Thermoplastic and Thermosetting Plastic

Plastics are synthetic polymers made of various monomeric units. We use plastics in almost every field of life. All plastics do not have the same type of arrangement of monomeric units. In some monomeric units, the arrangement is linear, whereas in others, it is cross-linked. Polythene is an example of a plastic. It is used for making commonly used polythene bags. Plastic can be classified as thermoplastic and thermosetting Plastic. Keep reading to know more details about thermoplastic.

What is Plastic?

Plastic is a polymer consisting of synthetic or semisynthetic organic compounds. Some plastic can be shaped when soft and then harden to keep the given shape.

Types of Polymers

1. Based on molecular force

• Elastomer

• Fibres

• Thermoplastic

• Thermosetting plastic

2. Based on occurrence

• Natural

• Semi-synthetic

• Synthetic

3. Based on structure

• Linear

• Branched

• Cross-linked

4. Based on thermal behaviour

• Thermoplastic

• Thermosetting plastic

What is Thermoplastic?

Thermoplastic is a plastic that has a strong force of attraction. These types of plastic become soft on heating and become hard on cooling. These types of plastic can be reshaped and remelted into a variety of shapes.

Common examples of thermoplastic are polyester, Teflon, polystyrene, and polypropylene.

Types of Thermoplastics

There are various types of thermoplastics. Below is the list of some thermoplastics.

• Polyethylene terephthalate (PET) is one of the most easily recyclable plastics and it has excellent moisture and a barrier.

• Polyvinyl chloride (PVC) is constituted by the polymerization of vinyl chloride. It is versatile plastic and used for packaging and the paper industries. It is resistant to wear and tear.

• Polypropylene (PP) is made of polymerization of propane. It is a partially crystalline and nonpolar compound. This polymer is produced by the chain growth polymerization reaction.

• High-density polyethylene (HDPE) is formed by the polymerization of ethylene. It exhibits less branching that's why it has a high density.

• Low-density polyethylene (LDPE) is also made by polymerization of ethylene but it shows less branching than high-density polyethylene.

What is Thermosetting Plastic?

Thermosetting plastic is a polymer that is obtained by irreversible stiffening a solid soft and liquid prepolymer. Thermosetting plastic is also known as a thermoset. Examples of thermosetting plastics are bakelite and vulcanised rubber.

Types of Thermosetting Plastic

Listed below are some of the thermosetting plastics.

• Epoxy Resin - These types of plastic contain an epoxide group. These are formed by the reaction of two or more compounds and emit heat and change the material from liquid to granular solid.

• Melamine Formaldehyde - These types of plastics are obtained by polymerization of the monomer unit called formaldehyde with melamine. It hardens when heated after the setting can't be changed to a different shape.

• Polyester Resin - Polyester resin is formed by the reaction of organic acids and polyhydric alcohols.

• Urea-formaldehyde - Urea formaldehyde is formed by the polymerization of urea and methanol. These types of polymers have more hardness and high modulus.

Difference Between Thermoplastic and Thermosetting Plastic 

Conclusion

Plastics are polymers of organic compounds. These can be divided into various types. The two most important types of plastics are thermoplastic and thermosetting plastics. This classification is based on the thermal behaviour of plastics. Thermoplastics are used for manufacturing toys, combs, and various types of containers as they can be remould after heating. Thermosetting plastics are used for making electrical switches, handles of various utensils, etc. as these plastics don’t soften on heating.