what are biodegradable plastics?suggest the sites to get more info. manufacture,usesabout it?

Question

manufacture,uses,disposal etc.

Answer 1

many of them are actually worse for the environment, becuase they are still plastic, but they contain some other things, like starch that breakdown, leaving a bunch of loose plastic

some of them are really good, made from things like soybeans and degrade into the environment

however, when you put something in a landfill, it just sits there and pretty much never degrades, no matter what it is, so the whole thing is kind of a bunch of bull

Answer 2

Biodegradeable plastics are those polymers which can be degraded by bacteria. They do not pose a danger to the environment and do not cause pollution. They can be discarded safely. Synthesis of bio-degradable plastics is an emerging field of Polymer Chemistry and Chemistry.
examples are- poly(hydroxy butyrate-co-beta hydroxy valerate), natural polymers like cellulose, lignin, starch, rosin, shellac, proteins.
You can refer the following books:
1. Gowarikar, V.R; Polymer Science; John Wiley; 2005
2. Brydson; Plastic Materials; John-Wiley interscience; 2005.
or any other book on polymer/ plastic science.

Answer 3

Biodegradable Plastics

Summary : Plastics have become an important part of modern life and are used in different sectors of applications like packaging, building materials, consumer products and much more. Each year about 100 million tons of plastics are produced worldwide.

Demand for plastics in India reached about 4.3 million tons in the year 2001-02 and would increase to about 8 million tons in the year 2006-07. Currently, however, the per capita consumption of plastics in India is only about 3 kg compared to 30-40 kg in the developed countries. The present market in India is of about Rs. 25,000 crore.

Hazards of Plastics: Most of today's plastics and synthetic polymers are produced from petrochemicals. As conventional plastics are persistent in the environment, improperly disposed plastic materials are a significant source of environmental pollution, potentially harming life. The plastic sheets or bags do not allow water and air to go into earth which causes reduction in fertility status of soil, preventing degradation of other normal substances, depletion of underground water source and danger to animal life. In the seas too, plastic rubbish - from ropes and nets to the plastic bands from beer packs -choke and entangle the marine mammals.

Bio plastics are biodegradable plastics, whose components are derived from renewable raw materials. These plastics can be made from abundant agricultural/animal resources like cellulose, starch, collagen, casein, soy protein polyesters are triglycerides. Large-scale use of these would help in preserving non-renewable resources like petroleum, natural gas and coal and contribute to the problems of waste management. Biodegradable plastics degrade over a period of time if exposed to sun and air.

Though the demand for biodegradable plastics is increasing, acceptance of biodegradable polymers is likely to depend on factors like

Customer response to costs;
Possible legislation by governments; and
The achievement of total biodegradability.

Immediate application areas identified in India for biodegradable plastics are Agricultural Mulch, Surgical Implants, Industrial Packaging, Wrapping, Milk Sachets, Foodservice, Personal Care, Pharmaceuticals, Medical Devices, Recreational, etc.

TIFAC report on biodegradable plastics highlights the Indian efforts in this direction, as well as activities at some of the major centres of development in USA/Canada, Germany, Scandinavian countries and Japan. This report also gives brief details of biodegradable plastic technology developed by University of Nebraska, Chronopol, Inc., EPI Environmental Products, Inc., Isolyser Company, Inc., Solpax Limited, Novamont, Federal Cartidge Company and a few other companies. In addition, the reader would find lists of worldwide manufacturers of polymers and additives, international organizations and standards for testing biodegradability.

Table of Contents : Executive summary; Few statistical figures on production of polymers in India, world and India's share; Steps taken by various State Governments & Government of India in this line; Plastics & biodegradable plastics; Plastics and environment; Global & Indian scenario; Total Production and Demand Scenario of Biodegradable Plastics in India & Worldwide; Preferred options for Indian industry; Application areas for biodegradable plastics; Details on the technology development in India by various R & D centres; Industries engaged in manufacturing biodegradable plastics/additives; Problems faced by the existing Indian biodegradable plastic product manufacturers; Worldwide manufacturers of polymers/additives; problems faced by the existing Indian biodegradable plastic product manufacturers; Worldwide manufacturers of polymers/additives; International organisations & standards for testing biodegradability; Societies & organisations working in this line globally; Products specifications for the range of biodegradable plastics & material classes; Various technological routes adopted for manufacturing biodegradable plastics; Cost comparison of various polymers/additives; Patents; Indian Market; Survey findings; Feed back of different sectors; Technology providers and suggested options for India; List of associated institutions/agencies which can be engaged for further developmental work; Useful information - News articles/publications giving information on plastics & biodegradable plastics, technologies, Norms & impositions in India - Extracts from Hindu, Tuesday, august 21, 2001 'management of plastic waste' - comparison of physical properties - Tensile strength test on a typical degradable polyethylene and polypropylene of M/s. Willo ridge plastics, inc Enlanger, KY USA.- rate of biodegradable of various materials; Specifications of "re-source-Bag TM", a totally biodegradable product, available from biocorp, USA; Annexures
Background
Biodegradable plastics are plastics that are produced from renewable resources and break down easily in the environment. Biodegradable plastics are becoming more popular because of their unique quality to break down a lot faster than traditional plastics. Biodegradable plastics have become increasingly common in the every day lives of many people and are replacing some of the traditional plastic products that have been known for so long. The reason why many biodegradable plastics can be broken down relatively easily is because they are being made of renewable resources. These resources can be broken down with the everyday activities of living organisms in the natural environment. When these biodegradable plastics are broken down by the microorganisms, they are decomposing into H2O and CO2. [1]Traditional plastics cannot be broken down easily because of their longer chains of polymers that are tightly bonded.

