Unsaturated polyester chemistry

Penczek, R, Czub, R and Pielichowski, ]. Unsaturated Polyester Resins Chemistry and Technology. Vol. 184, pp. 1-95. 

Unsaturated Polyesters. The chemistry of unsaturated polyesters was developed in the 1930s, and manufacture of glass-fiber-reinforced polyesters began in the early... 

Visiting Assistant Professor, Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio Alkyd resins Epoxy resins Polyesters, unsaturated... 

Penczek, P, Czub, P and Pielichowski, J. Unsaturated Polyester Resins Chemistry and... 

Chemical compounds that contain methylol groups (-CH2 OH) form stable, covalent bonds with cellulose fibers. Those compounds are well known and widely used in textile chemistry. Hydrogen bonds with cellulose can be formed in this reaction as well. The treatment of cellulose with methylolmelamine compounds before forming cellulose unsaturated polyesters (UP) composites decreases the moisture pickup and increases the wet strength of reinforced plastic [48,49]. 

Finally, glass-reinforced unsaturated polyesters are well known as building materials for boats, yachts and cars and generally termed fibre-glass resin . The preparation, properties and applications of these unsaturated polyesters are summarized in Chapter 21, while the chemistry and properties of a new unsaturated polyester resin for fibre-reinforced composite materials are discussed in Chapter 22. 

With the advancement of polymer chemistry, a wide range of polymers are now available for use as binders for HEMs. The extensive use of polymers such as unsaturated polyesters, epoxy resins, epoxy-PS blends and VAARs as binders for illuminating formulations has been reported in the literature. The chemistry of unsaturated polyesters and epoxy resins has already been discussed in Chapter 4 on propellants. Some salient features of liquid PS and its blends with epoxy resin and VAARs are given in this section. 

VINYL ESTER RESINS. The vinyl ester resins are a relatively recent addition1 to thermosetting-polymer-chemistry. Superficially, they are similar to unsaturated polyester resins insofar as they contain ethylmic lmsaturation and are cured throngh a free-radical mechanism, usually in the presence of a vinyl monomer, such as styrene. However, close examination of the chemistry and structure of the vinyl ester resins demonstrates several basic differences which lead to their unique characteristics. 

Other chemistries have been used to prepare preformed reactive modifiers for epoxy and unsaturated polyester resins. Particles are generally composed of... 

C-4 Chemistry (Butanes, Butylenes, Butadiene). Maleic anhydride is the main chemical made from w-butane. A complex catalyst is used for the oxidation reaction. The major uses for maleic anhydride are the making of unsaturated polyester resins (by reaction with glycol and phthalic anhydride) and tetrahydrofuran (by hydrogenation). 

Larsen, E. R. Some effects of various unsaturated polyester resin components upon FR-agent efficiency, Journal of Fire and Flammability/Fire Retardant Chemistry, 1975, 2, 209-223. 

U.R.Vaidya and V.M.Nadkarni (1987). Unsaturated Polyester Resins from Poly(ethylene terephthalate) Waste. Industrial Engineering Chemistry Research, Vol. 26, No. 2, pp. 194—198. 

Since the introduction of the first commercial thermoset, Bakelite, based on phenol formaldehyde condensation, a wide range of thermoset materials have been introduced. These are typically designed for specific properties related to their chemistry and processability. Some commercially important thermosets include phenolics, ureas, melamines, epoxy resins, unsaturated polyesters, silicones, rubbers, polyurethanes, acrylics, cyanates, polyimides, and benzocyclobutenes. ... 

Other modifications of vegetable oils in polymer chemistry include the introduction of alkenyl functions, the study of novel polyesters and polyethers and the synthesis of semi-interpenetrating networks based on castor oil (the triglyceride of ricinoleic acid) [42], and also the production of sebacic acid and 10-undecenoic acid from castor oil [44]. Additionally, the recent application of metathesis reactions to unsaturated fatty acids has opened a novel avenue of exploitation leading to a variety of interesting monomers and polymers, including aliphatic polyesters and polyamides previously derived from petrochemical sources [42, 45]. 

This chapter will deal with the chemistry and applications of epoxies, phenolics, urethanes, and a variety of current vogue high-temperature polymers. Applications in fiber-reinforced plastics will be discussed in the individual sections on resin chemistry where appropriate. Separate sections will deal with adhesives and sealants. Adhesives are most important because, as early history demonstrates, they led the way to the application of resins in aerospace. A section is also included on silicone and polysulfide sealants. Although these materials are elastomers rather than resins, no discussion of aerospace polymers would be complete without some mention. Some major thermosetting polymers have been omitted from this review. Among these are the unsaturated polyesters, melamines, ureas, and the vinyl esters. Although these products do find their way into aerospace applications, the uses are so small that a detailed discussion is not warranted. 

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