Epoxide-containing polyesters

Epoxide-containing polyesters were enzymatically synthesized via two routes using unsaturated fatty acids as starting substrate (Scheme 11)." Lipase catalysis was used for both polycondensation and epoxidation of unsaturated fatty acid group. One route was synthesis of aliphatic polyesters containing an... 

Uyama, H., Kuwabara, M., Tsujimoto, T., and Kobayashi, S. (2003) Enzymatic synthesis and curing of biodegradable epoxide-containing polyesters from renewable resources. Biomacromolecules, 4 (2), 211-215. 

Unsaturated maleic/fumaric acid-containing polyesters (UPEs) dissolved in styrene, (2) acrylate/methacrylate systems, (3) thiol/ene systems, and (4) epoxide- or vinyl ether-containing systems. In the case of systems (l)-(3), free radical polymerizations are operative, while in case (4) cationic species are involved (see Chapter 10). Regarding thiol/ene systems, the mechanism of free radical thiol/aUcene polymerization outlined in Scheme 11.1 is assumed to be operative... 

Polymeric materials are used as the basis of photoresists for making metal patterns on printed circuit boards, and also on the individual integrated circuit devices themselves. The circuit boards are made of various glass-fibre filled epoxides and polyesters, and are usually coated with other polymeric materials to prevent tarnishing and to improve solderability. The devices that are mounted on the completed printed circuit boards may have been manufactured using polymeric photoresists or have plastics such as polypropylene and polyester films in capacitors or epoxide resins in integrated circuits and transistors. The completed boards containing various devices are often then coated in another protective polymer. Finally, electrical connections are made... 

Blends that contain no nylon can also be prepared by reactive compatibilization. However, interest in these systems has been limited somewhat by lack of control of the reaction pathways. Eor polyester-based systems, epoxide functionaHty appears to be an effective chemistry, involving reaction of the polyester chain ends (183,184). 

Thermosetting Reactive Polymers. Materials used as thermosetting polymers include reactive monomers such as urea—formaldehyde, phenoHcs, polyesters, epoxides, and vinyls, which form a polymerized material when mixed with a catalyst. The treated waste forms a sponge-like material which traps the soHd particles, but not the Hquid fraction the waste must usually be dried and placed in containers for disposal. Because the urea—formaldehyde catalysts are strongly acidic, urea-based materials are generally not suitable for metals that can leach in the untrapped Hquid fractions. Thermosetting processes have greater utiHty for radioactive materials and acid wastes. 

For this use, the preferred powders are based on acrylic, epoxy or polyester and epoxy resins. For best colour, epoxy resins are crosslinked with anhydrides of dicarboxylic acids in the straight epoxy coatings, or with saturated polyesters of high acid content in the epoxy-polyester type. Acrylics contain epoxide rings via, for example, glycidyl methacrylate (CH2=C(CH3) —CO—O—CHj—CH —CH2), and these groups crosslink... 

Epoxides readily undergo anionic copolymerization with lactones and cyclic anhydrides because the propagating centers are similar alkoxide and carboxylate [Aida et al., 1985 Cherdron and Ohse, 1966 Inoue and Aida, 1989 Luston and Vass, 1984]. Most of the polymerizations show alternating behavior, with the formation of polyester, but the mechanism for alternation is unclear. There are few reports of cationic copolymerizations of lactones and cyclic ethers other than the copolymerizations of P-propiolactone with tetrahydrofuran and 3,3-bis(chloromethyl)oxetane, probably indicative of the difference in propagating centers (dioxocarbocation and oxonium ion, respectively) [Yamashita et al., 1966]. The copolymerizations tend toward ideal behavior with the product containing large amounts of the cyclic ether. 

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