BIO-PLASTIC - RAHUL YADAV, PREETI YADAV, V C BRIAN (smallest ebook reader .txt) 📗
- Author: RAHUL YADAV, PREETI YADAV, V C BRIAN
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Bioplastic
INTRODUCTION
From recent past, the world is becoming cognizant about the hazardous effect of plastic bags on the environment. To support this, researchers have come up with natural option of Bioplastics. Plastics are being used all over the world. Right from drinking cups to parts for automobiles. Plastics are extremely important to the job market as well as for packaging throughout the world. Since plastics are involved with peoples everyday lives. Therefore production of biodegradable plastics to make plastics more compatible with environment has become necessary.
Option of Bioplastics focus on performance and price to become viable packaging alternatives in future. It is better than the alternate bio fuel which is adopted in partial manner mainly in U.S.A., and is based on the corn crops in order to utilize excess land and food products and same can be utilized for the alternate plastic instead of wasting it. Currently, the bioplastics industry is in its infancy and, as a result, does not require a significant proportion of land for feedstock supply. Approximately 2.5 kg of maize produced on 2.5 square metres of land is required to produce 1 kg of PLA. In the USA around 36 million hectares of maize is grown annually and around 17 thousand hectares is required to produce 70 thousand tonnes of PLA. This land use equates to 0.1% of the total US maize land area. In UK the most likely crop feedstock for bioplastic manufacture is wheat. A plant producing 132,000 tonnes of PLA per annum would only require a small percentage of the wheat produced in the UK. This slight increase in demand could be met through use of some of our exported wheat, through improved crop yields and more efficient use of farmland. Considering this data we can predict that with improved crop yields and efficient use of farming we can meet the demand of crops used in the manufacturing of bioplastics without any diversion of land and on food availability. It is also safe in manifolds than conventional plastic because bioplastics are very much safe, and they contain no toxins at all. With traditional plastics harmful chemicals and by-products can be released during the breakdown and decay period, but this is not the case with plastic that is biodegradable. This all natural plastic breaks down harmlessly and is absorbed back into the earth. There is no chemical leaching into rain water or the ground to threaten the health and safety of people or animals nearby. It biodegrade and break down into carbon dioxide, water, biomass at the same rate as cellulose (paper). Bioplastic when disintegrate is indistinguishable in the compost and is not visible. Its biodegradation does not produce any eco-toxic material and the compost can also support plant growth. Biodegradable Plastic is plastic which degrades from the action of naturally occurring microorganism, such as bacteria, fungi etc. over a period of time. Considering the above faces of its productivity and properties of non-toxicity and biodegradability about 90% within one year depending upon the environmental conditions, this can also be used as food for fishes and other marine species.
Bioplastics packaging is being slowly adopted by food service companies and grocery store delis for use as film for sandwich wraps or for clamshell packaging for fresh products such as vegetables, fruits, salads, pasta or bakery goods. In view of this it becomes important to find durable plastic substitutes especially in short- term packaging and disposable applications. The continuously growing concern of the public and government for the problems related to plastic has stimulated research interest in bioplastics as alternative to conventional plastics; so, bioplastic packaging has a great potential in a country like ours where we have land, water and energy resources and we cannot rely on landfill or recycling of packaging wastes particularly when the non- biodegradable packaging materials are becoming a visible nuisance and eyesore in big cities. It seems, in the age where sustainability is one of the biggest issues facing the packaging and bulk packaging industry, its application will spread like wildfire.
Bio-Plastics are not a single class of polymers but rather a family of products which can vary considerably.
Bio-Plastics consist of
– Biobased plastics, based on renewable resources
– Biodegradable polymers, which meet all criteria of scientifically recognized norms for biodegradability and compostability.
From recent past, the world is becoming cognizant about the hazardous effect of plastic bags on the environment. To support this, researchers have come up with natural option of Bioplastics. Plastics are being used all over the world. Right from drinking cups to parts for automobiles. Plastics are extremely important to the job market as well as for packaging throughout the world. Since plastics are involved with peoples everyday lives. Therefore production of biodegradable plastics to make plastics more compatible with environment has become necessary.
Bio-Plastics are not a single class of polymers but rather a family of products which can vary considerably.
Bio-Plastics consist of
– Biobased plastics, based on renewable resources
– Biodegradable polymers, which meet all criteria of scientifically recognized norms for biodegradability and compostability.
From recent past, the world is becoming cognizant about the hazardous effect of plastic bags on the environment. To support this, researchers have come up with natural option of Bioplastics. Plastics are being used all over the world. Right from drinking cups to parts for automobiles. Plastics are extremely important to the job market as well as for packaging throughout the world. Since plastics are involved with peoples everyday lives. Therefore production of biodegradable plastics to make plastics more compatible with environment has become necessary.
