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i was wondering if anyone had any notes on Biopol/PHA.. (1 Viewer)
- Thread starter Enoch
- Start date
The Conquering Chemistry book has stuff on PHB (polyhydroxybutanoate).
The organism used to make the polymer is called alcaligene eutrophus. It is placed in a suitable medium where it is fed nutrients. Then after a while, you stop the supply of one nutrient to stop the organism from multiplying, such as nitrogen, and then it begins to make the polymer. Then the polymer is harvested. The organism can produce from 30- 80% of its own weight.
It has similar properties to polypropene but is biodegradable.
It's potential use is where biodegradability is a prime consideration. eg. plastic bags, disposable nappies,etc.
The organism used to make the polymer is called alcaligene eutrophus. It is placed in a suitable medium where it is fed nutrients. Then after a while, you stop the supply of one nutrient to stop the organism from multiplying, such as nitrogen, and then it begins to make the polymer. Then the polymer is harvested. The organism can produce from 30- 80% of its own weight.
It has similar properties to polypropene but is biodegradable.
It's potential use is where biodegradability is a prime consideration. eg. plastic bags, disposable nappies,etc.
Slidey
But pieces of what?
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Biopol: (polyhydroxyalkanoate)
• Thermoplastic like poly(propene)
• Co-polymer, as it consists of two monomers: polyhydroxybutyrate (PHB) and polyhydroxyvalerate (PHV)
• Produced industrially by bacteria (Alcaligenes eutrophus) when supplied with a medium rich in glucose and valeric acid
• Extraction of the plastic: breaking down the bacteria’s cell walls and separated from plant debris
• Purification: dissolving PHA in chlorinated hydrocarbon (e.g. trichloromethane), removing solid waste by centrifuging, precipitating the PHA from solution and drying the powder
Developments:
• Use of genetic engineering techniques to insert the genes from the micro organisms that make PHA naturally into E. coli bacteria
• E. coli has much faster growth, producing better yields, easier recovery and production of less waste biomass. Also, a wider range of cheaper substrates can be used to grow the bacteria
• Genetically engineering plants such as cresses and potatoes can cause them to store biodegradable plastic rather than starch
Properties and Uses:
• Insoluble in water
• Permeable to oxygen
• Resistant to UV light, acids, bases
• Biocompatible
• Thermoplastic
• High melting point
• High tensile strength
• Non-toxic
• Biodegradable: bonds within molecules may be broken down by bacteria and fungi— reducing waste
• Made from renewable resources
• Similar to polypropene: can be potentially used to replace current non-biodegradable synthetic plastics which are quickly disposed. E.g. bottles, bags, plastic containers, shampoo bottles
• Medical applications: produce non-toxic and decomposable sutures
• Carrier for slow release of insecticide, herbicides, fertiliser
Evaluation:
• Currently, the widespread use of PHA is far too expensive to be viable, since the price of petroleum derivatives are rather low
• Production is insufficient to supply demand for disposable items
• Advantage of being biodegradable and biocompatible enables for its current usage in medical applications (often no petroleum based alternative)
• However, there is potential with the decreasing supplies of crude oil and the development of transgenic plants to produce the plastic
hope that helps.. according to teacher, it needs 'trimming down'
• Thermoplastic like poly(propene)
• Co-polymer, as it consists of two monomers: polyhydroxybutyrate (PHB) and polyhydroxyvalerate (PHV)
• Produced industrially by bacteria (Alcaligenes eutrophus) when supplied with a medium rich in glucose and valeric acid
• Extraction of the plastic: breaking down the bacteria’s cell walls and separated from plant debris
• Purification: dissolving PHA in chlorinated hydrocarbon (e.g. trichloromethane), removing solid waste by centrifuging, precipitating the PHA from solution and drying the powder
Developments:
• Use of genetic engineering techniques to insert the genes from the micro organisms that make PHA naturally into E. coli bacteria
• E. coli has much faster growth, producing better yields, easier recovery and production of less waste biomass. Also, a wider range of cheaper substrates can be used to grow the bacteria
