass-reinforced plastic (GRP), the water absorption of the material, and the degree of polymerization of the resin.Mekhanika Polimerov, Vol. 3, No. 5, pp. 787–794, 1967     

Investigation of the structure and physicomechanical properties of polypropylene film

The authors have investigated the effect of the dynamic degree of crystallinity, stereoisomeric composition, intrinsic viscosity, and other factors on the nature of the structure formed when polypropylene is made into film and on the physicomechanical properties of the film.Mekhanika Polimerov, Vol. 3, No. 6, pp. 970–976, 1967     

Influence of acetone-soluble fraction content on physicomechanical properties of cellulose triacetate

The influence of a change in the acetone-soluble fraction content on the physicomechanical properties of irradiated triacetate (CTA) fibers has been investigated. The results obtained showed that irradiation of CTA sharply alters the acetone-soluble content of CTA fibers, which correlates well with the changes in physicomechanical propertiesKaunas Polytechnic Institute. Translated from Mekhanika Polimerov, No. 3, pp. 537–539, May–June, 1970.     

Effect of atmospheric conditions on the physicomechanical properties of grade P2015K polyethylene

It is shown that the physicomechanical properties of grade P2015K polyethylene depend both on the external conditions and, to a considerable extent, on the "history" of the part. Differences in supermolecular structure are responsible for the nonuniformity of the physico-mechanical properties of otherwise similar parts.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 4, pp. 737–740, July–August, 1969.