What are bio plastics?
When someone hears the word plastics, he or she usually automatically thinks of a kind of matter made from oil that can be used in making almost anything. If the person was asked whether or not it is good for the enviroment, the answer would probably be negative. But that is not necessarily the case. There are other ways of making plastics which are far more friendly to the environment. The main protagonists of one of these processes are bacteria. Plastics created this way are called bioplastics. They are one of the most perspective materials for future mankind.
How does it work?
In a way, these bacteria act similarly to humans. They want food and if they are getting a lot of it, they start to store it in their bodies as a reserve for a rainy day. As it happens, this reserve is also a material with physical and chemical properties similar to our everyday plastics. All we need to do then is just separate this material from the rest of the body and we are good to go. Basically, we just feed our bacteria and they will do most of the work for us. What do we feed them with then? Luckily for us, they are not picky and accept almost anything liquid with carbon in it. One of the examples would be waste oil which is used abundantly because of its incredibly cheap price. We let the bacteria live on their own, only regulate the amounts of food, oxygen and other necessities they are getting to make them produce as much plastic as possible. After some time, we are ready to collect the results.
Now another question arises. How do we get the plastic out of the body? First thing we must do is separate the cells from the medium in which they lived. We achieve that by centrifuging it. This isolates the liquid part – medium – from the solid part – cells. When we are done with that, we probably want to know how much plastic stored there really is. There are two main methods of gaining this information. The first one is based on the material’s ability to absorb light cast inside of a special machine. The second one, which is used the most, is very sophisticated and hard to catch the grasp of without diving too deep into the problem. We basically change the state of the plastic to gas and run it through a big expensive machine which then tells us what we want to know – what components the compound consists of and what are their respective masses.
All that remains is getting the desired material out of its shell. This can be done by either dissolving the shell and getting the material in a solid state or doing exactly the opposite – dissolving the material and then breaking the shell. Both have their pros and cons, the first mentioned being generally somewhat faster while using the latter brings better purity of the plastic.
What is the point of all of this?
All things set aside, why would we go through this horrendous time-consuming process when we can just continue synthesizing our materials from oil? There is a number of reasons. Oil is not a renewable source of energy and when we run out of it, not only we will have to deal with the lack of fuel for our cars and other vehicles, but we would also be unable to make materials that are essential for our everyday lives. Pressing this research forward reduces our reliance on oil and thus gives us more options for the future.
Another advantage that bioplastics hold over their synthetic counterparts is that they fall apart in nature far more quickly. This means that they do not pose a problem to our environment and as such present a nifty alternative to wrapping and other nonecological waste-producing materials.
Last but not least, they can be used in medicine, namely in tissue engineering. That means using external factors to improve or replace certain biological functions. An example could be a heart valve made of bioplastics to ensure no harm would come to the body.
If it is so great, why are we not using it everywhere?
As it often is, the biggest problem here is the money. Or more precisely, the lack of it. Major investors have not yet fully committed to this field of industry because it is simply not worth it. Making the same amount of bioplastic is about ten times more expensive than that of an oil-made synthetic. However, this gap is slowly shrinking and it is only a matter of time before the much awaited breakthrough finally comes. Decreasing this price was also the main goal of the experimental part of this work.
BIOPLASTICS
Bioplastics are a form of plastic derived from renewable biomass source, such as vegetable oil, corn-starch, potato-starch or microbia, rather than fossil-fuel plastics which are derived from petroleum.
History: - Bioplastics are not new, in the 1850s, a British chemist created plastics from cellulose, a derivative of wood pulp. Later in the early 20th century, Henry ford experimented with soy-based plastics in his automobiles. After that, biodegradable plastics began being sparking interest during the oil-crisis in seventies. The 1980's brought items such as biodegradable films, sheets and mold-forming materials. As prices of petroleum products are increasing day by day and therefore the need of bioplastic appeared and research started in this context.
Composition: - Bioplastics can be made from many different sources and materials. They are produced from renewable biomass sources, such as vegetable oil, corn-starch, potato-starch or microbiota, a number of fibers including those obtained from pineapple and henequen leaves and banana stems. Corn is the primary source of starch for bioplastics, although more recent global research is evaluating the potential use in bioplastics for starches from potato, wheat, rice, barley, oat and soy-sources.
Also, bioplastics can be made using bacterial micro-organisms or natural fibers such as jute, hemp & Kenaf. Sometimes various nanometer-sized particles especially carbohydrate chains called polysaccharides or other biopolymers that don't dissolve in water, with clay are added to add certain properties like, low water- vapour and gas permeability, increased shelf-life with better strength. But there is a need to identify the other suitable plants available for this specific purpose.
Polylactic acids (PLA)
Similar to regular plastic
Polyhydroxyalkanoic acids (PHAs)
Aliphatic polyester that
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