• Genetically engineering plants such as cresses and potatoes can cause them to store biodegradable plastic rather than starch
Properties and Uses:
• Insoluble in water
• Permeable to oxygen
• Resistant to UV light, acids, bases
• Biocompatible
• Thermoplastic
• High melting point
• High tensile strength
• Non-toxic
• Biodegradable: bonds within molecules may be broken down by bacteria and fungi— reducing waste
• Made from renewable resources
• Similar to polypropene: can be potentially used to replace current non-biodegradable synthetic plastics which are quickly disposed. E.g. bottles, bags, plastic containers, shampoo bottles
• Medical applications: produce non-toxic and decomposable sutures
• Carrier for slow release of insecticide, herbicides, fertiliser
Evaluation:
• Currently, the widespread use of PHA is far too expensive to be viable, since the price of petroleum derivatives are rather low
• Production is insufficient to supply demand for disposable items
• Advantage of being biodegradable and biocompatible enables for its current usage in medical applications (often no petroleum based alternative)
• However, there is potential with the decreasing supplies of crude oil and the development of transgenic plants to produce the plastic
hope that helps.. according to teacher, it needs 'trimming down'
Smuts
you wish
hi am magdy so please if you get any info. can you share it with me please bec. i have an assessgment too
am magdy? what does that mean? is that ur name?Smuts said:
anyway, the stuff i have on PHB:
produced by organism: alcaligenes eutrophus (A. eutrophus)
Development:
• Maurice Limoigne first produced PHB in 1925. PHB can be produced in a lab by feeding bacteria a diet rich in nutrients until large colonies form, and then withdrawing the glucose. The bacteria automatically start secreting PHB which provides them with an energy store.
• ICI, a British chemical company began growing large quantities of PHB with the bacterium known as Alcaligenes Eutrophus. This species can accumulate the polymer at up to 80% of its dry weight.
• In the 1980s, the three genes in Alcaligenes eutrophus needed for the production of PHB were successfully cloned and transferred into E.coli, a common bacterium which was well researched, reproduced quickly and had an easily manipulated physiology.
• Cargill Dow transported the PHB gene into corn and maize plants and allowed crops of PHB-producing plants to be grown and harvested.
Properties:
PHB has properties similar to polypropylene (which is used in the textiles industry): it is transparent, brittle, water-proof and lightweight, and would be suitable for bottles and other containers, and as a result it is widely used. Being a biopolymer, it is biodegradable; therefore it can be thrown out or buried without any environmental implications. Since PHB is non-toxic and can decompose in the body, it might also be used as medical sutures or for stabilisation of healing bones.
Evaluation:
PHB is more expensive to produce than petroleum-based polymers, which means research is slowed down. Whilst PHB wouldn’t have a market in areas where plastics should be non-biodegradable, such as piping, it would be potentially successful for use in plastic bags and containers. For research into PHB to be successful, PHB must be produced for less money than petroleum-based alternatives. Monsanto first put PHB on the shelves in the form of shampoo bottles but was unsuccessful due to the cost. Cost is still the major problem associated with the production of PHB. After being researched for over 20 years, the technology required to produce PHB is not a problem.
Impact on Society
- talk about the fact that it's biodegradable -- dogs etc won't chock and bateria and natural decomposers make sure it decomposes 100% over a short period of time
- produced from a renewable resource, as opposed to LDPE and HDPE which are produced from a non-renewable resource.
Current Research:
Cargill Dow are currently working on the biopolymer being produced by plants. This could well be the way of the future if they can produce something that is cost effective and maintain the useful properties of the compound.
Glen88
Member
Your mums a biopolymer
P
pLuvia
Guest
hahahaha your so funnyGlen88 said:
Glen88
Member
really? i thought it was quite immature of me...