Epoxy ethers ketones

Treatment of the epoxy ether 97 with hexafluoro-2-propanol (HFIP) or trifluoroethanol provided the rearranged trifluoromethyl ketone 98 as a single stereoisomer. NMR data for 98 did not allow the unambiguous determination of the configuration at C-9, which was confirmed by the single crystal X-ray structure (Equation 8) <2002JOC1253>. 

The primary resin of interest is epoxy. Carbon-fiber-epoxy composites represent about 90% of CFRP production. The attractions of epoxy resins are that they polymerize without the generation of condensation products that can cause porosity, they exhibit little volumetric shrinkage during cure which reduces internal stresses, and they are resistant to most chemical environments. Other matrix resins of interest for carbon fibers include the thermosetting phenolics, polyimides, and polybismaleimides, as well as high-temperature thermoplastics such as polyether ether ketone (PEEK), polyethersulfone (PES), and polyphenylene sulfide. 

Epoxy c Ketone, ethers, esters, toluene, xylene Marine coatings, enamels, containers... 

Matrix materials for commercial composites are mainly liquid thermosetting resins such as polyesters, vinyl esters, epoxy resins, and bismaleimide resins. Thermoplastic composites are made from polyamides, polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polysulfone, polyetherim-ide (PEI), and polyamide-imide (PAI). 

However, a-chloroketones are powerful alkylating agents and the bound inhibitor attacks His 57 of the catalytic triad system. The reaction is probably more complex than is indicated in the foregoing equation and may involve an epoxy ether intermediate/ Many other peptide chloromethyl ketone inhibitors have been devised/ 1 ... 

Tetrabutylammonium fluoride, 286 Silanes (see also Allylic compounds, a, 13-Epoxy silanes, Ketones, Silyl enol ethers, Vinylsilanes)... 

The synthesis (Scheme 9) begins with the appropriate 1-trifluoromethyl-substituted enol ether 43, where R1 is an amino acid side chain or another appropriate carbon chain. The enol ether undergoes reaction with MCPBA in CH2C12 to give the corresponding epoxy ether 44. The epoxy ether is cleaved by reaction of a wide variety of secondary amines to give the a-amino trifluoromethylated ketone 45. Only a few compounds have been synthesized by this method. 35,36 ... 

Recently, comprehensive World Wide Web (Internet) databases have been established on insect pheromones and semiochemicals The Pherolist , a database of chemicals identified from sex pheromone glands of female lepidopteran insects and other chemicals attractive to male moths (Am et al., 1999) and The Pherobase , a database of pheromones and semiochemicals for Lepidoptera and other insect orders (El-Sayed, 2006). These large databases on behavior modifying chemicals have extensive cross-linkages for animal taxa, indexes of compounds and source (reference) indexes. The indexes include those compounds cited in this chapter and many more with pheromone and semiochemical function acetate esters, diols, epoxides, ethers, ketones and secondary alcohols. For example, The Pherolist reports approximately 90 epoxy derivatives of C17-C23 of n-alkancs, mono-alkenes and di-alkenes as insect semiochemicals. 

Lee, Kun-Soo, et al., Preparation of Epoxy Resins Containing Ether Ether Ketone Unit and Then-Thermal Properties, Bulletin of Korean Chemical Society, vol. 22, no. 4, 2001. 

Within the past several years, improvements in the toughening of high-temperature epoxies and other reactive thermosets, such as cyanate esters and bismaleimides, have been accomplished through the incorporation of engineering thermoplastics. Additions of poly(arylene ether ketone) or PEK and poly(aryl ether sulfone) or PES have been found to improve fracture toughness. Direct addition of these thermoplastics generally improves fracture toughness but results in decreased tensile properties and reduced chemical resistance. 

