Rubber-water interface

Table II shows that morpholinium laurate is markedly less effective in enhancing mechanical stability than are the other laurates which have been investigated. This is attributed to specific counterion adsorption, with a consequent reduction of the effective surface potential at the rubber-water interface.

We interpret this observation as implying that, for these condensates, the effect upon mechanical stability is determined primarily by the binding of water to the ethylene oxide units which are anchored to the rubber-water interface by the fatty-alcohol moiety of the condensate. In the case of condensates for which the overall mole ratio of ethylene oxide to fatty alcohol exceeds ca. 30, the effect upon mechanical stability is much greater than would be expected on the basis of the total amount of ethylene oxide which has been added to the latex, as evidenced by the... 

Prepare a saturated solution of sodium sulphide, preferably from the fused technical sodium polysulphide, and saturate it with sulphur the sulphur content should approximate to that of sodium tetrasulphide. To 50 ml. of the saturated sodium tetrasulphide solution contained in a 500 ml. round-bottomed flask provided with a reflux condenser, add 12 -5 ml. of ethylene dichloride, followed by 1 g. of magnesium oxide to act as catalyst. Heat the mixture until the ethylene dichloride commences to reflux and remove the flame. An exothermic reaction sets in and small particles of Thiokol are formed at the interface between the tetrasulphide solution and the ethylene chloride these float to the surface, agglomerate, and then sink to the bottom of the flask. Decant the hquid, and wash the sohd several times with water. Remove the Thiokol with forceps or tongs and test its rubber-like properties (stretching, etc.). 

The ProteomeLab PA800 instrument was set up to analyze a sequence of five different labeled rMAb samples with a total of 10 duplicate injections. On many occasions, the electrophoretic analysis of approximately 60% of the injections did not take place due to pressure failures in the instrument. Upon closer inspection, some of red rubber caps of the gel matrix-containing vials were missing, electrodes were bent, and capillaries were broken. Additionally, it was observed that the interface block was coated with a sticky film of gel matrix. It was apparent that the build-up of gel buffer was causing the red rubber caps to remain stuck to the interface block and interfere with the contact of vials in subsequent steps. To improve the removal of gel buffer, the interface block and the surrounding areas were carefully flushed with deionized water. Then, cotton swabs were used to wipe the grooves on... 

To study the effect of contaminants (chlorides and sulphates) at the interface metal/coating, a set of panels (surface A Sa 3) was prepared and dosed with solutions of NaCl and FeSO in distilled water and methanol. Subsequently, two paint systems (chlorinated rubber and polyurethane) were applied on these contaminated surfaces. 

Moisture acts as a debonding agent through one of or a combination of the following mechanisms 1) attack of the metallic surface to form a weak, hydrated oxide interface, 2) moisture assisted chemical bond breakdown, or 3) attack of the adhesive. (2 ) A primary drawback to good durability of metal/adhesive bonds in wet environments is the ever present substrate surface oxide. Under normal circumstances, the oxide layer can be altered, but not entirely removed. Since both metal oxides and water are relatively polar, water will preferentially adsorb onto the oxide surface, and so create a weak boundary layer at the adhesive/metal interface. For the purposes of this work, the detrimental effects of moisture upon the adhesive itself will be neglected. The nitrile rubber modified adhesive used here contains few hydrolyzable ester linkages and therefore will be considered to remain essentially stable. 

To ensure a strong bond between liner and insulation as well as propellant to liner, it is necessary that liner as well as propellant cure well at the interfaces. This means that in many cases the rubber insulation must undergo some treatment to remove substances which may interfere with the liner cure. Such substances are usually low molecular weight compounds and can often be removed by heating—e.g., water, which would otherwise react with isocyanate in a polyurethane liner. In addition the insulation and/or the cured liner surface may be washcoated with a cure catalyst which will increase the reaction rate of alcoholic hydroxyl groups over the rate of reaction of water with isocyanate to such an extent that the latter reaction can no longer compete with the cure reaction. 

Fig. 12. Design of the galvanic cell with a flat liquid-liquid interface. (A) The four-electrode type of cell with the aqueous (w, w ) and the organic solvent (o) phases, silver/silver chloride reference electrodes (1,4), platinum counter electrodes (2, 3), a glass barrier with a round hole for the liquid-liquid interface (5) and a tube connected to a syringe for adjustment of the interface. (After [158]). (B) The two-electrode type of cell with the aqueous (1,3) and organic solvent (2) phases, water jacket (4), PTFE silicone rubber (5), silicone rubber cap, silver/silver chloride reference electrodes (7,8), glass tube (9) and polarized working (w) or nonpolarized reference (r) interface. (After [42]).

Aqualine. [Dexter/Fiekote] Water-based release agent semipermanent mold release interface for natural and synthetic rubber oompds., thermosets and thermoplastics. 

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