Unsaturated polyesters, world

World production of unsaturated polyester resins in 1997 was of the order of 1.7 X 10 tonnes, with the USA accounting for about 45% and Western Europe 27%. Over 75% is used in reinforced plastics, with the rest being used for such diverse applications as car repair putties, cultured marble , wood substitution and surface coatings. The pattern of consumption in 1993 of reinforced polyesters in the USA was reported as ... 

Addition poly(imide) oligomers are used as matrix resins for high performance composites based on glass-, carbon- and aramide fibers. The world wide market for advanced composites and adhesives was about 70 million in 1990. This amounted to approximately 30-40 million in resin sales. Currently, epoxy resins constitute over 90% of the matrix resin materials in advanced composites. The remaining 10% are unsaturated polyester and vinylester for the low temperature applications and cyanate esters and addition poly(imides) for high temperatures. More recently thermoplastics have become important and materials such as polyimides and poly(arylene ether) are becoming more competitive with addition polyimides. 

Maleic anhydride (1.17 Mt/a world installed capacity) finds its major use in the synthesis of unsaturated polyester resins ca. 41%), with the remainder going to produce butanediol (14%), maleic copolymers (8%), tetrahydrofuran (7%),... 

Commercial development of this field was aided by a fortuitous set of circumstances. Maleic anhydride became available commercially shortly prior to World War II and cheap styrene for synthetic rubber during this conflict. Glass fibers in woven cloth form appeared at about the same time. A demand for radomes for aircraft caused a search for a strong lastic material which literally would be a window for radar waves. Glass cloth-reinforced unSaturated polyester resins provided the strength necessary as well as the desired electrical properties. From this commercial start "in 1944, the imsaturated polyester resin production has grown to an estimated 70 million lb in 1956. The major part of the resin is used with reinforcing fibers of some tj e. 

Ellis and Rust solved this problem by dissolving the solid unsaturated polyesters in a liquid vinyl monomer, such as vinyl acetate.-2>12 However, the less volatile and more widely available styrene monomer was used instead of vinyl acetate for most of the fiber glass-reinforced "low pressure" polyester plastics that were produced during World War II and since that time. 

Between 1930 and the onset of World War II (WWII) in 1939, several polymer families were invented and commercially developed through bulk processes. The most important ones include low density polyethylene (LDPE), poly(methyl methacrylate) (PMMA), polyurethanes (PU), poly(tetra-fluoro ethylene) (PTFE), polyamides (PAs), and polyesters (PEs). The last three are attributed to Dupont s scientists Roy Plunkett and Wallace Carothers, respectively. During WWll, bulk polymerization was still instrumental in the development and commercialization of new families of PEs such as polyethylene terephthalate (PET) developed by ICI and Dupont and unsaturated polyester resins (UPRs) [1, 6-8]. 

Maleic anhydride is currently used in the production of unsaturated polyesters and butanediol. World consumption over the last few years has exceeded 1.3 x 10 metric tons per year. Currently, ca. 70% of MA is produced from -butane partial oxidation. In this way, partial oxidation of -butane to MA is the only... 

While the early 1930s and World War II saw the development of the newer family of thermoplastics, thermosetting plastics were still the most important until the early 1950s, as Table 3 shows [35]. Of the total production of 330,000 tonnes in 1968, 73% was accounted for by the older materials phenol-formaldehydes (PFs), urea-formaldehydes (UFs), and alkyds. The remaining 27% was accounted for by the newer materials such as unsaturated polyesters (UPs), epoxides (EPs), and polyurethanes (PUs). 

---