What is the Difference Between Atactic Isotactic and Syndiotactic Polymer?

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The main difference between atactic, isotactic, and syndiotactic polymers lies in the arrangement of their side chains along the backbone chain. The three types of polymers according to their tacticity are:

  1. Atactic Polymers: In atactic polymers, the side chains are arranged randomly along the backbone chain. These polymers tend to form amorphous and soft materials.
  2. Isotactic Polymers: Isotactic polymers have their side chains arranged on one side of the backbone chain. These polymers are semi-crystalline and provide long-range order, leading to higher crystallinity in the polymer chain. An example of an isotactic polymer is isotactic polypropylene.
  3. Syndiotactic Polymers: Syndiotactic polymers have their side chains arranged alternatively on both sides of the backbone chain. These polymers form the most rigid, crystalline structures. Syndiotactic polymers provide long-range order, leading to higher crystallinity in the polymer chain.

In summary, the key difference between atactic isotactic and syndiotactic polymers is the arrangement of their substituents along the carbon chain, which affects the properties of the polymers. Atactic polymers have a random arrangement, isotactic polymers have a unidirectional arrangement, and syndiotactic polymers have an alternating arrangement.

Comparative Table: Atactic Isotactic vs Syndiotactic Polymer

The main difference between atactic, isotactic, and syndiotactic polymers lies in the arrangement of their substituents or pendant groups around the backbone. Here is a comparison of the three types of polymers:

Type of Polymer Arrangement of Substituents Crystallinity Example
Atactic Random Amorphous Atactic polypropylene
Isotactic Regular, all on one side Semi-crystalline Isotactic polypropylene
Syndiotactic Regular, alternating pattern Crystalline Syndiotactic polypropylene
  • Atactic polymers have their substituents arranged randomly around the backbone, resulting in amorphous and soft materials.
  • Isotactic polymers have their substituents arranged in a regular manner, all on one side of the backbone, making them semi-crystalline.
  • Syndiotactic polymers have their substituents arranged in a regular, alternating pattern around the backbone, making them crystalline.

Tacticity affects the macroscopic properties of polymeric materials, such as strength, hardness, and solubility. Polymers with highly ordered tacticity, like syndiotactic and isotactic polymers, are sturdier and harder to dissolve compared to atactic polymers.