Hi,
Does anyone have recent developments for polylactic acid? The online thing I found was something about improving crystallisation rates but I have no clue what it means. Where can I find more info, and should I switch to a different biopolymer if I can't find a development?
Use these notes:
1.2.6 Use available evidence to gather and present data from secondary sources and analyse
progress in the recent development and use of a named biopolymer. This analysis should name
the specific enzyme(s) used or organism used to synthesise the material and an evaluation of
the use or potential use of the polymer produced related to its properties
Biopolymers are naturally occurring polymers found in living organisms.
BiopolThis biopolymer is called PHBV (poly-3-hydroxybutyrate-poly-3-hydroxyvalerate).
It is a co-polymer of polyhydroxybutyrate (PHB) and polyhydroxyvalerate (PHV).
The monomer of PHB is 3-hydroxybutanoic acid (common name 3-hydroxybutyric acid).
The monomer of PHV is 3-hydroxypentanoic acid (common name 3-hydroxyvaleric acid).
Production:
- This polymer is produced industrially by bacteria (Ralstonia eutrophus or Alcaligenes eutrophus) growing in tanks with a carbon-based food source, high in glucose or valeric acid.
The bacteria manufacture the PHBV which is stored in their cell walls as granules for later us as an energy source.
The polymer is then isolated and purified.
Uses in relation to properties:
- Biopol is mainly used in medical applications (e.g. surgical stitches and tissue scaffolding) as it is biocompatible and biodegradable (products decompose naturally and no surgery is needed to remove them).
The use of biopolymers in medicine will mean more lives can be saved due to biopolymer transplants and fewer allergic reactions.
Biopol is also used to make disposable items (e.g. bottles, razors and shampoo containers) as it is biodegradable and non-toxic. However, this is uncommon now, due to the high cost of production.
Recent developments:
- Recently, the gene for producing Biopol polymer strands from the Alcaligenes eutrophus bacteria was extracted and implanted into E. coli using genetic engineering techniques. E. coli bacteria are much easier to grow than other bacteria, and thus are cheaper.
Scientists have also attempted to genetically engineer plants such as cress so that they produce biodegradable plastics rather than storing starch. This results in a much cheaper process, although it is still more expensive than petrochemical polymers.
Evaluation:
- Biopol is currently much more expensive than petrochemical plastics, so research is being carried out to genetically modify bacteria to control the plastic that they form. There is a growing demand for it where biodegradability and biocompatibility are important.
It has an advantage over petroleum-based polymers of being renewable, as it is formed from a microorganism. Biodegradable polymers may eventually replace petroleum-based polymers, reducing our dependence on fossil fuels and allowing them to last longer.
Home
Help
Search
Login