[edit]Materials which biodegradable plastics are made of
Biodegradable plastics, as mentioned above, are being made by renewable resources. One of these resources is soy concentrate. The way biodegradable plastics are made from soy concentrate involves the compression of the concentrate. This concentrate is then tested at different temperatures to determine the sturdiest, yet biodegradable, product.[2] Since this product is made from raw material, it is easily broken down in a composting facility.

Another common product that biodegradable plastics can be made of is starch. Starch is developed through the photosynthesis of plants; it is a substance of granular carbohydrates. Starch is water soluble, but it can be modified into a less soluble polymer by microorganisms. These microorganisms can then transform the starch into lactic acid. Once this is done, the lactic acid is chemically treated so it links into polymer chains.[3] These chains, however, are not as tightly bonded as the traditional plastic which leads to easier breakdown of this substance.

Bacteria can also be used in the production of biodegradable plastics. Bacteria can produce granules of plastic called polyhydroxyalkanoate (PHA) inside their cells. These bacteria, with the genes produced, can be put into the corn, and the corn consequently manufactures plastic within its cells. (Image [4])

Bacteria can also be grown in cultures and the plastic growing in the bacteria can be harvested.[5]

It is also important to notice how gelatin and casein contribute to biodegradable plastics. Gelatin is a form of collagen that can be used in sausage casings and drug capsules. Obviously each of these plastics can be broken down easily in the human body. Another form of biodegradable plastic is Casein, which is made up of natural protein. Casein is made from organic substances such as the skimming of cow’s milk, corn, and vegetable products. Casein can be used in adhesives, binders and protective coatings.

Lastly, since cellulose makes up to 40% of all organic matter, it to has been used in the production of biodegradable plastics.[6] Parkesine was the first biodegradable plastic that was made with cellulose. It consisted of cellulose, nitric acid, and a solvent. This product appeared to be much like ivory and could be molded when heated.[7] Parkesine was only the start of the production of biodegradable plastics made with cellulose.

[edit]Uses of biodegradable plastics
With the recent advancements within the industry, there are biodegradable plastics that replace virtually all traditional plastic products. Today there are biodegradable grocery bags, food packaging, disposable razors, toothbrushes, cups, suture threads, bone fixation, and many other things that are made from these environmentally friendly products.

Scientists are actually researching methods to use plastics to help people make new bones. Biodegradable plastics are being designed and implemented to be growth-inducing properties in humans. An example of these biodegradable plastics used in the human body is shown here.(Image [8])

[edit]Why people should use biodegradable plastics
Although these biodegradable plastics are anywhere from 2 to 10 times more expensive than the traditional plastics, a fact that must be considered is that it takes traditional plastics a lot longer to break down. As soon as biodegradable plastics come into contact with microorganisms, they will begin to break down. The microorganisms break down the biodegradable plastics into soil. Biodegradable plastics are actually able to break down 60%-90% in just 60-180 days in a compost setting.[9] The items in the table are traditional plastics when scattered around as litter.[10]

Plastic coated milk cartons 5 years
Plastic bags 10-20 years
Plastic 6-pack holder rings 450 years
Plastic bottles Forever

Considering everything that has been presented about biodegradable plastics, it is up to everyone on their own whether they want to contribute to the safety of the environment or save some money.

Since biodegradable plastics are becoming more familiar in this world, it is most interesting to discover the process by which they are made and what they are made of. Ultimately, the chemical structure of the materials that make up biodegradable plastics is what makes them as environmentally friendly as they are.