Rapid method of determining temperature dependence of adhesion of polymers to metals

A new method of determining the temperature dependence of the adhesion of polymers to metals and an equipment for carrying this out are described. The adhesion of the polymer to metal is determined by stripping the film from a metal plate or bar with a temperature gradient in the plane of adhesive contact in the direction in which the film is stripped.     

New method of coating metals with polymers

A new method of obtaining polymer coatings on metals is described. The polymer is deposited on the metal substrate in the form of microbeads, which are imbedded in a second layer of metal electrolytically deposited on the parts of the surface free of polymer. After this a final layer of polymeric material is applied to serve as a coating or adhesive.Institute of Mechanics of Metal-Polymer Systems, Academy of Sciences of the Belorussian SSR, Gomel'. Translated from Mekhanika Polimerov, No. 2, pp. 347–349, March–April, 1871.     

Reversible changes in the adhesion of polymers to solid surfaces

The adhesion properties of coatings of polycrystalline hexafluoropropylene—vinylidene fluoride copolymer on steel and glass have been investigated. Coatings formed at 200–240° C suffer a reversible loss of adhesion following the diffusion of water and acid molecules to the interface, which is attributable to the mobile adsorption-desorption nature of the adhesion of this particular copolymer to steel and glass. Heat treatment at 280° C gives the coating improved resistance to the debonding action of water.Ural Scientific-Research Chemical Institute, Sverdlovsk. Moscow Institute of Fine Chemical Technology. Translated from Mekhanika Polimerov, Vol. 4, No. 6, pp. 1065–1070, November–December, 1968.     

Reversible changes in the adhesion of polymers to solid surfaces

The adhesion of low-density polyethylene to steel and glass changes when water and acid molecules penetrate to the polymer-substrate interface. Their removal leads to total or partial recovery of the initial adhesion. An adhesive bond between polyethylene and the substrate was observed at room temperature as well as at 50° C. The results are explained in terms of the dynamic adsorption-desorption behavior of polyethylene adhesion. It is suggested that the adhesion is based is based on the van der Waals interaction between the substrate and the polar surface groups of the polymer.Mekhanika Polimerov, Vol. 4, No. 2, pp. 309–313, 1968     

Increasing the destructiveness of pulsating jets by the application of hydrodynamically active substances

We give the results of experimental studies of the destruction of plaster and coal-cement blocks by pulsating jets of water and water solutions of water-soluble solid polymer compounds on a base of polyethylene oxide. It is shown that the use of water-soluble solid polymer solutions as the working fluid in the generator of the pulsating jet leads to an increase in the depth of the holes and grooves by a factor of 1.5–3.5. Three figures. One table. Translated fromTeoreticheskaya i Prikladnaya Mekhanika, No. 25, 1995, pp. 126–130.     

Effect of polymers with a conjugation system on the mechanical properties of phenol-formaldehyde resite

Certain mechanical properties of a phenol — formaldehyde resin of the novolac type cured with hexa methylenetetramine in the presence of PCB have been investigated. The curves representing the dependence of the flexural strength, impact strength, and hardness of the specimens on PCB concentration are extremal in character. It is shown by electron microscope techniques combined with oxygen etching of the cleavage surface that the improvement in mechanical properties is associated with a change in the structure of the crosslinked polymer.Communication 108 of the series "Polymers with a conjugation system."Institute of Chemical Physics, AS USSR, Moscow. Translated from Mekhanika Polimerov, Vol. 4, No. 6, pp. 1071–1076, November–December, 1968.     

Local compatibility and the adhesion of polymers

The role of the thermodynamic factor in creating an adhesion bond between partly or wholly compatible polymers is discussed. The importance of this factor depends on the fact that polymers brought into contact will diffuse into each other only if they are wholly or partly mutually soluble. This mutual solubility is confined to a surface layer and is determined by the local diffusion. In considering the mechanism of formation of an adhesion bond between two polymers it is necessary to take their surface properties into account. In the diffusion theory of adhesion diffusion is regarded as the motive force in the creation of an adhesion bond.Moscow Lomonosov Institute of Fine Chemical Technology. Translated from Mekhanika Polimerov, No. 3, pp. 455–459, May–June, 1969.     

