1,2 and 1,4 addition

The structural unit of natural rubber, isoprene can polymerize in cis-1,4 addition. Most of us know the mechanism of simple addition reaction, which is 1,2 addition but we do not  know about1,4 addition. Here in this post we will discuss about both 1,2 and 1,4 addition. 

Addition To Alkenes

Take an alkene 1-butene, and add HBr.

Here is the mechanism

This is 1,2 addition.

What happens when we try the same reaction on butadiene?
 You get two products!

This is the same product we saw in the previous (butene) example.

Here is the mechanism

This is the conclusion of both addition

Hope this helps you.  

For more detailed explanation, visit the following website
https://www.masterorganicchemistry.com/2017/03/22/reactions-of-dienes-12-and-14-addition/

RUBBER

A polymer that is used, after processing, in a great variety of products, including electric insulation and tires. It solves industrial problems involving impact, vibration, load, corrosion, wear, abrassion and noise.

Natural Rubber by Jim Livingston on Scribd

POLYPROPYLENE

Polypropylene by Jim Livingston on Scribd

PLASTIC GRADES

Plastic Grades by Jim Livingston on Scribd

PLASTICIZERS

Plasticizers by Jim Livingston on Scribd

polyesters

Polyesters by Jim Livingston on Scribd

polycarbonates

Polycarbonate s by Jim Livingston on Scribd

POLYETHYLENE

Here is the ppt of polyethylene.

PE by Jim Livingston on Scribd