How are polymers made from monomers

I know that monomers are alkenes, and that the carbon carbon double bond breaks to join with other molecules to form a polymer.... however, HOW DO YOU POLYMERISE A MONOMER?!! IS IT NATURAL? DO YOU DO A CATALYTIC PROCESS? HOW DOES IT HAPPEN? 10 POINTS BEST ANSWER!

THANK YOU!

There are many methods to produce polymers from monomers. The one you've mentioned is addition polymerisation, which is the most common. It is a chain reaction which generally happens in three stages. The first, initiation, involves splitting an initiator such as hydrogen peroxide into two free radicals. Then, during propagation, one of the radicals attacks an alkene molecule and this forms an 'activated monomer' which goes on to attack another alkene molecule, forming a new free radical which can attack another alkene molecule and so on. Eventually the reaction must end through termination. This is where two free radicals react with each other to produce the final polymer

You have described addition polymerization with monomers which are alkenes, high temperatures and a initiator needs to be used which is usually a peroxide. Another type of polymerization is condensation polymerization, also known as addition elimination. It involves monomers adding to form a polymer and a small molecule being eliminated ( usually water or HCL), two examples of this are polyesters and poly amides.

Alkenes are also called Olefins. and are very reactive. with the halogens, Zn , and many acids like
H2SO4. Oil refiners use catylsts to make long chained moleules