Investigation of the adhesion of epoxy resin ED-5 to metals

The strength and thermostability of metals bonded together by epoxy resin ED-5 pass through a maximum with increase in the concentration of curing agent (tetraethylene pentamine). Cohesion type fracture changes to adhesion type at a certain concentration of the hardener. It has been suggested that a change in the character of the polymermetal bond is the cause of the observed dependences.The appearance of breaks or maxima at 80°–120° C on the curves of the temperature dependence of the strength of the glued joints is explained by changes in the physical state of the polymer.Mekhanika Polimerov, Vol. 1, No. 6, pp. 108–113, 1965     

Correlation of adhesion characteristics of metals to polyvinylbutyral with the structural — Mechanical parameters of metallic substrates

It is shown that the adhesion characteristics of metals to polyvinylbutyral correlate with a series of structural and mechanical parameters of the metallic substrates. Periodicity was observed in the adhesion characteristics of metals to polyvinylbutyral. The work is of theoretical significance.Institute of Chemistry and Chemical Technology, Academy of Sciences of the Lithuanian SSR, Vil'nyus. Translated from Mekhanika Polimerov, No. 2, pp. 368–369, March–April, 1972.     

Properties of multicomponent polymers systems

In order to design materials having different mechanical properties combined with a permittivity of 2.2–2.6 and tg =2·10^–4-4.10^–4 at 20±1° C and 10⁶ Hz, it is possible to use compositions consisting of polystyrene, polyisobutylene and polyethylene. Projections of the three-dimensional triangular composition-property diagrams are presented for selecting the composition corresponding to spcified properties (hardness at 20 and 50° C and breaking stress and elongation).Central Scientific-Research Institute of Communications, Moscow. Moscow Krupskaya Regional Pedagogical Institute. Translated from Mekhanika Polimerov, Vol. 4, No. 6, pp. 133–1135, November–December, 1968.     

Role of diffusion in the formation of adhesion bonds between polymers

So-called "direct" proofs of self- and mutual-diffusion in the formation of adhesion bonds between polymers [3] are discussed critically. It is shown that in reality none of these direct proofs can be regarded as such. Accordingly, the question of the validity of the diffusion mechanism of adhesion as applied to thermodynamically incompatible or only "partly compatible" polymers remains open.Mekhanika Polimerov, Vol. 3, No. 5, pp. 850–853, 1967     

Effect of the conditions of bond formation and destruction on the adhesion of polymers to synthetic fibers

It is shown that the adhesion of linear polymers can be measured by shearing a monofilament relative to a microblock of adhesive [1]. Experiments have been performed on polypropylene, polyethylene terephthaliate, polycaprolactam, polyvinyl alcohol, and glass fibers. Broad variation of the diameter, structure, and physicomechanical properties of the various kinds of oriented fibers had practically no effect on the adhesion. The physicochemical properties of the adhesive solutions at the moment of application to the fiber likewise do not affect the adhesion which, other things being equal, is determined by the nature and supermolecular structure of the polymers in the contact zone.Belorussian Lenin State University, Minsk. Branch of the Karpov Scientific-Research Physicochemical Institute, Obninsk. Translated from Mekhanika Polimerov, No. 6, pp. 1042–1048, November–December, 1970.     

Factors in the adhesion strength of polymers toward a solid substrate

The true adhesion is looked upon as the sum of the experimentally determined strength of the glued area, internal stresses, and unaccountable technological losses (unrealized contacts). It has been established that the internal stresses do not depend on the value of the adhesion strength.Translated from Mekhanika Polimerov, No. 2, pp. 356–359, March–April, 1976.