A maleic anhydride

More recent processes involving the oxidation of butane to a maleic anhydride intermediate, using both fixed-bed and fluidized-bed processes, have been commercialized. The maleic anhydride is subsequently hydrolyzed to maleic acid or esterified in the presence of methanol to dimethyl maleate, which can be reduced to BDO in the presence of hydrogen and catalyst. These processes are attractive due to the low cost of the butane feedstock. The method of choice to make BDO is often dictated by the local availability of the desired chemical feedstock. 

The production of moisture resistant particleboard by treatment with a maleic anhydride -glycerol mixture and using phenol formaldehyde as the matrix material has been investigated (Fujimoto etal., 1987). Boards prepared from modified wood showed considerable improvements in modulus of elasticity and internal bond strength when compared to control boards. Composites made from aspen fibres modified with SA, MA or acetic anhydride using phenol-formaldehyde (PF) or polypropylene as binder have also been studied (Clemons etal., 1992 Rowell etal., 1993b). The reaction of wood with MA was found to proceed at a slower rate than with SA. The volume increase due to modification... 

The synthesis of dithienyl photochromes containing a maleic anhydride fragment (a furan-2,5-dione fragment) as the ethene bridge was a difficult problem. Initially, vicinal dinitriles 160 and 162 were used as the starting compounds (Scheme 49). But the latter compounds give a maleic anhydride only in the cis conformations. The separation of the cis and trans isomers is an additional time-consuming laborious problem. 

An example of 2,4,6-triphenylpyrylium-3-olate (65 R = R = R = Ph, R = H) reacting as a 1,3-dipole was first provided by Suld and Price who obtained a maleic anhydride adduct (C25HigO5). Subsequently, an extensive study of the cycloadditions of this species has been published by Potts, Elliott, and Sorm. With acetylenic dipolarophiles, compound 65 (R = R = R = Ph, R = H) gives 1 1 adducts that have the general structure 74 and that isomerize to 6-benzoyl-2,4-cyclohexadienones (76) upon thermolysis. This thermal rearrangement (74 -> 76) has been interpreted in terms of an intermediate ketene 75. The 2,3-double bond of adduct 74 (R = Ph) is reduced by catalytic hydrogenation. Potential synthetic value of these cycloadducts (74) is demonstrated by the conversion of compound 74 (R = Ph) to l,2,3,4,6-pentaphenylcyclohepta-I,3,5-triene (79 R= Ph) via the alcohol 78 (Scheme 1). ... 

Dibenzofuro[4,5-c]tropone (8H-dibenzo[a,e]furo[3,4-c]cyclohepten-8-one 368, X = CO) and the corresponding thiepin-5,5-dioxide (8//-dibenzo-[6,/]furo[3,4-retro Diels-Alder route. In refluxing benzene, the intermediate (367, X = CO) can be isolated. Further routes to 368 (X = CO) by retro Diels-Alder reaction exist. The 1-methyl derivative of 368 (X = CO) has been trapped as a maleic anhydride adduct. ... 

The benzyne functions as a dienophile towards reactive diene systems. The reactivity of the 9,10-positions in anthracene is well known (Diels-Alder reaction, Section 7.6), and addition of benzyne to 9-bromoanthracene yields the interesting cage-ring alkyl halide 9-bromotriptycene (9-bromo-9,10-o-benzenoanthracene). The reaction is incomplete and some unreacted 9-bromoanthracene remains in the crude reaction products, but may be removed by virtue of its ready conversion into a maleic anhydride adduct in a further Diels-Alder-type reaction. 

Lonza S.p.A. Maleic anhydride Benzene and n-butane Fixed bed technology, aqueous or organic solvent product recovery 3 1988... 

Lonza S.p.A. Maleic anhydride Phthalic anhydride offgas Maleic anhydride recovery, dehydration and azetropic distillation 2 1987... 

