Important Questions Test: Synthetic Fibres And Plastics

A polymer is a substance or material consisting of very large molecules, or macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life.

Developed in the late 19th century as a substitute for silk, rayon was the first man-made fibre.

The plastics which cannot be remoulded again on heating are called thermosetting plastics. The most common examples of thermosets are Bakelite and Melamine.

Polyester is a synthetic polymer made of purified terephthalic acid (PTA) or its dimethyl ester dimethyl terephthalate (DMT) and monoethylene glycol (MEG). With 18% market share of all plastic materials produced, it ranges third after polyethylene (33.5%) and polypropylene (19.5%).

Nylon is another man-made fibre. In 1931, it was made without using any natural raw material (from plant or animal). It was prepared from coal, water and air. It was the first fully synthetic fibre. Nylon fibre was strong, elastic and light. It was lustrous and easy to wash. So, it became very popular for making clothes. We use many articles made from nylon, such as socks, ropes, tents, toothbrushes, car seat belts, sleeping bags, curtains etc.

The correct answer is C as A synthetic fibre which works like wool is ACRYLIC

Cotton, like rayon and wood pulp fibers, is made of cellulose. Cellulose is a macromolecule made up of anhydroglucose unit connected by 1, 4 oxygen bridges with the polymer repeating unit being anhydro-beta-cellulose.

It takes 1000 years for polythene bags to degrade. Polythene bags don't Biodegrade, they photo - degrade, breaking down into smaller and smaller toxic bits contaminating soil and waterways. It pollutes our environment.
So, we should not use polythene bags.

"Cotton and jute” are the two common natural fibres not synthetic fibres.

PVC is a thermoplastic. Thermosetting plastics are crosslinking plastics that require a chemical reaction to cause them to harden. Epoxies and urethanes are two common examples of thermosetting plastics.

Thermoplastics harden by cooling. The plastic beads are melted by heat using mechanical means in an extrusion screw. Unless the thermoplastic is ruined by over heating, it can be reused many times. Unlike a thermosetting plastic that once the two chemicals have been mixed causing the reaction cannot be reused in the same way. They may become fillers but not have the same properties.