Epoxide Epoxy

The commercial interest in epoxide (epoxy) resins was first made apparent by the publication of German Patent 676117 by I G Farben in 1939 which described liquid polyepoxides. In 1943 P. Castan filed US Patent 2 324483, covering the curing of the resins with dibasic acids. This important process was subsequently exploited by the Ciba Company. A later patent of Castan covered the hardening of epoxide resins with alkaline catalysts used in the range 0.1-5% This patent, however, became of somewhat restricted value as the important amine hardeners are usually used in quantities higher than 5%. 

Epoxides. Epoxy resins are more expensive than other equivalent theimosets (e.g. polyesters) but they an generally out-perform these materials due to better... 

Polystyrene insulation on magnet wire 0.49 Encapsulated with phthalic anhydride cured bisphenol A-epichlorohydrin epoxide (epoxy hot melt cast). Impregnated. 

Epoxides. Epoxy compounds react with the carboxyl groups of CTPB to form polyesters. The reaction rates and extent of reaction of a number of epoxides have been determined with the model compound hexanoic acid (6). It was found that most epoxides undergo side reactions (as evidenced by the more rapid consumption of epoxide species) but that at least one difunctional epoxide, DER-332 (Dow Chemical Co.) (Table IV), exhibits a clean reaction with carboxylic acids, even in the presence of ammonium perchlorate. 

In plants a-dioxygenases (Chapter 18) convert free fatty acids into 2(R)-hydroperoxy derivatives (Eq. 7-3, step d).32a These may be decarboxylated to fatty aldehydes (step e, see also Eq. 15-36) but may also give rise to a variety of other products. Compounds arising from linoleic and linolenic acids are numerous and include epoxides, epoxy alcohols, dihydroxy acids, short-chain aldehydes, divinyl ethers, and jasmonic acid (Eq. 21-18).32a... 

In the system epoxide (epoxy resin) — anhydride, we can thus expect the presence of anhydride, epoxy- and proton donor groups. In their study of the reaction mechanism, Fisch and Hofmann 20 22-24) proposed a sequence of reactions leading to the crosslinking of epoxy resins or to the formation of linear polyesters. The first step is the reaction of the anhydride with hydroxyl groups giving a monoester (Eq.(l))... 

Cyclization of vinyl ether epoxides, Epoxy dihydropyranes undergo cyclization in the presence of Lewis acids. Thus treatment of 1 with basic alumina affords 2 in almost quantitative yield. The product can be converted into the keto aldehyde 5 by treatment with a mineral acid followed by oxidation. Another useful reaction of 2 is conversion to the keto lactone 3 by singlet oxygen. 

Keywords Epoxidation, Epoxy alcohol, Allylic alcohol. Titanium-mediated epoxidation. Titanium tartrate complex. Kinetic resolution. Ligand acceleration... 

Azide ion will replace mesylate (with inversion) under conditions which do not open epoxides. Epoxy-amines (e.g. 38) prepared by this route [from (36)] were converted into acetamido- and ureido-epoxides by standard methods. Azide... 

Trimethylolpropane epoxidation, epoxy resin precursors Peracetic acid... 

Several oxysterol classes present in oxLDL appear to be cytotoxic toward fibroblasts, ECs, and vascular smooth muscle cells, especially 7-hydroperoxycholes-terol (7-OOH-chol), 7P- and 7a-hydroxycholesterol (7-OH-chol), 7-ketocholesterol (7-keto-chol), and cholesterol epoxides (epoxy-chol). 7p-OOH-chol, a precursor of hydroxyl- and keto-oxysterols, was reported to be the most toxic. During LDL oxidation 7P-OOH-chol was produced in three to five times higher quantities than 7a-OOH-chol, other oxysterols and even hydroxy-nonenal, which is one of the most abundant lipid oxidation products. Cytotoxicity of oxysterols was connected to increased cellular oxidative stress. Some studies suggest that oxysterols are even involved in oxidative stress induction. Animal models indicate that dietary oxysterols can significantly decrease glutathione levels and increase expression of glutathione peroxidase and superoxide dismutase. In apolipoprotein-deficient mice, the NADPH-oxidase activity was induced by 7-keto-chol, 7p-OH-chol, and Sp,6P-epoxy-chol. The increased activity of NADPH oxidase yields more superoxide anions that amplify oxidative stress. 

EP Epoxide Epoxy Ciba Gcigy Aralditc/Redux... 

EP Epoxide epoxy PTFE Poly(tetrafluoro ethylene)... 

Novel functionalized peroxides which may be used as UPR curing agents as well as initiators for polymerization reactions and as monomers for polymerizations to form peroxy-containing polymers were elaborated [162]. Initiators may be prepared by reacting hydroxy-containing tertiary hydroperoxides with diacid halides, dichloroformates, phosgene, diisocyanates, acid anhydrides and lactones to form the functionalized peroxides. These reaction products may be further reacted, if desired, with dialcohols, diamines, aminoalcohols, epoxides, epoxy alcohols, epoxy amines, diacid halides, dichloroformates and diisocyanates to form additional fimctionalized peroxides. The use of monoperoxyoxalates of the structure (Scheme 24) as initiators... 

Epoxy Terminal epoxide Epoxy/ABS Ring opening Impact/tensile 212... 

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