Cellulose acetate butyrate (CAB) is a mixed ester

thermoplastic A thermoplastic, or thermosoftening plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling. Most thermoplastics have a high molecular weight. The polymer chains as ...

derivative of

cellulose acetate In biochemistry, cellulose acetate refers to any acetate ester of cellulose, usually cellulose diacetate. It was first prepared in 1865. A bioplastic, cellulose acetate is used as a film base in photography, as a component in some coatings, and ...

that contains both

acetate An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic, or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called ...

and butyrate functional groups. It has improved weathering resistance and lower moisture absorption compared to cellulose acetate. The exact properties of a CAB compound is determined by the composition of butyrate vs acetate functional groups. CAB is commonly used as a binder or additive in coatings. CAB is widely used for tool handles, due to its toughness and resistance to oil and gasoline. Tools with CAB handles can begin to outgas unpleasant

butyric acid Butyric acid (; from , meaning "butter"), also known under the systematic name butanoic acid, is a straight-chain alkyl carboxylic acid with the chemical formula . It is an oily, colorless liquid with an unpleasant odor. Isobutyric acid (2-met ...

odors with age, which one manufacturer combats by adding vanilla scent to the plastic. Another usage of CAB is the production of rigid gas-permeable contact lenses.

References

Thermoplastics Butyrate esters Acetate esters {{ester-stub