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The patent describes the reaction of the alkenes with excess maleic anhydride at 200 °C in an autoclave. The excess alkene is removed by distillation in vacuo, the resulting alkenyl succinic anhydride hydrolyzed with dilute sodium hydroxide solution and the disodium salt reacted with an acid to achieve an alkenebutanedioic acid.
Succinic anhydride hydrolyzes readily to give succinic acid: (CH 2 CO) 2 O + H 2 O → (CH 2 CO 2 H) 2. With alcohols (ROH), a similar reaction occurs, delivering the monoester: (CH 2 CO) 2 O + ROH → RO 2 CCH 2 CH 2 CO 2 H. Succinic anhydride is used in acylations under Friedel-Crafts conditions, as illustrated by the industrial route to the ...
Anhydrides experience even weaker resonance stabilization, since the resonance is split between two carbonyl groups, and are more reactive than esters and amides. In acid halides, there is very little resonance, so the energetic penalty for forming a tetrahedral intermediate is small.
In addition to the significantly more reactive alkenylsuccinic anhydrides (which do also hydrolyze rapidly in the presence of water) alkylated ketene dimers have begun to be preferred surface and mass sizes in the paper industry from the 1960s onwards, beginning in the 1950s. [19] Structural formula of a C 18-alkenylsuccinic anhydride (ASA)
Starch is the most common sizing agent. Cationic starch and hydrophilic agents are also applied, including alkenyl succinic anhydride (ASA) and alkyl ketene dimers (AKD). [5] Cationic starch increases strength because it binds to the anionic paper fibers. [6] The amount added is usually between ten and thirty pounds per ton.
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The condensation produces water, however, which can hydrolyze the anhydride back to the starting carboxylic acids. Thus, the formation of the anhydride via condensation is an equilibrium process. Under acid-catalyzed conditions, carboxylic acids will react with alcohols to form esters via the Fischer esterification reaction, which is also an ...
Isopropyl group Methyl group. In organic chemistry, an alkyl group is an alkane missing one hydrogen. [1] The term alkyl is intentionally unspecific to include many possible substitutions.