Epoxy-polyamides

In the freeboard areas, commercial ships use organic 2inc-rich primers extensively and usually topcoat them with a two- or three-coat epoxy system. U.S. Navy ships use an organic 2inc-rich primer, two to three coats of an epoxy-polyamide coatings, and a siUcone-alkyd topcoat (16) the entire dry system is 150—225 )J.m thick. 

The most common aerospace adhesives include nitrile epoxy systems, epoxy polyamides, epoxy phenolics, and various unmodified epoxies [18]. Polyimides... 

Epoxy based primer systems remain the best suited for the corrosion protection of magnesium. Cathodic epoxy electrophoretic paints , chromate inhibited epoxy-polyamide primers and high temperature stoving epoxy sealers are used to provide protection up to 180°C. For higher temperature applications up to 300°C, epoxy silicone or polyimide based systems can be used. 

The effect of iron oxide, zinc oxide and red lead on the percentage of D areas has been determined. Three vehicles were used, a pentaerythritol alkyd, a tung oil phenolic and an epoxy polyamide" . In the case of iron oxide, the D areas increased with all three vehicles in contrast zinc oxide had very little effect on the percentage D areas. However, red lead when dispersed in the alkyd and tung oil vehicles behaved in a similar way to iron oxide, whereas red lead when dispersed in the epoxypolyamide vehicle had very little effect. 

Epoxy-polyamide resin with a powdered oxide filler... 

Wedge test results suggest that the curing process (e.g., percent crosslinking) of the epoxy-polyamide primer system is not affected by the addition of organosilanes, but may be affected by NTMP. The results of substrate surface characterization, adsorption behavior of applied films, and evaluation of candidate inhibitors by chemical, mechanical, and electrochemical test methods are presented. Mechanisms to explain the observed behavior of the various phosphonate and silane polymer systems are discussed. 

An unplgmented epoxy-polyamide top coat (Shell EPON 1001-T75 epoxy and Versamld 115 amldopolyamlne). 

The FM 123-2, supplied as a supported film on a knitted mlcro-fllament nylon carrier, was applied directly to one pretreated (SAA or FPL) A1 panel (15 cm x 15 cm x 0.3 cm). A second panel was then pressed onto the exposed adhesive side and the "sandwich structure was subsequently cured at 120°C under 40 psi for 1 hr. A 1 1 1 mixture of the epoxy-polyamide formulation (EPON resin Versamld curing agent thinner, MIL-T-81772) was sprayed onto prepared 7075-T6 specimens to a thickness (dry) of 0.015 - 0.023 cm. 

Primer Epoxy vs. Nitrile-Modified Epoxy. The compatibility of the epoxy-polyamide primer with the nitrile-modified epoxy adhesive facsimile and the aluminum oxide surface was also evaluated by the wedge test, since earlier tests using the primer as the adhesive had failed immediately. As shown in Fig. 8, the addition of the primer directly to the prepared... 

The corrosion resistance and polymer-bonding compatibilities of the lonizable organophosphonates and the neutral organo-silanes are directly related to their inherent chemical properties. Specifically, NTMP inhibits the hydration of AI2O2 and maintains or Improves bond durability with a nitrile-modified epoxy adhesive which is cured at an elevated temperature. The mercaptopropyl silane, in addition to these properties, is compatible with a room temperature-cured epoxy-polyamide primer and also exhibits resistance to localized environmental corrosion. These results, in conjunction with the adsorbed Inhibitor films and the metal substrate surfaces, are subsequently discussed. 

Adsorbed NTMP exhibits a pH-dependent surface coverage on anodized aluminum, which Includes a region characterized by a multilayer of hydrogen-bonded phosphonate molecules. These thick layers are weak and fall to provide good bond durability in a humid environment. NTMP monolayers are protective against hydration and are compatible with a nitrile-modified epoxy adhesive, but not with an epoxy-polyamide primer topcoat. 

The advanced applications for nitrocellulose plastisol propellants require that they be integrally bonded to the motor case. Successful case bonding for the multiyear storage life of a rocket calls for special adhesives and liners which are completely compatible with these highly plasticized propellants. Best results have been obtained with a combination of an impervious rubber liner and a crosslinked adhesive system with a limited affinity for the plasticizers used in the propellants. Examples of effective liners are silica-filled butyl rubber and chlorinated synthetic rubber. Epoxy polyamides, isocyanate-crosslinked cellulose esters, and combinations of crosslinked phenol-formaldehyde and polyvinyl formal varnishes have proved to be effective adhesives between propellant and impervious liners. Pressure curing of the propellants helps... 

Fig. 5. Effect of outdoor weathering on the strength of aluminum alloy/epoxy-polyamide joints (chromic-sulfuric acid-etch metal surface pretreat-ment)61 (Reprinted from Ref. 61, p. 194, by courtesy of Gordon and Breach...

Fig. 17. Cathodic delamination rates of galvanized steel/epoxy-polyamide coating systems when a 0.1 M CoCl2 dipping pretreatment was applied to the metal substrate prior to the application of the coating 91K (Reprinted with permission from Ref. 91Copyright (1981) American Chemical Society)...

Epoxy phosphate Epoxy plasticizers Epoxy polyamide... 

Encycl) with a binder (such as epoxy-polyamide, expoxy-anhydride, and polyurethane resins) and loading the resulting mixture into the annulus between the inner and outer parts of a cylindrical mold. After curing for 24hr, this cylindrical part of cartridge was attached to a noncombustible base(metallic or plastic), which served as an obturator... 

Epoxy coatings. A high solids two-component epoxy coating was prepared (Ciba Geigy Araldiate 6010 epoxy/Polyamide 840 hardener) and spray-applied to CRS and aluminum (Table 8). The coating was cured at 25°C and 50% relative humidity for 7 days. 

A typical starting formulation for a two-component epoxy-polyamide emulsion is shown in Table 14.3. This formulation can be used as either a coating or an adhesive. In either application, once the mixed emulsion is applied to the substrate, the water must be evaporated. In the case of the adhesive application, this must be completed before nonporous... 

TABLE 14.3 Typical Two-Component Epoxy-Polyamide Emulsion Starting Point Formulation14... 

Environment Epoxy + polyamine Epoxy + anhydride Epoxy + polyamide Epoxy- phenolic Epoxy- polysulfide Epoxy-nylon Phenoxy (thermoplastic)... 

When the epoxy adhesive cannot be made flexible enough, the thermal conductivity and thermal expansion coefficient are controlled by appropriate fillers. General-purpose room temperature cured epoxy-polyamide adhesive systems can be made serviceable at low temperatures by the addition of appropriate fillers to control thermal expansion. 

Epoxy-nylon Epoxy-phenolic Epoxy-polyamide Filled epoxy... 

The hostility of certain moisture environments can be seen in Fig. 15.11 Aluminum joints were bonded with room temperature curing epoxy-polyamide adhesive and aged in a hot, wet (tropical) environment and in a hot, dry (desert) environment. Excellent durability is achieved under dry conditions while significant degradation is caused by the wet conditions. 

FIGURE 15.11 Effect of outdoor weathering on the strength of aluminum joints bonded with epoxy-polyamide.30... 

Room temperature cured paste (epoxy-polyamide, epoxy-anhydride)... 

TABLE 16.12 Tensile Shear Strength of Plasma Treated Polyolefin Substrates Bonded with Epoxy-Polyamide Adhesive69... 

Bonding of already vulcanized elastomers to themselves and to other materials is generally completed by using a flexible thermosetting adhesive such as epoxy-polyamide or... 

Typical two-component epoxy-polyamide emulsion starting point formulation... 

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