Question

Differentiate between a) thermoplastics and thermosetting plastics b) synthetic fibres and natural fibres

Answer 1

a)The primary physical difference is thatthermoplastics can be remelted back into a liquid, whereas thermosetplastics always remain in a permanent solid state. Think of thermoplastics as butter – butter can be melted and cooled multiple times to form various shapes.
b)Natural fabrics—such as cotton, silk and wool—are made of animal or plant-based fibres, while synthetics are man-made and produced entirely from chemicals to create fabrics like polyester, rayon, acrylic, and many others. 
Synthetic fibres -Synthetic fibre, man-made textilefibre produced entirely from chemical substances, unlike those man-made fibres derived from such natural substances as cellulose or protein.

Answer 2

thermoplastic- It becomes soft on heating and rigid on cooling.
thermosetting- polymeric material that undergoes irreversible chemical changes when it is cured through heat, catalysts.
synthetic fibres- fibres made by man in industries, factories etc.
natural fibres- fibres made by the animals and plants.eg- silk,wool