i had to do an assignment on biopolymers. here is the info. Enjoy!
1. Name the biopolymer
Biopol is the trade name of the biopolymer. This biopolymer is a polyhydroxyalkanoate (PHA) and it is a co-polymer, consisting of the monomers polyhydroxybutyrate (PHB) and polyhydroxyvalerate (PHV).
2. Name the specific enzyme or organism used to synthesise the material
Biopol is produced industrially, using the fermentation of sugars by the bacterium “Alcaligenes eutrophus” which grow in tanks with a carbon-based food source. The polymer is then separated and purified. More recently, it has been attempted to produce the biopolymer more economically by using genetic engineering techniques. Genetically engineering bacteria such as E. Coli so that it produces PHA is beneficial. Faster growth, better yields, easier recovery (accumulation of the biopolymer in the bacteria causes them to become fragile) and less waste biomass are all advantages of using genetically-engineered E. Coli. By also genetically engineering plants such as cress and potatoes, biodegradable plastics can also be produced cheaply. The plants create the biopolymer instead of storing starch. The polymers made from plants have the same structure as those produced by bacteria. The significance of these methods of production is that Biopol is produced naturally by renewable agricultural resources.
3. Describe the properties of the polymer
Biopol is stable in air and is quite stable when stored in humid conditions. Biopol is also fully biodegradable with degradation to carbon dioxide and water only occurring when Biopol is exposed to micro-organisms found naturally in soil, sewage, river bottoms, and other comparable environments. The rate of degradation depends on the thickness of the material and how much bacteria is present. Simulated landfill situations over a 19 week phase show that Biopol bottles experienced a weight loss ranging from 30% with oxygen present to 80% with no oxygen present. The fact that Biopol decomposes more speedily without oxygen is noteworthy because oxygen is not always present in large amounts in modern-day landfills.
Biopol is also insoluble in water, permeable to oxygen, UV light resistant, acid and base resistant, soluble in chlorinated hydrocarbons, and biocompatible (little chance of being rejected by the body). Biopol also has a high melting point, high tensile strength, is denser than water and is non-toxic.
4. Evaluate the use (or potential use) of the polymer
There are many potential uses for the biodegradable polymer Biopol. More uses are continually being found because of Biopol’s biocompatibility and biodegradability.
Applications for Biopol include:
• A replacement for petroleum-derived plastics because Biopol has high tensile strength, it is insoluble in water, non-toxic and biodegradable.
• Disposable products used in the food industry such as utensils, cups and plates because Biopol is strong, insoluble in water, non-toxic and biodegradable.
• Plastic wrap for packaging, coatings for paper and cardboard, moisture barrier films for hygienic products, disposable containers for shampoo and cosmetics, and disposable items such as razors, rubbish bags and disposable nappies because Biopol has high tensile strength, it is insoluble in water, non-toxic and biodegradable.
• Agricultural uses include a carrier for slow release of pesticides, herbicides or fertilisers because Biopol is biodegradable and non-toxic.
• Medical and pharmaceutical uses such as gauzes, sutures, filaments, implants, drug carriers, and coatings for drugs because Biopol is biocompatible, biodegradable and non-toxic.
• Biopol has also been used to make a bicycle helmet. The helmet was made with Biopol fibres and cellulose high performance fibres. It degraded after being buried 40 days in the soil.
Even though Biopol is at present more expensive to produce than conventional plastics, it is biodegradable, therefore allowing more effective waste management. Biopol is also made from renewable crops rather than fossil fuels. Using transgenic plants to produce Biopol is expected to lower costs so that this polymer becomes price-competitive with petroleum-based polymers.
The fact that Biopol is biodegradable is important because containers and disposable items would decompose more rapidly, therefore reducing the space occupied by landfill. Also using Biopol to produce the above products will reduce dependence on fossil fuels, thus making fossil fuels last longer. Biopol in medicine will also save more lives, due to biocompatibility and fewer allergic reactions.
Biopol is a viable, albeit more expensive alternative to current fossil fuel products. Using Biopol to make the above products reduces negative effects on the environment, as Biopol eventually degrades to only carbon-dioxide and water, instead of being present for a large amount of time like current plastic products. Future developments for the uses of Biopol will be beneficial, as landfill will be reduced and perhaps new life-saving drugs could be formed with the help of Biopol.
