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How Are Rubber Bands Affected by Temperature Changes?

Last Modified Date: February 01, 2024

You've probably got a handful of rubber bands sitting in your kitchen or desk drawer right now, but did you know that these useful little objects are uniquely affected by changes in temperature? In fact, they behave very differently than most other objects. Contrary to what you might expect, rubber bands expand and get stretchier when cooled and shrink when heated.

Most materials expand when heated because their molecules vibrate and bump into each other at an increased intensity, a process referred to as thermal expansion. This is what causes cracks to form in sidewalks and roads as the seasons change.

Rubber bands are different than many other materials because they are made up of long polymer chains that shorten when heated, causing the rubber bands to shrink rather than expand.

Getting warmer:

However, it's also worth noting that stretching a rubber band will make it warmer. When it returns to a relaxed state, it will cool.

The rubber used in rubber bands crystallizes over time. This process eventually causes the rubber band to become dry, crumble, and lose its elasticity.

Have you ever tried running hot water over the lid of a jar that just won’t come off? This is an effective solution because when hot water comes in contact with the lid, it will cause the lid to expand, making it easier to twist off.