The invention discloses a preparation of
cellulose acetate-
butyrate, including steps of: crushing cotton
pulp paper, activating it with
organic acid for 2-24 hours at the temperature of 40-110 DEG C., charging
acid anhydride and concentrated
sulfuric acid, esterifying them at the temperature of 25-110 DEG C. for 3-24 hours; charging adequate
magnesium acetate to neutralize residual concentrated
sulfuric acid after esterification, then prcipitate and filter it in
ethanol-water solution, and obtaining the
cellulose acetate-
butyrate after scrubbing and
drying. The invention avoids using toxic solutions such as DMF, DMAC as activation solution, and uses
organic acid both as solution and reaction
reagent, so that damage to environment and
human body in production process is reduced tremendously, and processes of production, after-treatment and product separation is simple. The prepared
cellulose acetate-
butyrate can be used as
adjuvant of multiple paint, has properties of improving leveling, outdoor durability and
toughness of paint, can be applied in biodegradable plastics and films.