---
title: "Fiber reinforced polymers and applications"
subject: "Engineering Chemistry"
chapter: 4
key: "semester_2/engineering_chemistry:fiber-reinforced"
source: https://www.bctengineer.com/q/semester_2/engineering_chemistry/fiber-reinforced
site: BCT Engineering
---

# Fiber reinforced polymers and applications

Engineering Chemistry · Chapter 4: Engineering Polymers

- Asked in: 2072 Asoj, 3 marks; 2069 Poush, 2.5 marks (asked 2 times)
- Video: [Fiber Reinforced Plastics (FRP): Composition and Applications | Engineering Chemistry Explainer](https://www.youtube.com/watch?v=3gqgFdghZhg) — My Notes with ai
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_2/engineering_chemistry/fiber-reinforced
- Whole chapter: https://www.bctengineer.com/md/semester_2/engineering_chemistry/chapter-4

## Question

What are fiber reinforced polymers? Write their application in the field of engineering.

## Short answer

Fiber reinforced polymers are composites of a polymer matrix (epoxy, polyester) reinforced with strong fibers like glass, carbon or aramid. They offer high strength-to-weight ratio, stiffness, and corrosion resistance. Engineering applications include aircraft wings, automotive body panels, bridge strengthening, boat hulls, and wind turbine blades.

## Answer

#### Fibre-reinforced polymers
**Fibre-reinforced polymers (plastics)** are composite materials made of a polymer matrix (epoxy, polyester, nylon, vinyl ester) reinforced with strong fibres such as glass, carbon, aramid (Kevlar) or boron. The fibres carry the load, and the resin binds them and transfers the stress.

```text
 resin matrix  ┌──────────────────────┐
  ═══ fibre ═══│ ═══════ ═══════ ═════│
  ═══ fibre ═══│ ═══════ ═══════ ═════│
               └──────────────────────┘
```
**Characteristics:** very high strength-to-weight ratio, high stiffness, corrosion and chemical resistance, good fatigue and impact resistance (glass, aramid), low thermal expansion, electrical insulation (GFRP) and ease of moulding into complex shapes. Disadvantages: costly (carbon), poor recycling, and some brittleness.

#### Applications in engineering
- **Aerospace and defence:** aircraft wings, fuselage panels, helicopter blades, rocket casings, body armour and helmets (aramid).
- **Automobile:** body panels, bumpers, leaf springs, racing car chassis.
- **Construction and civil:** reinforcing bars, strengthening of bridges and columns, roofing sheets, water tanks, pipes, chemical plant ducts.
- **Marine:** boat hulls and decks.
- **Electrical and electronics:** printed circuit boards (glass-epoxy), insulators, antenna covers.
- **Sports and energy:** tennis rackets, bicycle frames, golf shafts, wind turbine blades.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. In a fibre-reinforced polymer, what is the role of the resin matrix?
   A. It carries the main load
   B. It binds the fibres and transfers stress to them
   C. It conducts heat
   D. It makes the fibres crystalline
   Answer: B. Fibres carry the load; the resin binds them and transfers the stress. (Key point: Roles of fibre and matrix)

2. Which characteristic makes FRPs preferred in aircraft?
   A. Very high strength-to-weight ratio
   B. High density
   C. Low stiffness
   D. Easy recycling
   Answer: A. They are strong yet light, with high stiffness and corrosion resistance. (Key point: Key characteristic)

3. Which is listed as a disadvantage of FRPs?
   A. Poor corrosion resistance
   B. High thermal expansion
   C. Costly (carbon) and poor recycling
   D. They cannot be moulded
   Answer: C. Carbon fibres are costly, recycling is poor and some brittleness exists. (Key point: Disadvantages)

4. Which application pairs correctly with its FRP?
   A. Printed circuit boards: glass-epoxy
   B. Body armour: glass-epoxy only
   C. Non-stick pans: carbon-epoxy
   D. Aircraft wings: wood fibres
   Answer: A. Glass-epoxy laminates are used for PCBs; aramid fibres are used for body armour. (Key point: Applications)

## Related in Engineering Chemistry

- [Technical applications of fiber reinforced plastics](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Afrp-applications) — Engineering Chemistry, chapter 4
- [Biodegradable polymer; carbon reinforced polymers, chalcogenide glasses](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Abiodegradable-carbon-chalcogenide) — Engineering Chemistry, chapter 4
- [Conducting and biodegradable polymers; applications](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Aconducting-biodegradable) — Engineering Chemistry, chapter 4
- [Fibre-reinforced plastics: characteristics, applications](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Afrp-characteristics) — Engineering Chemistry, chapter 4
- [Paints, types and applications in engineering](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Apaints-types-applications) — Engineering Chemistry, chapter 8, asked 2×
- [Engineering applications of PVC and conducting polymer](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Apvc-conducting-polymer) — Engineering Chemistry, chapter 4

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