Addition Polymerization
Joe and Shelby
PolymerizationDP1-EN-C.jpg



Introduction:

Addition Polymerization is a chemical reaction in which simple molecules, called monomers, are added to one another to form long-chain molecules, called polymers without by-products. The molecules of the monomers join together, and the polymeric product is formed of repeating units, and is identical with that of the monomer. The molecular weight of the polymer is the total of the molecular weights of the monomers.


Examples:

This table shows a few examples of Monomers, becoming polymers through addition polymerization. Mono meaning one, and poly meaning many.

Monomer Name
Polymer
Name
Ethene
Polyethene
Propene
Polypropene
Vinyl Acetate
Polyvinylacetate
Styrene
Polystyrene



Ethene_polymerization.png

Reaction Mechanism:

There are many types of mechanisms involved with addition polymerization, one of the more common is the polymerization of ethene (CH2=CH2), making the product polyethene. (C2H4)n.

Step 1 (Initiation):
A peroxide molecule breaks into two reactive and free radicals. The energy is derived from heat or light.


ROOReqn.gif


Step 2:
The free radical initiator attaches to a monomer molecule, forming a new free radical, called the activated monomer. The double bond is broken on the ethylene during this step as well, this free radical is now very reactive, because they are unstable and want to be back in a stable state.



ROethyleqn.gif
Step 3 (Propagation):This is the step that creates the chain that continues on. In this phase, the activated monomer attaches to the double bond of another monomer molecule, this repeats again and again.









Chain.gif
Continuous Chain

Chain_2.gif
Equation
Step 4 (Termination):
This is the ending process to the chain, this happens when the polymer chain joins with another free radical. The two free radicals join to make a stable bond. 
Term.gif

Video Example:

http://www.youtube.com/watch?v=hbu71zsAdDU




References:


"Chemistry Tutorial : Polymers and Polymerization." AUS-e-TUTE for Astute Science Students. Web. 07 Nov. 2010. <http://www.ausetute.com.au/polymers.html>.
"Addition Polymer - Discussion and Encyclopedia Article. Who Is Addition Polymer? What Is Addition Polymer? Where Is Addition Polymer? Definition of Addition Polymer. Meaning of Addition Polymer." Welcome to Knowledgerush. Web. 09 Nov. 2010. <http://www.knowledgerush.com/kr/encyclopedia/Addition_polymer/>.
Category, By. "Addition Polymerization." About Composites – Learn about Plastic and Composite Materials. Web. 04 Nov. 2010. <http://composite.about.com/library/glossary/a/bldef-a132.htm>.
Way, By The. "Addition Polymerization." MWM - Science Modules: An Inquiry and Design-Based STEM and Materials Education Program. Web. 09 Nov. 2010. <http://www.materialsworldmodules.org/resources/polimarization/3-addition.html>
"YouTube - ADDITION POLYMERIZATION." YouTube - Broadcast Yourself. Web. 09 Nov. 2010. <http://www.youtube.com/watch?v=hbu71zsAdDU>.
"File:PolymerizationDP1-EN-C.jpg." Yu-Gi-Oh! Web. 09 Nov. 2010. <http://yugioh.wikia.com/wiki/File:PolymerizationDP1-EN-C.jpg>.