Adhesives, marine

Chem. Descrip. Polyamide in isopropanol Uses Curing agent for adhesives, marine finishes, flooring compds., pipe/ tank coatings, castings, potting, and encapsulation Properties Gardner 8 color sp.gr. 0.92 dens. 7.7 Ib/gal vise. 2900 cps ... 

Sikaflex -852 FR One component PUR-based sealing and bonding adhesive Marine flame-retardant sealing and bonding Flame-retardant properties... 

Recommended for products lacquers, nail lacquers, printing inks, adhesives, marine coatings ... 

For exterior appHcations, where water exposure is expected, phenol—formaldehyde (PF) or phenol—resorcinol—formaldehyde (PRF) adhesives are used. Only small quantities of this type of hardwood plywood are made, primarily for marine use. 

Vinyl resins ie, copolymers of vinyl chloride and vinyl acetate which contain hydroxyl groups from the partial hydrolysis of vinyl acetate and/or carboxyl groups, eg, from copolymerized maleic anhydride, may be formulated with alkyd resins to improve their appHcation properties and adhesion. The blends are primarily used in making marine top-coat paints. 

Silicone resins with high phenyl contents may be used with medium or short oil alkyds as blends in air-dried or baked coatings to improve heat or weather resistance the alkyd component contributes to adhesion and flexibiUty. AppHcations include insulation varnishes, heat-resistant paints, and marine coatings. 

Uralkyds have superior adhesion, hardness, abrasion resistance, durabiHty, and chemical resistance to the unmodified alkyds. They find appHcations in wood floor finishes, marine coatings, metal primers, and maintenance paints. 

Melamine or melamine—ureas are used in the manufacture of tmck and railroad flooring, laminated lumber, beams, exterior doors, marine plywood, toilet seats, and school furniture. The bonds in these products meet a variety of commercial, military, and federal specifications for exterior waterproof adhesives. 

Unsaturated Polyester Resins (UPR). The principal uses are in putty, coatings, and adhesives. Glass-reinforced UPR is used for marine, constmction, and vehicle materials, as weU as for electrical parts. 

The stabihty of the emulsions further permits them to be compounded in simple Hquid-blending vessels by means of agitators, eg, marine-type propellers, paddles, or turbines. The adhesives can be adapted to any type of machine appHcation, ie, from spray guns to rollers to extmder-type devices. Different appHcators are fairly specific in their viscosity requirements, as are the various substrates receiving the adhesive. 

Surface preparation, always important in obtaining optimal coatings performance, is critical for marine coatings (see Metal surface treatments). Surface preparation usually comprises about half of the total coating costs, and if inadequate may be responsible for early coating failure. Proper surface preparation includes cleaning to remove contaminants and roughening the surface to faciUtate adhesion. 

Phenohc resins (qv), once a popular matrix material for composite materials, have in recent years been superseded by polyesters and epoxies. Nevertheless, phenohc resins stiU find considerable use in appHcations where high temperature stabiHty and fire resistance are of paramount importance. Typical examples of the use of phenoHc resins in the marine industry include internal bulkheads, decks, and certain finishings. The curing process involves significant production of water, often resulting in the formation of voids within the volume of the material. Further, the fact that phenoHcs are prone to absorb water in humid or aqueous conditions somewhat limits their widespread appHcation. PhenoHc resins are also used as the adhesive in plywood, and phenohc molding compounds have wide use in household appliances and in the automotive, aerospace, and electrical industries (12). 

Pressure sensitive adhesives and adhesive-coated articles have found a growing list of applications in the automotive, marine, airplane and appliance industries. The main uses are in assembly and decoration, but applications in the areas of... 

About 8,000 metric tons of peroxides were consumed in 1972. This consumption was strongly stimulated by the rapid growth in reinforced plastics (Ref 23). The largest volume product is benzoyl peroxide which is used in polystyrene and polyester markets for such items as toys, automobiles, furniture, marine, transportation and mil requirements. Also, methyl ethyl ketone peroxide is used in large volumes to cure (as a catalyst) styrene-unsatur-ated polyester adhesive resins used in mil ammo adhesive applications, as well as in glass fiber reinforced plastic products such as boats, shower stalls, tub components, automobile bodies, sports equipment, etc. The monoperesters are growing slowly because of some substitution of the peroxydicarbonates and azo compds (Refs 8,9 23)... 

Also known as DCM or dichloromethane. Often used as an adhesive solvent for acrylics. Pure DCM can be found in craft stores. DCM must be distilled first from all non-flammable paint strippers beforehand (they contain a paste that holds several unwanted substances.) The paint stripper may also contain methanol (most marine grade paint strippers are 80-90% DCM. Methanol is also an organic solvent. DCM distills at 47° C or 116° F. Pure DCM is best. May cause cancer and blindness. Take necessary precautions. Methylene chloride sinks to the bottom of the jar. 

Freshwater and marine alga were unaffected at water diazinon concentrations that were fatal (i.e., 1000 pg/L) to aquatic invertebrates (Stadnyk and Campbell 1971 Shacklock and Croft 1981). However, diazinon at 1.0 pg/L induced extensive clumping of a freshwater alga (Chlorella pyrenoi-dosa) onto the antennae of Daphnia magna within 24 h (Stratton and Corke 1981). The affected daphnids were immobilized and settled to the bottom of the test containers. The causes of particulate matter adhesion are open to speculation, and additional research is merited. 

Marine coatings Organic coatings for corrosion control Paint acrylic ester polymers, 7 388-389 adhesion, 7 90-92 advanced ceramic, 7 704-705 alkanolamines from olefin oxides and ammonia, 2 136 alkyd resins, 2.T67-168 amino acid resin applications, 2 635—637 anticorrosion, 25 134 anticorrosion metallic, 7 713-714... 

Vreeland V, Waite J, Epstein L (1998) Polyphenols and oxidases in substratum adhesion by marine algae and mussels. J Phycol 34 1-8... 

Other applications for phenolics are switchgears, handles, and appliance parts, such as washing machine agitators (that s why they re usually black). Phenolics are widely used to bond plywood, particularly exterior and marine grades. Although urea-formaldehyde resins are cheaper for this purpose, they were not nearly as water-resistant and have been limited to interior grades. Abrasive wheels and brake linings also are bonded with phenolic adhesives. 

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. 

Much of the focus of the following work was aimed at the previously mentioned Chemlok adhesive system. This was because it had been used extensively in a familiar marine application, we were acquainted with its long term performance so it could be used as a baseline for comparison with other commercial adhesive formulations. All of the commercial adhesives used, including Chemlok 205/220, are proprietary formulations, thus the exact functional nature of each adhesive is not available. 

To further understand the action of the hydroxide ions on the primer properties, weight gain tests were undertaken on various, commercially available adhesives. We attempted to prepare neat samples of ten types of adhesive agents (ie top coats and primers) which had been recommended by the manufacturers as suitable for marine applications. The neat samples were prepared with the use of a commercial adjustable wet film applicator supplied by the Paul Gardner Company. This applicator will lay films up to 0.25inches... 

At least one conclusion can be drawn from all of this. Primers that experience large increases in swelling in the presence of hydroxide ion, despite stability and considerable bond strength in salt water, would probably perform poorly if a cathodic potential was applied. Thus, the qualification of an adhesive system for a marine application that includes exposure of the metal substrate to a cathodic potential, should Include examination of the... 

---