• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Plastics and Polymers

Extracts from this document...


´╗┐Plastics and Polymers Polymers were first made in the early twentieth century and were known as ?plastics?. Polymers are constructed from much smaller molecules (monomers) that are joined together to form long chains (polymers). The economy and many industrial companies rely on polymers as a vital resource. An advantage of using polymers over natural materials is that polymers can be manufactured very specifically with varying degrees of stiffness, density, heat resistance and electrical conductivity. The study of natural polymers has also led to great advances in medicine and nutrition. Polymers have a great many uses: sheets and films, adhesives, paints and inks and also synthetic fibres and yarns. A very common polymer used widely in modern life is polyethylene (the simplest polymer). When it?s made into bags for supermarkets and other uses, it?s typically flexible and transparent. Its monomer (a single unit that is repeated) is Ethene (C2H4). It can be polymerised into polyethylene that generally contains around 105 Ethene monomers within its structure. The diagram shows the polymerisation of ethane into polyethene/polyethylene. ...read more.


4. Cross Linking ? If polymer chains are linked together by covalent bonds throughout the structure, the polymer is harder and has a higher melting point. The monomers that are required to join together to make the polymer will not usually react with each other under standard conditions (i.e. room temperature and pressure) as they?re too stable. Condensation and addition polymerisation are two methods of polymerising monomers. Condensation polymerisation involves making an extra product, usually water in addition to the required polymer. A common biological condensation reaction is the formation of cellulose from glucose molecules. When two glucose molecules react, a hydroxyl group from each molecule ?condense? to a water molecule, leaving an oxygen atom to link the two monomers together. This is repeated throughout a very large chain of monomers to create the polymer: cellulose. Esters can also be polymerised to create polyesters. These chains are made into fibres and then woven together to create many types of clothing. Polyester fabrics and fibres are very strong and are extremely durable (resistant to most chemicals, stretching and abrasion). ...read more.


Kevlar is formed from benzene-1,4-diamine and benzene-1,4-dicarboxylic acid. Today, with a general opinion that global warming/climate change is being caused by humans, there is more focus than ever on renewable resources, especially in the plastics industry. There are many degradable polymers such as poly(lactic acid) which is used for waste sacks, which when put into a landfill site, will biodegrade. When a polymer is degradable, microorganisms break it down into a mixture of methane and other gases. Some polymers are photodegradable which means the reaction is catalysed by sunlight (UV radiation). Photodegradable polymers break up into small pieces that then do not biodegrade. However this is better than a completely non-biodegradable polymer. Polymers can also be hydrolysed by ?adding? a molecule of water at the ester or amide group to split the polymer. An increasing number of polymers can now be recycled. This reduces disposal problems and the amount of crude oil used to make new products. However, different polymers still need to be collected and separated before they can be recycled, which can prove time consuming and expensive. If incinerated, the polymers can produce toxic gases upon being burnt. For example, poly(vinyl chloride) produces HCl(g). ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Physical Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Physical Chemistry essays

  1. Marked by a teacher

    Revision Notes. Substances Manufactured for use in Industries. Chemicals, alloys and polymers.

    5 star(s)

    Manufacture of electrolytes in dry cells (d) Manufacture of cleaning agents such as washing powder and detergents (e) Manufacture of explosives such as trinitrotoluene (TNT) (f) Manufacture of dyes Properties of Ammonia Properties of ammonia are summarised as follows: Properties of ammonia Manufacture of Ammonia 1.

  2. Electrochemistry - Inventing Better Batteries

    Hypothesis Two (A) 1. Place two beakers side by side, filling them up half way with MgSO4 0.1M and CuSO4 0.1M. 2. Place the metals in their respective salts (sulfate solutions) 3. Connect the wires to each metal and plug the ends into the ammeter/voltmeter.

  1. Science at Work Research . Dulux Paints, a Hospital, a leisure centre and a ...

    The act provides a critical interface with the law of European Union on workplace health and safety. How is the H&S act used in Dulux? The health and safety act will be used in Dulux to make sure that paint is not left on the floor and so that the company is a safe environment to work in.

  2. Investigating how concentration affects rate of reaction

    This was exactly as I had predicted in my aim. I did not encounter any anomalous results whilst investigating this variable and so can be sure that these results are accurate. I carried out five repeats for each concentration for each variable, ensuring that I had accurate and reliable results.

  1. Polymers. Polymer means many monomers. Sometimes polymers are also known as macromolecules or large-sized ...

    Here are some examples: Each of these monomer molecules seems very different, but they do have some common features. Actually, these monomers have two distinctive features: carbon-carbon double bonds and side groups The highlighted areas show the side groups on these monomer molecules.

  2. Alkaloids are the most diverse group of secondary metabolites and over 5000 compounds are ...

    For example, the structure of the alkaloid dauricine was established by reductive cleavage of O-methyl-dauricine. Modern era: During the last 30 years, structure elucidation has benn facilitated by the use of mass spectroscopy, and 1H and 13C NMR techniques. It is now possible to determine the structure in days with a few milligrams or less of pure compound.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work