---
title: "Non-biodegradable polymers and demerits"
subject: "Engineering Chemistry"
chapter: 4
key: "semester_2/engineering_chemistry:non-biodegradable"
source: https://www.bctengineer.com/q/semester_2/engineering_chemistry/non-biodegradable
site: BCT Engineering
---

# Non-biodegradable polymers and demerits

Engineering Chemistry · Chapter 4: Engineering Polymers

- Asked in: 2072 Asoj, 2 marks
- Video: [Problems with Plastics & Biodegradable Plastics | Environmental Chemistry | Chemistry | FuseSchool](https://www.youtube.com/watch?v=N3m_NtQTnfc) — FuseSchool - Global Education
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_2/engineering_chemistry/non-biodegradable
- Whole chapter: https://www.bctengineer.com/md/semester_2/engineering_chemistry/chapter-4

## Question

What are non-biodegradable polymers? What are the demerits of using them?

## Short answer

Non-biodegradable polymers resist microbial decomposition, e.g., PE, PVC. Demerits: persistent solid waste causing pollution, microplastics, toxic gases when burned, harm to wildlife, reduced soil fertility, difficult and costly recycling.

## Answer

**Non-biodegradable polymers** are polymers that cannot be decomposed by microorganisms and stay in the environment for hundreds of years. Most have stable C–C backbones. Examples: polyethylene, polypropylene, PVC, polystyrene, PTFE, nylon 6,6, Bakelite.

**Demerits**
- Accumulate as solid waste in land, rivers and oceans, causing plastic pollution, choking drains (which leads to urban flooding) and harming animals that swallow them.
- Reduce soil fertility and block water seeping into the ground.
- Burning releases toxic gases (CO, dioxins, HCl from PVC, HCN) and CO₂.
- Break into microplastics that enter the food chain.
- Recycling is difficult and costly, especially for thermosetting plastics.

## Check yourself

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

1. What is a non-biodegradable polymer?
   A. One decomposed by microbes in months
   B. One that cannot be decomposed by microorganisms and persists for hundreds of years
   C. One made of ester links
   D. One that dissolves
   Answer: B. They resist microbial attack because of stable C-C backbones. (Key point: Definition)

2. How do they contribute to urban floods?
   A. By evaporating
   B. By choking drains
   C. By absorbing water
   D. By increasing rainfall
   Answer: B. Plastic waste chokes drains, causing flooding. (Key point: Environmental harm)

3. How do buried plastics affect soil?
   A. Increase fertility
   B. Reduce fertility and block water seeping into the ground
   C. Neutralise acid
   D. Add nutrients
   Answer: B. They reduce soil fertility and block percolation. (Key point: Soil effect)

## Related in Engineering Chemistry

- [Biodegradable vs non-biodegradable polymers](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Abiodeg-nonbiodeg-examples) — Engineering Chemistry, chapter 4, asked 2×
- [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
- [Biodegradable polymers; Nylon and Teflon](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Abiodeg-nylon-teflon) — Engineering Chemistry, chapter 4
- [Biodegradable polymers; epoxy resin and polystyrene](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Abiodeg-epoxy-polystyrene) — 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
- [Thermosetting vs thermoplastics; polymers for ropes, utensils](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Athermo-nylon-teflon) — Engineering Chemistry, chapter 4

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