Flubber (material)


Flubber, Glorp, Glurch, or Slime are common names referring to a rubbery polymer formed by cross-linking of polyvinyl alcohol with a boron compound. Flubber can be made by combining polyvinyl-acetate-based adhesives such as Elmer's Glue with baking soda, borax, and shaving cream as an elementary science education experiment.

Reaction

The gelation process entails formation of a borate ester that crosslinks the chains of the PVA. Borate esters form readily by condensation of hydroxyl groups and the B-OH groups.

Properties

Flubber is a non-Newtonian fluid that flows under low stress, but breaks under higher stresses and pressures. This combination of fluid-like and solid-like properties makes it a Maxwell solid. Its behavior can also be described as being viscoplastic or gelatinous.