Cellulose acetate butyrate

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Schematic (simplified) formula presentation from the polymer chain of cellulose acetate butyrate with an acetyl residue ( marked in blue ) from acetic acid and two further acyl residues ( marked in green ), which are derived from butyric acid . The distribution of the ester functions can vary within the polymer chain.

Cellulose acetate butyrate ( CAB ) is a biopolymer based on cellulose . Like cellulose acetate and cellulose propionate, it is an ester of cellulose with aliphatic carboxylic acids . While the esterification of cellulose acetate only takes place through acetic acid , here the acetic acid content in the CAB is around a third, around two thirds represent bound butyric acid , and some of the hydroxyl groups are still free.

history

The industrially manufactured plastic cellulose acetate butyrate was developed by Kodak in 1938.

Manufacturing

It is produced by esterifying cellulose with a mixture of the anhydrides of acetic acid and butyric acid.

properties

Cellulose acetate butyrate has a relatively low density and high strength, hardness and toughness compared to cellulose acetate and cellulose propionate. It is dimensionally stable in the temperature range from −45 ° C to 115 ° C and has a high temperature and UV resistance. The water absorption is also low compared to the plastics mentioned.

The plastic is mainly used for production as dust-free granulate or fine powder, which is suitable for both extrusion and injection molding . Injection molding compound can also be reinforced by glass fibers . The color of the plastic can be covered in all colors as well as transparent or translucent . Further forms of delivery are coating powder and semi-finished products in the form of pipes, sheets, foils and profiles.

Applications

The range of applications for cellulose acetate butyrate is very wide and includes almost all areas in which plastics are used. It ranges from handle coatings (e.g. handle shells for Swiss Army Knives ) to transparent domes, toys, cable conduits, explosion-proof windows, vehicle lights, automotive accessories, contact lenses, glasses and office machines to films and packaging material. Well-known trade names are Cellidor , Tenex and Tenite .

toxicology

Cellulose acetate butyrate, like cellulose, is a biopolymer and therefore has a high level of biocompatibility; there are no known toxic properties with respect to humans.

Nowadays, CAB is mainly used in galenics and pharmaceutical research.

literature

  • P. Eyerer, P. Elsner, T. Hirth (Eds.): The plastics and their properties. 6th edition, Springer, Heidelberg 2005, pages 1474–1477, ISBN 3-540-21410-0 .

Individual evidence

  1. ^ A b Karlheinz Biederbick: Kunststoffe , Vogel-Verlag, 4th edition, 1977, p. 170, ISBN 3-8023-0010-6 .
  2. ↑ a b c d e f g polysaccharides . Springer Berlin Heidelberg, Berlin, Heidelberg 1985, ISBN 978-3-540-13931-7 , doi : 10.1007 / 978-3-642-70099-6 ( springer.com [accessed June 23, 2019]).
  3. ↑ Dieter Klemm, Brigitte Heublein, Hans-Peter Fink, Andreas Bohn: Cellulose: fascinating biopolymer and sustainable raw material . In: Angewandte Chemie . tape 117 , no. 22 , May 30, 2005, ISSN  0044-8249 , p. 3422-3458 , doi : 10.1002 / anie.200460587 ( wiley.com [accessed June 23, 2019]).
  4. ↑ Tenite ™, Manufacturer Info Eastman ( accessed May 10, 2012).
  5. ↑ a b Xiaoyun Qiu, Shuwen Hu: “Smart” Materials Based on Cellulose: A Review of the Preparations, Properties, and Applications . In: Materials . tape 6 , no. 3 , February 28, 2013, ISSN  1996-1944 , p. 738–781 , doi : 10.3390 / ma6030738 ( mdpi.com [accessed June 23, 2019]).