PVC (polyvinyl chloride) is a thermoplastic and is used for making toys, chappals, etc. Bakelite is a thermosetting plastic and is used for making electrical switches, handles of various utensils, etc. Can you write the major difference between these two types of plastic?
Hint: As we know that thermoplastic materials generally have low melting points due to which they can be remoulded or recycled easily whenever we want whereas thermosetting plastic can withstand very high temperatures and if once they get hardened, they cannot be reformed or recycled even after a huge amount of heat is supplied to them.
Complete answer: The differences between thermoplastic and thermosetting plastic is given below:-
These are generally synthesized by the additional polymerization.
These are synthesized by condensation polymerization.
These are processed through various methods like extrusion process, injection moulding, thermoforming process, blow moulding and rotational moulding.
These are processed through methods like compression moulding, reaction injection moulding.
Molecular chains of thermoplastics have secondary bonds between them.
They have primary bonds between molecular chains and these are held together with the help of strong cross-links.
They generally havelow melting points and tensile strength.
They usually have high melting points and tensile strength.
They generally have low molecular weight.
Compared to thermoplastics, these have high molecular weight.
Examples of thermoplastics are polystyrene, PVC, Teflon, nylon, acrylic, etc.
Examples of thermosetting plastics are vulcanized rubber, Bakelite, polyurethane, epoxy resin, etc.
Note: The other minor differences are as follows:- -Thermoplastics are recyclable whereas thermosetting plastics are not. -Thermoplastics can melt if they are exposed to the sun for a long period of time whereas thermosetting plastics would not. The similar property of both types of plastics is that both are resistant to corrosion effect and water. Also they have low production costs.