Types of Polymerization
Polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains. There are many forms of polymerization and different systems exist to categorize them.
- Condensation Polymerization
Condensation polymerization is a process by which two molecules join together, resulting loss of small molecules which is often water. The type of end product resulting from a condensation polymerization is dependent on the number of functional end groups of the monomer which can react. The most commonly known condensation polymer are proteins, fabrics such as nylon, silk or polyester.
- Addition Polymerization
Addition polymers are formed when the monomer starting materials are bonded together without the loss of any of the atoms of the monomer. Polystyrene is prepared by the addition polymerization of styrene. Polymers are generally named by placing a "poly" in front of the monomer name.
High density polyethylene (HDPE) is mostly linear and is stronger, stiffer, more heat resistant, more flexible at lower temperature and more chemical and UV resistant than los density polyethylene (LDPE). HDPE has a melting point of 130oC and is used to manufacture kayaks, toys, gasoline tanks, electronic equipment cases and food containers. The higher melting point allows items made from HDPE to be washed in a dishwasher, which can melt items made from LDPE. A special fiber made of HDPE is called Spectra. It is used to make surgical gloves because it is very resistant to cutting.
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