# Describe how the structure of a thermosetting polymer makes it suitable for use in electrical plug casings, which must remain rigid and not melt when they become hot.

> Cambridge International IGCSE Chemistry (0620) — 11.8 Polymers · Describe · 4 marks

> Electrical plug casings are made from thermosetting polymers. These casings must withstand the heat generated during normal use without softening or deforming.

## Mark scheme (4 marks)

1. Thermosetting polymers have cross-links between polymer chains
2. The cross-links hold the structure permanently in a rigid network / prevent chains from moving
3. The structure does not soften or melt when heated
4. This rigid, heat-resistant structure makes it safe / suitable for use where heat is generated / as an electrical casing

## Key terms

- [thermosetting polymer](https://www.gradenine.co.uk/glossary/thermosetting-polymer)

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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-the-structure-of-a-ef971f77) · Published by Druglandscape Ltd.