Adsorption-active Medium Research Articles

An investigation of the connection between micro-crazing and the mechanical behaviour of glassy polyethyleneterephthalate during deformation in adsorption-active media

The mechanical properties of glassy polyethyleneterphthalate have been investigated in a number of liquid adsorption-active media. The tensile curve of the polymer in an adsorption-active medium has been found to contain information about features of micro-cracks which determines the transition of the polymer into the oriented conditions; this enables the rate of micro-crack growth to be found directly from the polymer's tensile curves. The rate of micro-crack growth has been shown to be controlled by the surface reactivity of the liquid medium, its viscosity and molecular dimensions which determine the migration of the liquid into the active deformation zone of the polymer, as well as by the conditions of loading.

Structure and adsorption properties of the material of crazes in glassy polyethylene terephthalate

The processes of adsorption of iodine and the organic dye, Rhodamine C from their aqueous solutions by glassy PET (polyethylene terephthalate) samples strained in an absorption active medium have been studied, up to various degrees of elongation. It was found that these samples are able to absorb a significant quantity of iodine but Rhodamine C is not adsorbed at all. This effect is explained by the ability of the structural elements of the craze to undergo a type of Brownian movement and to peptization due to the action of the adsorption-active medium.

The structure and adsorption properties of glass-like polyethylene-terephthalate deformed in an adsorption-active medium

The adsorption properties of glass-like polyethylene-terephthalate extended up to various draw ratios have been investigated in an adsorption-active medium (n-propanol). The ability of materials of the type of PETP to adsorb considerable amounts of various substances from their solutions has been observed, and is related to the development of a highly developed surface when polymers of the type in question are stretched in an adsorption-active medium. In particular, it has been found that in the case of high draw ratios the effective pore diameter in the polymer structure is markedly reduced.

Low temperature contraction of amorphous glassy polymers oriented in adsorption active media

Abstract It was found that amorphous glassy polymers oriented in adsorption active media practically completely recover their dimensions in annealing at a temperature lower than T g . It is assumed from a structural and mechanical study that low temperature contraction is due to surface effects and is related to properties of the highly dispersed material of micro-cracks formed during the orientation of polymers in adsorption active media.

Mechanical behavior of glassy polyethylene terephthalate deformed in liquid adsorption active media

A study was made of the relation between mechanical, thermo-mechanical properties of amorphous glassy PETP and the degree of elongation in liquid adsorption active media. It was shown that with an increase in the degree of elongation starting from ∼200%, the mechanical and thermo-mechanical properties of PETP change markedly. Using results a mechanism was proposed for the effects observed, according to which deformation of PETP in an adsorption active medium is regarded as a transition process to the oriented, highly dispersed state inside micro-cracks. As deformation develops the amount of highly dispersed material continously increases, which results in the accumulation by the system of a considereable excess of a highly developed surface and the possibility of coagulation of the material of micro-cracks directly in the adsorption active medium.

Mechanism of action of adsorption active media on deformation of glassy polyethylene terephthalate

Elongation of glassy unoriented PETP was examined in eight organic liquids not causing swelling at room temperature. It was shown that PETP samples deformed in liquid media show considerable reversible deformations at room temperature, the extent of these deformation epending on the adsorption active medium used. Results were compared with mechanical test results of PETP in the same media and an inverse relation was established between the limit of forced elasticity and reversible deformation in these media. It is assumed that the correlation found is due to surface effects, which depend on properties of the highly dispersed material of micro-cracks; these cracks are formed and increase in size during elongation of glassy polymers in adsorption active media.

Mechanical properties of crosslinked polymethacrylate glass

A study was made of the mechanical properties of methyl methacrylate-dimethacrylate ethylene glycol copolymers. The effect of an adsorption active medium and a plasticizer on deformation and strength properties of crosslinked glass was examined. Results were interpreted using the irregular distribution of intermolecular chemical bonds in the polymer.

Substantial reversible deformations in glassy polymers

A study was made of processes taking place in glassy polymers during deformation in adsorption-active media. It was shown that glassy polymers are able to undergo considerable non-entropy type reversible deformation. A mechanism is proposed for the effect.

Inversion of the effect of a notch on the cyclic effect of steel in adsorption-active media

Inversion of the effect of a notch on the cyclic effect of steel in adsorption-active media

Increasing the contact fatigue strength of drill steel by burnishing the working surface in adsorption active media

Increasing the contact fatigue strength of drill steel by burnishing the working surface in adsorption active media