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.