Interpretation:
Predict the result of the catalytic hydrogention of natural rubber and will the product obtained show syndiotactic, atactic or isotactic behaviour.
Concept introduction:
Isotactic, syndiotactic, and atactic are the stereochemical forms. The
Syndiotactic are the macromolecules in which the (-R) groups are arranged in an alternate manner along the long chain of the polymer. Gutta-percha is also an example for Syndiotactic polymer.
In atactic form, the substituents are placed in a random manner along the long chain.
The important point to note here is that the polymer obtained from the chain-growth
The catalytic hydrogenation natural rubber requires the breaking of double bond and the addition of hydrogen. The double bond of
Therefore, it breaks and hydrogen adds to it. When the hydrogen adds, then the double bonds are replaced with the single bonds. The hydrogenation of double bond releases energy therefore, known as an exothermic reaction. The heat released is called the heat of hydrogenation.
The catalyst used for the purpose of hydrogenation can be Ra-Ni (Raney-Nickel), PtO2 (Platinum oxide), Pd-C (Palladium on carbon) etc. They can be used to enhance the
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Chapter 31 Solutions
Organic Chemistry
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