Showing papers on "Nitrile rubber published in 1974"

Heat-resistant fuel cell

Abstract: A container capable of passing the temperature requirements of U.S. Defense Department Specification MIL-T-25783 B and C (ASG) Tank, Fuel Aircraft and Missile Non-Self Sealing High Temperature Removable consisting of an inner layer of polyurethane elastomer of 2 to 30 mils adhered to at least one ply of nitrile rubber coated polyester fabric, said ply of nitrile rubber being adhered to an inner side of a barrier layer of a polyamide epoxy resin mixture and a nitrile rubber compounded with phenolic resin being used as a tie coat between the barrier and the polyester fabric.

Hydrocarbons separation with polymer membranes. I. Butadiene–isobutene separation with nitrile rubber membranes

Abstract: The permeation characteristics and the selectivity of four nitrile rubber films with respect to 1,3-butadiene and isobutene were studied as a function of experimental conditions and the nature of membrane material. A specific research apparatus was developed, allowing the determination of both permeation rate and selectivity, at a temperature varying between 0° and 30°C and under a pressure of from 1 to 3 bars. The inverse proportion of permeation rate to membrane thickness was verified for a thickness of from 12 to 500 microns. An increase in temperature promotes liquid permeation and is detrimental to gas permeation, the latter being facilitated by an increase in pressure. The introduction of an inert gas pressure on the liquid did not bring about an increase in the liquid permeation rate. The permeation rate decreases as a result of an increase in the proportion of acrylonitrile in the rubber, which also affects selectivity; the latter reaches a maximum value when said proportion is about 23%. The effect of the composition of the feed mixture was also studied and curves were determined relating, simultaneously, selectivity and permeation rate to the 1,3-butadiene content. Selectivity is maximal with mixtures having a very high 1,3-butadiene content. The solubilities of 1,3-butadiene and of isobutene in the four types of nitrile rubber were measured at 0°C and at 20°C (68°F). Selectivity can be interpreted in terms of the solubilities of the two hydrocarbons.

Impression material for use in an impression packer

Abstract: An impression packer for use in obtaining impressions in wells and having an impression sleeve formed of a mixture of partially curved synthetic nitrile rubber, natural rubber smoked sheet, silica powder and rubber processing oil.

Manufacture of prefabricated panels

Abstract: The invention relates to the manufacture of prefabricated panels from tiles, for example of sandstone, earthenware, metals, wood or rubber, the tiles being joined by a composition consisting of a heat-cured mixture of a substantially stoichiometric mixture of an epoxy resin and certain resins containing functional groups reactive therewith, and a polymer selected from polyvinyl chloride, polyvinyl acetochloride and nitrile rubber. Panels in accordance with the invention can be laid rapidly without the problems encountered with conventional methods in which the bonding agent between the tiles must be left to harden before loads are applied to the tiles.

Impression packer sleeve

Abstract: An impression sleeve for use in an impression packer comprising a smooth rolled sheet adapted to be connected on the outside of a packer to form an impression cover therefor, said sheet composed of about 60% to 80% by weight synthetic nitrile rubber, about 10% to 20% by weight natural rubber smoked sheet, about 5% to 15% by weight hydrated amorphous silica, and about 2% to 6% by weight of rubber processing oil.

Kinetic study of hydrolysis of butadiene-nitrile rubber in alkaline medium

Abstract: A kinetic study was made of the interaction of butadiene-nitrile rubber dissolved with alkali in o-xylene. It was found that, in the complex process of hydrolysis of polyaer molecules, hydrolysis of the polyamide obtained is the decisive stage. The activation energy of hydrolysis of polyamide was determined at temperatures of 125 to 145°.

Study of the mechanism and kinetics of conversion of micro-gel to macro-gel in nitrile rubber

Abstract: It is possible that three types of formation may exist simultaneously in polymer, which differ markedly in dimensions: sol fraction, micro-gel and macro-gel structure of the polymer, which is characterized by the presence of a high content of individual micro-gel particles, is unstable owing to spontaneous conversion of micro-gel to macro-gel The rate of this process varies within wide limits according to conditions of preparing the specimens This process depends on crosslinking of micro-gel particles as a result of thermochemical, oxidizing and other reactions The structural mechanism of conversion of micro-gel to macro-gel is similar to the mechanism of gel formation from linear macromolecules

An investigation of the change in the properties and orientation effects of phenoplasts of phenolaniline–formaldehyde resol resin and kaolin filler depending on the degree of elastification of the resin with nitrile rubber

Abstract: An investigation is made of the dependences of the values of 13 types of standard physical, mechanical, and electric insulation indicators for phenoplasts of phenolanilineformaldehyde resol resin on the degree of kaolin filling (within the limits of 24 to 47 vol-%) and different degrees of elastification (expressed in SKN-40 nitrile rubber content ranging from 0 to 40 vol-% as to the polymer). After expressing these dependences as a function of the recalculated average thickness of the adsorption coating of elastified resin on the filler particles, it is established that the characteristic periodical recurrence of concave and convex sectors in the curves for the individual indicators with the nonelastified phenoplasts, which is due to the orientation effects, is preserved also with the elastified phenoplasts. A method is elaborated of determining the average weighted value of the average thickness of the adsorption coating in the points of the orientation extremums of these curves. It is found that the places of the individual extremums change relatively little with the increase in the degree of elastification. A considerable change in the relative values of the orientation effects is observed after the point of phase inversion of the elastified resin (18 to 20 vol-% of SKN-40 as to the polymer) in connection with the sharp increase in the mobility of the resin globules. The author believes that the proposed mechanism of change of the properties with the filling will be observed, under definite conditions, also when filling with powdered fillers other polymers or blends of polymers, in so far as the latter are made up of supramolecular structural formations with a definite statistical distribution of their average sizes.

Resin molding composition

Abstract: A resin molding composition based on a nitrile rubber modified acrylonitrile-methyl acrylate copolymer and particularly suitable for forming bottles and containers of the beverage or other food containing type. The composition includes a multi-component additive which renders the basic resin readily subject to extrusion, blow molding, injection blow molding, injection molding and extrusion.