Butyric anhydride (98%), 1-Methylimidazole (1-MIM) and dimethyl sulfoxide-[d.sub.6] (DMSO-[d.sub.6], 99.5%, a solvent of lignin for NMR experiments) were purchased from Alfa Aesar.
Lignin modification was carried out with a reaction between lignin and butyric anhydride. Briefly, in a 50-mL two-headed flask, 5 g of lignin was mixed with 15 g of butyric anhydride, which was then catalyzed by 1-MIM (0.25 g).
Acid anhydrides including butyric anhydride and hexanoic anhydride were purchased from Sigma-Aldrich (St.
Butyric anhydride, hexanoic anhydride, octanoic anhydride and decanoic anhydride were added to their individual chitosan solutions in different mole ratios to the glucosamine unit of chitosan under magnetic stirring and left to react overnight.
The chemicals include anhydrides (such as acetic, butyric, phthalic, succinic, malaic, propionic, and butyric anhydride
), acid chlorides, ketene carboxylic acids, isocyanates, formaldehyde, acetaldehyde, difunctional aldehydes, chloral, phthaldehydic acid, dimethyl sulfate, alkyl chlorides, [beta]-propiolactone, acrylonitrile, and epoxides (such as ethylene, propylene, and butylene oxides, and difunctional epoxides).
Louis, MO): castor oil, glycerol (99.5%), maleic anhydride (99%), hydroquinone (99%), methanol, sodium hydroxide, acrylic acid (98%), calcium hydroxide (99+%), N, N-dimethylbenzylamine (99+%), 2-methylimidazole, styrene (99% pure), butyric anhydride (98%), tertbutyl peroxy-benzoate, and chloroform-D with 0.03%v/v of trimethylsilane (TMS).
Kraft lignin and butyric anhydride were added in a 1:2 weight ratio.
The starting material for cellulose esters is natural anhydroglucose polymer from renewable sources that is esterified using mixtures of acetic, propionic, or butyric anhydrides
to form a product with controlled ester content, hydroxyl content, and molecular weight.