Compound 87 (R = r-Bu, R = Ph, R = H) has been prepared by addition of tert-butylmagnesium chloride to 1-phenylphthalide (102) and subsequent dehydration with p-toluenesulfonic acid. It is described as a yellow oil with brilliant fluorescence under UV light, which on oxidation with sodium dichromate yields diketone 103. Compound 87 (R = /-Bu, R = Ph, R = H) with dimethyl acetylenedicarboxylategives 104(mp 128-129 C, 80%) on reduction 105 is obtained 105 is also accessible from 87 (R = <-Bu, R = Ph, R = H) and dimethyl maleate (mp 151-152°C, endo) a maleic anhydride adduct has also been described (mp 147.5-148°C, 83%). Diels-Alder adducts have been also prepared from the benzo[c]furan precursors 106 (R = CHjPh, R = H, Ph) in the presence of catalytic amounts of acid 107 (mp 141-142.5X, 70%) and 108 (mp 140-141.5°C, 49%) were obtained, which on catalytic hydrogenation (Pd/C) gave the exo isomers 109(110-1 irC) and 110(90-92°C, 125.5-127°C, dimorphism). The basis for these stereochemical assignments remains unclear, however. Compounds... 

For polypropylene barrier containers incorporating a maleic anhydride grafted polypropylene tie-layer, normally, no migration (as maleic acid) is seen with distilled water over ten days at 40 °C. 

Figure 21.14 TEM of a maleic anhydride-functionalized polymer in polyamide 66. The styrene domains are stained dark with Ru04- The maleic anhydride in the rubber phase reacts with the polyamide producing a diffuse interface and fine dispersion of the block copolymer...

The nomenclature of copolymers includes the names of the monomers separated by the interfix co-. Thus 1-25 would be poly(vinylchloride-co-vinyl acetate). The first monomer name is that of the major component, if there is one. This system applies strictly only to copolymers in which the monomers are arranged more or less randomly. If the comonomers are known to alternate, as in 1-26, the name would be poly(styrene-a//-maleic anhydride). Interfixes may be omitted when the name is frequently used, as in styrene-acrylonitrile copolymers (Section 1.5.3). 

The principles of nomenclature for copolymers are based on their structure and are given in Table 1.2, where A and B represent the names of repeating units. For example, a statistical copolymer of ethylene and propylene would be called poly(ethylene-stat-propylene), and a triblock copolymer of styrene (A) sand isoprene (B) would be called polystyrene-Z)/oeA -polyisoprene- /ocA -polystyrene. In some cases it is necessary to introduce square brackets in the nomenclature to clarify the notation. Let us see an example An alternating copolymer of styrene and maleic anhydride would be called poly[styrene-a/ (maleic anhydride)]. 

Structopendant prepolymers generally have relatively high functionality, /pp, and a low molecular weight between cross links, M. A maleic anhydride-ethylene glycol polyester with a molecular weight of 1600 would have an /pp of 11, and a backbone of 116, if fully cross-linked. 

Fig. 50. Possible mechanism by which chains with multiple reactive sites can graft to an interface. This example, which would be typical of a maleic anhydride functionalized polymer reacting on a polyamide, shows on one side end-grafted chains and on the other side of the interface, a loop structure. The effect of this loop structure on the mechanical strength of the interface is not fully clear but loops that are too short will weaken the interface...

Natural products with a maleic anhydride structure, nonadrides, tautomydn, chaetomellic anhydride and other compounds, X. Chen, Y. Zheng and Y. Shen, Chem. Rev., 2007, 107, 1777. 

As is customary for redox reactions, the yield of the useful product (maleic anhydride) rises with (n-butane) conversion, while selectivity to maleic anhydride declines with conversion. Under the conditions studied, the highest maleic anhydride yield of 30.6%, at a conversion of 57.8%, was obtained at 500 °C, using a feed composition of 1 n-Cy 15 O2 / 84 N2, a contact time of 4.9 sec, and a WHSV of 0.04/hr. Under comparable conversion conditions we obtained with the most celebrated, n-butane to maleic anhydride catalyst (VO)2P207 [16], a maleic anhydride yield of 38.5%. 

M.A.- maleic anhydride, P.A.- phthalic anhydride, Me-M.A.- methyl maleic anhydride... 

Licomont series (Clariant, Germany) is represented by Licomont AR 504, that is a maleic anhydride-modified polypropylene, density of 0.89-0.93 g/cm, acid value of 37-45 mg KOH/g. Other Licomonts in the series are lubricants. 

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