Addition and Condensation Polymerisation

This article will highlight the difference between Addition and Condensation Polymerisation.

What is Addition Polymerisation?

The addition Polymerisation process involves the addition of two or more unsaturated monomers. In addition, the process does not involve covalent bond formation. In addition, polymers are formed by complex formation between the two reactants through associative and cooperative mechanisms. Addition polymers are thermodynamically favored to form due to their lower activation energy when compared with condensation polymers’ formation. Addition Polymerisation is the Polymerisation reaction that involves the addition of unsaturated monomer molecules at varying temperatures and pressure. During addition reactions, it is possible to add at least one unreacted monomer and a small amount of catalyst.

Functions of Addition Polymerisation:

Addition Polymerisation involves the formation of by-product products such as furan, acetaldehyde, and other light hydrocarbon products. Thus addition Polymerisation is a very wasteful process. Adding these by-products is important to prevent the formation of long-chain polymers with high onset viscosity, in contrast, condensation reaction does not produce any by-products and thus does not produce any waste.

Addition Polymerisation forms low molecular weight polymers which are thermodynamically favored in comparison to their high molecular weight counterparts when added at varying temperature and pressure. In addition, polymers tend to form a complex structure that is thermodynamically unfavorable compared to condensation polymers’ tendency to form high molecular weight products.

The molecular weight of the addition polymer is as low as 1-100,000 Mg/mol. Condensation polymers can have molecular weights in the millions of Mg/mol.

Polymers formed by addition Polymerisation tend to be soluble in solvents and possess high reactivity making them suitable for use in the pharmaceutical industry and other industrial uses involving strong solvents like benzene, toluene, etc.

Polymers form more facets than those produced by condensation reaction due to their higher reactivity and relatively higher flexibility when compared with highly crystalline condensation polymers which are very rigid, stiff, and thick.

What is Condensation Polymerisation?

Condensation Polymerisation is the Polymerisation of polymers by the addition of two or more reactive monomers or by-products at varying temperatures and pressure. The process involves the formation of covalent bonds between the reactants during Polymerisation. Condensation polymers are prepared by chemical condensation of different types of comonomers using either a catalyst or no catalyst. To perform condensation reactions, we need to add a large amount of catalyst and other reactants which are very difficult to handle as compared to condensation reaction which requires a small number of reactants and therefore very easily handled.

Functions of Condensation Polymerisation:

Condensation Polymerisation involves the formation of high molecular weight polymers which are thermodynamically favored to form due to their higher activation energy. Condensation polymers tend to form a complex structure that is thermodynamically unfavorable in comparison with addition polymers’ tendency to form low molecular weight products.

Polymers formed by condensation reaction tend to be soluble in solvents and possess low reactivity making them suitable for use in the pharmaceutical industry and other industrial uses involving weak solvents like water, ethanol, etc.

Condensation polymers form more facets than those produced by addition reaction due to their higher reactivity and relatively higher flexibility when compared with highly crystalline addition polymers which are very rigid, stiff, and thick.

Condensation polymers have a broad molecular weight distribution (MWD) of 1-100,000 Mg/mol.

Polymers formed by addition Polymerisation tend to be very slow in rate of reaction and their rate increases only when the temperature is raised. Condensation polymers’ reactivity increases as the temperature increases.

Differences between Addition and Condensation Polymerisation:

1) Polymerisation Reaction: Addition Polymerisation involves the addition of two or more reactive monomers. In addition, Polymerisation does not involve the formation of covalent bonds between the monomers through associative and cooperative mechanisms. In addition, addition reaction is also fast and easy as compared to condensation reaction which requires a large amount of catalyst, and other reactants which very difficult to handle as compared to condensation reaction which requires a small number of reactants and therefore very easily handled.

Condensation Polymerisation involves the formation of high molecular weight polymers by adding both monomers or by adding one or more comonomers with their reactive derivatives at varying temperatures and pressure. Condensation Polymerisation is a very wasteful process as it involves the formation of by-products such as furan, acetaldehyde, and other light hydrocarbon products. Adding these by-products is important to prevent the formation of long-chain polymers with high onset viscosity, in contrast, addition Polymerisation does not produce any by-products and thus does not produce any waste.

2) Addition Polymerisation forms a low molecular weight polymer that is thermodynamically favored in comparison to their high molecular weight counterparts when added at varying temperatures and pressure. In addition, polymers tend to form a complex structure that is thermodynamically unfavorable in comparison with condensation polymers’ tendency to form high molecular weight products.

3) The molecular weight of the addition polymer is as low as 1-100,000 Mg/mol. Condensation polymers can have molecular weights in the millions of Mg/mol.

4) Polymers formed by addition Polymerisation tend to be soluble in solvents and possess high reactivity making them suitable for use in the pharmaceutical industry and other industrial uses involving strong solvents like benzene, toluene, etc.

5) Polymers form more facets than those produced by condensation reaction due to their higher reactivity and relatively higher flexibility when compared with highly crystalline condensation polymers which are very rigid, stiff, and thick.

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Conclusion:

Addition polymers are thermodynamically favored to form due to their lower activation energy when added at varying temperatures and pressure. On the other hand, condensation polymers are thermodynamically unfavorable due to their higher activation energy and chain length at varying temperatures and pressure.