6. Bioplastics: 6.1 Biodegradable, biobased plastics

lactic acid is obtained from starch or sugar by fermentation using lactic acid bacteria
Polylactide is synthesized from the lactic acid
available in large quantities,
important plastic for the packaging industry
Prices for PLA have fallen in recent years (approx. 2 EUR/kg)
PLA is currently being produced in large quantities in the USA, the Netherlands and Germany/China

PHA is produced by biosynthesis of various algae and bacteria as an energy storage molecule
For this, bacterial cultures must be fed with glucose or other carbohydrate-rich nutrients
Polyhydroxybutyrate (PHB) are polyhydroxyvalerate (PHV)
and polyhydroxybutyrate-co-valerate (PHBV)
not soluble in water, UV-resistant
not resistant to acids and bases
non-toxic and biocompatible, biodegradable
relatively expensive (3-15 EUR/kg)
are used for beverage packaging, disposable items, agricultural films or bin liners

the most common biodegradable plastic
Plastics made from starch blends consist of two phases.
Hydrophobic polymer (mostly degradable polyester) and hydrophilic thermoplastic starch (25-70%)
both phases are combined during a melting process to form a waterproof starch plastic
Industrial production in Italy, Germany, Netherlands, Austria

Polyester from cellulose

esters and ethers from cellulose, which is obtained from wood, are used = cellulose acetate
in principle, it is viscose in film form (see viscose production)
as technical acetic acid and plasticizers are used in production, the product is not 100% bio-based
Film made from cellulose hydrate, also known as cellophane
In principle, the material is biodegradable, but coatings delay degradation
Used as packaging, coatings, cigarette filters
Industrial production in UK/USA, Japan, Germany, Austria