Stereochemistry in polymer molecules

In many fields of organic synthesis (such as drug development) it is necessary to control the stereochemistry (chirality) around the reaction centre. In the case of a 

If the monomers add in an alternating manner, the polymer is termed syndiotactic. Polymers without any control of the chiral addition, which is the case for normal free radical polymerisation, are termed atactic. The physical properties of polymers prepared with and without stereochemical control can be very different. For example, isotactic polypropylene is a hard crystalline material and can be used to make pipes used in domestic hot water systems, whereas the syndiotactic and atactic polymers are soft tacky materials, which are used as thickening agents for lubricating oils and as components in adhesives. 

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