Polylactide or Polylactic Acid (PLA) is a
biodegradable, thermoplastic, aliphatic polyester from lactic acid.
Lactic acid is made from dextrose by fermentation. Bacterial
fermentation is used to produce lactic acid from corn starch, cane sugar
or other sources. However, lactic acid cannot be directly polymerized
to a useful product, because each polymerization reaction generates one
molecule of water, the presence of which degrades the forming polymer
chain to the point that only very low molecular weights are observed.
Instead, lactic acid is oligomerized and then catalytically dimerized to
make the cyclic lactide monomer. Although dimerization also generates
water, it can be separated prior to polymerization. PLA of high
molecular weight is produced from the lactide monomer by ring-opening
polymerization using a catalyst. This mechanism does not generate
additional water, and hence, a wide range of molecular weights are
accessible (bM 01/2009).
Saccharins or carbohydrates | Saccharins or
carbohydrates are name for the sugar-family. Saccharins are monomer or
polymer sugar units. For example, there are known mono-, di- and
polysaccharose. à glucose is a monosaccarin. They are important for the
diet and produced biology in plants.
bioplastics MAGAZINE
Polymedia Publisher GmbH
Tel. +49 2161-664864
info@bioplasticsmagazine.com
© 2012 bioplastics MAGAZINE