Science · Class 8
Synthetic Fibres and Plastics
Types of synthetic fibres and plastics; biodegradable vs non-biodegradable.
4 sections15–25 min read6 MCQs · 2 examples
Chapter Overview
Synthetic fibres are man-made polymers — nylon, polyester, acrylic, rayon. Plastics are versatile but non-biodegradable; thermoplastics vs thermosetting plastics differ in recycling.
Synthetic Fibres
- Nylon: strong, elastic — ropes, socks, parachutes
- Polyester: wrinkle-free fabric with cotton (terrycot)
- Acrylic: wool-like — sweaters
- Rayon: artificial silk from wood pulp
Plastics
- Thermoplastics: soften on heating, remoulded (polythene, PVC)
- Thermosetting: hard permanently on heating (bakelite, melamine)
- Non-biodegradable — persist in environment
Safe Use
- Do not burn plastics — toxic fumes
- Reduce, reuse, recycle; carry cloth bags
- 5 R's include recover and refuse
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
Identify fibre
Why is nylon used for climbing ropes?
- 1High tensile strength
- 2Elastic and light
- 3Resists wear
Answer
Strong, durable synthetic fibre
Plastic type
Can thermosetting plastic be recycled by melting?
- 1Cannot remelt once set
- 2Permanent cross-links form
- 3Thermoplastics can be remoulded
Answer
No — thermosetting cannot be remelted
Key Points to Remember
- ✓ Teflon coats non-stick pans
- ✓ Biodegradable plastics being developed
- ✓ Rayon is semi-synthetic from cellulose
Exam Tips
- • Compare natural and synthetic fibres
- • Distinguish thermoplastic and thermosetting
- • Why are plastic bags harmful?
Practice MCQs — Synthetic Fibres and Plastics
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Question 1 of 6Score: 0/0
Nylon is a: