can anyone please explain polymerisation?Watch
Polymerisation is the process of small molecules called monomers joining together to make large chains of molecules called polymers. Alkenes are heated and the c-c double bond is replaced with additional c-c single bonds that connect the long chain of monomers together. Polyethene is used for plastic bags as it is easy to mould, is strong and is transparent. Polypropene is strong and thick and is used to make things such as carpets.
1) Addition Polymerisation:
This is where you have identical monomers containing a C=C double bond. This C=C is broken, and replaced with C-C single bonds throughout the length of the material. Examples are polyethene, polypropene etc.
2) Condensation Polymerisation:
This is where you have two different monomers, and when they join together a small molecule is condensed (ie, forms and is given off). This small molecule is normally something like Water or Nitrogen Dioxide. The important bits of the monomers are the functional groups at the end - the stuff in the middle doesn't really matter and is often just replaced with a square or a circle etc on a diagram. The most well-known example of a condensation polymer is nylon.