Biopol is a member of a family of environmentally friendly performance plastics made from renewable resources. Commonly called PHAs, they can be processed into molded goods, fiber, and film, are biodegradable, and are useful in numerous applications.

Photo: thinkquest.org  

PHAs can also be supplied as water-based latex products useful as water resistant coatings. Metabolix is now producing PHAs by microbial conversion of natural sugars and oils, and is developing ways to produce them directly in plant crops. Biopol is very likely to come up on your A2 graphics exam!
source: plastics.inwiki.org

In 1996 Monsanto (who sold PHB under the trade name Biopol) bought all patents for making the polymer from ICI/Zeneca. However, Monsanto’s rights to Biopol were sold to the American company Metabolix in 200 and Monsanto’s fermenters producing PHB from bacteria were closed down at the start of 2004. The focus is now on producing PHB from plants instead of bacteria. But now with so much media attention on GM crops, there has been little news of Monsanto’s plans for PHB.

In June 2005, a US company, Metabolix, received the “Presidential Green Chemistry Challenge Award” for their development and commercialisation of a cost-effective method for manufacturing PHAs in general, including PHB.

Properties of PHB

• Water insoluble and relatively resistant to hydrolytic degradation. This differentiates PHB from most other currently available biodegradable plastics, which are either water soluble or moisture sensitive.
• Good oxygen permeability.
• Good ultra-violet resistance but poor resistance to acids and bases.
• Soluble in chloroform and other chlorinated hydrocarbons.
• Biocompatible and hence is suitable for medical applications.
• Melting point 175°C., and glass transition temperature 15°C.
• Tensile strength 40 MPa, close to that of polypropylene.
• Sinks in water (while polypropylene floats), facilitating its anaerobic biodegradation in sediments.
  Nontoxic.