Why Lesson Planet?
Do the properties of a thermoplastic polymer change after successive cycles of heating and cooling? In this lab assignment, young chemists find out by melting, molding, and re-melting hot glue gun sticks one, two, and three times. They measure the mass and viscosity of each. Use this engaging exercise as a reinforcement of the scientific method or as an enrichment when surveying the properties of polymers with your chemistry class.