Polymers can be classified based on their source, structure, polymerization method, and physical behavior. Understanding the different types of polymers is crucial in organic chemistry due to their broad applications in both natural and synthetic materials.
1. Based on Source of Origin
- Natural Polymers: Found in nature. Examples: proteins (keratin), polysaccharides (starch, cellulose), natural rubber.
- Semi-synthetic Polymers: Chemically modified natural polymers. Example: cellulose acetate.
- Synthetic Polymers: Man-made. Examples: polystyrene, nylon, Teflon, polyethylene.
2. Based on Polymer Structure
- Linear Polymers: Monomers form long straight chains. Example: High-density polyethylene (HDPE).
- Branched Polymers: Side chains attached to the main chain. Example: Low-density polyethylene (LDPE).
- Cross-linked Polymers: Chains interconnected via covalent bonds. Example: Bakelite, vulcanized rubber.
3. Based on Mode of Polymerization
- Addition Polymers: Formed by repeated addition of unsaturated monomers. Example: Polyethylene, PVC.
- Condensation Polymers: Formed by elimination of small molecules (H₂O, CH₃OH). Example: Nylon-6,6, polyester.
4. Based on Molecular Forces
- Elastomers: Weak intermolecular forces, stretchable. Example: Rubber.
- Fibers: Strong forces, high tensile strength. Example: Nylon, polyester.
- Thermoplastics: Soften on heating, remoldable. Example: Polythene, polystyrene.
- Thermosetting Polymers: Harden permanently on heating. Example: Bakelite, melamine.
5. Based on Tacticity (Stereo-regular Arrangement)
- Isotactic: All substituents on the same side. Example: Isotactic polypropylene.
- Syndiotactic: Substituents alternate sides. Example: Syndiotactic polystyrene.
- Atactic: Random arrangement. Example: Atactic polystyrene.
Quiz: Types of Polymers
Q1. Which of the following is a natural polymer?
A) PVC
B) Nylon-6
C) Cellulose
D) Polystyrene
✔ Answer: C
Explanation: Cellulose is a naturally occurring polymer made of glucose units.
Q2. Which polymer type softens when heated and can be remolded?
A) Elastomer
B) Thermoplastic
C) Thermoset
D) Fiber
✔ Answer: B
Explanation: Thermoplastics soften on heating and can be reshaped multiple times.
Q3. Nylon-6,6 is an example of which type of polymerization?
A) Addition
B) Condensation
C) Radical
D) Chain
✔ Answer: B
Explanation: Nylon-6,6 forms via condensation reaction with elimination of water.
Q4. Which of the following polymers is isotactic?
A) Atactic polystyrene
B) Isotactic polypropylene
C) Vulcanized rubber
D) Teflon
✔ Answer: B
Explanation: Isotactic polypropylene has all methyl groups arranged on the same side, making it crystalline.
Related Reading: Important Polymers in Organic Chemistry |
External Reference: Britannica – Polymer Chemistry
