Polyester resins constructional materials

Polyester resins, reinforced with glass fibers, are used widely in the construction of process equipment. Some physical and mechanical properties are presented in Table 3.48. Table 3.49 lists various materials used as filler and the properties they impart to different plastics. 

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. 

Since the stiffness of a laminate varies as a cubic relationship with the thickness, there are alternate methods employed to achieve thickness - and hence stiffness - than by using multiple layers of fiberglass and resin. Lightweight core materials, such as end-grained balsa wood, high-density polyurethane foam, PVC foam, and honeycombed materials, are available. These materials are sandwiched in between layers of unsaturated polyester resin to achieve increased laminate stiffness. The common terminology used for this technique is sandwich construction . 

Bathtubs, showers and sinks account for significant consumption of unsaturated polyester resins. Fiberglass-reinforced bathtubs and shower stalls account for as much as 90% of the unsaturated polyester used in construction. Unsaturated polyesters have significantly replaced cast-iron bathtubs as a lower-cost material. Similarly, highly filled cast unsaturated polyesters have replaced ceramics and steel in bathroom sinks and countertops. 

The use of FRP is desired to replace older materials of construction such as concrete, stucco, etc. They have been used in many historical preservation projects. The reason they are desired is because of light weight, durability ease of installation, and low maintenance (no dry rot, attack by insects, mold, etc.). These are typically nonstructural parts made by spray-up process or continuous panel process. An example are shown in Figure 23.11. This market is expected to continue to grow. The main resin used for exterior architectural applications are halogenated polyester resins. Since there is not a smoke requirement, resins that meet the ASTM E-84 flame spread requirement of <25 can be used for this application. The other common material used for these applications is polyester resin or modified acrylic resins that are filled with ATH. The ATH filled resins can also be used in interior applications since they will typically also have low smoke values. 

Dry chlorine has a great affinity for absorbing moisture, and wet chlorine is extremely corrosive, attacking most common materials except Hastelloy C, titanium, and tantalum. These metals are protected from attack by the acids formed by chlorine hydrolysis because of surface oxide films on the metal. Tantalum is the preferred construction material for service with wet and dry chlorine. Wet chlorine gas is handled under pressure using fiberglass-reinforced plastics. Rubber-lined steel is suitable for wet chlorine gas handling up to 100 °C. At low pressures and low temperatures PVC, chlorinated PVC, and reinforced polyester resins are also used. Polytetrafluoroethylene (PTFE), poly (vinylidene fluoride) (PVDF), and... 

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

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. 

The characteristic brittleness of unsaturated polyester resins was overcome by reinforcement with silane-treated fiber glass. While over 750 thousand tons of these reinforced plastics are produced annually in the U.S., the emphasis in this chapter will be on room temperature-curable-filled unsaturated polyester mortars or concrete. As discussed in Chapters 1 and 7, these anaerobic polyester mortars are widely used as materials of construction.—... 

The economic design of high-quality tanks for storing hypochlorite solutions has been a long-standing problem [75]. Iitanium would be an excellent material of construction, but only at a yery high cost. Rubber-lined carbon steel has been widely used in both horizontal and vertical tanks. Fiber-reinforced polymers are attractive candidates, but results often have been unsatisfactory. Vinylester resins (e.g., Derakane 411) are preferred, and polyester resins also may be satisfactory. Those with high chemical resistance are best, and bisphenol A resins, for example, are preferred to those based on isophthalic acid. 

Ashland Inc. (USA) 300,000 Pre-accelerated polyester resin. Adhesive, pigment, construction materials, additives, etc. http //www.ashland. com/... 

---