Polymer

Definition?????

• A Polymer is adalah recur chain from the long atoms, formed by bonding as identic molecul that called monomer (Greek: monos = one + meros = part)

• Although polymer usually as organic compound (have C- chain), there are also many Polymerinorganic compounds.
• A material that has many molecul consist of great recurrence units, if there are increase or decrease for some units, so it will not change the characteristics

Plastic is example of Polymer. Necessary and dependence to plastic is very high and this material become unchange by other material. The elasticity of plastics used as subtitute materials like metal, wood, etc.
Even plastic which has > 10000C is prepared to subtitute aluminium for aero plane. Plastic very usefully at 1960. At that year, world necessary of plastics reach 9 million ton per year. At 2000, world necessary of plastics reach 170 million ton.

Types of Polymer

1. Based On Bond

• Polymer Adition

          Formed by molecules that content double boding.

• Polymer Condensation

         Formed by molecules that content two functional groups in both of side main chains.

2. Based On Types of Molecular Composition

• Homopolymers :

           Polymer that formed by one type of monomer.

• Copolymers:

           Polymer thet formed by some types of monomer.

3. Based On the Characteristic to Temperature

• Termosetting:

Thermostable but can not be formed again with heating. Termosetting is polymer that has cross bonding and only can be heated once time at its production. When we heat it again, polymer will crack or broken. Example: Bekelit, Melamin, and Teflon

• Termoplastik

Soften if it be heated and harden at cool. Termoplastic is polymer that has cross bonding and can be heated again and again. If We heate it again, so it will melt and harden at cool. Example: PVC, Polietilen, and Polipropena