Methyl tetrahydrophthalic anhydride

Resins used were two types of epoxy resins (EP) and an unsaturated polyester resin (UP) as shown in Figure 1. EP is the bis-phenol-A type resin cured with methyl-tetrahydrophthalic anhydride (MTHPA) or 1,8-p-menthandiamine (MDA). UP is the iso-phthalic type resin which has ester bonds in the main chain and is crosslinked by styrene (10). 

A survey of the extensive literature of kinetic results reported for epoxy-anhydride-tertiary amine systems is surprising. Both nth order and autocatalytic expressions have been reported for the same system. As an example, we analyze the results reported for the copolymerization of a diepoxide based on diglycidyl ether of bisphenol A (DGEBA) with methyl-tetrahydrophthalic anhydride (MTHPA), initiated by benzyldimethylamine (BDMA). 

In 2001 Uozomi et al. reported that the (3-methyl)tetrahydrophthalic anhydride rac-21 undergoes parallel kinetic resolution when treated with methanol in the presence of the hydroxy proline derivative 13e (Scheme 13.10) [17]. The resulting esters 22 and 23 were formed with up to 80% ee, albeit at chemical yields of 12% and 29%, respectively. 

Sugano reports that the area of the p transition is proportional to the impact strength 67 This result was obtained on a series of DGEBA resins cured with different amounts of methyl tetrahydrophthalic anhydride (MeTHPA) with Im as a catalyst. The area of p transition is the largest when MeTHPA/Epoxy = 0.4 (Fig. 20). 

Some low molecular weight chemicals, such as, the conventional epoxy resin hardener methyl tetrahydrophthalic anhydride that can stay as a remnant in the system, can cause immunologic contact urticaria . 

A methyl-tetrahydrophthalic anhydride (41) was diacylated to 42 with acetyl, butyryl, and valeryl anhydrides using perchloric acid. ... 

Different results are obtained for high-thermal-stability epoxies. In this case the nanocomposite shows a decrease in the onset of decomposition temperature compared to the neat polymer. Hussain et al. showed that the onset of decomposition of an amino-cured epoxy is 420°C, whereas a nanocomposite containing 5 wt% octadecylammonium montmorillonite exhibits, at the same temperature, 420°C, a weight loss of 10%. It is obvious that in this case the weight loss in the nanocomposite is not only a direct effect of volatilization of the surfactant but is attributed to the catalytic effect of onium decomposition. Camino et al. compared the effect of different organo-modified montmorillonites on the thermal stability of a DGEBA cured with methyl tetrahydrophthalic anhydride. They observed that the octadecylammonium montmorillonite nanocomposite has the lowest onset at 5 wt% loss (288°C), compared to bis(2-hydroxyethyl)ammonium montmorillonite... 

The reduction in the PHRR observed by Camino et al. in a similar DGEBA-anhydride system is considerably higher. They used methyl tetrahydrophthalic anhydride as the curing agent and 10 wt% organoclays. The resulting nanocomposites had an ordered intercalated-exfoliated structure. A reduction of 68 and 38% in the PHRR compared to neat epoxy was observed in a nanocomposite... 

Reaction of 8-amino-2,5,6,7-tetrahydro-3//-pyrido[l,2,3-de]-l, 4-benzox-azin-3-one with tetrahydrophthalic anhydride gave 100 (91EUP406993). The hydroxy group of 9-[2,2,2-trifluoro-l-hydroxy-l-(trifluoromethyl)-ethyl]-2,3-dihydro-5//-pyrido-[l, 2,3-de]-l,4-benzoxazin-5-ones was acy-lated (79GEP2854727). Treatment of 9-fluoro-10-phenyl-3-methyl-7-oxo-2,3-dihydro-7//-pyrido-[l,2,3-de]-l,4-benzoxazine-6-carboxylate with CISO3H afforded the 10-(p-chlorosulphonylphenyl) derivative, which was converted to the 10-(p-aminosulphonylphenyl) derivative with NH3 (86EUP184384). 

Reduction of 5,6,7,8-tetrahydroquinazolin-2(l//)-one with sodium boro-hydride gave 3,4,5,6,7,8-hexahydroquinazolin-2(l//)-one (87) in high yield. When this hexahydro compound was fused with nitroacetic acid a stereospecific cis addition of the elements of nitromethane occurred and the 8a-nitromethyl adduct 88 was formed in quantitative yield. The stereospecificity was deduced by converting 88 into 89 which was synthesized from ds-l-methyl-l,2,3,6-tetrahydrophthalic anhydride in several steps without affecting the known stereochemistry of the chiral centers. The related 8a-aminomethyl-3,4,4a,5,6,7,8,8a-octahydroquinazolin-2(lH)-one... 

Endomethylene tetrahydrophthalic anhydride and the methyl derivate are also claimed for imide formation with aminoethanol [209]. The reaction of the endomethylene tetrahydrophthalic anhydride with hexahydro-p-aminobenzoic acid followed by a esterification with ethylene glycol and terephthalic acid yields an unsaturated imidoester curable by Michael addition with polyamines [210]. 