Organic matrices are divided into thermosets and thermoplastics. The main thermoset matrices are polyesters, epoxies, phenolics, and polyimides, polyesters being the most widely used in commercial applications (3,4). Epoxy and polyimide resins are applied in advanced composites for structural aerospace applications (1,5). Thermoplastics Uke polyolefins, nylons, and polyesters are reinforced with short fibers (3). They are known as traditional polymeric matrices. Advanced thermoplastic polymeric matrices like poly(ether ketones) and polysulfones have a higher service temperature than the traditional ones (1,6). They have service properties similar to those of thermoset matrices and are reinforced with continuous fibers. Of course, composites reinforced with discontinuous fibers have weaker mechanical properties than those with continuous fibers. Elastomers are generally reinforced by the addition of carbon black or silica. Although they are reinforced polymers, traditionally they are studied separately due to their singular properties (see Chap. 3). 

In Table 15.3 are shown the chemical structures and Tg and of some representative thermoplastic polymers for use at high temperature (3,9). These matrices have high continuous service temperatures (120-200° C) even under wet environmental conditions. Advantages of thermoplastic over thermoset matrices are their shorter fabrication cycle (generally controlled environment storage is not required) and the possibility to be reprocessed and reconsolidated after manufacture. Poly(ether ether ketone) is a strong contender with epoxy resins for use as a matrix in composite prepregs with carbon fibers to be utilized in structural aircraft components. 

Tetrabutybrnmonium fluoride, 286 Silanes (lee obo Allylic ctmipounds, Epoxy ubnes. Ketones, StIyI cix ethers, Vinylsibrws)... 

Besides graphite, carbon and glass fibers, organic fibers, e.g., Kevlar, have also been used to reinforce thermosetting resins, e.g., epoxy resin (38). One of the newest developments is fiber-reinforced thermoplastics, e.g., carbon fiber-reinforced polyether ether ketone (PEEK) ( ). These materials are rather tough as demonstrated in the interlaminar toughness values (Table... 

The literature published on fracture mechanics testing of FRPs in the last 40 years comprises a large database on delamination resistance or fracture toughness of different types of FRPs. An early review [51] compiled the data available at that time. Selected data from quasi-static mode I and mode II tests on FRPs were compared by O Brien [52], and quasi-static mode I test data from carbon—fibre epoxy and poly-ether-ether-ketone (PEEK) by Brunner [53]. Mechanical properties of FRP composites are compiled in the Composite Materials Handbook version F (2002) [9—11], but this does not comprise fracture mechanics data. Hence, there is no comprehensive and up-to-date database on the available data or literature. 

Intrinsically non-flammable polymers are few, but phenolic resins have a good reputation both in Are and smoke performance, which has resulted in their becoming increasingly favoured for reinforced plastics structures, for example, underground transport, where such concerns are greatest. Polyether ether ketone (PEEK) is also a low fire and smoke polymer. Unsaturated polyesters, vinyl esters and epoxy resins bum readily, but modified versions are available with improved behaviour. For example, both bromine and chlorine are used extensively in the form of chlorendic (HET) acid, tetrachlorophthalic anhydride (TCPA) and tetrabromo-phthalic anhydride (TBPA) which can be reacted into the polyester in small quantities and can act as permanent (non-migrating) flame retardants. 

Uses Plasticizer, tackifler, processing aid in nitrile rubber tackifler in adhesives (hot-melt, hot-melt pressure-sensitive, pressure-sensitive) diluent, modifier in epoxy coatings rubber cements antiskinning agent in varnishes food pkg. adhesives, rubber articles Regulatory FDA 21 CFR 175.105,177.2600 Properties Gardner 8 liq. sol. in alcohols, esters, ethers, ketones (except acetone), and chlorinated, aromatic, naphthenic, and terpene hydrocarbons m.w. 250 sp.gr. 1.091 soften. (R B) pt. 12 C iodine no. (Wijs) 80 hyd. no. 200 flash pt. (COC) 365 F Nevoxy EPX-L [Neville]... 

Zho Zhong, Z.-K., Zheng, S.-X., Huang, J.-Y., Cheng, X.-G., Guo, O.-P., Wei, J. Phase behaviour and mechanical properties of epoxy resin containing phenolphthalein poly (ether ether ketone). Polymer 39 (1998) 1075-1080. 

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