Unsaturated polyesters marine application

Consumption of unsaturated polyesters in the marine industry consists of broad usage for hulls, decks and numerous small parts such as hatch and engine covers. Hulls and decks are generally produced with unsaturated polyester resins and multiple layers of fiberglass cloth knits and chopped fibers. Most marine applications require the use of unsaturated polyester resin gel coats for exterior appearance and for protection from the elements. 

The growth of unsaturated polyesters will continue to be fueled by their versatility and their ability to provide cost-effective solutions to end-use requirements. Unsaturated polyester composites will continue to provide solutions to engineering demands for corrosion resistance, strength-to-weight and cost performance. Marine, transportation and construction opportunities currently identified and being developed will provide growth beyond the existing applications presented. Some examples are as follows ... 

The weatherability and hydrolytic stability of unsaturated polyesters based on neopentyl glycol have made it a popular intermediate for use in formulations exposed to severe conditions, eg, in gel coats for cultured marble and marine applications (see Coatings, MARINE) (13). 

The largest use for propylene glycol is unsaturated polyester resins. Propylene glycol is an intermediate in the synthesis of these versatile materials, which, because of their corrosion resistant properties, have application in the marine, automotive, and construction industries. 

Resins based on dicyclopentadiene (DCPD) offer better wettability of fillers and better prevention of print-through than conventional unsaturated polyesters, making them particularly suitable for appearance parts in transportation and marine applications. Polyesters based on DCPD require special chemical competence on the part of the fabricator, but... 

Unsaturated polyesters (UPs) have been used extensively in the reinforced plastics industry in the manufacture of products for transportation, construction and marine applications. They are also used for coatings, finishes, lacquers, cements and glues... 

As mentioned earlier, mono and dialkyl esters are commercially important in a number of applications.The single largest commercial use of MA is for the manufacture of unsaturated polyesters. The latter are used in automobile and marine applications.Besides, they have been extensively employed as intermediates for wetting agents, surfactants, dye leveling agents, and cosmetic ingredients (see Sec. 3.2.6). Dialkyl esters have been widely used as monomers and as plasticizers " " (see chapters 8-10). Dialkyl maleates have often been used as reactants or monomers in place of MA since the esters are liquids and hence easier to handle. Esters of MA are also employed as intermediates for insecticides and as insecticides themselves. 

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)... 

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