Marine reinforcement

Advanced composites and fiber-reinforced materials are used in sailcloth, speedboat, and other types of boat components, and leisure and commercial fishing gear. A ram id and polyethylene fibers are currentiy used in conveyer belts to collect valuable offshore minerals such as cobalt, uranium, and manganese. Constmction of oil-adsorbing fences made of high performance fabrics is being evaluated in Japan as well as the constmction of other pollution control textile materials for maritime use. For most marine uses, the textile materials must be resistant to biodeterioration and to a variety of aqueous pollutants and environmental conditions. 

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. 

Expandable VDC copolymer microspheres are prepared by a microsuspension process (191). The expanded microspheres are used in reinforced polyesters, blocking multipair cable, and in composites for furniture, marble, and marine appHcations (192—195). Vinylidene chloride copolymer microspheres are also used in printing inks and paper manufacture (196). 

Further reduction in the price of carbon fibers may enable penetration into the automotive market. A primary carbon fiber producer has armounced that prices will drop to 700 yen/kg ( 6.80/lb) by 1995 (73) and that cooperative development efforts with a main Japanese automobile producer are underway. Development for use in constmction, such as cement and cable reinforcement, and marine apphcations will result in sustained growth volume through the eady twenty-first century. 

The resins have wide appHcation. In nonreinforced form they serve as insulating coatings for electrical coils (46—47). As fiber reinforced resins, they can be made by reaction injection mol ding into laminates, castings, and coatings (48—49). Fiber-reinforced resins are used in marine appHcations (recreational boats) automotive parts (50) bathroom countertops and shower stalls and tubs and more recendy as baUistic protection for military vehicles and aircraft. 

Maleic anhydride is important as a chemical hecause it polymerizes with other monomers while retaining the double bond, as in unsaturated polyester resins. These resins, which represent the largest end use of maleic anhydride, are employed primarily in fiber-reinforced plastics for the construction, marine, and transportation industries. Maleic anhydride can also modify drying oils such as linseed and sunflower. 

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)... 

Unsaturated polyester resins based on maleic anhydride are widely used in coatings to manufacture boat hulls and truck caps and a variety of other uses where a smooth, weatherproof, hard-surfaced material is desired. Because these resin types are inherently brittle, hberglass is frequently added for reinforcement. Consumphon of unsaturated polyesters in the U.S. is well over a billion pounds per year, with about 50% going into construction and the marine industry. 

Concrete exposed to deicer salts, or to a marine environment is subjected to chloride and sodium loading. The ability of concrete to resist the penetration of chlorides and sodium is a primary design consideration in marine or cold environments. The ingress of chlorides into concrete is a major problem due to chloride-induced corrosion of the reinforcing steel and deicer salt scaling [a process by which a thin layer (< 1 mm) of concrete deteriorates from the surface of the concrete]. The penetration of sodium from sea water or deicer salts is generally... 

A plastic waste processor (from Carderock Division) has been developed to compress the Navy s plastic wastes into discs, solving the environmental and space problems from 600 kg daily plastic waste (20 m ) per ship. Seaward International Inc and Carderock Division are developing a marine piling (The SeaPile) in structurally reinforced composite with a core made of these discs. 

The activities of the Working Parties cover corrosion topics associated with inhibition, education, reinforcement in concrete, microbial effects, hot gases and combustion productions, environment sensitive fracture, marine environments, refineries, surface science, physico-chemical methods of measurement, the nuclear industry, the automotive industry, computer based information systems, coatings, tribo-corrosion and the oil and gas industry. Working Parties and Task Forces on other topics are established as required. 

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