A Short Note on Polymerization

There are  different polymers available like bakelite, PVC, and protein. All of them have specific differences in their physical properties and appearance. The polymerization process and the monomers in the composition affect this condition. 

This process deals with converting monomers with low molecular weight to polymers with higher molecular weight. Polymers are easier to create long-lasting solutions like adhesives, coatings, rubber, and plastic due to their high plasticity, elasticity, film-forming, and fibre-forming. 

Here, you will learn more about this process. 

What is Polymerization?

The chemical reaction of polymerization generally deals with the formation of polymers. The organic monomers react within a solution containing the necessary particles to get the coating. During the procedure, each monomer loses some of the existing chemical groups. Plus, the polymers can notice a different reactivity level and chemical properties than the original monomer. 

The process of polymerization is not complex. However, the sequence of monomers combining to form polymers can vary for different solutions. Thus, the description of the procedure can differ.

In the matter of what are polymers and their formation, there are varying reactive mechanisms with different levels of complexity that affect the process. This occurs because of the functional groups that exist within the reacting compounds.

Type of Polymers 

Different types of polymers are available. 

Synthetic Polymers

The following are the types of synthetic polymers. 

• Thermoplastics- This mainly relates to plastic products. They have a linear structure and the monomers that form the polymer notice some cross-linking. It is possible to heat these objects and then reform the structure. This comes with two variations: Semi-crystalline, which can get ordered, or amorphous with no clear, ordered structure. Fibres like polyester and nylon fall under this variation of synthetic polymer classification. 
• Thermostats- This type of polymer composition is very cross-linked, giving it a rigid structure. These components tend to degrade when heat is applied to the structure. A typical example of it is resin.
• Elastomers- Polymers of this type are cross-linked but to a moderate level. So, the object holds a noticeable elasticity. After getting stretched, they quickly get back to the original structure they hold. An example here is rubber.  
• Dendrimers- These polymers are widely branched at regular intervals. 

Biopolymers 

Here are the different types of biopolymers that are available for use. They are naturally formed in the body of living organisms. 

• Nucleic acids- The DNA or RNA structure have a biopolymer structure. 
• Polypeptides- These heteropolymers are the types of proteins with bound amino acids.
• Polysaccharides- Sugars are also a form of biopolymer. 
• polysaccharides—sugars

Polymerization- Different Types of Processes 

Polymers are forms of macromolecules that occur when multiple smaller molecules called monomers link together. There are two specific types of approaches or synthesis noticeable here. They include:

• Addition-based or chain-growth polymerization 
• Condensation-based or step-growth polymerization 

The primary difference between the two synthesis processes is the type and structure of the initial monomer units. Plus, it also depends on the conversion extent and how it relates to the molecular size of the polymer. 

Chain growth polymerization 

Chain growth or addition type of polymerization is a notable process in which monomers change into polymers. After an additional reaction happens, the additional polymers originate. Based on the monomer type, the adjoined monomers create a branch-like or linear polymer structure while they attach. 

The rearrangement of the monomers creates a new type of structure with no molecule or atom loss. There are four specific types under this process. 

• Cationic polymerization- A cation in the equation creates a chain reaction. Then, the existing monomers join together to form a long chain due to the reaction, which turns into a polymer. 
• Free radical polymerization- Different atoms attach while a free electron is present inside the valence shells, also called free radicals. That results in the growth of an Addition Polymer. The free radicals attach to a successive chain structure. 
• Coordinative polymerization- The process here occurs due to the application of catalysts that control the polymerization of free radicals. Common choices of catalysts are transition metal complexes and salts. 
• Anionic vinyl polymerization occurs when some of the polymers react with another electronegative group holding a high charge. This causes a chain reaction and results in the polymerization process.

Step growth polymerization 

Another name for step-growth polymerization is condensation polymerization. The monomer molecules react and create a bond, which takes the place of other molecules. The polymer molecules occur after the reaction, and one example of it is the water molecule. 

The quality and structure of the created polymer depend on what type of monomer the condensation polymerization process took place with. To note, some monomers hold a single reactive group. They possess a low molecular weight. 

If the monomers contain two reactive groups, they form linear polymers with more weight. Additionally, monomers that hold over two reactive end groups create a three-dimensional polymer network. 

Notable examples of this process are nylon and polyester (synthetic type) or carbohydrates and proteins (biological type). 

Conclusion 

Polymerization is a crucial process that results in the creation of different natural, synthetic, or semi-synthetic polymers. They occur by combining different types of monomers into one long continuous chain. 

Converting monomers into the polymer chain differs for multiple types of monomers and gives them different structures and properties. There are further distinctions in the process under the two polymerization process types, i.e., step-growth and chain growth-based polymerization. They form different polymers, so knowing the techniques first is essential.