The rubber tubes used in chemical experiments and the rubber tips on the rubber dropper will stick together for a long time, and the damage or even become very viscous. They cannot be handled and can only be thrown away. Is there any good way to preserve it without spoiling it?
After hardening, it can be soaked in diluted hydrochloric acid for a while and then softened. Be sure to dilute it, or it will not leak easily ... Normally, avoid direct sunlight for a long time. After the experiment, you need to clean it and dry it.