Recommendations for adhesion

Rather similar are the 5.5-dimethylhydantoin derivatives shown in Figure 26.18 (b, e). These resins are said to eonfer improved weathering resistance but also exhibit higher water absorption. Another trifunctional material is p-glycidyl-oxy-A,A/-diglycidylaniline. This has been recommended for adhesive systems in conjunction with benzophenonetetracarboxylic acid dianhydride, which is a room temperature curing agent in this case. 

In general, titanates with the more polar organic moieties such as isopropyl tri(iV-ethylenediamio)ethyl titanate and neoalkoxytri[-P-iV-(p-aminoethyl)amino phenyl] titanate are recommended for adhesion promotion to polar substrates. Titanates with relatively nonpolar moieties, such as aliphatic carboxy titanates and isopropyl tri(dioctylphosphato)titanate, will adhere better to the nonpolar substrates. 

Solvent cements are usually preferable to conventional adhesives for thermoplastic structural foams. Some solvent cements and solvent-containing, pressure-sensitive adhesives will collapse thermoplastic foams. Water-based adhesives based on SBR, polyvinyl acetate, or neoprene are frequently used. Solvent cementing is not effective on polyethylene foams because of their inertness. Recommendations for adhesives for thermoplastic foams are ... 

Very little has been published on specific recommendations for adhesive bonding GRTP. When specific recommendations are not available, the reader should query the material supplier or start with the recommendations for the base material. 

Figure 9.14 Repellent nanocoating over painted substrate Table 9.3 Coating Methods and Recommendations for Adhesion...

A summary of coating methods and recommendations for adhesion based on coating weights and viscosity ranges by process are listed in Table 9.3. 

Recommended apphcations include transformers, insulators, bushings, wire and cable, generators, motors and switchgear, additives for adhesives, vinyl stabilization, and as viscosity depressants. 

There is a need for an accurate assessment of the mechanism of cathodic debonding of thick adherends. This would contribute to better control over the selection of formulations resistant to attack. One of the objectives of this work was to develop an accelerated screening test. The screening test was used to evaluate the relative performance profiles of a number of commercial adhesives which were recommended for marine applications. It is hoped that a screening test such as this one could be used to isolate measurable primer properties which can be related to the long term prospectus of the primer, and the variability of this prospectus under permutation of substrate type or additives. 

One of the more advanced technical offerings from castor oil is a line of polyester diols, triols, and higher functional polyols derived from 100% castor oil as products for the preparation of polyurethane prepolymers and elastomers [68]. The Polycin line of polyols are prepared by transesterification of ricinoleic acid and derivatives. The producers (Vertellus) offer diol and triol products, as well as a recently developed series of diol and triol glyceryl ricinoleate esters that are stated to be prepared from 100% castor oil, making them fully renewable in content. The products are recommended for coatings, sealants, and adhesive applications. 

Compatibility of ethanol with tank and piping materials such as carbon steel, stainless steel, and Fiberglas is good. Zinc linings and epoxy linings are not stable in ethanol systems and are not recommended for use. Also, epoxy adhesives and resins are dissolved by ethanol. Teflon and nylon are compatible elastomers. In... 

Mercaptosilane has long been recommended for use in crosslinkable rubber compositions [10], i.e. NBR, SBR, etc., both as an adhesion promoter to aid bonding between rubber adherends (or rubber to metal) and to enhance bonding... 

Adhesive formulations may also be prepared in combination with urea-formaldehyde resins107 or polyvinyl alcohol108 the latter is particularly recommended for use in the manufacture of pre-gummed wallpaper. 

The actual metal surface that takes part in the bonding is illustrated in Fig. 16.1. Adhesives recommended for metal bonding are in reality used for metal-oxide bonding. They must be compatible with the firmly bound layer of water attached to surface metal-oxide crystals. Even materials such as stainless steel and nickel or chromium are coated with transparent metal oxides that tenaciously bind at least one layer of water. 

Brass is an alloy of copper and zinc, and bronze is an alloy of copper and tin. Sandblasting or other mechanical means of surface preparation may be used for both of these copper alloys. Surface treatment combining mechanical and chemical treatment with a solution of zinc oxide, sulfuric acid, and nitric acid is recommended for maximum adhesion properties. Adhesives similar to those recommended for copper may be used on brass and bronze substrates. 

TABLE 16.7 Starting Formulations for Several Epoxy Adhesives Recommended for Bonding Plastic Substrates52... 

As with metal substrates, the effects of plastic surface treatments decrease with time, so it is important to carry out the priming or bonding as soon as possible after surface preparation. The surface preparation methods suggested in App. F are recommended for conventional adhesive bonding. Greater care must be taken in cleaning thermoplastics than... 

Adhesives recommended for polyphenylene sulfide include epoxies, and urethanes. Joint strengths in excess of 1000 psi have been reported for abraded and solvent-cleaned surfaces. Somewhat better adhesion has been reported for machined surfaces. The high heat and chemical resistance of polyphenylene sulfide plastics makes them inappropriate for either solvent cementing or heat welding. 

In mixing, cleanliness is almost as important as accuracy. Scoops, weighing pans, mixing spatulas, and other accessories should be kept clean. Organic solvents are recommended for cleaning. Adhesives that appear to be similar may be ruined if one is contaminated with the other. Water will spoil many adhesives and sealants. 

Starting formulations for several epoxy adhesives recommended for bonding plastic substrates... 

Test Method for Adhesion in Peel of Elastomeric Joint Sealants Recommended Practice for Surface Preparation of Concrete for Application of Chemical Resistance Resin Monolithic Surfaces Method of Testing Release Papers Used with Preformed Tape Sealants Test Method for T-Peel Strength of Hot Applied Sealants Test Method for Tensile Adhesive Strength of Preformed Tape Sealants by Disk Method... 

Bonding techniques, involving adhesives, are also common. An in-depth study of PVC adhesion is available, together with the recommendation for a solvent borne pressure sensitive adhesive (229). A report is also available on solvent based pressure sensitive adhesives suitable for PVC surfaces (226). 

The Government of the German Democratic Republic published a standard TGL 10596/03 in 1977 for a product containing not less than 40% in a stabilised paste with mineral oil and adhesive components . This material was recommended for a wide range of applications, including -... 

Particularly recommended for sizing synthetic and blended staple yarns but also suitable for use on cellulosics. It has good adhesion to most fibres and dries to.a tough flexible film. The product is water soluble and presents no difficulty in de-sizing. 

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