Polymer & Polymerization
Polymer Classification
Polymer Classification on the basis of Source:
Polymer Classification on the basis of Structure:
Polymer Classification on the basis of Molecular Forces:
Polymers
|
Monomers
|
Monomer Formula
|
Use
|
1. Teflon
|
Tetrafluroethene
|
CF2=CF2
|
Oil seals, Gasket
|
2. Polyacrylonitrile
|
Acrylonitrile
|
 |
Commercial Fibers
|
3. Terylene or Decron
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Ethylene Glycol
Teryphthalic Acid
|
HOCH2-CH2OH
 |
Commercial Fibers
|
4. Nylon 6,6
And
5. Nylon 6
|
Hexamethylene-diamine
Adipic Acid
Caprolactum
|
NH2(CH2)6NH2
HOOC(CH2)4COOH
 |
Making Sheets, bristles of brushes, textile industry, tyre cords,
fabrics, ropes etc.
|
6. Phenol
Formaldehyde Polymer
|
|||
i.
Novolac
|
Phenol + Formaldehyde
|
HCHO
|
Used in paints
|
ii.
Bakelite
|
Phenol + Formaldehyde
|
HCHO
|
Comb, Electric switches
|
7. Malamine
Formaldehyde Polymer
|
Malamine + Formaldehyde
|
HCHO
|
Unbreakable crockery
|
8. Buna S
|
1,3-Butadiene + Styrene
|
CH2=CH-CH=CH2
 |
Auto tyres, cables insulation, floor tiles
|
Plastics are synthetic or semi-synthetic materials made from polymers, which are long chains of molecules. They’re versatile, durable, and widely used in everything from packaging to car parts. The type of plastic depends on its chemical composition, properties, and intended use. Most plastics are categorized by a resin identification code (1 to 7), which you’ll often see on packaging, though these codes are more about recycling guidance than a strict classification.
Here’s a breakdown of the main types based on those codes:
- PET (Polyethylene Terephthalate, #1)
- Used for: Soda bottles, water bottles, food packaging.
- Properties: Clear, strong, lightweight, recyclable.
- Example: Your typical single-use water bottle.
- HDPE (High-Density Polyethylene, #2)
- Used for: Milk jugs, detergent bottles, toys.
- Properties: Tough, resistant to chemicals, recyclable.
- Example: The sturdy bottle your laundry detergent comes in.
- PVC (Polyvinyl Chloride, #3)
- Used for: Pipes, window frames, vinyl flooring, some packaging.
- Properties: Rigid or flexible (when plasticizers are added), weather-resistant.
- Example: The plumbing pipes under your sink.
- LDPE (Low-Density Polyethylene, #4)
- Used for: Plastic bags, shrink wrap, squeeze bottles.
- Properties: Flexible, lightweight, less rigid than HDPE.
- Example: Grocery bags that stretch easily.
- PP (Polypropylene, #5)
- Used for: Yogurt containers, bottle caps, straws, car parts.
- Properties: Heat-resistant, tough, recyclable.
- Example: The lid on your takeout container.
- PS (Polystyrene, #6)
- Used for: Foam cups, takeout containers, plastic cutlery.
- Properties: Lightweight, brittle, can be foamed (like Styrofoam).
- Example: The white foam box your burger came in.
- Miscellaneous (#7)
- Used for: Miscellaneous plastics like polycarbonate (old baby bottles), nylon, or bioplastics.
- Properties: Varies widely; not always recyclable.
- Example: Some reusable water bottles or specialty containers.
Beyond these, plastics can also be classified by broader categories:
- Thermoplastics: Soften when heated, can be reshaped (e.g., PET, HDPE, PP).
- Thermosets: Harden permanently after heating, can’t be remolded (e.g., epoxy, phenolic resins).
- Elastomers: Stretchy plastics like rubber (e.g., silicone, polyurethane).
- Bioplastics: Made from renewable sources like corn starch (e.g., PLA), though not always biodegradable.
Each type has trade-offs. For instance, PET is great for clarity but not heat resistance, while PP can handle hot liquids but isn’t always crystal-clear. Recycling rates vary—HDPE and PET are more commonly recycled than PVC or PS due to infrastructure and demand. If you like 👍 then share with your friends and help us in spreading Science education…❤️🚀⚛️📚