Reaction of 4,5-dimethyl-tetrahydrophthalic anhydride with methyl dithiocarbazate results in formation of hydrazide (110), which is cyclized in hot sulfuric acid to the 5,2,3-benzothiadiazocin-1,6-dione (111), as shown in Scheme 18 <88MI 925-0i>. Similar cyclizations are reported to occur using 3-nitrophthalic <87MI 925-01 > and quinolinic anhydrides <87MI 925-02>. 

Cyclohexene-1,2-dicarboxylic acid. See Tetrahydrophthalic anhydride Cyclohexene, 1-methyl-4-(1-methylethenyl)-. See dl-Limonene... 

Phenylthioglycolic acid C8H8O3 Allyl 2-furoate o-Anisic acid p-Anisic acid Mandelic acid Methylparaben Methyl salicylate Phenoxyacetic acid Resorcinol acetate Tetrahydrophthalic anhydride Vanillin C8H8O3 K... 

Methyl endo-methylene-tetrahydrophthalic anhydride Methylhexahydrophthalic anhydride (MHHPA) [19438-60-9] Methyl nadic anhydride [25134-21-8]... 

Figure 10.23 The Diels-Alder reaction between isoprene (the diene) and maleic anhydride (the dienophile) to yield 4-methyl-1,2,3,6-tetrahydrophthalic anhydride...

Tetrahydrophthalic anhydride (7.775) was converted directly to c -5-amino-3-cyclohexene carboxylic acid, 7.77 by reaction with ammonia and then NaOCl. 107.14 If 7.775 is first opened, isomerized, and converted to the trans-diester (7,775), formation of the trans-anhydride is possible (7.179). This anhydride was then converted to trons-5-amino-3-cyclohexene carboxylic acid, 7.180. A related route converted 7.175 to racemic cis-methyl 2-carboxylcyclohex-4-enoate, which was resolved with cinchonidine.lO The resolved (+) or (-)-half-esters were then converted to (-)-7.77 or (+)-7.77. 

Tetrahydro-2-furylsuccinic anhydride, MA-tetrahydrofuran adduct, 203 Tetrahydro-2-methyIfuran, MA radical adduct, 203 (Tetrahydro-2-methyl-2-furyl)succinic anhydride, MA-tetrahydro-2-methylfuran adduct, 203 Tetrahydronaphthalene, MA radical adduct, 198 l-(Tetrahydronaphthyl)succinic anhydride, MA-tetrahydronaphthlene adduct, 198 1,1,2,2-Tetrahydroperfluoroalkyl fumarate, grafting on polyethylene, 462 Tetrahydrophthalic anhydride MA copolymerization, 586 preparation, 15... 

Epoxy-polyester - methyl isobutyl ketone, tetrahydrophthalic anhydride, benzo-ine (a-hydroxy-a-phenylaeetophenone), and glycol... 

Alkenylsuccinic anhydrides made from several linear alpha olefins are used in paper sizing, detergents, and other uses. Sulfosuccinic acid esters serve as surface active agents. Alkyd resins (qv) are used as surface coatings. Chlorendric anhydride [115-27-5] is used as a flame resistant component (see Flame retardants). Tetrahydrophthalic acid [88-98-2] and hexahydrophthalic anhydride [85-42-7] have specialty resin appHcations. Gas barrier films made by grafting maleic anhydride to polypropylene [25085-53-4] film are used in food packaging (qv). Poly(maleic anhydride) [24937-72-2] is used as a scale preventer and corrosion inhibitor (see Corrosion and corrosion control). Maleic anhydride forms copolymers with ethylene glycol methyl vinyl ethers which are partially esterified for biomedical and pharmaceutical uses (189) (see Pharmaceuticals). 

Crosslinking of epoxy plastics through the hydroxyl groups of the repeat unit is used for prepolymers with low epoxide group contents. The most common curing agent is phthalic anhydride although other acid anhydrides such as tetrahydrophthalic, nadic methyl, and chloroendic anhydrides are used in specialty applications ... 

Polymer networks derived fi-om the curing of epoxidized LO have also been prepared and characterized [53]. The crosslinking agents were phthalic (PA), tetrahydro phthalic (TEA), tetrahydromethyl phthalic (TMPA), hexahy-dromethyl phthalic (HMPA) and methyl endomethylene tetrahydrophthalic (MTPA) anhydrides and the reaction was catalyzed by different tertiary amines. The effect of the steric hindrance and stiffness of the hardeners was also studied. 

The half-life (x) of e-N-maleyl lysine is 11 h at pH 3.5 and 37 °C. More rapid cleavage is observed with the 2-methyl-maleyl derivative (x < 3 min at pH 3.5 and 20 °C) and the 2,2,3,3-tetrafluoro-succinyl derivative (x very low at pH 9.5 and 0°C). Cysteine binds maleic anhydride through an addition reaction. The S-succinyl derivative is quite stable. This side reaction is, however, avoided when protein derivatization is done with exo-cis-3,6-end-oxo-l,2,3,6- tetrahydrophthalic acid anhydride ... 

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