Epoxy compounds epichlorohydrin

This group, commonly called epoxy, characterizes the epoxy resins. Epichlorohydrin and ethylene oxide are well-known epoxides. The compounds are also used in certain types of cellulose derivatives and fluorocarbons. 

However it was found that no further conversion of the chlorohydrin ester to epoxy compound was obtained indicating that epichlorohydrin is required in the reaction system to effect ring closure. 

Accordingly, sodium hydroxide (17% aqueous solution) was stirred with the chlorohydrin ester masterbatch prepared above. The reaction was followed at 40 C using a molar ratio of sodium hydroxide to chlorohydrin ester of 2 1. The reaction was followed by gas chromatography. Fig. 18 shows the rates of conversion of epichlorohydrin and chlorohydrin ester during the reaction. Again, it was shown that after 6.5 hours all the sodium hydroxide had been consumed (cf. sodium hydroxide/sodium carbonate reaction at 40 C) at which time only 64% conversion to the epoxy compound was observed. Correspondingly the epichlorohydrin hydrolysis (25%) had increased in comparison to the sodium hydroxide/sodium carbonate method (15.6% at 40 C). 

Heterocyclic Epoxy Compounds. The technically most important heterocyclic epoxy resin is triglycidyl isocyanurate, obtained by reacting cyanuric acid with epichlorohydrin (Araldite PT 810, Ciba-Geigy Tepic, Nissan). This trifunctional epoxy resin is combined with carboxy-terminated polyesters to give weather-resistant powder coatings [2.122]-[2.124]. 

Depending on the conditions, reactions (I) and (E) can be carried out either concurrently or consecutively. If one works from the outset in alkaline medium, for example, by dropping the desired amount of epichlorohydrin into the mixture of hydroxy compound and the equivalent amount of aqueous alkali hydroxide at 50-100°C, then the addition reaction and the HQ elimination occur side by side (Example 4.24). On the other hand, if the hydroxy compound and epichlorohydrin are allowed to react in nonaqueous medium in the presence of acid catalysts, the corresponding chlorohydrin is first formed this can then be transformed into the epoxy compound in a second step by reaction with an equivalent amount of alkali hydroxide. 

Compounds such as vegetable oils, fatty acids, di/polyhydroxy compounds, epichlorohydrin and catalysts are required for the preparation of vegetable oil-based epoxies. The resinification or epoxy formation methods are similar to those of conventional petrochemical-based epoxy resins. 

The epoxy compound from bisphenol A (from two molecules of phenol and one of acetone at pH = 1-5) and epichlorohydrin is of particular commercial importance. Under the action of catalytic amounts of alkali, a chlorohydrin intermediate product first forms ... 

Aliphatic polyols such as glycerol [36], 2,5-bis(hydroxymethyl)tetra-hydrofuran [37], and chlorinated butenediol [38,39] have been reported to be used to give epoxy compounds. More recently it has been reported that epichlorohydrin and methylepichlorohydrin can be reacted with polymercaptonaphalene to give glycidylthioethers for use as curable epoxy resins [40]. 

TABLE II Preparation of Epoxy Compounds from Phenolic Compounds and Epichlorohydrin... 

Epoxy resins are thermoset polymers prepared by the reaction of an epoxy compound, typically a low molecular weight diepoxide, with a curing agent. These two parts are combined and a chemical reaction causes the cure. They are often called two-part epoxies. They come in two tubes for home use. There are many variants of epoxy compounds and curing agents but diglycidyl ethers of bisphenols cured with diamines are common. The diglycidyl ethers are readily prepared from epichlorohydrin. The reaction is... 

A novel epoxy resin with low refractive index, high optical transparency from UV to near infrared, high adhesive strength, and high resistance was obtained by Maruno et al. [32]. This resin is synthesized from benzene, hexafluoroacetone, and epichlorohydrin as shown in Schemes 1 and 2. Uncured epoxy resins IV and V (Scheme 2) show high UV transparency because they consist of nonaromatic hydrocarbons. Therefore, these resins should be advantageous in formulating UV curable epoxy compounds. 

The majority of 2-methylphenol is used in the production of novolak phenoHc resins. High purity novolaks based on 2-methylphenol are used in photoresist appHcations (37). Novolaks based on 2-methylphenol are also epoxidized with epichlorohydrin, yielding epoxy resins after dehydrohalogenation, which are used as encapsulating resins in the electronics industry. Other uses of 2-methylphenol include its conversion to a dinitro compound, 4,6-dinitro-2-methylphenol [534-52-1] (DNOC), which is used as a herbicide (38). DNOC is also used to a limited extent as a polymerization inhibitor in the production of styrene, but this use is expected to decline because of concerns about the toxicity of the dinitro derivative. 

Uses. AEyl chloride is industrially the most important aHyl compound among all the aHyl compounds (see Chlorocarbons and CHLOROHYDROCARBONS, ALLYL CHLORIDE). It is used mosdy as an intermediate compound for producing epichlorohydrin, which is consumed as a raw material for epoxy resins (qv). World production of AC is approximately 700,000 tons per year, the same as that of epichlorohydrin. Epichlorohydrin is produced in two steps reaction of AC with an aqueous chlorine solution to yield dichloropropanol (mixture of 1,3-dichloropropanol and 2,3-dichloropropanol) by chlorohydrination, and then saponification with a calcium hydroxide slurry to yield epichlorohydrin. 

Specialty Epoxy Resins. In addition to bisphenol, other polyols such as aUphatic glycols and novolaks are used to produce specialty resins. Epoxy resins may also include compounds based on aUphatic, cycloaUphatic, aromatic, and heterocycHc backbones. Glycidylation of active hydrogen-containing stmctures with epichlorohydrin and epoxidation of olefins with peracetic acid remain the important commercial procedures for introducing the oxirane group into various precursors of epoxy resins. 

Epoxy resins are usually understood to be products of reaction of polyfunctional hydroxy compounds with l-chloro-2,3-epoxypropane (epichlorohydrin) in basic medium. In the simplest case two mol of epichlorohydrin react, for example, with one mol of bisphenol A, according to the following scheme ... 

Epoxy resins are generally prepared by the reaction of epichlorohydrin with active hydrogen-bearing compounds ... 

Allyl chloride is used to make intermediates for downstream derivatives such as resins and polymers. Approximately 90% of allyl chloride production is used to synthesize epichlorohydrin, which is used as a basic building block for epoxy resins and in glycerol synthesis. Allyl chloride is also a starting material for allyl ethers of phenols, bisphenol A and phenolic resins, and for some allyl esters. Other compounds made from allyl chloride are quaternary amines used in chelating agents and quaternary ammonium salts, which are used in water clarification and sewage sludge flocculation (Kneupper Saathoff, 1993). 

Uses. Allyl chloride is industrially the most important allyl compound among all the allyl compounds. It is used mostly as an intermediate compound for producing epichlorohydrin, which is consumed as a raw material for epoxy resins. 

Cross-Linked Polymers. In the 1980s, not only glass and BPA-PC but also uv-curable cross-linked polymers, eg, epoxy resins, were used as substrate material for optical mass storage disks with laige diameters (12 in., 14 in.) (219). The epoxy resins consisted of compounds containing one or several highly reactive epoxy or hydroxyl groups. The common epoxy resins (EP) mainly are reaction products of bisphenol A and epichlorohydrin ... 

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