Epoxy aldehydes, polymerization

Polymerization of Substituted Oxiranes, Epoxy Aldehydes, and Derived Oxacyclic Monomers... 

This paper is a review of studies on the ring-opening polymerization of cyclic ethers, e.g., styrene oxide, phenyl glycldyl ethers, epoxy aldehydes and derived oxacyclic monomers. Model reactions involving ring-opening processes occurring in those compounds have alsobeen discussed. 

Polymerization of Epoxy Aldehydes and Derived Oxacvclic Monomers The epoxy aldehyde shown below is an asymmetrically-substituted oxirane in which the aldehyde group is the substituent. It might be supposed that two possible routes for the polymerization of this monomer by either aluminum alkoxldes or trlalkylaluminum compounds could take place on the reaction temperature, as follows ... 

The primary oxidation products (hydroperoxides) are unstable and susceptible to decomposistion. A complex mixture of volatile, nonvolatile, and polymeric secondary oxidation products is formed through decomposition reactions, providing various indices of lipid oxidation (5). Secondary oxidation products include aldehydes, ketones, alcohols, hydrocarbons, volatile organic acids, and epoxy compounds, among others. Methods for assessing lipid oxidation based on their formation are discussed in this section. 

When this polymerization reaction was studied for monomers such as 2,3-epoxypropanal (above) or 2,3-epoxybutanal, however, an unusual Initiation step was found to take place by the Tishchenko-Claisen reaction, which is a well-known disproportionation reaction of aldehydes to esters, and an intermediate product, the dlepoxyester was identified. This intermediate product on polymerization formed, up to about 20% conversion, linear polyethers with both oxlrane and ester side groups by an epoxy ring-opening reaction, as follows ... 

A sigruficant use is as a catalyst in a multitude of reactions, such as the formation of acrjdic and methacrjdic acid amides from fatty acid amides (81) of cychc ketones such as 4-phen5icyclopentane-l,2-dione and 2,5-dihydroxy-/)-benzoquinone from benzaldehyde diethji acetal and 2,4-dioxo-5,5-dimethoxy-hexanoic acid methyl ester (82) of dimer aldehydes from propane (83) and for the polymerization of epoxy compounds (84). Mag nesium Kthylate. Magnesium ethoxide [2414-98-4]y Mg(OC2H 2 niol wt 114.4, is an almost white hygroscopic powder density,... 

An aqueous Friedel-Crafts reaction has also been used in polymer synthesis. The acid-catalyzed polymerization of benzylic alcohol and fluoride functionality in monomeric and polymeric fluorenes was investigated in both organic and aqueous reaction media. Polymeric products are consistent with the generation of benzylic cations that participate in electrophilic aromatic substitution reactions. Similar reactions occurred in a water-insoluble Kraft pine lignin by treatment with aqueous acid. A Bisphenol A-type epoxy resin is readily emulsified in aqueous medium with an ethylene oxide adduct to a Friedel-Crafts reaction product of styrene and 4-(4-cumyl)phenol as emulsifier.Electrophilic substitution reaction of indoles with various aldehydes and ketones proceeded smoothly in water using the hexamethylenetetramine-bromine complex to afford the corresponding Z A(indolyl)methanes in excellent yields.InFs-catalyzed electrophilic substitution reactions of indoles with aldehydes and ketones are carried out in water.Enzymatic Friedel-Crafts-type electrophilic substitution reactions have been reported. ... 

Crosslinked HRs can take part in further polymerization reactions with some natural or synthetic resins (epoxy, phenolformaldehydic, aldehydic, unsaturated polyesters) [173-177]. 

Other cationic processes include ring opening polymerization of epoxies, discussed below, and acid-catalyzed polymerization of aldehydes, discussed above. 

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