Epoxy-carboxylic acids

CTBN Carboxylic acid Epoxy/CTBN Ring opening Impact 222, 223... 

Azonine-l-carboxylic acid, 4,5-epoxy-, ethyl ester AGi,. , 7, 724 <77JA2651>... 

Carbon, hydrogen and possibly oxygen Resin and derivatives Natural drying oils Cellulose derivatives Alkyd resins Epoxy resins (uncured) Phenol-formaldehyde resins Polystyrene Acrylic resins Natural and synthetic rubbers Carbon monoxide Aldehydes (particularly formaldehyde, acrolein and unsaturated aldehydes) Carboxylic acids Phenols Unsaturated hydrocarbons Monomers, e.g. from polystyrene and acrylic resins... 

Carboxylic acids with multifunctional epoxides or epoxy functional monomers... 

Even the earliest reports discuss the use of components such as polymer syrups bearing carboxylic acid functionality as a minor component to improve adhesion [21]. Later, methacrylic acid was specifically added to adhesive compositions to increase the rate of cure [22]. Maleic acid (or dibasic acids capable of cyclic tautomerism) have also been reported to increase both cure rate and bond strength [23]. Maleic acid has also been reported to improve adhesion to polymeric substrates such as Nylon and epoxies [24]. Adducts of 2-hydroxyethyl methacrylate and various anhydrides (such as phthalic) have also been reported as acid-bearing monomers [25]. Organic acids have a specific role in the cure of some blocked organoboranes, as will be discussed later. 

Epoxy plastics Group of plastics composed of resins produced by reactions of epoxides or oxiranes with compounds such as amines, phenols, alcohols, carboxylic acids, and anhydrides, and unsaturated compounds. 

The synthesis of key intermediate 12, in optically active form, commences with the resolution of racemic trans-2,3-epoxybutyric acid (27), a substance readily obtained by epoxidation of crotonic acid (26) (see Scheme 5). Treatment of racemic 27 with enantio-merically pure (S)-(-)-1 -a-napthylethylamine affords a 1 1 mixture of diastereomeric ammonium salts which can be resolved by recrystallization from absolute ethanol. Acidification of the resolved diastereomeric ammonium salts with methanesulfonic acid and extraction furnishes both epoxy acid enantiomers in eantiomerically pure form. Because the optical rotation and absolute configuration of one of the antipodes was known, the identity of enantiomerically pure epoxy acid, (+)-27, with the absolute configuration required for a synthesis of erythronolide B, could be confirmed. Sequential treatment of (+)-27 with ethyl chloroformate, excess sodium boro-hydride, and 2-methoxypropene with a trace of phosphorous oxychloride affords protected intermediate 28 in an overall yield of 76%. The action of ethyl chloroformate on carboxylic acid (+)-27 affords a mixed carbonic anhydride which is subsequently reduced by sodium borohydride to a primary alcohol. Protection of the primary hydroxyl group in the form of a mixed ketal is achieved easily with 2-methoxypropene and a catalytic amount of phosphorous oxychloride. 

Functional alkoxyamines used as initiators for NMP include 283-287. The functional alkoxyamines can be formed in situ by use of a functional azo compound or peroxide. NMP has been shown to be compatible with hydroxy, epoxy, amide and tertiary amine groups in the initiator. Carboxylic acid groups can cause problems but may be tolerated in some circumstances.106... 

Besides fragmentation or rearrangement, the carboxylic acid anions, formed by an enzymatic hydrolysis, can also act as nucleophiles. Kuhn and Tamm used the asymmetric hydrolysis of meso-epoxy diester 8-28 with PLE to synthesize y-lactone... 

Shibasaki et al. have reported a new approach to a,/3-epoxy esters the epoxidation of cv. j-unsaturated carboxylic acid imidazolides with a La(OPr )3, BINOL, Ph3As=0, and TBHP system provides epoxy-peroxy-esters (41), which are generated in situ from the intermediary epoxy acid imidazolide and converted to the corresponding methyl ester (42) upon treatment with methanol (Scheme 27).134... 

The rearrangement of isopent-3-enyl epoxy esters with Cp2ZrCl2/AgC104 yields ABO esters (2,7,8-trioxabicyclo[3.2.1]octane Asymmetric Bicyclo-Octane esters), which are base-stable protecting groups for carboxylic acids [57,79,80] (Scheme 8.40). 

Another highly effect chain extender is trimellitic anhydride (TMA) which gives rise to branching of the PET structure. Note that the multifunctional epoxies (see Table 14.2) react quickly with the terminal carboxylic acid groups of PET but can also react with the film former and the silane coupling agent on glass fibre reinforcements. 

As discussed earlier in this book (Chapter 3) there are many potential chemical routes toward functionalizing nanocarbons. The most popular is the oxidation of nanocarbons, particularly for CNTs by treatment in acidic solutions (e.g. HN03/H2S04) or the oxidation of graphene to GO. These oxidation methods produce a range of chemical functionalities on the nanocarbons including hydroxyl, epoxy and carboxylic acid. 

Crosslinking of epoxy resins with carboxylic acid anhydrides is catalyzed by tertiary amines thus,if 50 mg /V,/V-dimethyl aniline are added to the initial mixture in the above example, the curing process is already complete after 1 h at 120 °C. 

By studying the nucleophilic opening of 2,3-epoxy carboxylic acid derivatives it has been found that the regioselectivity was dependent on the acid function (ester, amide, carboxylate), as well as on the nucleophile [78]. In the examples... 

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. 

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